Rt:NDICONll DELLA SOCIETA ITAL!A:-IA DI MINER ALOGIA E PETROLOGIA, 19115, Vol. ~O, pp. ~5·56

Radiometric geochronology in the Calabrian Arc:a review

ANTQNIQ PAGLIONICODipartimento Geomineralogico dell'Universit1l, Piazza Umberto I 1, 70121 Bad

ABSTRACT. - This work is a review of mherwisedispersed geochronological data relative to themelamotphics and plutonics cropping out along theCalabrian Arc, The most significant geochronologicalevents are evidentiated.

Kty words: geochronology, prealpine, alpine,met:tmorphics, plutonics.

RIASSUNTO. - Viene presentala un'analisi crilkadelle datazioni radiometrkhe eJlelluate sino ad oggisu rocce affioranti nell'Arco calabro-peloritano cvcngono messi in evidenza i prindpali eventi ge<:>­cronologid registrati.

PaTole chiave: geocronologia, prealpino, alpino,metamorfiti, plutoniti.

Introduction

The Calabrian arc is a complex structuremade up of Palaeozoic, Mesozoic and Recentterrains. Geochronological data are relativelyscarce; only in the last years they have beenobtained to highlight geological problems andthey concentrate essentially on palaeozoicmetamorphics and pIu tonics.

Geological picture

The Calabrian arc is a « foreign» elementconnecting the Apenninic and Maghrebianchains which are formed essentially of nappesof Mesozoic and Tertiary sedimentary rocks.Two basic current opinions concern theformation of the belt: 1) it represents anAlpine s.l. structure (AMoDlo MORELLI et aI.,1976; BoNARDI et al., 1980; HACCARD et

al., 1972; SCANOONE, 1983) and 2) it resultsfrom the juxtaposition of Alpine andHercynian ranges (LoRENZONI et al., 1983;ZANETTIN LoRENZONI, 1982) (fig. 1). Ac­cording to the former, there are two sectorspresent in the Calabrian Arc, which behaveddifferently during the Alpine tectonism.

The first one (Northern sector) representedby I) the calcareous apennines, 2) theeo-Alpine chain (ophiolitiferous and austral­pine units) and 3) the Longobucco Unit; thesecond one (Southern sector) is formedof I) the crystalline nappes of the SouthernSerre, Aspromome and Mt. Peloritani, 2) thecalcareous Maghrebian units and 3) the Lon­gi·Taormina unit.

According to the latter hypothesis it ispossible in the Calabrian Arc to distinguishan «AJpine chain» lying upon the Apenninescropping in central and northern Calabria,and a Hercynian chain cropping out on theIonian side of Central Calabria and formingessentially the Serre, Aspromonte and Pe1o­ritani ranges.

Diversities relative to the significance andcomposition of some lower rank structuralunits, such as Mt. Gariglione Unit, StiloUnit, ... exist too.

On the basis of both available and un­published data, the present author thinksthat a totally Alpine history of the CalabrianArc also involving a pre-alpine basement, ismore realistic.

Thus the geochronological data, whichplay a fundamental role in the restorationof the evolution of the Calabrian arc, willbe arranged accordingly (fig. 2).

46 A. PAGLIONICO

'--"..

..-

•1

•-.-•

Northern a Eoalpine chain (australpineophiolitiferous units) "d I'.;.>~.' I "onte Gariglione Uni t

sector ~ longobucco UnitL--:-~3 Tiriolo Unit

m Apenninic and Maghrebian units

Southern

sector

ImIor.'77lL..2J

IDDD

Upper.ost Oligocene-lower.ostMlceene terrigenous deposits

Sti 10 Uni t

Crystalline units of Serre-Aspro_.cnte and Peloritani

Longi-Taor.ina Unit

~ "Alpine chain"

I: :: ::1 Stilo Unit

• Apenninique chain

~ Hercynian chain

Miccene

Fig. 1. - Structural ~kctch of the Calabrian Arc acrotdmg to current opmlons. uti the Calabrian arcis a compoSIte belt of Alpme 1s age Right the Call1brllln ilK IS due to )UxtapoSlllon of Alpme 1.5.and Hercynian ranges.

Geochronological data

Most of the radiometric data concernPalaeozoic rocks. The earliest, scarce datawere determined without II well-establishedgeological frame. They ace mineral ages(biotite and uraninite) from intrusives crop­ping out in Serre and Aspromonte (FEIl.RARAet al., 1959; FERRARA & LoNGINELLI, 1960).

These data point to a palaeozoic magmaticactivity.

A more comprehensive geochronologicalstudy was performed by BoRSI & DUBOlS

(1968) which investigated minerals fromplutonics and metamorphics of Central andNorthern Calabria. This study was basedon a framework developed from geological

RADIOMETRIC GEOCHRONOL(X;Y IN THE CALABRIAN ARC; A REVIEW "

1~

d.3_41..<'.<:'15 =~6007m

BOIlSleDUBOIS~~~-1968

".o!

Laf1!6za,Terme 0

~~S~C~H~E~N~K~1g~~~~:CIVETTAetalii 1980 BOR.r~;J alii

1973 DEl MORO et aliii" prep

BECCALUVAet.h,1981

Fi,. 2. - Sltucrural sketch map of the CaI.brian .re and location of gmchronologically invcstiaatedareas. Symbols u in Jig. I (f#t).

and Structural studies carried our by theLaboratoire de Geologie Dynamique de laSorbonne. The major results were; 1) theconfirmation of the Hercynian intrusion ofhuge masses of granitoides; 2) the occur­rence of mesozoic and tertiary rejuvenationof minerals of crystalline palaeozoic base­ment; 3) the Eocene age for the alpinemetamorphism.

An extensive study on whole rocks andminerals was carried out by CIVETTA et alii(I 973) on tonalites and pegmatites from theCapo Vaticano area. These data show thatthe intrusions are Hercynian, and that therewas a later rejuvenation of both biotite andmuscovite. In particular the authors havepointed out two post-hercynian geochrono­logical events dated at 181 roa and 116 roarespectively.

In 197.5, Maastrichtian-Paleocene volcanic;crosscutting a dolomitic sequence of theApennines (Verbicaro Unit) affected bv meta-morphism were investigated. .

The whole rock K/Ar isoc:hron reveals

an upper Aquitanian age meramorphism(18 mal.

A comprehensive geochronological surveyconcerning metamorphics (6g. 3) and piu­tonics (6g. 4) of the Scree (Southern Calabