SIXTH INTERNATIONAL SYMPOSIUM ON THEORDOVICIAN SYSTEM

GUIDEBOOK FOR FIELD EXCURSION 1

THE CAMBRIAN - ORDOVICIAN BOUNDARYAT BLACK MOUNTAIN, WESTERN QUEENSLAND

by

John H. Shergold l , Robert S. Nicoll", John R. Laurie' & Bruce M. Radke

'Bureau of Mineral Resources, P.O. Box 378, Canberra, ACT, 26012 18 Hartley Street, Turner, ACT, 2601.

RECORD 1991/48BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS

CANBERRA

II* R 9 1 0 4 8 0 1 *

Refer to this publication as:-SHERGOLD, J.H., NICOLL, R.S., LAURIE, J.R. & RADKE, B.M., 1991. The Cambrian -Ordovician boundary at Black Mountain, western Queensland: Sixth International Symposiumon the Ordovician System, Guidebook for Field Excursion 1. Bureau of Mineral Resources,Geology and Geophysics, Record 1991148, 50p.

Editor: John R. Laurie, Onshore Sedimentary and Petroleum Geology Branch, Bureau ofMineral Resources, Geology and Geophysics.

© Commonwealth of Australia, 1991This work is copyright. Apart from any fair dealing for the purposes of study, research,criticism or review, as permitted under the Copyright Act, no part may be reproduced by anyprocess without the written permission of the Director, Bureau of Mineral Resources, Geologyand Geophysics. Inquiries should be directed to the Principal Information Officer, BMR, GPOBox 378, Canberra ACT 2601.

CONTENTS

Itinerary^.^.^.^ .^.^. 4Introduction .^.^.^ .^.^. 5Georgina Basin^.^.^.^.^.^. 5Burke River Structural Belt .^.^.^.^. 8Stratigraphic Perspectives^.^ .^ . 10

^

Chatsworth Limestone^.^.^ . 10

^

Ninmaroo Formation.^ .^.^. 17Unbunmaroo Member^.^.^. 18Jiggamore Member^ . 21Mort Member^.^.^ . 22Collie Member^.^.^ . 23Datson Member^.^.^.^ . 24

Type Section of the Ninmaroo Formation^.^ . 25References^.^ .^.^. 37Appendix: Checklist of Black Mountain conodonts^.^.^. 46

FIGURES

1 Geology and location of Black Mountain^ .^. 62 Structural features of the Georgina Basin^ .^. 73 Stratigraphy of the Georgina Basin^.^.^.^. 94 Lithostratigraphy, conodont and trilobite biostratigraphy^ . 125 Ranges of essential conodont taxa^.^ .^. 166 Australian - North American correlations^ .^. 207 Detailed location of Black Mountain section^.^.^ . 268 Detailed graphic log of Black Mountain section .^ 29-36

4

ITINERARY

Excursion starts in Mount Isa, Queensland on Wednesday, July 3 and finishes in AliceSprings on Sunday July 7. Travel from Mount Isa to Alice Springs will be by bus.

JULY 2.Arrive in Mount Isa, accommodation at Overlander Motel

JULY 3.0900 Assemble in Mount Isa at Overlander Motel, depart for Black Mountain via Boulia.1600 Camp near creek, east of base of section.

JULY 4.0800 To base of Black Montain section, examine lower part of section.1200 LUNCH1300 Continue examination of lower part of section1630 Drive back to campsite

JULY 5.0800 To top of Black Mountain section, examine upper part of section.1200 LUNCH1300 Continue examination of upper part of section1600 Drive back to campsite

JULY 6.0800 Strike camp and drive to Boulia1100 Depart Boulia, drive towards Alice Springs1200 LUNCH1300 Continue towards to Alice Springs1700 Camp along Plenty River Highway

JULY 7.0800 Strike camp and continue towards Alice Springs1200 LUNCH1300 Continue towards Alice Springs1700 Arrive Alice Springs, accommodation at Alice Sundown Motel

5

INTRODUCTIONThe aim of this excursion is to demonstrate the Cambrian-Ordovician sequence at BlackMountain, situated in the southern Burke River Structural Belt, eastern Georgina Basin, 59km NE of Boulia, in western Queensland. At this locality (Fig. 1), it is possible to examinea continuously exposed, measured section, containing in excess of 1 km of peritidalcarbonates which straddle the Cambrian-Ordovician boundary at whichever horizon undercurrent debate it may be eventually located. This section has been describedlithostratigraphically in great detail (Radke 1980, 1981, 1982). A detailed trilobitebiostratigraphy has been proposed for the lower (Late Cambrian) part of the section. Adetailed conodont biostratigraphy was proposed originally for the upper part of the section(Druce & Jones 1971), but subsequently revised and extended to the base of the section(Nicoll & Shergold 1991). Results of recent (1989-90) magnetostratigraphic studies arecurrently being evaluated (Ripperdan, Kirschvink, Apollonov, Ma & Zhang 1990). At BlackMountain it is therefore possible to assess the relationships of stratigraphic units, discusspossible models of sedimentation, and evaluate the biostratigraphic succession.

This guidebook sets the Black Mountain section into a briefly described regional perspective;gives an up to date account of the litho- and biostratigraphy; gives a detailed description ofthe section on the ground; and presents an appendix of revised conodont determinations.

GEORGINA BASINBlack Mountain lies in the southeastern quadrant of the Georgina Basin which occupies anarea of approximately 325 000 sq km in western Queensland and the Northern Territory, andextends over twenty-one 1:250 000 scale Geological Series Sheet areas.

The basin contains predominantly marine Palaeozoic rocks, mainly carbonates in the north andeast, and mixed carbonates and siliciclastics in the west, of Middle Cambrian to LowerOrdovician age. These rocks overlie paralic, neritic and glacigene elastic sediments (to thesouth, southeast and southwest), and terrestrial extrusive rocks to the north and northwest, ofLate Proterozoic to Early Cambrian age, which crop out at the margins of the Basin.

To the northwest, the Lower Palaeozoic Daly River Basin is conterminous with the GeorginaBasin, but a western appendage, known as the Wiso Basin, is separated by the PrecambrianTennant Creek Block. To the south and southwest the Georgina Basin is flanked byPrecambrian metamorphic rocks of the Arunta Block, which separates it from the Proterozoicand Palaeozoic Amadeus Basin; the Proterozoic McArthur Basin lies to the north. To thenortheast and southeast, the Georgina Basin is overlain respectively by the MesozoicCarpentaria and Eromanga Basins.

Within the Georgina Basin, competent limestone units are, in general, flexed into broadshallow basins and domes with low flank dips. However, three major tectonic features occuraround the eastern and southern margins of the Basin (Fig. 2): the Burke River StructuralBelt, forming an eastern appendage to the Basin between Duchess and Boulia; the TokoSyncline and attendant folds and faults (Toomba, Craigie and Tarlton Faults), south of`Tobermory', along the southern margin of the Basin; and the Dulcie Syncline with associatedfolds and faults in the vicinity of 'Huckitta', also on the southern margin. These structuresstrike north-northwest or northwest, the dominant strike direction of the underlyingPrecambrian. The Toko and Dulcie Synclines, and their associated structures, are thought to

OTb

Ols

EARLYORDOVICIAN

Datson Member

Corrie Member

Mort Member

Jiggamore Member

Unbunmaroo Member

cc< 0 /—=LATE CAMBRIAN

Lily Creek Member

Thin bedded limestone or dolomite with interbedded chert

Limestone (pelmatozoan, peloid, clast and ooid grainstone)dolomitic sandstone, calcareous siftstoneLimestone (intraclast, ooid and peloid grainstonecalcareous siltstone)Thin to thick bedded limestone (peloid and intraclast grainstone,micrite, two-toned limestone), calcareous siltstoneMedium to thick bedded limestone (intraclast and peloid grainstone,mudstone, stromatolitic boundstone), dolomite, calcareous siltstone

Calcareous cross stratified sandstone, sandy limestone,calcareous siltstoneThin bedded light to medium grey limestone (peloid grainstone),limestone, calcareous siltstone

eac

11,1== ; •

OUSENSLAND

1^SOUTHAUSTRALIA

NEW SOUTH

L WALES

;; VICTORIA'

140°

2 15 km

23°

N,^IL^l'LL■\II^II 141°LI^‘, ■\

‘■,,,,^,L„LILILL,=-- -_,,.....,..._ 'LL,LL„'ANN'll 'Chatsworth^—

-.-/'^ 22°

/11

. UNBUNMAROO

,ININMARO)3

MT DATSON \\

Line of section

CRETACEOUS

ORTO

TERTIARY

Silcrete, silicified ferruginized chert, breccia

Sandstone, siftstone, coquinite (all silicified in part), chert

Limestone

Alluvium, sand, black and brown soil, clay

Sandstone, ferruginous sandstone, conglomerate,sfttstone, claystone

-Bond

-Cone

-eqnm

reoni

-Conu

BuoIL

Digby Peaks Breccia

Swift Formation

-eonj04.

Ci

Cz •

22 ° 32 —

K -eon

22°36' =

-eonj

OlsCz

40 18'

30 km

• L.*•Ci^Cz

• Con

Cz

Figure 1. Geology and location of Black Mountain (Unbunmaroo) and Ninmaroo inliers, andposition of the Black Mountain Section (after Nicoll & Shergold, 1991).

DOMAIN 3

p Alice Springs

WESTERN

AUSTRALIA

ALEXANDRIA—WONARAHc57, ,^IBASEMENT HIGH /^ UNDILLA,

0 Tennant Creek^ ,,,,^SUB—BASIN

,'^ I

-20°^ DOMAIN 1^1

STRUCTURAL

BELT i/---

\^/

^1 ^1I

^Black 1^1Mountain •—

1 -.--^ 0 ■,_---'^--,^<../^"--../^ •.--...____1_,

//^ I

---^0^ 200km

20/F54-10/4

GULF

OF

CARPENTARIA

TASMAMI

BARKLY SUB—BASIN

DULCIE SYNCLINE

DOMAIN 2

7

Figure 2. Principal structural features of the Georgina Basin and extent of geophysicaldomains (after Southgate & Shergold, 1991)

Il1i, 9 1 Ill 1 1s 0 21

8

have formed during the Alice Springs Orogeny of Carboniferous age (Bradshaw & Evans1988). Smith (1972) follows Opilc (1960) in thinking that the faults of the Burke RiverStructural Belt are related to Early Ordovician deformation. More recently, however,Southgate & Shergold (1991), have presented evidence from sequence stratigraphical analysisthat suggests movement of the Mount Isa Block within the duration of what is currentlydefined as the Templetonian (Middle Cambrian) Stage (see Shergold 1989).

The base of the Georgina Basin sequence coincides with the base of Lower Cambrian (butprobably not earliest Cambrian) sandstones in the southwest in the vicinity of the DulcieSyncline (Fig 2). Elsewhere the sequence commences later, in the early Middle Cambrian(Ordian/Early Templetonian stratigraphic sequences of Southgate & Shergold, op. cit.).Complex basal Middle Cambrian lithofacies mosaics, containing a variety of rocks, such asperitidal and ramp carbonates, black shales, evaporites, phosphorites etc., are overwhelmedby elastic deposition from the late Templetonian to late Undillan Stages of the MiddleCambrian. Predominantly carbonate deposition occurring during the latest Middle and earliestLate Cambrian (Undillan-Mindyallan) was followed by a brief phase of deeper watercarbonate sedimentation in the Georgina Basin during the Late Cambrian Idamean Stage. Theinterval post-Idamean (see Shergold 1982) through Warendian (early Ordovician) ischaracterised by shoaling shallow water carbonate sequences which became briefly emergent(e.g. aeolianites assigned to the Lily Creek Sandstone Member of the Chatsworth Limestone).This interval contains several yet undescribed sedimentary sequences constrained by suchrecognisable events as the Lange Ranch and Black Mountain Eustatic Events of Miller (1984)and the Kelly Creek Movement (Webby 1978). The last of these curtails Cambrian - earlyOrdovician deposition in the Burke River Structural Belt, but elsewhere along the southernmargin of the Georgina Basin younger formations may extend into the Late Ordovician(Nicoll, Owen, Shergold, Laurie & Goner 1988).

Overlying Devonian sedimentary sequences are preserved in the main synclinal regions,particularly the Toko and Dulcie Synclines. The distribution and relationship of thestratigraphic units of the Georgina Basin is summarised in Fig. 3 (after Freeman, Shergold,Morris & Walter 1990).

BURICE RIVER STRUCTURAL BELTThe dominant structural components of the Georgina Basin are shown on Fig. 2 (afterSouthgate & Shergold 1991). Domains 1-3 are geophysically discriminated regions based onBouguer anomalies and total magnetic intensity contours, and on the gravity anomaliesrecognised by Tucker & others (1979).

The Burke River Structural Belt is a N-S aligned eastern appendage of the Georgina Basinwhich extends from Malbon to Springvale, a distance of 145 km. It contains approximately2875m of Cambrian and lowest Ordovician rocks, unconformably overlain by thin veneers ofJurassic-Cretaceous (up to 325m) and Tertiary (40m) sediment (Fig. 3). This sedimentpackage is preserved as a westerly thickening wedge (half graben) which extends in a N-Sdirection from Malbon to Springvale. The western margin of the Structural Belt is heavilyfaulted by a series of en echelon faults, the Camel, Pilgrim, and Black Mountain faultsystems, mostly throwing down to the East, and is periclinally folded. The eastern margin isless disturbed structurally, or may be undisturbed. Surrounding Proterozoic rocks andinterpretation of some of the structural elements of the Burke River area have been discussed

1 1

1 II 1 II 1 II

II

* R 9 1 0 4 8 0 3 *

AGE WEST GEORGINABASIN

NORTHWESTGULCIE SYNCLINE

SOUTHEASTDULCIE SYNCLINE

WEST TOKOSYNCLINE

EAST TO KOSYNCLINE

I

.-3K7kirSwift

^.

BURKE

Limestone

Hooray

i^1I^1

N in

Noranside

Fm

Formatmaroo

(795m)

Sst

1

ion

P, ,

RIVER

(20m)

(20m )

Age

'UNDILLA

PoLees

Creek

ardWat

VVater

Undi

rhol

BASIN"NORTH

eren

Sp i,1^,^.t,

MaiV, Creek

la

Saniis

Rock\

1/4.ole

Change

ed

•

Ls

ale• ne

Sst..,t ,^„H

Ls

(60m)

. (33-36m)

(33m

50m,^I

. (^5m)

GEORGINA

-,

_. , ,I,,

TERTIARY I

../9Dulcie

./-,,..,..7,..,

Undifferentiated

Sandstone-‘,/,

i^I

,i,

Dulcie

. L j

Undifferentiated

(660m)

, [

Sandstone

1j 1 _

II

PoodyeaAustral

Hooray

Cravens

i

(280m)

'

Formation/Downs

Sandstone

Peak Bed

-)._.)-),„/).

Lst'

I

I

Hooray

= Ethebuke

11',

.^I

Austral

'Limestone

Sst (1

Downs

Sandstone

.

.47m)

1

'Oufi2 (52 N

LATEJURASSIC-

CRETACEOUSL.±1Z00a L.>.,

2 0

EMSIAN

LATE ORD/SIL

LLIo 2In <29tb '

0>- a,,fr 0‹Lu

LLANDEILIAN

LLANVIRNIANNora Fo

. ,^— Mithaka Fitt (94 127m)Sat (125.174m)Fin (114-250m)

matron113m) ____ )_.) A..,.)-)./ .^ —Carlo

ARGENIGIAN1

7,,,,,,_, ^—Nora

Lrj-Tomahawk

pre-PAYNTON

(190m)

..owie

Beds

,

(15-30m) ^

rtrt_ir

Sst

Tomahawk(—

\ A_,/

MI.—;\17- .

200m)

.■_,4

Beds

■_1'

,

,,,,kr,_

, .

,,,,,,,,,,,,,,,,,,,i7

NinmarooFormation(225-500m)

ArrinthrungaFormation

.,,,,,‘„,„,

1^'

'-'--7-r,

TrJrArnlil

Coolibah

Formation(100-400m)

Ninmaroo

, lAIY,I,Fr734.1,1■Fme-79m)

/V

.9_--,1_.

f. ,,,

WARENDIAN

z<rEco

U

DATSONIAN

ChatsworthLimestone

(885m)

PAYNTONIAN

post-IDAMEAN

PomegranateLimestone (30-430m)

IDAMEAN

0 Hare Sh 560m)MINDYALLAN Selwyn Rge

Lst (40rn)Devoncourt Limestone

•20m)

(601-770m) GeorginaLimestone

(409m)ArrinthrungaFormation(390-680m ) Margua Formation

(490m)

BOOMER -ANGIAN

Roz;rjr,(91

1,^Ca

^''''4F . F" -‘C'n

r moreMb' f5m)

(60-75m)1JVIJI,1_,/}./10.

,1111

bonate

a mbsteryr

s10,,,, 1

Chen/horn

11 1 ,

"Cr

45)(

(106m)

,")-4"

?.^.^f,

1

'171-F.;,'-cIi-:'

Lstrt ,

U. Hay R. Fm. Mbr 2(62-85m) ----_

UNDILLANFm (1200m)

,MM=MIEFW■,Currant Bush Lst

(30-150m)

j1‘ 'AL

i^IWonarah

Gum

(15-430m)

lhBeds

Ridge

Chabal-owe Fm

-,-,.,,,,-,(150-200m)

Hagen''''

Arthur Creek^`"'TFormation(30-418m)

U Hay R. Fm Mbr1----- ,_,

1' r"if ''f I' „^ ,

,,,,,SItst

Blazan Shale (8m)

^

Mbr (90m)^'

^

rttt_k_1-;_ti,r46-1,-t_^_Thorntonia Lst

FLORAN

PhDs Beetle Creek• 111.

Pm

Inca Fm (3-60m)

1111 I, ?.1^-T

TEMPLETONIAN

ORDIAN Lst TOErnIk ..s--------MbrFormation^(150m) 1(iLpLim

Helen Springs^,voicanis^s-_, Andagera^ErrarraFormation

Formation

.^RR^IL Hay R Frn k—mr

Errarra^Red Heart

ylveser^uS^t^Sst/SHill Arkose'

-^`-').7 "-rn.O. TrATfi';4',11

Mount Birnie Beds(Restricted)

'Mt.'

Hendry

•'

Fm

I'll'^1

• • 1.

Yelvertofedt B

l•^1^11•1^I^,EARLY

CAMBRIAN(Undiff)

Rising Sun^,`'"?

Conglomerate '2^(< 50m)^\

T'''^'N ^''^,-. -1'511Clastics)---,

^Formation^Dolomite^(20-129m)^(20w)^9 ^7

Baldwirl.Fm^Adam Shale (16m)11/,V133 -2

Figure 3. Stratigraphic units currently recognised in the Georgina Basin (after Freeman,Shergold, Morris & Walter 1990).

10

by Blake & others (1984).

According to Casey (1968), basement lineaments have controlled the distribution, faulting andfolding of both Palaeozoic and Mesozoic sediments, and the whole area has been tilted to thesouth during the Tertiary. Casey (op. cit.) also records the faulting of Lower Cretaceous rocksimplying post-Cretaceous movement in addition to that (presumably late Palaeozoic)responsible for the initial emplacement of the Structural Belt (See also de Keyser 1968;Russell & Trueman 1971). Contemporary activity is recorded by lines of mud springs for adistance of 90 km between Dribbling Bore and Elizabeth Springs along the southerly traceof the Black Mountain fault.

Early geological references to the Burke River area are given in explanatory notes for theDuchess and Boulia 1:250 000 Sheet areas by Carter & Opik (1963) and Casey (1968)respectively. Most recent stratigraphic work stems from that of Whitehouse (1936, 1939) andOpik (1956a, 1960, 1961b, 1963, 1967a, b), e.g. Cambrian stratigraphy (de Keyser 1973; deKeyser & Cook 1973), conodont biostratigraphy (Druce & Jones 1971; Nicoll 1990, 1991;Nicoll & Shergold 1991) trilobite biostratigraphy (Opik op. cit., 1961a 1970a, 1970b, 1975,1979, 1982; Shergold 1969, 1972, 1975, 1980, 1982), bradoriids (Opik 1968; Fleming 1973,1975; Jones & McKenzie 1980), echinoderms (Jell, Burrett & Banks 1985; Smith & Jell1990), and molluscs (Pojeta, Gilbert-Tomlinson & Shergold 1977).

The discovery of commercial grade phosphorite in the Middle Cambrian rocks of the BurkeRiver Structural Belt in 1966 at Monastery Creek, spurred detailed mapping of the Cambrianrocks of the Burke River area (de Keyser 1968); a reappraisal of the stratigraphy of thephosphatic sequences (Russell 1967; Russell & Trueman 1971; de Keyser & Cook 1973;Shergold & Southgate 1986; Cook 1989 inter alia); detailed petrological and sedimentologicalstudies (e.g. Nordlund & Southgate 1988; Soudry & Southgate 1988); and more recently afurther set of micropalaeontological data is beginning to appear (e.g. Hinz, Kraft, Mergl &Muller 1990; Shergold 1991; Muller & Hinz (in press)). Much of this information has beenrecently synthesised in a sequence stratigraphic context by Southgate & Shergold (1991).

STRATIGRAPHIC PERSPECTIVESThe Burke River Structural Belt has also become the focus of recent Cambrian-Ordovicianresearch in northern Australia because of its thick and relatively well exposed MiddleCambrian through Lower Ordovician carbonate sequences. At Black Mountain, the Cambrian-Ordovician transition is contained in two formations: a lower (Late Cambrian) ChatsworthLimestone, and an upper (Late Cambrian - Early Ordovician) Ninmaroo Formation.

CHATSWORTH LIMESTONEThe type section of the Chatsworth Limestone is at Lily Creek, 7 km East of ChatsworthHomestead, 54 km north of Black Mountain. The formation is regionally extensive,intermittently outcropping over a north-south belt 97 km long between Mount Murray, 23 kmwest northwest of Chatsworth, and the Boulia-Winton Highway, south southeast of BlackMountain. Its distribution and internal stratigraphy have been described by Shergold (1975,1980, 1982), Shergold & others (1976), Kennard (in Shergold & Walter 1979), and reviewedby Shergold (in Druce & others 1982).

Prior to 1971 (Jones & others 1971), a carbonate formation lying below the Ninmaroo

11

Formation at Black Mountain, Ninmaroo, Mount Datson and Dribbling Bore in the South ofthe Burke River Structural Belt was referred to the Chatsworth Limestone with a measure ofuncertainty. Subsequent sedimentological and palaeontological investigation have identifiedthe formation as upper Chatsworth Limestone.

At Black Mountain the rocks referred to the upper Chatsworth Limestone are 420m thick, andare now divided into seven lithological units (A-G) by Druce & others (1982) (see Fig.4). Theuppermost 40m (unit G) is regarded as representing the Lily Creek Sandstone Member, aregressive sandy limestone, originally described as aeolianite in the vicinity of the typesection, which is time transgressive from north to south along the Burke River Structural Belt(Radke in Shergold & others 1976). The revised Chatsworth Limestone lithostratigraphyremains essentially as described by Druce & others (1982). Their account is repeated hereenhanced by additional or revised palaeontological data (see also separate section onbiostratigraphy). This part of the Black Mountain sequence was magnetostratigraphicallysampled in 1989, reported upon by Ripperdan & others (1990) and circulated as a preprint.

Stratigraphy of the Chatsworth LimestoneBelow we give lithological and palaeontological documentation of the upper ChatsworthLimestone. Ranges of quoted taxa refer to Black Mountain only (unlike fig. 4 in Druce &others 1982). Revisions and additions to taxa given in that paper are from Westrop (1986),Zhang & Jell (1987), Shergold & others (1988), Ludvigsen & others (1989), Shergold &others (1990).

The revised stratigraphy of the Chatsworth Limestone is as follows:

Unit A. This comprises the interval 0-40m from the base of the measured section.Lithostratigraphically it is characterised by interbedded skeletal grainstone, intraclasticgrainstone, laminated silty micrite, and calcareous siltstone, deposited during the time spanof the Rhaptagnostus clarki patuluslCaznaia squamosa Assemblage-Zone on the trilobitebiochronological scale.

Eleven trilobite species have been described by Shergold (1972, 1975) : Caznaia squamosa,Hapsidocare chydaeum, idahoiid gen. et. sp. indet., Koldinioidia sp. cf. K. cylindrica,Neoagnostus coronatus, Neoagnostus sp. A, Plecteuloma strix, Rhaptagnostus clarki patulus,R. elix, Sigmakainella primaeva, Wuhuia sp. cf. W. dryope (Walcott).

Five species of conodonts were described by Druce & Jones (1971), both coniform speciesand westergaardodinids: Furnishina furnishi Proconodontus primitivus (Muller), P.rotundatus (Druce & Jones), P. tenuiserratus Miller, Prooneotodus tenuis Miller,Westergaardodina bicuspidata Muller. Subsequently, Nicoll & Shergold (1991) recoveredconiform elements throughout the Chatsworth Limestone, but no westergardodinids. Thisconodont assemblage is insufficiently differentiated for useful zonation on the conodontbiochronological scale.

Unit B. This unit extends between 40-128m on the measured section and contains interbeddedcalcareous siltstone, mottled micritic limestone, and skeletal wackestone grainstone and clastgrainstone, more thickly bedded than in Unit A.

12CHATSVVORTH^LIMESTONE NINMAROO^FORMATION

UNIT A UNIT B UNIT C UNIT D UNITE UNIT FLILY^CRMEMBER

UNBUNMAROO^MEMBER

S .eq^..,^g^E'^ °^5^ E^-:^g1

1,^1 , 1^„ 1 imetres

Lithological Section

1975 Trilobitesamples.0^7,^7,...

0,Coln^?^28 8 —

11111-13a.^!^11111^11_1111.111111111,'$11_111111[1].11011111111_1111[1t.• .

^7,.........7,.....^,,2, at0 ....^'''', .^1.• ,-.' 4-1.,-,,' ;,' z;;:,- 8' ^1:', le, ;2 ,^,,'^...,0

I, I,..

111[

0

IL -11-1,

75....

(.44,1.0(44.,..1005A0)0)

I

7,

CO

i

7,41

4,-...

it

A.

AA, CO^0-•

AA

,I,(OA

1^11'_ ,^--]

X

A01

11 il

1^11_111 II'--: 1 rii

11

1 ,

-4^I

-,^-.^N)^IV^C...)^(.4o^crt^0^c.7.^0^tr,^0^c.n

i^1^t

4,^A^CA^C.7'^0)0^cri^0^LT^0

t^1^..^le^1^1

CI^-4^...1at^0^011^1..^.^■^.

0^ali^.^1

1989Palaeomagneticsamples

ASSEMBLAGE 1E. nokeineroi

ASSEMBLAGE 2it resimus

ASSEMBLAGE 3H oppresses

ASS 4H discrete:

ASS 5Cordylodus

PROCONODONTUSPOSTEROCOSTATUS

PROCONODONTUSMULLER!

EOCONODONTUSCORDYLODUS

PROAVUS

Phakelodus tenuis

002000Z...IIA

Westergaardodina bicuSPidataProconodontus tenuiserratusProconodontus primitivusProoneotodus rotunda/us

• Furnishina furnishiTendontus nakarnurai

Proconodont. posterocostatusProoneotodus gal/at/noWestergaardodina amplicava

^Nogamiconus trIcarinatusWestergaardodina mossebergensisProsagdtodontus dahlmant

-^Prooneotodus terashirnaiProconodontuss muelleriConiform sp. AGranatodontus amHispidodontus resimusConiform sp. 8

Eoconodontus notchpeakensisHirsutodontus sodasProconodontus serratusHispidodontus appressus• Wuhuia cf W. dryope

Rhaptagnostus elix^ •^Coniform sp. CTeridontus sp. nov ANeoagnostus sp. AConiform sp. DHapStdocare chydaeum

PleCtellIOMa Strix^ •^Eoconodontus minutusSigmakainella Primaeva^ Hispidodontus chscretusCaznaia squamosa^ —^Eodentatus bicuspatus

Rhaptagnostus clarki patulus^ Cordylodus Ppmffivus^—Koldinioidia 0 K cyclindrica^ Fryxellodontus mornatus^.Idahoiid^et. sp. indet^ Hirsutodontus hirsutus^—gen.Neoagnostus coronarus^ Teridontus sp. nov B

• Neoagnostus sp. B^ Cordylodus proavus^.

• Ceronocare SP.^ Clavohamulus spp.Taishania sp.•

• Pagodia (Pagoda)spProsaukia sp. A

•••1_I-003

71RIcn

Caznaia sectatrixAtopasaphus steriocanthus

• Neoagnostussp. CLotosoides turbinate

Hapsidocare grossumAtratabia nexosa

• Pagodia (Oreadella) cf. P. (0.) buda• ?Richardsonella sp.-^Rhaptagnostus clarki prolatus^ .

Lotosoldes calcarataOuplora claraCernocare pandumSigrnakainella translira

Lorrettina rnacropsLophosaukia torquataRhaptagnostus hi/au

—^Lophosaukia acutaNeoagnostus clavus

Oncagnostus (Strictagnostus) chronius

^

—^Oncagnostus (0.) conspectus

^

—^Neoagnostus denticulat.• Parakoldinioidia bigranulosa—^Lotagnostus (Distagnostus) irretitus—^Golasaphus simus

Oncagnostus (0.)cf. . acrolebes—^Golasaphus Piquet,.

?Sigrnakainella trispinosa• ?Protopeltura sp.

Rhaptagnostus clarki maxim.Rhaptagnostus papilio

-^ Ma/ad/aide//a cf. M. chinchiaensisPalacorona sp.Mansuyites op indet.

• •^Sigmakainella long/liraLophosaukia sp. A

.^Prosaukla sp inden.Sinosaukia impages?Prosaukia cornigraMansuyiacf. M. orientalis.

• Wanwanaspis sp. Md..^Shergoldia antidictys

Anerssonella beauchampiKoldinioidia payntonensis

.^Galerosaukia sp

.^Wanwanaspis of W semicircularis• Wanwanaspis sp.

Sinosaukia op indet.Asioptychaspis deltaWanwanaspis pygidionHanlwa rnucronataShergoldia necopinaLichengia? absonaRhaptagnostus orbicular.Neoagnostus quasibilobus

Shergoldia namesMansuwa cf. M. raniGalemsaulua galentaOncagnosrus (0 ;cf. a (al intermediusLophosukia sp. C

• Shergoldia sp.

Z...^ •^Shergoldia cf. S. trigonalis

-^Anderssonella eweyi• Microsaukia perplexa

Rhapt. clerk,pandas/Carnoia squemese

RAW dark,prelates/Celasia sectaries

8"Pt bd.'Neeagnastdenticelates

Rbaptageostes clAki

'"n"s/fi- POill°Sieestukie impacts

Altetrestesquestallebus/^

Mictosaukis

Shergaldia 110/11aS^postdate^ No trilobite zonation

PRE PAYNTONIAN PAYNTONIAN DATSONIAN

Figure 4. Correlation of lithostratigraphy, conodont and trilobite biostratigraphy andmagnetostratigraphic sampling in the Chatsworth Limestone and Lower Ninmaroo Formationat Black Mountain (modified from Druce & others 1982).

13

Twenty seven trilobite species occur in Unit B : Atopasaphus stenocanthus, Atratebia nexosa,Caznaia sectatrix, C. squamosa, Ceronocare pandum, Ceronocare sp., Duplora clara,Hapsidocare chydaeum, H. grossum, idahoiid gen. et. sp. indet., Koldinioidia sp. cf. K.cylindrica, Lorrettina macrops, Lotosoides calcarata, L. turbinata, Neoagnostus coronattts,Neoagnostus sp. B, Neoagnostus sp. C., Pagodia (Pagodia) sp., P. (Oreadella) sp. cf. P. buda(Resser & Endo), Plecteuloma strix, Prosaukia sp. A, Rhaptagnostus clarki patulus, R.c.prolatus, ?Richarclsonella sp., Sigmakainella primaeva, S. translira, Taishania sp. Thesespecies indicate deposition of Unit B during the span of the Rhaptagnostus clarkiprolatuslCaznaia sectatrix Assemblage-Zone on the trilobite biochronological scale.

Seven conodont species are also reported from Unit B, including all of those listed from UnitA. Additionally, Proconodontus posterocostatus Miller and Teridontus nakamurai (Nogami)make their first appearances. The latter defines the first diagnostic conodont faunalassemblage in the Chatsworth Limestone, Assemblage 1 (of Nicoll & Shergold 1991), and theformer indicates that this equates with the first diagnostic conodont Subzone (Proconodontusposterocostatus) recognised by Miller (1975, 1978, 1980) in western North America. This isan important datum for Late Cambrian correlation, permitting the correlation of endemictrilobite biofacies between Asia, North America and Australia (Shergold 1988).

Unit C. This unit outcrops between 128-158m on the measured section. It is characterised byskeletal packstone and grainstone, and laminated micritic limestone, in a predominantlycalcareous siltstone sequence which also contains discontinuous layers of orange-brown chert(unit 2 of Shergold 1975).

There are 34 determinable species of trilobites which indicate deposition within the trilobiteassemblage-zone of Rhaptagnostus bifaxINeoagnostus denticulatus. Ten of these speciesextend from earlier units : A. stenocanthus, A. nexosa, C. pandum, D. clara. H. grossum, L.macrops, L. calcarata, L. turbinata, N. coronatus, R. c. prolatus and S. translira. Occurringfor the first time are: Golasaphus simus, G. triquetrus, Lophosaukia acuta, L. torquata,Lotagnostus (Distagnostus) irretitus, Neoagnostus clavus, N. denticulatus, Oncagnostus (0.)conspectus, 0.(0.) acrolebes, 0. (Strictagnostus) chronius, Parakoldinioidia bigranulosa,Rhaptagnostus Wax, and Sigmakainella trispinosa. The occurrence in Unit C of provincialisedearly asaphid trilobites and Sauldidae together with globally distributed species of agnostidtrilobites gives great potential for the international correlation of this Australo-Sinianbiofacies.

Of the nine conodont taxa reported, however, three occur for the first time: Problematoconitesperforata MUller, Proconodontus tricarinatus (Nogami) and Westergaardodina amplicavaMuller. The continuing occurrence of Proconodontus posterocostatus and Teridontusnakamurai indicate that this conodont assemblage remains within the P. posterocostatusSubzone of Miller (1975) and Assemblage 1 of Nicoll & Shergold (1991).

Unit D. The interval 158-248m on the measured section comprises thinly bedded micriticlimestone with siltstone interlaminae and layers of skeletal and clast grainstone, skeletalpackstone and wackestone, with sandier horizons becoming more common towards the topof the unit.

14

Deposition commenced late in the span of the R. InfaxIN. denticulatus A.-Z. and continuedinto that of Rhaptagnostus clarki maximusIR. papilio.

Seventeen species of trilobites occur, eight extending from earlier units : A. nexosa, G. simus,G. triquetrus, L. (D.) irretitus, N. clavus, N. coronatus, 0. (S.) chronius, and S. trispinosa.Of the nine new taxa, an olenid trilobite, Protopeltura sp., and the agnostoids Rhaptagnostusclarki maximus and R. papilio have considerable correlation potential. Associated taxa are,however, provincialised Lophosaukia sp. A, Maladioidella sp. cf. M. chinchiaensis (Endo),Mansuyites sp. indet., Palacorona sp., Prosaukia sp. indet., and Sigmakainella longilira.

Unit D is enriched in conodonts, sixteen taxa occurring including seven new arrivals. Firstappearing in Unit D are : Granatodontus ani (Wang), Proconodontus muelleri Miller,Prooneotodus terashimai (Nogami), Prosagittodontus dahlmani Milller and Westergaardodinamossebergensis and coniform element A of Nicoll & Shergold (1991). The occurrence of P.muelleri is considered to permit the correlation of the terminal part of Assemblage 1 (ofNicoll & Shergold 1991) with the P. muelleri Subzone, thought to represent the seconddiagnostic latest Cambrian conodont biostratigraphic unit in North America (Miller 1975,1978, 1980).

Both trilobites and conodonts become scarce in the uppermost part of Unit D and an almosttotal faunal reorganisation, previously recognised by Druce & others (1982) but inadequatelydocumented, occurs.

Unit E. Unit E (unit 4 of Shergold 1975) comprises sandy, cross-laminated, locallybioturbated tnicrific limestone which contains interbeds of clast grainstone and calcareoussiltstone. The unit is severely impoverished faunally, the trilobites listed coming from a singleskeletal grainstone layer.

Only six species of trilobites have been reported, including Oncagnostus (Strictagnostus)chronius and Rhaptagnostus clarki maximus ranging from Unit D, Sinosaukia impages andMansuyia sp. cf. M. orientalis (Endo) which range through it, and ?Prosaukia cornigra and?Wanwanaspis sp. indet. which are confined to it. These trilobites were considered byShergold (1975) to represent a pre-Payntonian Zone of Sinosaukia impages. However,agnostoids apart, none of the listed taxa are useful biostratigraphically. Essentially, thetrilobite fauna of Unit E bridges the earlier pre-Payntonian occurrences, and the typicalPayntonian fauna that succeeds.

Previous conodont sampling from Unit E failed to yield fauna to Druce & Jones (1971). Morerecent processing (Nicoll & Shergold 1991) has revealed the occurrence of seven long rangingtaxa : Granatodontus ani, Proconodontus muelleri, P. tricarinatus, Teridontus nakamurai andconiform element A are known from Unit D or earlier, and they range through Unit E andbeyond. Occurring for the first time, however, are Hispidodontus resimus and coniformelement B. The first occurrence of Hispidodontus is considered biostratigraphically significantand to characterise Assemblage 2 at Black Mountain. The continuing presence ofProconodontus muelleri suggests that the FAD of Hispidodontus occurs within the later partof the P. muelleri Subzone of Miller (1975, 1978, 1980). The conodonts therefore place thetrilobite biostratigraphy in a more meaningful context and the combination may eventually

15

prove significant for interprovincial correlation.

Unit F. This unit contains alternating calcareous siltstone and skeletal clast grainstone,wackestone, packstone and lime mudstone over the interval 285-380m on the Black Mountainsection. Characteristically the sequence is thick-bedded, with some siltstone beds up to 4mthick, and was deposited from late in the Sinosaukia impages Assemblage-Zone to early inthe Neoagnostus quasibilobusIShergoldia nomas A.-Z. on the trilobite scale, and within thetime span of Assemblage 2 (Hispidodontus resimus) - mostly early Eoconodontus Zone timeon the international conodont scale.

Fossils are relatively uncommon in the lower beds of Unit F, but those in the upper partcontain twenty two trilobite taxa of almost total Australo-Sinian provenance (sauldid-tsinaniidbiofacies of Shergold 1988), all but two of which (Mansuyia sp. cf. M. orientalis andSinosaukia impages) occur for the first time: Anderssonella beauchampi, Asioptychaspis delta,Galerosaukia galerita, Galerosaukia sp. indet., Haniwa mucronata, Koldinioidia payntonensis,Lichengia? absona (Shergold), Lophosaukia sp. C, Mansuyia sp. cf. M. tani Sun, Neoagnostusquasibilobus, Oncagnostus (0.) sp. cf. 0. intermedius (Palmer), Rhaptagnostus orbiculatus,Shergoldia antidiays, S. necopina (Shergold), S. nomas (Shergold), Sinosaukia sp. indet.,Wanwanaspis pygidion, W. sp. cf. W. semicircularis (Kobayashi), Wanwanaspis sp. andWanwanaspis sp. indet.

In addition nine species of conodonts belonging to Assemblage 2 of Nicoll & Shergold (1991)occur: Eoconodontus notchpeakensis (Miller), Granatodontus ani (Wang), Hirsutodontusnodus (Zhang & Wang), Hispidodontus resimus, Proconodontus muelleri Miller, P.tricarinatus (Nogami), Teridontus nakamurai (Nogami) and coniform elements A and B. Onlythree of these taxa were originally recorded from Unit F at Black Mountain by Druce & Jones(1971).

Unit G. The uppermost lithological unit of the Chatsworth Limestone at Black Mountain,between 380-420m, has been correlated with the Lily Creek Sandstone Member (Radke &others 1980), and the upper part of Unit 5 of Shergold (1975). It is characterised by thicklybedded cross-stratified sandy tnicritic limestone with thin interbeds and lenses of calcareoussiltstone and skeletal grainstone.

In terms of trilobites, the Lily Creek Sandstone Member is impoverished. Only four taxa arerecorded, of which three occur for the first time : Anderssonella eweyi, Shergoldia nomas(Shergold), S. sp. cf. S. trigonalis (Kobayashi) and Shergoldia sp. nov. (Zhang & Jell 1987).Probably these indicate an early Payntonian age, late in the NeoagnostusquasibilobusIShergoldia nomas A.-Z.

However, eight species of conodonts have been reported by Nicoll & Shergold (1991), whereonly a single taxon, Teridontus nakamurai, had been recovered by Druce & Jones (1971).These occur late in the span of Assemblage 2 (Hispidodontus resimus) of Nicoll & Shergold(1991), in the early part of the Eoconodontus Zone: Eoconodontus notchpeakensis,Granatodontus ani, Hirsutodontus nodus, Proconodontus muelleri, P. serratus Miller,Teridontus nakamurai and coniform elements A and B.

16CHASTVVORTH^LIMESTONE NINMAROO^FORMATION^',,,,S.V.VIFT FM

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Figure 5. Ranges of essential conodont taxa in the Chatsworth Limestone and NinmarooFormation.

17

Miller (1977 in litt., 1984; also Druce & others 1982; Nicoll & Shergold 1991) reported theoccurrence of `Oneotodus nakamurai' and Hirsutodontus hirsutus from one metre below thetop of the Lily Creek Member of the Chatsworth Limestone and at 18m above the base of theoverlying Ninmaroo Formation. Another species, assigned to Hirsutodontus (aft H. simplex),was also reported at 67, 76 and 81m above the base of the Ninmaroo Formation. On the basisof these determinations, which would normally indicate the presence of the early Cordylodusproavus Zone, the top of the Lily Creek Member and overlying basal Ninmaroo Formationwere considered by Druce & others (1982), Webby & others (1983), and Shergold (1989), tohave a Datsonian age since that stage was originally defined (Jones & others 1971, p.17) bythe first appearance of 'diagnostic conodonts of the Cordylodus proavus Assemblage-Zone'.Recent research (Nicoll & Shergold 1991), however, has demonstrated Miller's determinationsto be in error, and that stratigraphic conclusions drawn from them have led to seriousaberrations in correlation.

Essentially, the findings of Nicoll & Shergold (1991), based on stratigraphically closelyspaced samples which had been collected and cored for palaeomagnetic analysis, aresummarised in Figs 4 - 6. Specimens referred by Miller to the genus Hirsutodontus actuallyrepresent the newly described genus Hispidodontus, as justified by Nicoll & Shergold (op.cit.), of which four time successive species characterise their assemblages 2-5, and in theCordylodus proavus Zone do overlap the earliest species of Hirsutodontus. As the trilobitesinitially indicated to Shergold (1975), the Lily Creek Member of the Chatsworth Limestonelies well below any of the stratigraphic levels currently under consideration for use in thedefinition of the Cambrian-Ordovician boundary in shelly platformal carbonate sequences, andis truly latest Cambrian in age.

NINMAROO FORMATIONThe Ninmaroo Formation (Whitehouse 1936, emended by Casey 1959) extends as a thicksequence of carbonates over much of the southern and southeastern Georgina Basin. Its typesection is at Black Mountain (Unbunmaroo), where there is a continuous section 610m thick,and where five successive lithostratigraphic members are recognised: Unbunmaroo, Jiggamore,Mort, Corrie, and Datson Members. Detailed mapping in the southern Burke River StructuralBelt shows that a consistent lithofacies pattern exists from Mount Merlin in the north toMount Datson in the south (Radke 1981), and that these lithofacies approximate closely tothe members recognised at Black Mountain. The three uppermost members are essentiallythose recognised by previous workers (Jones & others 1971; Smith 1972). The lower twomembers are equivalent to the variegated limestone/dolomite member of Jones & others(1971). The lowest member is equivalent to units 1 and 2 of Smith (1972).

The Ninmaroo Formation comprises a sequence of repeatedly interbedded carbonates and siltycarbonates. Predominant carbonate types include biostomal and rare biohermal, mounded andlaminar cryptalgal carbonate, ooid grainstone, peloidal and pelletal grainstone to wackestone,with variegated "two-tone" overprints on the muddier limestones, flat-pebble conglomerateand intraclast-rich grainstone, coarse well-sorted echinodermal grainstone, mixed skeletallimestones with varying textures, and sandy carbonate.

This thick sediment package, comprises an mixture of very thin complete and incompletecyclic units which were very sensitive to local conditions, and resulted from shoaling

18

processes in very shallow, predominantly non-tidal, metahaline to hypersaline conditions.Radke (1980) recognised three types of cycle containing a diversity of sediments. These weredifferentiated on the basis of dominant component rock types: A-cryptalgal (subtypes includeAl-cryptalgal domes, A2-cryptalgal domes and cryptalgalaminites, and A3-cryptalgalaminites); P-peloid, and SO-skeletal-ooid cycles.

Accumulation of these shoaling-upward deposits in varying order and frequency has producedlarger-scale sequences that are subdivided into lithofacies on the basis of dominant rock type.The lithofacies recognised in the type section of Radke (1981) are:

0-30m lo Ooid carbonate lithofacies30-370m llp Peloid carbonate dominant lithofacies370-440m 111c Flat-pebble conglomerate carbonate lithofacies440-450m lo Ooid carbonate lithofacies450-500m Ilk Flat-pebble conglomerate carbonate lithofacies500-520m Vs Skeletal carbonate dominant lithofacies520-550m lo Ooid carbonate lithofacies550-590m Vs Skeletal carbonate dominant lithofacies590- + m lips Peloid and skeletal carbonate lithofacies

Thicknesses of intervals are rounded to the nearest 10m.

SubdivisionPrevious studies on the Ninmaroo sequence have subdivided the Formation with a generalconsistency except in the lower part of the sequence (Table 1 of Radke, 1981, Figure 3 ofDruce & others 1982). Informal units 1, 2, and 3 of Brown (1961) and Casey (1968) werecombined by Jones & others (1971) into a 'Variegated Limestone/Dolomite Member'. Druce& others (1976) combined Units 1 and 2 of Brown (1961) into the `Unbunmaroo Member'.Although they recognised the distinction of Brown's units, his Unit 1 was too thin to bepracticable for the purposes of 1:100,000 scale mapping. Since 1976, this subdivision into fivemembers has been used by Shergold & others (1976) and Druce & others (1982). With therepetitive interbedded nature of the sequence and gradational changes, boundaries of themembers are not distinct and there has been some debate on selection of member boundariesin the sequence. The subdivision of Druce & others (1982) accommodated the generalconsensus at that time. We would now suggest placing the boundary between the Jiggamoreand overlying Mort Member at 375m, whereas Druce & others (1982) placed it at 351m.Horizon 375m is the uppermost horizon of abundant muddier carbonates with "two-tone"overprints.

UNBUNMAROO MEMBERLithostratigraphyThe Unbunmaroo Member comprises 69-250m of medium to thick-bedded limestone peloidalclast and peloidal grainstone, sandy peloidal grainstone, and thrombolitic biostromes. Evidenceof former sulphates (gypsum crystals and anhydrite nodules) are relatively common in thelimestones and chert nodules. A massive, cross-stratified peloidal and ooid grainstone, sandyin places and locally dolomitized, occurs at the base: within this bed are biohermal moundsof stromatolitic boundstone. In the type section (Radke 1981), this member is 165m thick.

19

The Unbunmaroo Member conformably overlies the Lily Creek Sandstone Member of theChatsworth Limestone at Black Mountain, Ninmaroo, Mount Datson, and possibly atDribbling Bore. In the Lily Creek area to the north, mapping suggests there is anunconformity, identified in stratigraphic drilling as a karst surface.

The base of the Unbunmaroo Member, and thus the Ninmaroo Formation in the Burke Riverarea, lies within the Payntonian Stage at Black Mountain and Ninmaroo. Early Datsonianconodonts occur 9m above the base of this member at Mount Datson and immediately belowit at Dribbling Bore (Shergold 1975, figs. 7-8).

Discussion of sedimentationThe lowermost 30m thick bed is the ooid carbonate lithofacies (1o) of Radke (1980), andincludes poorly-developed skeletal-ooid (SO) cycles up to 4.5 metres thick. This lithofacieshas distinctive cross-stratification with trough-shaped bases, moderately angled foresets, andsets up to 1 m thick. The presence of herringbone cross-lamination indicates tidal conditions.The skeletal debris comprises, in decreasing abundance, pelmatozoans, trilobites, brachiopods,rostroconch, nautiloid and other molluscs, and conodonts. Random pseudomorphs afteranhydrite nodules and thin collapse breccias indicate a limited evaporitic overprint. Thissequence is interpreted as a barrier shoal complex with active ooid formation, that delineateda significant transition from open-marine to warmer, more tidally restricted, and shallowerconditions with extensive shoals.

The overlying 135m is incorporated in the peloid-carbonate dominant lithofacies (11p) (Radke1980) which comprises peloid carbonate (P) cycles and three variations of cryptalgalcarbonate (Al, A2, A3) cycles. This lithofacies accumulated under increasingly metahalineconditions. As a result, nonskeletal sediments predominate, but there still survived a variedbut low abundance fauna of trilobites, ellesmeroceroid nautiloids, rostroconch molluscs,brachiopods, chitons, gastropods, pelmatozoans, ostracodes, ichnofossils, and calcareoussponges. Cryptalgalaminites and thrombolitic biostromes are recurrent in the sequence, as adistinctive characteristic of the member. There is increased evidence of an evaporitic overprintwithin the shoaling-upward cycles. 'Two-tone' limestone fabrics are repeatedly abundant, butnot as distinctive in thickness as in the Jiggamore Member. 'Two-tone' or 'variegated'limestone is indicative of hypersaline to evaporitic overprinting. Evidence of tidal conditions,including channels and herringbone lamination, ceases just above the upper boundary of thismember until well into the Corrie Member.

Fauna and ageOf the skeletal elements noted above little has been described. Trilobites are extremely rarein the Unbunmaroo Member at Black Mountain, only a single taxon, Mictosaukia poplexaoccurring in a thin chert layer at horizon K145 (Fig.4) (Shergold 1975). More commonlyoccurring are nautiloids (undescribed); sclerites of the polyplacophoran Chelodes whitehouseiRunnegar & others (1979); and the rostroconch molluscs described by Pojeta & others (1977):Apoptopegrna dickinsi, Bransonia chapronierei and Eopteria struszi.

Some twenty one species of conodonts have now been identified, mostly as a result of recentresampling, e.g. the collective fauna from samples BMA 65-90 of Nicoll & Shergold (1991),which are equivalent to trough samples 74-101 of Druce & Jones (1971), includes:Clavohamulus spp., Cordylodus primitivus Bagnoli & others, C. proavus

20

GREAT BASIN, USA BURKE RIVER STRUCTURAL BELT, WESTERN QUEENSLAND

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Proconodontus tenuiserratus

Hispidodontus discretus z4Z 0I--Z>-

13-

Eoconodontus notchpeakensisHispidodontus appressus

Hispidodontus resimus

an=+.•C0-0oco020_

Proconodontus muelleri

Teridontus nakamurai Z<-z0I—z>-a0_

IwI:00-

Proconodontus

posterocostatus

No Zonation

20/F54-10/6

Figure 6. Australian - North American conodont biostratigraphic correlations.

21

Eoconodontus minutus (Miller), E. notchpeakensis, Eodentatus bicuspatus Nicoll & Shergold,Fryxellodontus inornatus Miller, Granatodontus ani, Hirsutodontus hirsutus Miller, H. nodus,Hispidodontus appressus, H. discretus, H. resimus, Proconodontus muelleri, Teridontusnakamurai, Teridontus n.sp. A, T. n.sp. B, and coniform elements A, B, C and D (Nicoll &Shergold 1991).

These conodonts represent the combined Assemblages 3 (Hispidodontus appressus), 4 (H.discretus) and 5 (Conlylodus proavus) discriminated by Nicoll & Shergold (1991) which spanthe late Eoconodontus and early Cordylodus proavus Zones recognised by Miller (op. cit.)globally. In Australian biochronologic terminology the Unbunmaroo Member of the NinmarooFormation is largely of Payntonian and earliest Datsonian ages.

JIGGAMORE MEMBERLithostratigraphyThe Jiggamore Member varies from 92 to 210m thick in the Burke River area. At BlackMountain, it is 210m thick within the interval 165-375m from the base of the NinmarooFormation. It is characterised by the predominance of 'two-tone' limestone, and comprisesthin to thick-bedded limestone (clast peloidal and peloidal grainstone, ooid grainstone, andmicrite, frequently bioturbated), dolostone, and dolomitic breccia. Diagnostic 'two-tone'patterns in these carbonates are a conspicuous diagenetic overprint which has gradationallimits. The unit is regionally stratiform, but its boundaries may be discordant on a small scale.

Discussion of sedimentationThe Jiggamore Member is a continuation of the peloid carbonate-dominant lithofacies (Radke1980) from the Unbunmaroo Member but there are subtle changes; the sudden increase inabundance of 'two tone' overprints in the lower 30m of the Jiggamore Member, the absenceof evidence for tidal conditions, the relative increase in abundance of A2 and A3 algal cycles,and changes in the sparse fauna. Echinodermal debris increases in relative abundance in thismember.

Fauna and ageTrilobites, conodonts and rostroconch molluscs have been described from the JiggamoreMember by Shergold (1975), Dnice & Jones (1971), and Pojeta & others (1977) respectively.Additionally, polyplacophoran sclerites assigned to Chelodes whitehousei (Runnegar & others1979) occur, together with undescribed ellesmeroceratid nautiloids, quantities of echinodermalmaterial, various problematica and stromatolites.

Taxa identified to date include the trilobite Leiostegium (Leiostegium) floodi andindeterminate and undetermined leiostegiid fragments (Shergold 1975). Ribeirioid andconocardioid rostroconchs include Eopteria struszi, Euchasma caseyi, Ribeiria sp.,Ptychopegma burgeri and Wanwania drucei. (Pojeta & others 1977).

Conodont determinations by Druce & Jones (1971) have been considerably updated by Miller(1980), Chen & Gong (1986) and Nicoll (1990). Taxa now identified are: Acanthodusuncinatus Furnish, Cordylodus angulatus Pander (=C. intermedius of Druce & Jones 1971),C. sp. nov. A (=C. aff. caboti Barnes & others, =C. oklahomensis of Druce & Jones 1971),C. proavus, C. prolindstromi Nicoll (1991), Hirsutodontus rarus Miller, H. simplex (Druce

22

& Jones), Monocostatus sevierensis (Miller), Oneotodus bicuspatus Druce & Jones,Semiacontiodus nogamii Miller, Teridontus gracilis (Furnish), T. nakamurai (Nogami) andUtahconus utahensis Miller.

The Jiggamore Member was deposited during a time span extending from late in theCordylodus proavus Zone into the Cordylodus prolindstromi Zone. It thus contains thebiostratigraphically important datum based on the co-occurrence of C. caboti (as interpretedby Nicoll 1990), C. proavus, C. prolindstromi, Hirsutodontus simplex, Utahconus utahensisand Monocostatus sevierensis which appears to have a wide distribution in carbonate platformsequences, perhaps globally. The first appearance of C. lindstromi sensu stricto occurs in theoverlying Mort Member of the Ninmaroo Formation. Nicoll (1991) has demonstrated that theearliest occurrences of C. lindstromi are actually that of the related but separate species C.prolindstromi.

MORT MEMBERLithostratigraphyThe overlying Mort Member, ranging from 40-130m thick, is 111m thick in the type section,within the interval 375-486m from the base of the Ninmaroo Formation. It comprises thin-bedded, flat-pebble limestone conglomerate and intraformational breccia, together withpeloidal ooid and peloidal clast grainstone. Stromatolitic and thrombolitic biostromes aredistinctive beds. The characteristic of this member is the predominance of flat-pebbleconglomerates which were formed by the exfoliation of algal mounds and the breakup ofhardgrounds during periods of high energy conditions. The Mort Member lies conformablybetween the underlying Jiggamore Member and the overlying Corrie Member. The upperboundary is defined by a bed of flat-pebble conglomerate with a distinctive red-green clastcolouration in a yellow-orange cloudy cement matrix.

Discussion of sedimentationThis member comprises the flat-pebble conglomerate carbonate lithofacies of Radke (1980)with a thin, central incursion of ooid carbonate lithofacies. The sequence is still cyclic, witha predominance of modified P cycles in which only the basal flat-pebble lag is well preserved,contributing to the increased abundance of this lithology. All cryptalgal carbonate cycles arerecognised, but types A2 and A3 are relatively more abundant (Radke 1980). Shoal relief waslower with less accumulated fine sediment. This appears to have influenced the correspondingreduction in evaporitic overprints. In summary, shallow submarine induration along with theincreased formation and accumulation of ooids has produced this distinctive member.

Fauna and ageOnly indeterminate trilobite fragments have been recovered so far from low in the MortMember (Shergold 1975). Chelodes whitehousei, the polyplacophoran mollusc described byRunnegar & others (1979) ranges from the Jiggamore Member, as do the rostroconchmolluscs, Wanwania drucei and Pauropegma jelli (see Pojeta & others 1977). Undescribedgastropods, nautiloid cephalopods, inarticulate brachiopods, and stromatolites occur morerarely than in the Jiggamore Member.

The Mort Member is dated mainly by the occurrence of conodonts. Druce & Jones (1971) andDruce & others (1982) reported the simple cone form genera Scolopodus bassleri (Furnish),

23

Semiacontiodus nogamii Miller, Teridontus gracilis (Furnish), and Utahconus utahensisMiller. Associated cordylodids have been treated in terms of assemblages by Nicoll (1990,1991), and Nicoll & Shergold (1991): Cordylodus prolindstromi and C. lindstromi are theonly common cordylodid species found in the Mort Member.

The first appearance of Cordylodus lindstromi occurs 32m above the base of the MortMember (407m above the base of the Ninmaroo Formation) in sample GB 90-002/54. Itcharacterises the upper part of the member to the near exclusion of other cordylodids, saveone occurrence of C. angulatus in the topmost beds. Nicoll (1990) regards C. prion LindstrOmsensu Druce & Jones (1971) as a synonym of C. lindstromi, hence the C. prionIScolopodusAssemblage-Zone recognised by Druce & Jones is not biostratigraphically viable. The MortMember therefore spans a time interval from late in the middle Cordylodus lindstromi Zoneto late in the Cordylodus lindstromi Zone (sensu Nicoll 1990).

CORRIE MEMBERLithostratigraphyThe Come Member comprises medium- to thick-bedded encrinite (echinodermal skeletalgrainstone), together with ooid and peloidal grainstone, skeletal peloidal clast grain stone, andcross-stratified dolomitic sandstone, 98.7-210m thick. In the type section, it is 98.7m thick,within the interval 486-584.7m from the base of the Ninmaroo Formation. The distinctive andcharacteristic rock type is white to pale yellow echinodermal limestone, which weathersspheroidally and has a uniform crystalline appearance. In places, the Corrie Member has beendeeply weathered, resulting in the silicification of the skeletal grainstones and thedevelopment of chert lenses. A regolith developed over this unit has been mapped separatelyas the Swift Formation (see also Datson Member).

Discussion of sedimentationThe Corrie Member comprises a variety of lithofacies, but the skeletal carbonate one isdominant, although the ooid carbonate lithofacies is also locally abundant. Conditionsapparently changed gradually from deposition of the Mort Member and there is a transitional14m of flat-pebble conglomerate carbonate lithofacies. This relates to evidence of structuralinfluence on sedimentation, the growth of the Black Mountain dome during late Mort andearly Corrie deposition. In the Corrie skeletal-ooid carbonate cycles, basal erosional surfacesshow linear features like rillenkarren that align down dip (Radke 1980, fig. 3). Thisorientation corresponds to thrombolite mound alignment in the upper Mort Member.

With increasing shelf gradients, whether local or regional, salinity appears to have reducedsignificantly, with a consequent proliferation of fauna. The massive echinodermal bedsprobably reflect selective winnowing and accumulation, and there was correspondingformation of ooids under these conditions. Only skeletal-ooid carbonate (SO) and cryptalgalcarbonate (A3) cycles are recognised in this sequence, the latter forming a thick anddistinctive "birdseye" horizon in the upper part of the member.

Fauna and ageThe rostroconch mollusc Pauropegma jelli Pojeta & others (1977) and the trilobite Asaphellussp. undet. (Shergold 1975) occur sparsely in the Corrie Member which is especiallycharacterised by silicified articulate brachiopods referrable to ?Apheoorthis sp..

24

The age of the member is given more specifically by conodonts. Nicoll (1990, 1991) hasgiven revised determination of the cordylodids which include the overlap of ranges ofCordylodus lindstromi (sensu Nicoll 1990), C. angulatus, C. caseyi Druce & Jones andCordylodus sp. nov B (Nicoll 1991). These are associated with Acanthodus costatus Druce& Jones, Chosonodina hetfurthi Miiller, Clavohamulus sp. nov. A (Nicoll, in prep). Druce &Jones (1971) and Druce & others (1982) additionally recorded the form genera "Acontiodus"staufferi Furnish, Drepanodus acutus Pander, D. suberectus (Branson & Mehl), D. tenuisMoskalenko, Oistodus inaequalis Pander, 0. lanceolatus Pander, Scolopodus bassleri(Furnish), S. gracilis Ethington & Clark, S. quadraplicatus Branson & Mehl, S. transitansDruce & Jones, S. triplicatus Ethington & Clark, Semiacontiodus iowensis (Furnish), S.nogamii Miller, Teridontus gracilis (Furnish) and Utahconus utahensis Miller.

DATSON MEMBERLithostratigraphyThe Datson Member comprises thin- to thick-bedded limestone or dolostone (skeletalgrainstone, boundstone, peloidal grainstone, clast grainstone, lime mudstone), and chert. Thismember is 24.3m thick at Black Mountain, within the interval 584.7 - 609m, but has amaximum thickness of 295m at Mount Datson. Because of its general exposure off the domalstructures and its proximity to the Swift weathering surface, it is characterised bydolomitisation and silicification overprints.

The Datson Member conformably overlies the Corrie Member. The boundary is sharp anddistinctive because of the immediate change to thin-bedded and laminar peloid and skeletalcarbonate (lips) of Radke (1980). A regolith comprising red soil with numerous chertfragments derived from the Corrie and Datson Members has been mapped as the SwiftFormation, but correlates with the Digby Peaks Breccia and unconformably overlies theDatson Member.

Fauna and ageThe fauna is dominated by trilobites, with less common rostroconch molluscs, siliceoussponges?, brachiopods, bellerophontid gastropods, hyoliths, calcareous algae, conodonts,nautiloids, and bryozoans. Burrows are locally well-preserved in the unit.

To date, only a single trilobite, Warendia bidecorata Gilbert-Tomlinson (1969) has beendescribed. Undescribed, although of very common occurrence, is a species of Asaphellus.More rarely, the trilobite assemblage also contains a metagnostid, harpidid, remopleuridaceanand protopliomeroid, among others yet undetermined. All taxa occurring appear to have closerelationships with previously described Chinese material considered to have a terminalTremadoc age (see Peng 1990).

Associated conodonts, originally described by Druce & Jones (1971), have been reanalysedby Nicoll (1991). Among taxa recognised by the latter are: Cordylodus angulatus, C. caseyi,Chosonodina herfurthi and Clavohamulus sp. nov. B. Druce & Jones (1971). Druce & others(1982) also recorded Acanthodus costatus, Acodus oneotensis, Drepanodus acutus, D.subarcuatus Furnish, D. suberectus, Oistodus inaequalis, 0. lanceolatus, Oneotodus variabilis,Scolopodus asymmetricus Druce & Jones, S. bassleri, Semiacontiodus iowensis, S. nogamiiand Teridontus gracilis. Possibly only three of these taxa, A. oneotensis, D. subarcuatus and

25

S. asymmetricus characterise the Datson Member which has been referred to the Chosonodinaherfurthi I Acodus Zone by Druce & Jones (1971) but which we now prefer to regard as theCordylodus angulatus I Chosonodina helfurthi Assemblage-Zone (see above).

THE TYPE SECTION OF THE NINMAROO FORMATION AT BLACK MOUNTAIN

LOCATION OF TYPE SECTIONThe type section at Black Mountain offers the thickest exposed sequence of NinmarooFormation with the least structural complications, and with minimal dolomitisation. Thesection generally follows ridge tops to optimise accessibility and minimise scree cover. Tomaintain continuity, several laterals were necessary to avoid structural complications. BlackMountain (Fig.1) is a faulted peridomal structure with apparent continuous reduction of dipof beds off structure. On the mesoscale, gullies normal to strike tend to follow faults of smalldisplacement. In the upper section, there is apparent faulting parallel to strike which may havehad thrust components at some stage of dome development. The section (Fig.7) minimisesstructural complications, although some are still evident. Additionally, at the mesoscale, dipsare erratic as is most apparent on dip slopes where "egg carton" folding is observed with anapproximate 2 metre wavelength.

The type section, described by Radke in 1981, was originally measured in 1976, and there hasbeen significant deterioration and loss of marking since this time. During integration ofbiostratigraphic and palaeomagnetic sampling of the Ninmaroo Formation in 1989 and 1990on the Radke section, relocation, remeasuring and remarking was attempted for particularlyimportant stratigraphic intervals.

The type section, section GE0202 of Radke in Shergold & others (1976), comprises eightlegs.

LEG!Approximately 50m to the north of the trig station on Black Mountain (Unbunmaroo) thereis a steep gully incising the highest and most prominent thick scarp. The section starts at thebottom of this gully, at the base of the Ninmaroo Formation, directly on top of the uppermostbed of Chatsworth Limestone. The conformable contact is on top of a distinctive thick orange-brown bed of dolomitised, cross-stratified sandy grainstone. This bed is the uppermost andthickest of several similar recurring beds.

The section starts at the base of the scree slope overlying this distinctive Chatsworth bed, andproceeds up the northern side of the gully to a light blue-grey fenestrate mudstone at 33m.

LATERAL TO NORTH for approximately 30m.

LEG 2This leg proceeds in a north-westerly direction up to a crest and then along a descendingridge to a saddle where a distinctive and prominent thin bed of ooid grainstone with whiteflat pebbles marks the top of this leg at 104.5m (paint marked 102.5m).

LATERAL TO NORTH for approximately 50m to next saddle.This lateral crosses a small fault that displaces beds a distance of several metres.

ADATSON MEMBER 593 m

20/F54-10/71 Leg of Radke 202 measured section

— B6

65

2co

1

551 m

co

375 m

o Vo^ 324 mCC^ dip slope

2 312 m

JIGGAMORE MEMBER^A 115

287 m

584.7mGB 90-003

7-8

CORRIE MEMBER

488 m

MOAT MEMBER

26

Figure 7. Detailed location of the Black Mountain Cambrian-Ordovician transition section.

111^11111111 11* R 9 1 0 4 8 0 4 *

27

LEG 3The section continues from the distinctive bed with white flat pebbles (metal stake in place)directly up slope in a northwesterly direction, following the ridge-top to 287m, a prominentbed of light brownish grey ooid grainstone with biostromal patches of boundstone. A metalstake marks this bed.

LATERAL TO NORTH for approximately 100m to a low stone cairn on this same bed.

LEG 4This leg continues along a bearing of 310°M, to a prominent medium bed of interbedded flat-pebble conglomerate and bioturbated two-tone mudstone at 312m. A metal stake marks thishorizon.

LATERAL DOWN-DIP SLOPEFrom the top of Leg 4 at 312m, the metal stake at the start of Leg 5 can be seenapproximately 250m distant on a bearing of 290°M.NOTE: The type section published in Radke (1981) has a thickness error between Legs 4 and5. Horizon 312m of Leg 4 is equivalent to Horizon 324m at the start of Leg 5. The sectionhas been repainted as originally marked in 1976.

LEGSA metal stake marks recommencement of the section at 324m. This stake is on a steepnortherly slope of the ridge. The section proceeds on a bearing of 310 degM generallyfollowing the ridge top of a westward descending spur to a metal stake at 487.5m. Thishorizon is a distinctively thick bed of encrinite (skeletal grainstone) on a low scarp justbeyond a small creek.

LATERAL TO NORTH for approximately 150m to another metal stake.

LEG 6Section recommences at a metal stake on top of the encrinite bed, marked 488m, andcontinues on a bearing of 310°M to 549.5m, also marked by a metal stake.

LATERALFrom the top of Leg 6, the metal stake at the base of Leg 7 is across the creek on a bearingof 245°M.The area between Leg 6 and Leg 7 has apparent monoclinal faulting with associated localiseddolomitisation and steepening of dip. There is a signcant reduction in dip from Leg 6 (15-200) to Leg 7 (6°).

During remarking of the section, an apparently less disturbed sequence 15m thick wasmeasured in a creek to the south, between horizons 549.5m and 551m. This adds 135m tothe section.

LEG 7From the metal stake at 551m, the section continues at 305°M up the creek bank to 570m(marked by another metal stake). From this point, one can proceed direct to the top of thesection on a bearing 285°M. However, this direct route misses some better exposures.

! II I^14118

28

LATERAL TO NORTH for approximately 30m.

LEG 8(No metal stake). Proceed up rise on bearing of 320°M from 570m to 578m at the top of agentle dip slope. The marked section has a slight change in direction to the southwest to thelevel of 581.5m.(581.5m mark lies at 270°M from 578m mark. Section runs at 45 degrees to dip direction).From 581.5m, the section line runs at 250°M (45 0 to dip direction) to the top of the section(metal stake) at 593m. The distinct base of the Datson Member is at 584.7m.

Figure 8 (opposite and following pages). Detailed graphic log of Black Mountain section ofNinmaroo Formation (from Radke 1981).

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456 -1

v gy 6,051, skit/ Cv02; um; Oro); (s/ grams)^ 0 «511

it pp, pp orn pk, Pros!, f, ooici, skill, sd,sre , restrd, grades uP lo of Proof, , s2.__'nef^ 0 3

v 11 gy, 5O0k Pros/, ooid Cf eiong.7, skit/ srl, mtl^Slyl , reklzd^ 0 3

j gy aro plr Prost, sd, of p/d/ XsIrol (4cm se/s, sep by , vs& Lam ],cpcla

^= ^of 11 Ors 6,15450,p/0/ Cvf_ 7 • Jr,

of^gy Pros/, SO, vl pld/, Lomd , (bnotrbo)

of /8 /so gy Mtbda Pros/, v1,50, p10/, (b/Olrbo), Prost, skill , O/d/

^= ^A of olv gy mtbdd Xstrol Pros!, of p/d/, sd, (skill) and Grosl, skill, (Oast), p/Ol^ p^0 6 0

of // olv gy Pros/, sr!, p/d1 Cv1.7

0^= ^pk gy Pros!, Oast Cv f Gros1.7,sd,p/01? - si rep/ MOO, vemmg, pyit pl fed Pros/, clost Cvary,rodd, laM,Prost ?2, p/d/

125

p

gy ProLt, 000d C f _7, clost Co sm], skill; lomd. Si skill grotoS^ 0 0 0

o/v gy inftdd MPs/, Pros/, c/ost C WV, skill Woks/_7, skill, 6,05/, sod C1_7, skill^ 0 0 0

=11 gy Mast, eroded over/om by ProsI, otos, CMOst, lath], skill py^ 0 0 o1/95 Pros/, skit/ C frog], pidl, srl ..si base, Styl contort^ p 0 PI^•Karst ?

..,, op red arnst,00,c/ Cv1_7„IclastrePlch.Y2. wthrd^ 0 0---= (of) v II o/v gy Pros!, of p/c11:;s..0fe (v1) c//sly gy Pros/, /sd, sod.' C f..7, (Oast); eroded, Pros!, Oast &odd Prost iath] logs under dod's^ 7' 0^- 081e,01-:L.- op red Grost, skill C frog], syl, par^ 0(1:5;

^

5,1^ 6^6P 1 =^//67c gy Prost, skill CR/b, sk/N,rnudfdied frags_7,(clost) road - 'c/irk^

,-^9

^1 ^/t boo Proof, skIN Cc-vc..7; fr,,wthra^ 0

/I brn gy Proof, of, p/01; uni^ P

Pros!, clost Crock/ lath, Fe ',oh], Ml.r Cv I colcile_7 rugs under closts^ 0

^

L=^op red Grnsl,sk/t/ C frogs], um .; over/,es karst ?wthrd sur loco^ 0^•Korst,

1-_, of Er. v// gm gy Pros/, tics , Csd Prnst, 'odd loths_7,sd, p101.0, cpcId^ 0 P

^

'-,^It gyorn pc/s, skit/ Pros/, I/ grn go Prost, sd,p/di Cv1_7,(clos1); /dend, dtbdd Grnsl, dos/ Csd Pros/]^ o 0

), it grn gy Pros/,d/a4' &odd loth, sd f Pros/], p/d/ ?,sd, trilbad klarnd sd Prost, p/al, Ng^ 2 P,.,(-: v(

op red 6,775/,501/ , , tics, C f Pros/], ft'', pc, wIhrg^ 00

op red Gros', omd, clast,,,vOdd of Pros/, pia/ blotroto, wthrd^ 0 0 P

op red 6,751, odd Cm_7, Probes Vas/ Pros/- wIhrd^ 00^r .- ^) h. gy Grosr, of ford, sxiti, 2/one Earn, pie orn^ 0 0

,--, ''< o 1/ gy Pros!, ocorl Crn_ 7, dos,. Come> Prost, andd_7, skill; mtbdd Grnst,sidll,00ld,clost ond Dlotrato, Po's!? pkorn 2 lone bonds^0 2 '‘.>

op oro Pros/, clos/ Crndd loth, I Pcksl- Pros/], skill, pid/ ?. re/sad, - wIhrc/^ 0 c Pof -.,, It oh, g,y Grose, oold CI], sd, um clost Patches- rek•/,1^ r'. (0)

v /1 o/vgy Prost, dos/ Crndd sm 10Ih, p/d/ skill Grns1_7, ooid, skill. Vug under cies', orn co/cite Mlil^0 0 G- of (1,7) V 0. o/v gy Pros!, ciast Crndd 1010,1 Grast],sd p/d/, grades to lcund pldl skill Prost. Vugs under closIs^0 o ( 0)

^, ^it brogy Pros/, tics/ Coal, rndcf laths,/ Pros/- Pck51.7; sd p/d/ MO, red.rd^ 2, p, -1:3./ Gros/ clop. C kg road loths,vf so Pkil 6 ,nst-7,sialli grodos 4' Is fcma Pros ,^0 C a

^i ^ P 2.^13,-); /8 9/ Gros , ' Fckst Oidt, (skill) 2 tone, ye/ orn m11 In diotrto-_,_ v No& gy, Prosl,p/d/ Cvf .7, 5081 C frog], srt, Lamp; (Bm1rto)^ D 3

^c_,^v /I brn gy Pros!,clost Croce laths, pId/ Prost], skill; size decrease up: wthrd resizd^ 0 0

c of 0 brn gy Pros!, Oast f trg car, rodd laths, of pp Gros/2,p/d/ s/ Pexl.rd^ 0 o

Pros!, Oast Crodd 1,M, f o/d/ pros/2,p/di CO^ 0 oO If gy G,,Sr, 5107 Cv1_7 srl; sod; cioSt POICheS 5i5trb10^ 2 0e v p yel Mast, b/otrbta, mtbdd of ploi skill Pros/; grade mto Worst 2 /one 9tec

P 3

-4' of /0 9/ Pros/, aost Crodd loth, 1 so' Pros/], rots Cy/ sa] (P.V) m mf.; roxl,a^ 2".

/1 gyto bm gy Pods/? stromo1 Clobulor,domed_7,9/501 Gros/ al base sMolled^ L---L? 12)

1/5,0 gy Pros/, 0100/ Cloth, oold skill Pros/, r00o'_7, sk/0; (d-I)^ .C' 0

d gy orn Grnsl, Ooid C I -m_7,clost Cloth,rodd of Grnst_7,slrg/ . Vug under 4,nsis^ C.- 0 0z, gy orn G").st, rhos/ 1- road, loth, of arnst_7,00id .2, vugs under clasis^ e

^olg pld1,05,0,m bro gy Pros/, oold Cc], clos/. 2, fostrt?; '&1,0,010 p0 co/c allro, cpctd, Sly/^

'S.-- o 0 --.0

^

r-_^!,^/nd skill,intl C bostrorne3 2 lo'^ne tnI; s/ foss^•s^-,^07 o/v gy Pods

O Q., ? ---8, 2

I/ Pro go Pros/, class r vorl,rodd-ang, pidl Prost_7,skIll, pidtrekird,orng oft, of vug cement^ 0 ':'' 3 P

g gy 6,75'40a/0 CI 7, skill C frog_7, 50; clog, Patch^ (.' 3 4 0)Wok s/-Pcksl, (skill), botrbld,m11 2 Ione Lon, 4- blotrbn oltro

8 -'20i gy Gros!, 50,dskili, 057/ grades Ink ooid Pros!, blotrbld 2 lone Pooas^ co,

0.

^- 1 -^it gy Pros/, oo,d, skill clost Cf skill Pcks/3 (st Fogs)^ 0 ,')' 0 -,- (...... :v 11 brogy Pros!, 50,0, skill,c/osl &odd-009,f Pros/3' rex/id, gy or, ollrn^ OF 00Noy Grost,00ld Cm], clost Cloth, rodd, sd 1 Pros/], skiff Sty/^ 0 0 c),

^

= -4= or' It gy Grnst,sd, p101, /amd,s/orod,(bnotrbtd);porting lloeatmen 3/0° ' chlorite^ 1^._, -

498 -

495- ,

492

409 -

• Korst ?

C

p

000 0 0 p

Op0 ,2

CO 2Cr0 7272-

oe 032000 0

e

P0

31,.. _, .^_^.^.^. .^.^.^ -^•^-

v /I brngy Grnst, oold, skill, dos, Crndcf-ang,1 Grns13 , rek/zd;gy orn oil rn^ 0 P 0 0II gy 5,05/, Paid Cm2,c/osf CloM,rndd,sd f Grns13, skiff Sly/^ 0 C 0/7 gy Ginsl,sd,p/d1,1omd,klomd,(biolrbfd);pOrling lineofion 3/0' 3' ChlOrile^ u

m gy Grnsl,00fd,pkIl CelongJ, skirl; 8ndS1? patches^ 0 0 d g za-

d olv qy Grnsl, of oofd?, (clost)^ 011 gy Gros'', Closl C/a/n, Mg, rndd, f pld/ Grnst_7, p/d1 C f 3, srt - Virg under :fasts^ 0 oro olo gy 0m51,Clost Cmmeg,rndaskill Mist,/ p10/ Gins/3, pldl, Skill, (ort), Vug Csm3 under closls^ 0 P 3

if p/c gy ands!, Coold, o/d/, skill, 'end' 3 domed 's/ Foss, do/ Porch^ p--ral

O /1 orn gy 8ndsf, biostrome Cooml,plcil,skill,ind'_7; domed (oug), si Foss^ G.

rn o/v pr Grnsl, f //0/, mfbob 430540018,5rosf,c/osl^0/01, (54171) cpcfd sty, or 2 fooe coo/ac'S 80 °mgDpi a//.6

029 -

rn /7 Oro pp, Grnst, v.'s , CI skill Pcksf3,^pld/' rugs rmder clost; co/co do/ znfi/

▪ m o/v gy Pckst?p101 Cf 7, Ala (DM/IVO), polo/7 Gros 1,c/osf^ 01v gy Grost,^C rube°, subrnOd, vori, skill Pcks.72, skill, p/d/,^s/ Foss

• m brn 72, Grnsf, Pcl- sl. I picir,sk/fl,um C v bfolrbtd.P2 s/ rek8c1

orngy Gros', clos/ von,rodd,50/7/• p/d/ P72s13, p/di^J, 0/8 cpc10

PP 17 o/v gy Pcksl? p/d1 CI 3, 0,o1rOrd; In1000 Ws/ /I bro oltrn en Bmfrbnv olv gy Gros!, cMs1^mth,sd Grns1_7, fnMdd Land sd I old/ Grost- ch/orMe.' becks

v /70/v gy Grnst, closf C. Min, v f Grost3

v/ v // pp Grose, mmo, 0104 so, overlying Grnst, dos/ Crndd, Gros, J, old/ Vugs under closIs

^ gy Gros', clop. Cloth, Mg, opal, old/ 6rns/3, arm:, coCld; (py)

426 -

423 -

no", Oces,, cies' ['le', /odd, if Grnsi + skill WCkSf..7,0Old C13, skiff rep/id, 2 lone, by, OugIi Oro^Grnsl, closf Crndd, of Grns1.7,0010 Co f_7,Sk/II? reflzd

gy Gros?, gips/ CM14,of 5rns13, in/bdo . Grnst, of sip/dl' reazd, 2 lone

v // Orn gy 5r70f,vf,sd,p/d4p0mf,x/amol,(b/o/rbld); inlbdd Grosl, °lost, oold

If ye/ gy Grnsf, sd,p/d/ Cf3, in/Odd Grnsl,c/osl Crndd loth, Si Grnst

v1,_^gy Grns7, v1,sd,p/0/.?; over/om by Grnsl,clost (p0/f Grns1_7,s0/1/ , wthrd

rn Mgy Grnsl,oe d CIJ, sr/ moe/id; IvIhrd PatchMoly gy Grnsi, ciost Crodd-ong,^Wckst3,sk/b,p1d/ rerfrd 4flx/70/v gy Grnst, dos, Cmdd lo ong sk/t/ Wcks,..3p/d/,' Vug under closts^ o/v^Grasi.c/ose Crndd,skliI,Wcksf_7,p/d/ C 1.3; so 7000 vl skit/ p/d/ Grnst

L^

lt of, gy ands/ Cdomed,e/ongo/e / • 5fn 3 ;Woks!, p/d1,51r/7/,orb Grnsf,clos/ Fbss

c'' wn. Fr, °Mose

of If^Grosyon■d Cyr famd,overlom Gros7,closl CI,ocod Gros! _7Grost,clos'Crodd,/e/h,GrnsIPJ rex/7d Cc!. Vugs under closfs

v//p/c oy Gros', oO/d, sk/fl o Lomb,lbion'Ord), over/roc Grns,,Icios1),p/d/

,•." n o/c gy Gros., o'ns'Crodd,/ol , ,v old/ sd Grnsf,l'oyi 7 (oidlICv I _2 Ilugs code , slos ,

Gros'. oc/o^- 2, notches Gros', clop oomf

^ Pro Grost, oord CC, pp/3 ], (sr!) sl rer/zd• oy Gros/ ,ocod Col 2,c/osr Clod ;rodd skit/ over/png Si-oaf ,^, skO7

k 1 M olv gy Grns1,o/ost:rodd /01/75,sd o/d/ Gros/ 2, 0/01 f v12 , overly/no Grks1 5111/

gy Grosr,orno ..,/ost [poi, grades UP I, Sr,d5I^,^mil CL, Oslrgrne 1 5 , 1-055

oy 6,1,0 ,00,0 .7(1 orodes fcc, eroded, Over/01,1 by 00,..C/051, 51111 Gros,gy Grost,c/os , Op rodd,/ofh, sd Grost 2,(s1d11),grodeS up 10 fOldio/v qy Grost,^C /ro rodd Si Gros', 44dst , oora , skiff

=J=^gy Groso,r pid.', sk/l/ , sr/^odOur

gy Gros', old/ C 3,closl Crc,ong _^rloord, sl ,erlod

=^v v/' oy Gros', so^r ,

gy Grnsf , closl^op , p/d/ Si-so, 1141512, 0/0/C yr 2, rntbdd Loma WS/ .of sk ,t pm/1 Cifos.,Wcks , ro,fo^72 p

is^0 gY 1555t, old" Cy _ mfbrid Grosi,clost mg Grnst2^o I .2 tone ..orn^ P

C",./ pc Boost, orec,Sfnsf,clost rood • Vidst2,o/0/ 2,12^ rp, 72 p

olv gy Oodsf , rrsr, , Ws.", Lama' Breg f do/ _7

Ii 0/i- p1 Grosr,o'd , yi _7. 0/0020^refiza , (PY

If tro of Sr,/ .C151.5 , ['nod pld ,^, cpcid 72q , co/c,py, Son P

,

• Pro 72, 3,751,^o/d/ Cm. 3, skln oy :plc?, 7

Drool, v I 0'00 cross - lomd

oArgy^f, oold frni,sri, 0,1 odou r, 00/, 2 loneo/v gy Bodsf, 50/7/,p/d/,50,0,020 , (sr?), 051 sf vug , 8 0

. /1,5 gy Gros,' , clos1.2ndd,^p/d/ GrnstJ,p1dIC v/ J vogs under clos78nds1 slob .p/c11 Coop]

=^m p/c gy Grosi, old/ C ong,m , ads, Csm,ong3oo/d,C m , xsirot ' 8.0 , re

°log Cy Groot. vf o/d/ P rexlzd , 0,7 odourv oiv gy Grnsi, cies! .7 /alb ,/rg , Gros, sk/t/, p/d/ 3 rerlzdv °iv gy Gros,. m, 55/0,004 P;^, rexlzd, ; (OM odour)

ii olo gy Grnsl , clost Crndd , Mds/ mams13,p/d/ cpc1dv moiv gy Grnsf pidl Cc !a 13 , Pc ks7 • Cob&

C P

rex/zd , nof,,./oM do% Mos^C Pik,SpS^p .67

'no^ op',,

0 ° OP03 0

00O p

378-

=

Fault?

C P

--c,"O p

P

Øp

t -e.)^c p ye/Oro ends!, Cdomed bfostrome ,2/n^, ooml , pleb, dos/ Sly/, 2/one Nod

^T - ^ v fis o/v gy Bods1, lobe/or Coofd,sk/7/,p/d/ 2,11,78 s, Fossit OA, qy Grnst, dos/ p/d/

^1 , 1I^ "^p, Grns , , crest Crndd,Mcfs1J , croded , over/o , /^p10/. skill vugs under closfs

J-

'1 =

On' gy Ork5I;Clas' Cc,dd loth , Mast 3, pldIP Cv f3 mix ,Vug under closts/7 gy blot!, (blob -67d' Cspor filled 3, CP,M, wavy, ,,,ne ton

CO

3 5p0

PO 3

300

3 P0 0650 00 00

5 3

P

3

0^-.6. '2's

0

P

P^Lateral

00 *

Fault

2 97 -

294

32J

/03-

318-1

'" bin 9[ '35/ ^/olh,Mdst _7, plc/I2Cv f _7 Infx ,Vug under closts

4km , , 't ,00ttd sp, Oiled _7, coot", wavy, 2 'one Lam

r1; 1 .7_11 m gy Grnst,v1 p/o0 , skill so Ma's/, 0,n/rbsd of resiza,2 tone

1 -. 1.* qfbr-^. I _^

no^1.7, 9,_7.1m , una Cht• gy^ r,d0 m *105/ Ski.1 5043/0 scorry patches

^, I^ 't gy G,nss, 0r,gradog up to bp/rbldMdst 2/one ,ye/ gy Lam .t b,o1rOn

I^1 -^ Mdst , ,niadd old! Crust^brec , 2 tone, OP odourv fibre gy Crust, f pat, oold^grodng up to biatrbld Mdst re.rizd ,12 ,10e;

I^1^

▪^

II 0/a by /2/dot, bPfrOld Cis-9,61,st infi/J,Mtbdc/ Grnst,00ict , skill^oi/ odour- -r

spy iPckst 2,5101^mortzd , Lam ,Vn, ye/ gy 2/oneI

gy Crust, 43/00/ [at hose], pi& C v f_ 7 ,111oksi,skIO 2/one Lam ,yel qy

gy Acks',. skiff, pfd/ C vf_7 Nod,yel gy 2 tone Lom

rn gy Most, olopoto ',Woks?, skl I, p/c/I,Grnst,p101 pkgy 2/one Lam ,vug: colt ,n1 ,1_7

gy Crust, sk/t1 I. -complete frogs J,aold2,clostCsubrnddJ 80, text"!

-=It7.? ,7rns.',,c,d1C1],skitrflog,- tarnd,2tone bonds

j^,^'t /3,0 p Gros!,^p/r1/, skin, grdtni to Mds1 2 lone cpctn

olv gy Mdst, ItiotrOld IC Irg,sm]. op orn 2/000 Lam,

vC Orr gy Moss, eroded overlain by Grnsl,clos/ Crndd,Irg,skIll Wc000 -

- C by 1.1 ,-1ss, erodes' r overroir by Wckst, skill, Olotrbtd r Nod 2 tone▪ E^m Orr gy^old/ ? C12, ,rstrat C 3 cm sets]; grOdeS '5.s0 OsOtrbfd Mast,^y/o Lam

Grnst,c,ost, over/ying 0rnst,00fd^Old; grodIng to Pckst 2 tone Lam

", 9? ends , ? C tabular brOstrOMe7, ad, Grnss; pIdl,oOld Cm.7,CloS1C3 mm. 7 ;,srt. ,

repealed 6cm bands Ss Foss; lug 0 In/coon F

• gy Grnst,skill,clostCrndd Grnst7,p/c0 8 0 , cogs under clo,ts L-poi

lt gy 1;rnst,p/a/ ? (of], sd, lama Cpctd, nodular at tose Sty/

Is Or// gy Gros] p/d/ Ca f.), xstrot,lenses boost, otos, , pIcs/ cpcici

It gy Grnss,p/dI(IL, so/Odd Mdst any cpctn Lam

gy cicles-Grnst,v1 p/d1;gradIng to (0iolrbfd)Mds1, - eroded and repeated .• 2 tone Lam

,^e^

It gy M.ist,biotrbtd ; , ntbdd Bobs , ,p/d/ .7v1.7.• of rexlzd; sty/ cock up urn^tone Lam, Nod

.121-^v It olv^GrnSI, 00/a Cm] ,C1051(oold GrnstJot base ; upper rntl Wckst/Bndsf,ocua,^vug, .rreg,/vg,co/c,'embl

▪ Orr gy Pckst 7,010/ Cab], Lamd p orng mti re,r/zd

1,0)^.1 oh, gy Mdst, (blotrald); intbdcf Grnst, old; :vf.7, (clostl: cPcId; Sty/

-^/1 olv p 11 brn gyi intbdd; Grnst, of Pt& ?'cOctd 2 tone caf”

(8)^II bra gy Srnst;ciastC/rg,rndd , Mdst 2.1 p/dI Grnst_7;Int000 Mdst, blotrb/c/ • cpcfl bym It Orr gy Grnst,p/d/ Cv f_1,c/ast C ,` p/d/ Grns1,7" 8 0 cpctd

v o/v by Grnst, p/d/ CvfJ, ad, grades into Mdst (b/Otrb/d): cpc/d

*fel^o/v^Grn ss, Oast Csd,p/d/ Grnst2.' Cpctd ; no no/C) 2 tone ; sty/alt

= it o/v by Mast, ( Ototrb/d ); Overlain by p/d/ Grnstit o/v gy Grnst otos , ['odd, lot Pfds17

6.,sr,ovdc,”-a,CIOSIC rndd,Mdst_7; ad/ Grnsl,sd Cc], otos ,' 1:Md st, skill; 0'0'1,0, sold, OrSohte

338

336 -

It gy Mort, Camel 2 tone Lam 1- Brec

1 ":-' 1.e " g? Uds1,141ckst,biatrb/d at rex/id ,cpc1d, 2 tone, Chl Nod1- . 1 --,^C^v /fr 0/0 95'Bndst,tuoshorne (domed, shomot,30 cm 07" adj Brea • re,Ird

315.- ii I, I ^E-:^177 gy Mast ?, Wr.kst ?Lenses re.r/zd, 2 tone bonds (30%]E 4T7--^= m M qy Bnds t, domed (50 cm 0,7,0/9 • 9y urn us, 2 tone ( 70 %Jcpc/dIt o/v gy clost Co Irg rndd (se// pidl Grnst_7 Vugs under [lasts; Orng cm!

312- L ; I ; --^

C 0^It gy Grnst,clast Crndd lath, Mast* pldl GrnstJ, ski//; an/Odd Mdst, f plat Cur's! cyclic 2/one will",,.^

b/otrbld Mdst

(;- 1 -- LI

•^

m It gy Grnst, Oast Cool° . Grnst, 'add toth_7,00/c1 80

=^pk gy Grnst, 0001; If, wthrcl : re.rIza

I ...1. -7- .^=^,, 11 brn by Grnst,vf ,ocud; '0 8c/lot,sk/11eroded; Grnst,clost, staff ; 2/one Lam=

- Loteral

7 ) ,,C) ; dip

2 3 P

000

000

gy Gros'', skit/ (frog:, Oast lath subang, Pod 0t_7. 0 51m oiv^ands,'? skill; Choohc, 2 ease breccia of top in "'up-Ponds Mdst,desiccn cracks (arose

v It^gy Grant, skIll C frag..7,00id,(clast) r re.rizd ; rug, st foss^ oaf,/12 tone

m gy Post; tntadd Grnst,clost 2 tone, Bret, nodules_,re,r/zdno gy ,ntbdd Grnst,p/d/,sd, Xiornd Grnst,clast Csd,I GrnS12; erossonal

m by Grnst, c/ost Clrg,sd Gros!, rndd, /nths.7,,mbrcfcl

Or Grnst,pidi ( 'Jo/as/ (rode, Irg loths,Mds1J, skit/

^ b.-r Mc,' opo,lexlza; Clot NodIt duo, Grnst on/dc/not Comb Groat]; so/ Stromot ( Skill Woks , 1 - Cht

v It on gy Gros^(/mg, rnda, of p/d/ skIll Grns1.1,P1d, clO“ as?

m 0/0 gy Aids!, biotrbfd Comb fro]; (eroded Grnsll- - 2 tone C 70%7

gy 41,1; L ornc/ restzd; 2 tone; cpctdolv gy 5nds 1 ,stromos Cconnr,6 cm 0. 7,14'ckt- Mdst mtx^Pugsgy Grnsf ,00tcl(c_7 to gropestone; m ciost 060 bands 51y1

a/api SrnSf,o/d/ C^, ski 11 cpcte/ ; 80▪ /00/, p., Pckst,p/d/, skit', grading to lions!, skIlll, to Grnst,ciast, skill cubs, F1'

^ o/0 gy^Gros/,p/d/ vf _Maid Cvf 2, ski s/,' Grnst,c/oslCrnda,000d Gros^Vug, 2 tone

m gy Gra st, oota Cm,sph superficlal.7- - Cht, B 0 ; .51y/ cpc/d of baseGrnss .pldl Cf-7 ,0050, close bonds Cp/01,00id 6rnst_.7 Vugs,vadose

a It 01, .7.0 Crust, P101 ?Cvf2,skItl ( frogs]; (clost bonds) , c,octd; real.rd

0/ 0/43 gy ,ntbad Ornst,ciast S omd Groat, Mdst,Inotrblci Cr f_7 cpctd, 2 tonem cu gy Grns",,Oir1Cvfl, (Loma,) rexizd ye/ gy bondsIt Orr gy Grnst,aold Cm-c], (skit/ ); Potches 8ndst 7,00i0,skit,o/g 2 Vugs,n,onk,1

v .9/, g, Grnst,00ld (vi], skill, x/o/nd; fntbda Grnst clost Vug,/rg,Calctle ,ntbdd 2/one Lam

,it gy Grnst,00id r vf_7; int Odd with Grnst, clost rndd,omdd Grnst],00ld, Sly! vug

431/ no gy drnst, oold vf_7,srt,bnoa; mtbdd biotrbld Mdst, in/Odd Grnst,c/ast , rondon mo Vug calm

v11 olv Jr clost Cloth, rndd,I-3 cm, °old Grnst_7 , Vug under closts ;F ?v11 gy Srnsf,p,di C vf _7, srt v tn Lam 2/one Intbddm^,vckstP, o/d/ Cv"-f-j; shanpstrures 'md orng p02/one COM, 8rec Cnodule.7

or,- Ornst,0Iost /Also',/oth,rndd _7 skit] ,nterbanded 2/one Lam.^.

0 0 m^04

O p

,7N 5 0 -4,

Pp dp000pop 0 0

00

O 5^?

00

o

000 6

5

M79-

33o/v pp clost Cloth, /odd /-3 Cm, sold Prosy] - Vag under closts

.1 go 5rns",p;d/ vf_7,srl. v In Lorn 2/one intbddm o/v pp Vckst7, old/ Cvf 2; slumps'rures .'rnd orng ph 2lone Lam, 5recCnodule_7

/1brr Grnst,c/ost EMdsl,lotA,Indd.7 shill. mIerbondect 2/506 Lom/1,0, 5,,st,p/01 C vf_7, srt: tnlerbooded 2 lone

mIt pp Mdst,Wchst no/id, gperd 2 lone wavy ereccia, Vug,trreg,_- 5/011ern^•Wckst,vf, (Lomd) 2 tone wavy bonds (p red -7 obc 1

It Lyn gy, gyorng bk Grnsl,o0id,Skill,closl,onco/illt; ElndstP^ 0 0 ,a 0^?it No Grost,clost Crndd,subeg,/rg,Mds! I (p/dl Grns1.7,5kIll,p1M. Vugs underc/osls^ --■e2 P

It olv pp Grost,clostC/r9,vori,Mdst ,Wid Groot]; intbodd^pill Gros,' e skit, Srnst 'hug under ,rosl ,'Os:^p0 0","

It No gy Grosl ro/c1Cc.7,5011l,c/ost Cf pld/ Gros",rodd_7;grades 10 5580? ?sk/1/,00ld vog,colt .-,f/1 - 51 Foss C 0 0.^?

o c 6

ce 5

It brn gy Groot, p/ol P Cvf _7 .cpcld ; 2 lone Lon,

- pk gy Grose, intbdd f phdl shIll Gros"; C Irg,rndd,Pcksl_7; s FOSS. vugs under clostsIt g Pckslpp/orl C v1.7, °Old ?alas! )Csm,loth.7 rex/rd ,Cpcld, 2 tone gyon dol vugII Or,, Grnsl,00,d Crn-c.7,sk/11,clost:res/zd; s/ F05.5

gy Grns.,c/ost C/r9,/ato,rndd,Mast,sd Grns1_7•CpCld, Vug,51 . In fa/

gy oh Grnst.plo/ (of] • rex/re' ; 2 toneb:rzy^orooldorfrf,k,.;,,,rtjadsd,7,,,r,/as,.1‘;-^tied/ l;v„ 91: "2, l,c2,s; no/il rones

orn pk Grnsl,sd,c/ostIt gy Grnsl.c/os"C sa ',loth ,55/g-ro88,M0s1-3r5027,phil Cs f 'rek/zo

v it of., gy Grnst,c/ostC/rg,rodd,lotn,Mdst omcl^hogs under Masts

e m It gv Mast ?: rek/zd ; /2 97 orn 2 lone bonds; gpc/d; Bret

/1 On, .7y andst,stromol C fostrl 0(851.7, domed, C/mnr Cht- m gy /2,552, 0/552 Crodd,/r9,eg-loth,p/d1 Groot], p/d/: Vuo [under gdos ,dolor F

=^It Cm gy M851, btotrbld C (leg)7f vsm (2 lone Lam aro ; 0.

273-

270-%

267-

264-

It Oro p. Grnst, Most Crodd,/rg,MrIst e I Groot g,p/d1 (m?; (sr! ' 50; (of)

It 0/ 9.1' Wckel ?, ald/ Cs']?

O p^5P 0O 0 0

O

0P 00

P

rnTh• P

Bench^ a

-----^4,2 )^5/2/8,oh, 9, Grnst,closl,p/d/ Cv/.7 ,eroded CsoIn_7;Grost,oma,p1M,clost, , n11///ng Vug rn tower Proof^0 D 0

v /r. 0/, .5,. , 1+cks• 7; ,ntbodd Grnst,clost,p/diCv f..7.(rek/rd, 1 2 Ione Los', hogs^ . 0 P

8 5 /, 0/5 7/ Mdst,Wckst,b,o1rOttl,p/d/ Cvf_7;rex/rd; m orng pk 2 lone bonds

258 -^ =

= 9-

/2 0/s 9 , ricks'? o/d/ rex/r^ rnd, 2 lone w5sps of gy orn , Zm wh do/ nodules

,,..^ j ^ P

- ,^ 1,,., It olv gy Mdsl,Instrt .2 lone bonds and Bret

^

....=---^1 'G=^'' it olv gy Woks,' P,c/ost C v 5m .7, p/d/, skill fnstrt Csol/ P2 do/ Fastr(gy ph:^ 0 0 -,-,' 4& .'-I

^

, ^It Ors gy Grost,Poe Cm.7,Most, skill ; erostono/ ; Strotnot(Cl/n or, lost,. _7 Ss Foss^ fj) 0 0 ,,°) -.--.7 .0

hi 7L,_____=-=^=^it brn gy Grnst,omd L. f.7; bnds of Grnsl,clost ['odd Grnst 2,00td .Vugs^ C 0

2 52--=^It 0/v gy Grost,ctost (00/8 Grost.7,p/c/lgpctd; i^',g,do/ colt Will; Si; Sly//71 gy 'Srost,omd Cf.7,c/ost C/rg,rndd, Grns1 r Mds1_7, (sr?) 80 ; si^

0 P ■ 0 /

. KT-27i --: le_ ^0 0

rn Oro gy Os-sot, p/d/ Cvf_7,(ciost)Csm,ong-rndd.7 (skill)” cPc/ct,Ile ,rd), 8 0 a (0)( 0) (8)-..--,^/1 Pro I, Grnst 7,v f p/d/ , pith Grose, otos/ '(do/I; Cpctd; rex/rd^ P 0 ( 0 )

b.I, e/ • .- P].W-1_• U^m gy Mdst; Gros), vf pld/ overlying. 2 tone cpc1n ; 5.0^ .-r,- 7 pm gy ends, (Insirt 4183, soap, tobufor, r Bret ; 5 0 • 0//I Nod^ -Ti` r-r,

,._.' I ■ 1.^-,e,L^_. ^1t gy Mdst, (blotrbtd);eroded e. ovelyIng plc// 2r55t 'p red mt/ 2 lone . chl Nod^ P

v if 8, gy Grost,clost C/rg,rodd,Aldst,sm7,pIdl C Irg _7 gronding up old/ Grnsl 8 C^ 0 71

246-^ 6 P E^rn cle gy Pod,. 7 Ind ,clost, Skill ;chooht - 9,8 orn ph Plch,vug Infhl, zio , si foss lost', Ponds^0 --F.% -..7

. e A^m 12p Mdst,P,Wchst,boods; some eroded infils by Grnst,clost cpctd , 2 lone'7^'^

861'^11 bra: 7/ Mdst 7,(Lornd ): 2 tone; ,ea/rd, cpctd

243-^'T^I

=^m Pro gy Boast C ,051/1 Md_ 7 ;Lom cpc/d Lon', 2 lone , 5 2--k3sp! v II olv 9/ Mort :2 tone] overlain by tirost,c/ost 2 - Vug,d0I,LaCy (ye" ornJ^ 0-2,

It olv gy Grost,00ld C 8_7; x stral ; over/pop 0rnst,clost C/ort_7,Vug,do/ or F Inr,n^ 0 07fl - ':=1*^j' '

j^h• c+/., gy Pckst 2 vf p/d/ ; grothng 10114,1 re.r/,- d. 2 tone Lome Bret, repealed^ :-.•240.^

s) -7^, al it gy Grnst, most Crodd,lrg t 050, grading^ /25/ading to dst rind; eroded . .-yr,i

T -=.^ 1' /797 Gros!, Most( lrg, /odd, so/ Gro .7s , lot Mtx^ K ',^_, f 35 P r =36^Grost,Closi t Irg,rndcl, vori .7, skIli,p/d/ ; Mdst,b , otrbtd ' 8rec 2 'one

1. : 1 .V .ZIL"^).-_.- _

E .9,,,i ll gy Groo(55,0, sd,p10/, Lod cps/d; s/ rex/rdv It gy,crn Grost, scl 'I, &et of base, 0/2( 2/2^

‘6 if 5oo.o11:151.^

p. - '

2 '-,.Mast^M. bonds asts rest/rd , 2 ton^is/dote In is/dot^ 0Li.1 -_. I .^i f '/pp Grns-I, otos , Clg,lolh, rndd,scl Grns1.7,sd,vori, Xstrol 12 1046 ,)^ 0

^

_^1', f 1_ .',^= ,_, ,f It 015 9, Gros, .30 ,p/d/ 2 C vf .7, (Clost,1^ P

olv gy WcIrst 7 /d/ Cvf_7,skIN C frogs], 2 lone wasps ; Foss srr - I - 17^, _,,,t0)

-.... 6^0'^j j^.7-^€11 It gy ands/Po:di (vf _7, sh/l/ (frogs, pokes licks , so Foss^ Pp..„,,,,

T . -.C■ '^/I gy an/f, dos, C/rg, loth,r,dd.7, (Md.' ) Vugs under closts^ 0

0;,^

;'.ci o, rn/c nf, .7It gy 2rost,cias , C/rg, tom ,rodd,Lomd sd Grost :1,,o/d/ CI ,Isidli, mtr;•a• /.190 under cias"s^2..

C: _1 " 1^17:^/t Pro gy Grns , ,c/nst L . lrg,/oth,rndd,klornd Gr50lZpIdl,r'sk/1/1^ 0- 1 _220-^ It brn g) Grost,p.d/ (clang ,rndr1.7,c/ost Crodd,/oth, vary 3 , 5c

1 l '-- I -^v If gy Mcrt . reklzd , 2 lone bonded,gy orng

- It 0/5 gy 5rnst f f..7,1C/os1)Cloth,rodd, 18061 7- -x▪ It o/v gy Mort; f/ss rest/id, (py )

1- —

/2 0/, gy lids, 0- Pthst,p/d/P - rexlzd; gy orng 2/056 Lom e 8rec^ P P

-. 9,gy Ornst , r/ost C kg rndd, Ma's/ e Grost.7,p/dt Cm-c.?; /5,1; 8 0 Chl^ 0 P

)._ I^T^,..=^8 5 i , gy 02‘15/,e/ovetd; eroded i- over/oin by Grost,p/M,clost xstrot to Mast 2 tone^ P 0222 - ,^i 1-_,^1-_,,, -_,_- e^ye/ g, Mast, 1 r 5,1, Lama 2 tone Larnd It orn,w/th‘n Addst^ -9-

brn gy 6,51,00/1 Cm 7,rioslCrodd, Mdst,3ros1.7, fostrI C/rg,horir 8 0^ 0 0

L i L'^ g,^/ frg^ _7;

'FR^/cps ,075.5 C/051.5, F ,51/1; rex rd Lan" 0 P

:10-1 [1.7^i _^=..^171 015 9/ Grnst,p/d/ Cf_7,omd ?Most (mg erndd,eg,sd Gros', Mdst_7; srl ' 52^ P C 0

^Bancl^4--_'-i

^1^r-,- - 1-^'-e-) ,,, if gy Mdsl,b/olrbtd,over/ying Grost,Most (In laths; irrg_7; srt . roctcl^ 0:9--3

^

1 _,_ .^=^It 0/S py Gros, - Wcks1 - itfdst - 2 lone; yel,0,g L0m, Sly/207-

__,^. h. o/v 7/ Gro st - Pelts!, p/M, Most ..),, el orn 2 tone do/ Lon, Irreg^ P 0?8 Ms ppGroot, closi, pld/ , skit/ ; ft', 'PC.; hug, colt mft/^ 0 0 --,'" C',80

- /75/i' ^rest/id :2 tone bonds, do/E^' " I' : 5gCv

gyGrp's', ctost Cirreg,rodd, Mdst,tothl,p/d/,50/2/ '

orn°^—^ g_^ 0(P, 'e)

249-

234-

84— — 111 IR

229-

219-

2-^(---.1,.. - ;_L_^

:C, .t Lyn o,• Mdst.byotrbld ; eroded 8 500,10,5 Op Groot, 2,/sot Crnd,d,A.st 2, pith^ 0m brn ,-y Sods!, stromat (lobular, slrotiform,undulose , gently co^.5nvex 141rt Mdsl _7; a 0 ;Cnt^,7;

,. •^r I_ I^'^Gros,. Mort ,ntOdd 2 tone.

215 -^I .1._^ " pp grosr, p/di C f_ 7, Lo/nd; grades up to PM,/ 7 '2 tooe,rex/r d ,yei gy_

^1 .1^=^v I , g, P,51, 00/5., /2/0/; it Gros!, p/M,closl Plato, subong, sm,Mdst.7 • Vug under mosts,F 2^Z P 0

^,L!' . 6_ 1 ...: ^=^m brn gy Pckst,p/M, skill, (Most ); 10 Mdst .. Most bonds rex /rd • c .Pctr Ores bonds^ 0 0 0- - r

153-

34

it olv gy Groat- Wckst-MdSt .2 tone ; yel,orag Loot; Sly/

/I olv^Grnst-Pckst,^alas, :ye/ orn 2 3008 dOl Lem irregIt o/v gy Grest,clost,p1d/ , skit/ ; fri :50.; Aig,co/cIto/app btd.St , biotrbld pea/ad .2 tone bonds, do!, orng

gy Groat, Oast Cirreg,rndcf, Mast, /alhl,p/d1,siall

v it gy Olds' to o/d/ Grnst,mtbanded Sty/, sutured G7nst, 00/0,m gy, overlying

6R 1E:^v It gyg Pckst,Mdst,p/dI - cpa/a; Sty/ Cverli.horiZ.3;d0f 2 lone

orn

L T1

^

20 -^L I^1PG

v ,t^ .Vdsl,(fnstrr 0197;Grnst,clost tact& ;^tone;

=.^

re,r12,1

ir gy^ord',Closr, GkIll, Grnsr,plal; Woks'', o/d/ 2 tone mwrksto; m LamJ

393^C/a 9, .5rns,, ,,o/dr.lclast,,,(Larnd ) cod', Loot rn 3/

/12y^s,, clost.o dl re kird ,c lop; banded 9,0!96-

_7, Mist, ernde9, nver -an ty Sans , -los, o/d/, grades rr

c'^ rn^gy 8ndsr s ,,orno ,c/rnnr , Mast, (air,^ _7rt,I7am. ,gtumr^0 „;n ,

^495 -^r^ I,ecrr ',silo,^CE I .dst^grd^rc Grn.sr,p1d/ vf1;reylzd;Cpcld

g, 6 ,, s • .^so, pid/, XLgrad, moadd Mast reslid

=It oh,^,:irnar,c/ostreq ,radd,gron,Mdsr.7,p/d, ,aoid. 1, 8

It^3ms4rdoer Fgron,rndr13,ploa,00rd: art 5 0

air- -^-

gy Mdsr; eroded, Infining Grnsl,ciast,pldl; Pckst,CyCver frerr/SC

o pt Gras!? , ^'rey/zd,porcelloneous; Syneresis in 2 tone

IL,L1^v gs Grnsl,vf Mdst 7 2 tone band/ng ; 8 0E^gy Mcrt CGrnsr 73 2 lone , Cpcld=^/1 oGras!, 91/,'C f ad, intLomd Mds1 6,0,6/0,2 2 to//k

,•tt gY Ma's t, mrp if tall' , GrnSI,Clast Cloth,sm],pldl 2 lone ,F Infil^brotrbn

a It pa'Mdsr,rsy^Wcksl • rrexlzd ; (2 lone) banding

I -^Pr:^Mdsr,blotrOld tn,vert3 ,(2 rate

!e)^/v gy Md sl,biorrbtd,over/,ying Grnst,clost (In laths; irrgl;^rpcld

207-

-rBenc3

1 204 '

P

CI pi (0)

P 0 O

G,9

P 0

p

O p

,

PC p COp

Øc

0

7

0O p0'53 2

p 5/

31o,or

86 -

^r __1^1 _^ // brn gy Grnsr,c/ost CMdst 4 sd Grnst,rndd,/olhi,p1 / cpc.td

^= ^gY Grnst,oldl , .otbdd Mcrl ; vf reklzd; 2 tone , (pyl

83 -/to, 9,,^v _7 Wcksr intrbda 'cpcli ;2 tone, ok gy ,Lame py

^m it^gy , n7't^We.kst^Grnsr,o/di; Iicrt : 2 ■one ,^,Id ; [..21 find

^

ff^Ci ,,rnst^v f^X,..oraci,mrodd Mort 2 tone, cp c yd, ,T, Atd

^f :^ rn gy Grnsr , sins, [eq,rndd -...2mm2p/c/C rn_l, 15”)ben 391

// gy grnst,clast Ceg ,rnad,?74mm.7,p/dICt (sil snOra'7117:^ gy Grnsl, c.ost, prd / , grading up lc Woks, with eroded sur face , cycl/c

^I^ v^gy Grnsr,g_Lt C Larnd Mc/sI,Loths,arn_7,p/d1,. erosional chane/whit 0/, gy Mdsr, Lamd v cperd ; v cpc1d ; vf cpcta Com

=_.

^

o^ E^v fr gy Mosr,tvotrbtd; Grnst,pidi,clost , 2 lone go_nds,11 gy cm,reOiacIng

v /' gy Grast ,c/ost , pidl ; vf re.r1,1lonj 7

-C —

^

I^ /1^Ornst,clast,pldl, gradrs three Pckst,skIll rc Mdsl , vf resl.rd erOded; repeole y 4

cf 98 m

0 a G-

162-

v^9)' k ad, cter/ym g Grnst,clast

,cpcld, rex/rd

v gy Gros,. P . rexlzd C13,- )0in" 2 tone

It gy Grasr.clasl Crndd, sd Grnst.7,p/d1 ; grades up to Xstrat Grnst,sd , old/ 2 tone ?

165-v 13 py Grnst, p/di,Clost C al-c.7

.— e^a It gy Groat, said C1,1, tam]; art ; blolrbtd (ye' calc infl/J[...t (.%^it ye/ Ira qrnsr, old/ Cal] um; Xstrar [ -sets 2-8 Crn3 21one bands CI -/5cm_7

=---"-^sl^-^It ye! Mdsr 7 C2 tone. 7, Over/yr/2g Gras!, cleat, pldl,fnstrl, 8 0

. l'- T - - •1:::^)^'^I, gY- I.1^C^It gy Grnst,c/a5r Crndd McIs13,p1d1 Pckst.7,p1d/ ; varl

159^J'^i^= =^It Ora 9/'Pckst, old', fast! '2 tone, cperd , Lomd; F in vert frac ; pa'

a II gy Grnst , old/ C rn- a 7 2 graded to Mdst; eroded overlain by Gimp', cloStS p/Or

F,-

T-1. 7-11 2 .,;1_,-,= , v/r gy Gin at, c/osr , p15/, fining up la Mast (indurated eroded3, cycle renett„,,ecf,,./oer l/we:ea,^i____ I__,___.,^, %^ I Aids

C-0-) /3 9/ Sands Gras?, p/d/ L ml grading up lc Mdst; erosione bgse ,nrCndd 2 tone1'..^-= (e) it

pp Grnst, plat C7_7, clast Car, loth _ 7 ; Xstrot i art intbdd desalt Mast

(e- )it gy 5/carp/al C72, olds , C vc.7, ,Ksrat,srl,inttdd with Mdst,desicca crocks , decorcrfred

9L-_

v / // bin gy Grnsr o/c1/ Cvf1,c/ast Cc_ 7 ,sd; art, Xstrat sl rexizd

as orng, Grnsl,ciast Svc /0112,11g,olg# f plat Groat], srl ,variv It gy arnsr,clasts, at base, pisolittc, gropestone,p/d/,crost , indurated Lam

rn gy Grnsl,sd,p1dI LW]; Xstral Clow 009/6 3, eroded topor it gy Grnstisd,n/dI C vf.7;overlyn Grnst,c/asr;rex/zd

=1/I) v /tpy GrnS1,5d,b/c// Cv f_ 7; mtbdd Mdst(Instr1) rex/4,1,130'

decalcified 2 tone

Etsat gy .Ndst ; Pcksl,sk/II CinCh13:m olv gy 2 lone; CM' Nodat

gg;^udnf f6.;;^ :211a;e'T F ?

'rt. n /04,7frst

v It gy Groat ?,ad pld/ Ca17, Caned; Xstrat C/0Cm sets] , re,r/zd ; Sty/

E.:^If gy Grnst , sd,pldt Cy f _7; Overlying Grose, clost Erndd,eq3,p/d/ Cc 2

it gy Grnsl,p/d1 fvfJ,sd,xlamd,Larnd , cpctd; s/ rexlzdf

or Itgy Gras!, sd,o/d1 Cv7.7 Lamd,A ,Lomd;intbdd Grnst,c/astEsd Grnst.1oldl ,cpcld

,seit gy Grnst#Pc/ksr,sadr?(biorreld)ieracIed,orrorlain by Grnsr,c/ost Cold/2

1,^( 0^Srna, ,P

d /,c/aslCrndd..7,skill; lot/add Wckst,00id,sk/t/ • yoga under alas/n.2 one

bra gy Grast,p/d/,(clos1),(Sk/1/),fnstrt; mtbdd andsl,p/dI,Instrt^with desic Crks

It bra gy Grnst,pld/ Cvf _7rXstrat,hornog fibiolrb/d tot tap^•5 0G^= vf It brn gy Grnst,p/d/Cyfl,Scl , re.r/zd; 2 tone Pry• Lain

=^at gy Gros! ,c/ast Cloth, /rg,rncld, ad Groat^dst_7, 'Intricate ; Xstrat Sty,C^or it gy Grnst,sd,p/d/ Cvf.7, Xlornci bialrbld,eroded,overlain by clog , Groat

—^gy Groat, sd,p/cll Cv7.7; X/amd , (;ay),vf dIssern(at) mbra gy Grast,clast,Crndd Moist sc/ p/d/ GEnsf7; (art). sat Iraq, F an fill

tone

v gy Mdsr; Mdsr,(fnstrt): 2 tone Loot dommont,It yel orng

9•^ ye/ am Lam [In 2 tone3.F in Jug

7 0

P C

p

013

P

'P 0

pci

p0

0@ P

Pp

0

p

P

'V 0P (01 te)--s-or

0

O p

2

r

2

- 0^- Lateralpl10:1;

▪ '1 0 11

P

0 6 1 0 le, 1ce^sec 202,

'F'•

• 00( a

p 2° 434

p^,

c,

P "0-

• -.arl^*P

C,

cl 202/16

e I

• /-6."

P

p /01 _creel g^;;..‘,

35

Ci.-.1^lir v li gy bids?; Mast,/ instrt 1- 2 tone Lam doininont,11 yet orng^ ,-

---",'^E. -^in /I g, Mdst,(thstrt)Celongote7 -m ye/ orn Lam C fn 2 tone]. Fin Sup^ -15

..= )0^If gy Gros , . otos , Co/g7 ;aver/ain by Mdst; overlain by Pros?, tics,. Csm7 F rugs In Gros)^0 - -b-

L -. e) v It gy Wcks! 2 (0,01rbrd ),deSSiCr cracked ,,s1rot Crosl above,ex/zd,2 lane.^=^ b

II _.,...4 2 3^! T. ,..-..

. / • Orno Prost, clas1 Colg coated ,alg Lom,toths7;c”Ing Illdsl C tot, of sm rugs^ 0

to - Y.'3- ' /0 it gy Moot; 44,ast, Instil relong7,,,oind ;.Grnst said : v tort d C it oro 2 lone 1 - cht Nod^-7o-• 0.2o 2

▪ 91,-; , I gy Prost ,:cIgio,clas1 Crndd,log,00lci Gonst_ 7,pldl • vf reaird^

C- 3 P

,ruP^2 tone

g, Grns! ,I! gy Gins?, oil!, ,71,eiong..7, skill Crodd frogs]: rexl.rd^0

Or, gY Grnst P, bid! vf rexlzd (51y0; (8 0 1; F P-2 lone

m gy It Don gy MOs,; Pros?, pid&fostrt Cpalche5J , Vug,co/c 1, I by; 50if gy Goost, plc/ P, Xstro.yolnd, biolrbld; m re,r/zd,dol vf disseo-opy

brn gy Gras,. 2l01 7 (51],clast C log,^Pros?,], 5k/ft foogs Vug,:aicm bon gy Woos! 7, p/d/ 7 C v1_7rek•lzd, v I ; 8 0n amp Mdst 7 relict wisps 2 tone

" a/spy "Adst P,Lomd, 0i0trbld,syneres ,5 , k0 orng '2 tone Mcr1 rep/acement;stAsuloreaC2 -5-10-cm. amph'ude:

olv gy C■/nol,0101,0 111 ; fointLom,rexlzd

, .1 202 Woks!, old. . Inslr - (re x/2. d); Vug, so/n, m s, spar/wk.'• '1 g„, i4dI pa gy Lon, C2 tone 2; re xl.'d

oh Wort Cc/era/offs& Ls? 1_7; fri

gy Ernst Poo,d sd,skIti rexizdi deCO/cdled ,dol on iota; (12y )• ye/ GraSl?,lendes; 'fob doi; Vug, sm, ms do/ iota

it gy Ponsl,clost Irg,ondd illd5t,Prost_7,p/d/ C sari] rerlra to topGrn5/,,,00ld C sph,m_7, clost Crndd, eo to /01/2,41dst_ Xstral^cm]•• Odcld

rib^Claysrone , fiss; friIt 7, Ions'P p/dl C^s/ re.r/zd

l/ gY^ad, p10/ (skill) s/ moo /00 ; sly/ en/tended Corn

^ ye/ bon Gonst,plol,ciost Condo', /oth7, to Wckst,p/ali vari , Vug,,Brec a) top

it olv gy^srit o/v gy Wckst,P ntoi , of reklzd; 2 tone Lom, ye/ gy mt/ bonded

/I ye/Ore Gros', clast Cloth rndd,picf/ Sons? to 3cm7, bid/ Cf_7,skililt gy Soda?' Gros!, clost ang,epuontl,pidl, skill :2 tone 8rec bands; si fossIt ye/ gy Illdst,:tostrt ); Woks?, p/di Cvf^intbd with shale

cdcrered surfaceIt ye/ gy Pcksf 7, 0104510/l :comp/ 74 frogs _7 , 2 tone wisps (ye, cots ..7;rextzdv it ye/ orng Prnst,oairi,(skitd,sot ; up to Pckst-Prost,pidi,aoid, (skit/ ) , 2 tone grey

Wckst,^overlying Gonst,clost,pidl: Sty/ contact; 2 lone /n WckstIt g, Woks', skill, old/ Grog', Ala/ elost EverI, e5500t3,,411/ ,n1bdd.' 80,vog,coic , r,

/I ye/ gy; Grnsl, p/d/ of baseCbialrbld7 to Grnst,p/dl,cl000rirreg7,skill a) tooit gy Woks! 9 , fnstrt,tiotobld:2 tone matt Cfnstr tB,gtrdo preserved os spot' inhl7

it gy Prost ,p/d/ Grost,clost, old/ 51 rexl.rd , 2 tone Brer C oo/C, mtk _7

n ye/ bon Sods,' pid/ , mo',sir/11.7,1%5ra^foss; do. 9, ,,rog,a0 or co/c ',Pr in

/09/ Gros?, old,'? Cvf_7sk111 frogs of top: vf re,r1.1d, coon, Lam C so/ con,:

rn bon gy Gonst? p/d/ ? • of (reklzd);cpcln Corn conc with f do/ rombos concentrated

v it gy Ma's), fnstrt ; thrombolites.• 2 tone cpCIn band

m It gy Prnsf,clost,grading to Bonds?? fastrt,skill , overlying 2 tone brecclv gy Genst,clost Clrg,vori,roptl,wckst?.7,(P/di),(5k/ 11 . 1 :Vog code/ dos'',

m gy Gossip/dl^7. skill Cfrogs _7; bionbld I weft ,conlca _7.*^C f

it Cr.o gy Groat, rad/ C f-m_7,(clost); sof ; overlYto Clost,b/cil Pros?,- X 5 trat (5 - /0 cm sets)'

toO Glaystone, f ,, fiss

(42.;(--alyel gy,v/1 gy Wckst ?, bid/ Cv1.7,fnstrt C nortz,elong..7,Mdst intbdd , rekird, (pp:

gy,^gy Grnsf,p/d/ Cvc,irreg_7 to clast Cirreg, sm,srt_7; ciost polChea

!= e^/1 gy Wcks1,2 pta/C fl,Lamd a) base, homogt. biolobld 00100

m py Woks,* P ,vf ; odj Grast,clastCWckst_7,p/dl , rexird

it gy, ye/ gy Bndst Cp/d1_7 domes .refickate,irreg yel gy 2 tone, dol; (frac),F inn/gd, 6.'7,51,0051.2 lone alteration

it gy grgst,clost f Irreg,eguont,rndd,Wckst7p/d1; some 419 Wckst bOds _Sly/O.' dose , closts f loth,3con,rned bids?]' fracturing

it bra gy Woks). 2, vf,^Chor, 0/009, soar filled 749 0.1

it bon gy Wok^p/d/S, Lomd, fiss. oex/zd .0 -29/0 ,^; Vag, spor , co/c

•it ye/ gy 41dst,Gonstfp/d12; inttdd 10 overloln by drnsl,:1001 100/;F Pin biotrOn

gy Prost, old/ iV01,,00ng - rndd_7,Cloal C Mdst ?rndc1.7, isrl

• /I gy Grnsl,p/d/ Cvoro , rndd_7,00td,P (skit/J.' sot grdtni:(Styl,'

1.^_7Y,Ito/spy Pc/tot Lamb , 2 tone ,am, grdtn/

te pp it o/v gy Pgkstfnstot,Lomd • 2 tone; grdtnl barn; py),olcreied rubble

PGgy Pon st,o1d/Cvari-7,clost Csm,rndd,Pckst.7,fnstrt , Vug,orng,colo

it gy Pros?, p/d/ C^with patches clost C irreg,Mdst_7."2 tone of base

It bon pp Ends Cvori lobri:1,md plc11,5101 , VugCirreg7; si Noun/olds

grn gy (Goof, Sods?

!I gy woks, ?- bids? - 2 tone; re.riod;^st foss

'I-n, g, Gros!, pidl (of clost;intbdc/ bldst,Skitl;F P or do/i, ontxit m Os ";rn st,p/d/, Woks!, Skiti,with erosive p.kches of Grast,c/o51,5kitl - 2 rcoe,8 0it gy ,Sost,c/ast, o/d/ ,^grades into Woks/; skilP si Foss; 2 lone

ir^G'ros1 .(/05t^ Go55t7,SkitV mix cspor; F 0, sl foss

7^cf r/rr,^•^ •^0, 7: 0r2

37

REFERENCES

AN Tai-xiang 1982. Study on the Cambrian conodonts from North and Northeast China.University of Tsukuba Science Reports of the Institute of Geoscience, Section B 3, 113-59.

AN Tai-Xiang, ZHANG Fang, XIANG Wei-da, ZHANG Youqui, XU Wen-hao, MANGHui-juan, HANG De-biao, YANG Chang-sheng, UN Lian-di, CUT Zhang-tang & YANGXin-chang 1983. The Conodonts of North China and the Adjacent Regions. Science PressBeijing, 223 pp., 33 pls.

BAGNOLI, G., BARNES, C.R. & STEVENS, R.K. 1987. Lower Ordovician (Tremadocian)conodonts from Broom Point and Green Point, western Newfoundland. Bollettino dellaSocieta Paleontologica Italiana 25, 145-158.

BLAKE, D.H., BULTITUDE, R.J., DONCHAK, P.J.T., WYBORN, L.A.I. & HONE, I.G.1984. Geology of the Duchess - Urandangi region, Mount Isa Inlier, Queensland. Bureau ofMineral Resources, Australia, Bulletin 219, 96pp., maps.

BRADSHAW, J.D. & EVANS, P.R., 198888. Palaeozoic tectonics, Amadeus Basin, centralAustralia. The APEA Journal 29, 267-282.

BROWN, G.A. 1961. Stratigraphy, structure and sedimentary petrology of some LowerPalaeozoic limestones in the Boulia area, western Queensland. MSc. Thesis, University ofMelbourne (unpublished).

CARTER, E.J. & OPIK, A.A. 1963. Duchess, Qld: 4-mile Geological Series Sheet SF/54-6.Bureau of Mineral Resources, Australia, Explanatory Notes 23, 29pp.

CASEY, J.N. 1959. New names in Queensland stratigraphy (part 5). Australian Oil and GasJournal 5, 31-35.

CASEY, J.N. 1968. Boulia, Queensland - 1:250,000 Geological Series Sheet SF/54-10 Bureauof Mineral Resources of Australia, Explanatory Notes.

CASEY, J.N., Reynolds, M.A., Dow, D.B., Pritchard, P.W., Vine, R.R. & Paten, R.J. 1960.The geology of the Boulia area, western Queensland. Bureau of Mineral Resources, Australia,Record 1960/12: 132 pp.

CHEN Jun-yuan & GONG Wei-li 1986. Conodonts. In Chen Jun-yuan (Ed.) Aspects of theCambrian - Ordovician Boundary in Dayangcha, China. China Prospect Publishing House,Beijing, 93-223.

COOK, P.J. 1989. Phosphate deposits of the Georgina Basin, northern Australia. InNOTHOLT, A.J.G., SHELDON, R.P. & DAVIDSON, D.F. (Eds). Phosphate Deposits of theWorld, 2: Phosphate Rock Resources, pp. 533-544. Cambridge University Press, Cambridge.

de KEYSER, F. 1968. The Cambrian of the Burke River outlier. Bureau of Mineral

38

Resources, Australia, Record 1968/67, 48pp.

de ICEYSER, F. 1973. Review of the Middle Cambrian stratigraphy in the Queensland portionof the Georgina Basin. Bureau of Mineral Resources, Australia, Bulletin 139, 13-27.

de 10EYSER, F. & COOK, P.J. 1973. Geology of the Middle Cambrian phosphorites andassociated sediments in northwestern Queensland. Bureau of Mineral Resources, Australia,Bulletin 138, 79pp.

DRUCE, E.C. 1978a. Clavohamulus primitus - a key North American conodont found in theGeorgina Basin. BMR Journal of Australian Geology & Geophysics 3, 351-355.

DRUCE, E.C. 1978b. Correlation of the Cambrian-Ordovician boundary in Australia. InBelford, D.J., & Scheibnerova, V. (Eds.). The Crespin volume: essays in honour of IreneCrespin. Bureau of Mineral Resources of Australia, Bulletin 192, 49-60.

DRUCE, E.C. & JONES, P.J. 1971. Cambro-Ordovician conodonts from the Burke RiverStructural Belt, Queensland. Bureau of Mineral Resources, Australia, Bulletin 110, 158pp.,20 pls.

DRUCE, E.C., RADKE, B.M. & DRAPER, J.J. 1976. Southern Burke River Structural Belt,Queensland, 1:100,000 Geological Series Sheet, provisional edition. Bureau of MineralResources, Australia.

DRUCE, E.C., RADKE, B.M. & SHERGOLD, J.H. 1981. Appendix 4: Proposed stratigraphicmembers of the Chatsworth Limestone and Ninmaroo Formation, Georgina Basin. In Radke,B.M. 1981 (q.v.), 136-141.

DRUCE, E.C., SHERGOLD,^& RADKE, B.M. 1982. A reassessment of theCambrian-Ordovician boundary section at Black Mountain, western Queensland, Australia.In Bassett, M.G., & Dean, W.T. (Eds.). The Cambrian-Ordovician Boundary: sections, fossildistributions and correlations. National Museum of Wales, Geological Series 3, 193-209,Cardiff.

FLEMING, P.J.G. 1973. Bradoriids from the Xystridura Zone of the Georgina Basin,Queensland. Geological Survey of Queensland, Publication 356, Palaeontological Papers 31,9PP.

FLEMING, P.J.G. 1974. Origin of some Cambrian bedded cherts, and other aspects ofsilicification in the Georgina Basin, Queensland. Geological Survey of Queensland,Publication 358, 9pp.

FLEMING, P.J.G. 1975. Character of the phosphate deposits of the Duchess area, Queensland.Geological Society of Australia Field Conference Mt Isa region 1975, pp. 7-15.

FLEMING, P.J.G. 1977. Faunas, lithologies, and the origin of the phosphorites in parts of theMiddle Cambrian Beetle Creek Formation of northwest Queensland. Geological Survey of

39

Queensland, Publication 364, 21pp.

FREEMAN, M.J., SHERGOLD, J.H., MORRIS, D.G., & WALTER, M.R. 1990. LateProterozoic and Palaeozoic basins of central and northern Australia - regional geology andmineralisation. In HUGHES, F.E. (Ed). Geology of the Mineral Deposits of Australia andPapua New Guinea, pp. 1125 - 1133. The Australasian Institute of Mining and Metallurgy,Melbourne.

HINZ, I., KRAFT, P., MERGL, M. & MULLER, K.J. 1990. The problematicHadimonpanella, Kaimenella, Milaculum and Utahphospha identified as sclerites ofPalaeoscolecida. Lethaia, 23, 217-221.

JELL, P.A. 1970. Pagetia ocellata, a new Cambrian trilobite from northwestern Queensland.Memoirs of the Queensland Museum, 15(4), 303-313, pls 23-24.

JELL, P.A. 1975. Australian Middle Cambrian eodiscoids with a review of the Superfamily.Palaeontographica [A], 150, 1-97.

JELL, P.A., BURRETT, C.F. & BANKS, M.R. 1985. Cambrian and Ordovician echinodermsfrom eastern Australia. Alcheringa, 9, 183-208.

JONES, P.J. 1971. Lower Ordovician conodonts from the Bonaparte Gulf Basin and the DalyRiver Basin, northwestern Australia. Bureau of Mineral Resources, Australia, Bulletin 117,80 pp., 9 pls.

JONES, P.J. & MCKENZIE, K.G. 1980. Queensland Middle Cambrian Bradoriida(Crustacea): new taxa, palaeobiogeography and biological affinities. Alcheringa, 4, 203-255.

JONES, P.J., SHERGOLD, J.H., & DRUCE, E.C. 1971. Late Cambrian and Early OrdovicianStages in western Queensland. Journal of the Geological Society of Australia 18(1), 1-32.

LANDING, E., BARNES, C.R. & STEVENS, R.K. 1986. Tempo of earliest Ordoviciangraptolite faunal succession: conodont-based correlation from the Tremadocian of Quebec.Canadian Journal of Earth Sciences 23, 1928-49.

LUDVIGSEN, R., WESTROP, S.R. & KINDLE, C.H. 1989. Sunwaptan (Upper Cambrian)trilobites of the Cow Head Group, western Newfoundland, Canada. Palaeontographicacanadiana 6, 175 pp., 50 pls.

MILLER, J.F. 1975. Conodont faunas of the Cambrian and lowest Ordovician of westernNorth America. Geological Society of America, Abstracts with Programs 7, 1200-1201.

MILLER, J.F., 1980. Taxonomic revisions of some Upper Cambrian and Lower Ordovicianconodonts with comments on their evolution. The University of Kansas PaleontologicalContributions, Paper 99, 39 pp., 2p1s.

MILLER, J.F. 1984. Cambrian and earliest Ordovician conodont evolution, biofacies, and

40

provincialism. Geological Society of America, Special Paper 196, 43-68.

MILLER, J.F., 1988. Conodonts as biostratigraphic tools for redefinition and correlation ofthe Cambrian-Ordovician Boundary. Geological Magazine 125, 349-362.

MILLER, J.F. 1978. Upper Cambrian and lowest Ordovician conodont faunas of the HonseRange, Utah. In MILLER, J.F. (Ed.). Upper Cambrian to Middle Ordovician conodont faunasof western Utah. SW Missouri State University Geoscience Series 5, 33 pp., 4 figs.

MOLLER, J.K. & HINZ, I. (in press). Cambrogeorginiidae n. fam. (Problematica) from theMiddle Cambrian of Australia. Alcheringa.

NICOLL, R.S., 1990. The genus Cordylodus and a latest Cambrian-earliest Ordovicianconodont biostiatigraphy. BMR Journal of Australian Geology & Geophysics 11, 529-558.

NICOLL, R.S. 1991. Speciation of Late Cambrian-Early Ordovician elements of the conodontgenus Cordylodus with dual tipped basal cavities. BMR Journal of Australian Geology &Geophysics 12:

NICOLL, R.S. in press. Evolution of the conodont genus Cordylodus and theCambrian-Ordovician boundary. In Webby, B.D. (Ed.), Global perspectives on Ordoviciangeology. Proceedings of the 6th International Symposium on the Ordovician System, Sydney.

NICOLL, R.S., OWEN, M., SHERGOLD, J.H., LAURIE, J.R. & GORTER, J.D. 1988.Ordovician event stratigraphy and the development of a Larapinta Seaway, central Australia.In BMR 1988 Research Symposium - Palaeogeography, Sea Level and Climate: Implicationsfor Resource Exploration. Bureau of Mineral Resources, Australia, Record 1988/42, 72-77.

NICOLL, R.S. & SHERGOLD, J.H. 1991. Revised Late Cambrian (pre-Payntonian-Datsonian)conodont biostratigraphy at Black Mountain, Georgina Basin, western Queensland, Australia.BMR Journal of Australian Geology & Geophysics 12, 93-118.

NORDLUND, U. & SOUTHGATE, P.N. 1988. Depositional environments and importanceof the early Middle Cambrian sequence at Rogers Ridge, Georgina Basin, westernQueensland. Acta Universitatus upsaliensis, Comprehensive summaries of UppsalaDissertations from the Faculty of Science 170, paper 6, 19pp.

OPIK A.A. 1956. Cambrian geology of Queensland. In El Sistema Cambrico, suPalaeogeografia y el Problema de su Base 2, 1-24 20th Session International GeologicalCongress, Mexico.

OPIK, A.A. 1960. Cambrian and Ordovician geology (of Queensland). Journal of theGeological Society of Australia, 7, 89-109.

OPIK, A.A. 1961. The geology and palaeontology of the headwaters of the Burke River,Queensland. Bureau of Mineral Resources of Australia, Bulletin 53, 249 pp.

41

OPIK, A.A. 1963. Early Upper Cambrian fossils from Queensland. Bureau of MineralResources, Australia, Bulletin 64, 133 pp.

OPIK, A.A. 1967a. The Mindyallan fauna of north-western Queensland. Bureau of MineralResources, Australia, Bulletin 74, volume 1, 404 pp.; volume 2, 167 pp.

OPIK, A.A. 1967b. The Ordian Stage of the Cambrian and its Australian Metadoxididae.Bureau of Mineral Resources, Australia, Bulletin 92, 133-170.

OPIK, A.A. 1968. Ordian (Cambrian) Crustacea Bradoriida of Australia. Bureau of MineralResources, Australia, Bulletin 103, 44 pp.

OPIK, A.A. 1970a. Nepeiid trilobites of the Middle Cambrian of northern Australia. Bureauof Mineral Resources, Australia, Bulletin 113, 48 pp.

OPIK, A.A. 1970b. Redlichia of the Ordian (Cambrian) of northern Australia and New SouthWales. Bureau of Mineral Resources, Australia, Bulletin 114, 66 pp.

OPIK, A.A. 1975a. Templetonian and Ordian xystridurid trilobites of Australia. Bureau ofMineral Resources, Australia, Bulletin 121, 84 pp.

OPIK, A.A. 1975b. Cymbric Vale fauna of New South Wales and Early Cambrianbiostratigraphy. Bureau of Mineral Resources of Australia, Bulletin 159, 78 pp.

OPIK, A.A. 1979. Middle Cambrian agnostids: systematics and biostratigraphy. Bureau ofMineral Resources, Australia, Bulletin 172, volume 1, 188 pp.; volume 2, 67 pls.

OPIK, A.A. 1982. Dolichometopid trilobites of Queensland, Northern Territory and NewSouth Wales. Bureau of Mineral Resources, Australia, Bulletin 175, 85 pp.

PHILLIPS PETROLEUM CO. LTD. 1963. Phillips-Sunray Stratigraphic drilling, Boulia area,ATP 54P, Queensland. Well completion report by GREEN, D.C., HAMLING, D.D. &KYRANIS, N. [unpublished].

POJETA, J., GILBERT-TOMLINSON J. & SHERGOLD, J.H. 1977. Cambrian andOrdovician rostroconch molluscs from northern Australia. Bureau of Mineral Resources,Geology & Geophysics, Australia, Bulletin 171, 1-54.

RADKE, B.M. 1980. Epeiric carbonate sedimentation of the Ninmaroo Formation (UpperCambrian-Lower Ordovician), Georgina Basin. BMR Journal of Australian Geology andGeophysics 5, 183-200.

RADKE, B.M. 1981. Lithostratigraphy of the Ninmaroo Formation (Upper Cambrian-LowerOrdovician), Georgina Basin, Queensland and Northern Territory. Bureau of MineralResources of Australia, Report 181, BMR Microform MF153.

RADICE, B.M. 1982. Later diagenetic history of the Ninmaroo Formation

42

(Cambro-Ordovician), Georgina Basin, Queensland and Northern Territory. BMR Journal ofAustralian Geology and Geophysics 7, 231-254.

REPETSKI, J.E. & ETHINGTON, R.L. 1983. Rossodus manitouensis (Conodonta), a newEarly Ordovician index fossil. Journal of Palaeontology, 57, 289-301, 5 figs.

RIPPERDAN, R.L., KIRSCHVINK, J.L., APOLLONOV, M.K., MA, G.G. & ZHANG, Z.C.1990. Magnetostratigraphy of the Cambrian-Ordovician boundary interval. Reprint of papersubmitted to and distributed at the 3rd International Symposium on the Cambrian System,Novosibirsk, August 1990, 106 MS pp.

ROGERS, J.K. & CRASE, N.J. 1980. The Phosphate Hill rock phosphate deposit, northwestQueensland, Australia - an outline of geological development. In SHELDON, R.P. &BURNETT, W.C. (Eds), Fertilizer Mineral Potential in Asia and the Pacific. Proceedings ofthe Fertilizer Raw Materials Resources Workshop, August 20-24, 1979, Honolulu, Hawaii,pp. 307-328. East-West Resources Systems Institute, Honolulu.

RUNNEGAR, B., POJETA, J., TAYLOR, M.E., & COLLINS, D. 1979. New species of theCambrian and Ordovician chitons Matthevia and Chelodes from Wisconsin and Queensland:evidence for the early history of polyplacophoran molluscs. Journal of Paleontology 56(6),1374-1394, 3.

RUSSELL, R.T. 1967. Discovery of major phosphate deposits in northwest Queensland.Queensland Government Mining Journal, 68, 153-157.

RUSSELL, R.T. & TRUEMAN, N.A. 1971. The geology of the Duchess phosphate deposits,northwest Queensland, Australia. Economic Geology, 66, 1186-1214.

SHERGOLD, J.H. 1968. Appendix: Cambrian Palaeontology. In de ICEYSER, F. 1968 (q.v.).

SHERGOLD, J.H. 1969. Oryctocephalidae (Trilobita: Middle Cambrian) of Australia. Bureauof Mineral Resources, Australia, Bulletin 104, 66 pp.

SHERGOLD, J.H. 1971. Résumé of data on the base of the Ordovician in central andnorthern Australia. In Colloque ordovicien-silurien, Brest, Septembre 1971. Memoire de laBureau de Recherches geologique et mineralogique 73, 391-402.

SHERGOLD, J.H. 1972. Late Upper Cambrian trilobites from the Gola Beds, westernQueensland. Bureau of Mineral Resources, Australia, Bulletin 112, 12 pp., 19 pls.

SHERGOLD, J.H. 1975. Late Cambrian and Early Ordovician trilobites from the Burke RiverStructural Belt, western Quensland, Australia. Bureau of Mineral Resources of Australia,Bulletin 153 (2 vols.), 251 pp., 58 pls.

SHERGOLD, J.H. 1980. Late Cambrian trilobites from the Chatsworth Limestone, westernQueensland. Bureau of Mineral Resources, Australia, Bulletin 186, 111 pp., 35p1s.

43

SHERGOLD, J.H. 1982. Idamean (Late Cambrian) trilobites, Burke River Structural Belt,western Queensland. Bureau of Mineral Resources, Australia, Bulletin 187, 69 pp.

SHERGOLD, J.H. 1988. Review of trilobite biofacies distributions at the Cambrian-Ordovician boundary. Geology Magazine 125(4), 363-380.

SHERGOLD, J.H. (Compilor) 1989. Australian Phanerozoic Timescales, 1: Cambrian. Bureauof Mineral Resources, Australia, Record 1989/31, 25 pp., charts.

SHERGOLD, J.H. 1991. Protaspid and early meraspid growth stages of the eodiscoid trilobitePagetia ocellata Jell, and their implications for classification. Alcheringa, 15(1).

SHERGOLD, J.H., BURRETT, C., AKERMAN, T. & STAIT, B. 1988. Late Cambriantrilobites from Tarutao Island, Thailand. New Mexico Bureau of Mines and MineralResources, Memoir 44, 303-320, 5 figs.

SHERGOLD, J.H., COOK, P.J. & SOUTHGATE, P.N. 1989. New facts on old phosphates: Middle Cambrian, Georgina Basin. BMR Research Newsletter 10, 14-15.

SHERGOLD, J.H., COOPER, R.A., DRUCE, E.C., & WEBBY, B.D. 1982. Synopsis ofselected sections at the Cambrian-Ordovician boundary in Australia, New Zealand andAntarctica. In BASSETT, M.G. & DEAN, W.T. (Eds). The Cambrian-Ordovician Boundary:sections, fossil distributions and correlations. National Museum of Wales, Geological Series3, 211-227.

SHERGOLD, J.H. & DRUCE, E.C. 1980. Upper Proterozoic and Lower Palaeozoic rocks ofthe Georgina Basin. In HENDERSON, R.A. & STEPHENSON, P.J. (Eds). The Geology andGeophysics of northeastern Australia, pp. 149-174. Geological Society of Australia,Queensland Division, Brisbane.

SHERGOLD, J.H., DRUCE, E.C., RADKE, B.M., & DRAPER, J.J. 1976. Cambrian andOrdovician stratigraphy of the eastern portion of the Georgina Basin, Queensland and easternNorthern Territory. Excursion Guidebook 4C, 54 pp., 25th International Geological Congress,Sydney.

SHERGOLD, J.H., LAURIE, J.R. & SUN Xiao-wen 1990. Classification and review of thetrilobite order Agnostida Salter, 1864: an Australian perspective. Bureau of MineralResources, Australia, Report 296, 91pp., 19 figs.

SHERGOLD, J.H. & SOUTHGATE, P.N. 1986. Middle Cambrian phosphatic and calcareouslithofacies along the eastern margin of the Georgina Basin, western Queensland. AustralasianSedimentologists Group Field Guide No. 2, 89 pp. Geological Society of Australia, Sydney.

SHERGOLD, J.H. & WALTER, M.R. 1979. Stratigraphic drilling in the Georgina Basin,1977-78. Bureau of Mineral Resources, Australia, Record 1979/36:

SMITH, A.B. & JELL, P.A. 1990. Cambrian edrioasteroids from Australia and the origin of

44

starfishes. Memoirs of the Queensland Museum 28(2), 715-778, 53 figs.

SMITH, K.G. 1972. Stratigraphy of the Georgina Basin. Bureau of Mineral Resources,Australia, Bulletin 111, 156pp., 6p1s.

SOUDRY, D. & SOUTHGATE, P.N. 1989. Ultrastructure of a Middle Cambrian primarynonpelletal phosphorite and its early transformation into phosphate vadoids: Georgina Basin,Australia. Journal of Sedimentary Petrology, 59(1), 53-64.

SOUTHGATE, P.N. & SHERGOLD, J.H. 1991. Application of sequence stratigraphicconcepts to Middle Cambrian phosphogenesis, Georgina Basin, Australia. BMR Journal ofAustralian Geology & Geophysics, 12(2), 119-145.

TUCKER, D.H., WYATT, B.W., DRUCE, E.C., MATHUR, S.P., & HARRISON, P.L. 1979.The upper crustal geology of the Georgina Basin region. BMR Journal of Australian Geology& Geophysics, 4(3), 209-226.

WANG Zhi-hao 1985. Conodonts. In Study on Cambrian-Ordovician Boundary strata and itsbiota in Dayangcha, Hunfiang, Jilin, China. China Prospect Publishing House, Beijing, 27-34,83-101.

WEBBY, B.D. 1978. History of the Ordovician continental platform and shelf margin ofAustralia. Journal of the Geological Society of Australia 25, 41-63.

WEBBY, B.D. & NICOLL, R.S. (Compilors) 1989. Australian Phanerozoic Timescales, 2:Ordovician. Bureau of Mineral Resources, Australia, Record 1989/32, 42pp., charts.

WEBBY, B.D., VANDENBERG, A.H.M., COOPER, R.A., BANKS, M.R., BURRETT, C.F.,HENDERSON, R.A., CLARKSON, P.D., HUGHES, C.P., LAURIE, J., STAIT, B.,THOMSON, M.R.A., & WEBERS, G.F. 1983. The Ordovician System in Australia, NewZealand and Antarctica : correlation chart and explanatory notes. International Union ofGeological Sciences, Publication 6, 64pp., maps, chart

WESTROP, S.R. 1986. Trilobites of the Upper Cambrian Sunwaptan Stage, southernCanadian Rocky Mountains, Alberta. Palaeontographica canadiana, 3, 179pp., 41p1s.

WHLt EHOUSE, F.W. 1936. The Cambrian faunas of northeastern Australia. Pt 1.Stratigraphic outline. Pt 2. Trilobita (Miomera). Memoirs of the Queensland Museum 11(1),59-112, pis 8-10.

WHITEHOUSE, F.W. 1939. The Cambrian faunas of northeastern Australia. Part 3 -Thepolymerid trilobites (with supplement No. 1). Memoirs of the Queensland Museum, 11, 179-282, pls 19-25.

ZHANG Huijuan & XIANG Weida 1983. See An Taixiang & others 1983.

ZHANG Wentang & JELL, P.J. 1987. Cambrian trilobites of North China - Chinese

45

Cambrian trilobites housed in the Smithsonian Institution. Science Press, Beijing, China, xvi+ 469pp., 125p1s.

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APPENDIX: CHECK LIST OF BLACK MOUNTAIN CONODONTS AND RECENTSYNONYMIES

This list is centred about the conodonts originally described by Druce & Jones (1971) fromBlack Mountain, and material subsequently described by Nicoll (1990, 1991) and Nicoll &Shergold (1991). Recent synonymies for selected groups of taxa have been adopted from An(1982), Bagnoli, Barnes & Stevens (1987), Chen & Gong (1986), Landing, Barnes & Stevens(1986), Miller (1980, 1984), Wang (1985) and Zhang & Xiang (1983).

Acanthodus costatus Druce & Jones

Acanthodus uncinatus Furnish[= New gen A., n. sp. A plus Drepanodus simplex sensu Dnice & Jones 1971]

Acodus oneotensis Furnish[= Oneotodus? Landing & others 1986; = Rossodus manitouensis Repetski &Ethington, 1983]

Chosonodina herfurthi Muller

Clavohamulus elongatus Miller

Clavohamulus hintzei Miller

Clavohamulus sp. n. A

Clavohamulus sp. n. B.

Ceolocerodontus burkei Druce & Jones[Proconodontus muelleri Miller or other species of Proconodontus like P.posterocostatus, P. serratus and P. tenuiserratus, fide Miller (1980)].

Coelocerodontus primitivus (Miiller)

Coelocerodontus rotundatus Druce & Jones[= Prooneotodus rotundatus (Druce & Jones) fide Chen & Gong (1986)]

Coelocerodontus tricarinatus (Nogami)[= Nogamiconus tricarinatus (Nogami) fide Miller (1980)]

Cordylodus angulatus Pander

Cordylodus caboti Bagnoli, Barnes & Stevens

Cordylodus caseyi Druce & Jones

Cordylodus intermedius Furnish

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[= Cordylodus angulatus Pander, Nicoll (1990)]

Cordylodus lindstromi Druce & Jones

Cordylodus oklahomensis Miller[= Cordylodus sp. nov. A : Nicoll (1990); = Cordylodus sp. nov. cf. C. caboti Bagnoli& others; herein]

Cordylodus prion Lindstriim[= Cordylodus lindstromi Druce & Jones, Nicoll (1990)]

Cordylodus primitivus Bagnoli, Barnes & Stevens

Cordylodus proavus Muller

Cordylodus sp. cf. C. proavus Muller[= ?Cordylodus proavus Milner, Nicoll (1990)]

Cordylodus prolindstromi Nicoll

Cordylodus rotundatus Pander[= Cordylodus angulatus Pander fide Nicoll (1990)]

Cordylodus sp. nov. A (Nicoll)

Cordylodus sp. nov. B (Nicoll)

Drepanodus acutus Pander

Drepanodus simplex Branson & Mehl1= Monocostodus sevierensis (Miller) fide Miller (1980); = New gen. A, n. sp. A]

Drepanodus subarcuatus Furnish

Drepanodus suberectus (Branson & Mehl) fide Landing & others (1986)

Drepanoistodus suberectus (Branson & Mehl)

Eoconodontus minutus (Miller)[formerly Oistodus and Cambrooistodus fide Miller (1980)]

Eoconodontus notchpeakensis (Miller)[formerly Proconodontus fide Miller (1980)]

Eodentatus bicuspatus Nicoll & Shergold

Fryxellodontus inornattts Miller

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Furnishina furnishi Muller[fide Wang (1985)]

Granatodontus ani (Wang)

Hirsutodontus hirsutus Miller

Hirsutodontus nodus (Zhang & Xiang)[formerly Teridontus nakamurai nodus Zhang & Xiang (1983), = Dasytodus Chen &Gong (1986)]

Hirsutodontus simplex (Druce & Jones)[formerly Sagittodontus fide Miller (1980)]

Hirsutodontus sp. nov. A.

Hirsutodontus sp. nov. B.

Hispidodontus appressus Nicoll & Shergold

Hispidodontus resimus Nicoll & Shergold

New genus and species A

New genus and species B

Oistodus inaequalis Pander[= Rossodus manitouensis Repetski & Ethington, 1983]

Oistodus lanceolatus Pander[= Rossodus manitouensis Repetski & Ethington, 1983]

Oneotodus bicuspatus Druce & Jones

Oneotodus datsonensis Druce & Jones[= Semiacontiodus nogamii Miller fide Miller (1980)]

Oneotodus erectus Druce & Jones[= Semiacontiodus nogamii Miller fide Miller (1980)]

Oneotodus gallatini MUller[= Prooneotodus gallatini (Milner) fide Miller (1980)]

Oneotodus gracilis (Furnish)[= Teridontus gracilis (Furnish) fide Chen & Gong (1986)]

Oneotodus nakamurai Nogatni

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[= Teridontus nakamurai (Nogami) fide Miller (1980)]

Oneotodus tenuis Muller[= Phakelodus tenuis (Milner) fide Miller (1984); = Rossodus tenuis (Muller) fideRepetski & Ethington (1983)]

Oneotodus terashimai Nogami[= Prooneotodus terashimai (Nogatni) fide Wang (1985)]

Oneotodus variabilis LindstrOm

Phakelodus tenuis (Muller)

Problematoconites perforata Muller[= Prooneotodus gallatini (Milller) fide Chen & Gong (1986)]

Proconodontus gallatini (Milner)[= Prooneotodus gallatini (MUller) fide Chen & Gong (1986)]

Proconodontus muelleri Miller

Proconodontus posterocostatus Miller

Proconodontus primitivus (Miller)

Proconodontus rotundatus (Druce & Jones)[= Prooneotodus rotundatus (Druce & Jones) fide Chen & Gong (1986)]

Proconodontus serratus Miller

Proconodontus tenuiserratus Miller

Proconodontus tricarinatus (Nogami)[= Nogamiconus tricarinatus (Nogami) fide Miller (1980)]

Prooneotodus gallatini ller)

Prosagiuodontus dahlmani (Miller)

Rossodus manitouensis Repetski & Ethington[formerly Acodus]

Rossodus tenuis (MUller)[formerly Phakelodus]

Sagittodontus dahlmani Milner[= Prosagittodontus dahlmani (Millie') fide An (1982), Chen & Gong (1986)]

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Sagittodontus furnishi (Milner)[= Furnishina furnishi Muller fide Wang (1985)]

Scandodus furnishi Lindstr6m[= Utahconus utahensis (Miller) fide Miller (1980)]

Scolopodus asymmetricus Druce & Jones

Scolopodus bassleri (Furnish)

Scolopodus gracilis Ethington & Clark[= Variabiloconus bassleri (Furnish) fide Landing & others (1986)]

Scolopodus iowensis (Furnish)[= Semiacontiodus iowensis (Furnish) fide Landing & others (1986)]

Scolopodus quadraplicatus Branson & Mehl

Scolopodus staufferi (Furnish)

Scolopodus transitans Druce & Jones

Scolopodus triplicatus Ethington & Clark[= Variabiloconus bassleri fide Landing & others 1986]

Scolopodus warendensis Druce & Jones[= Variabiloconus bassleri fide Landing & others 1986]

Strigaconus simplex Druce & Jones1= Hirsutodontus simplex (Druce & Jones) fide Miller (1980)]

Teridontus nakamurai (Nogami)

Teridontus sp. nov. A.

Utahconus utahensis (Miller)

Variabiloconus bassleri (Furnish)

Westergaardodina amplicava Muller

Westergaardodina bicuspidata Miller

Westergaardodina mossebergensis Miller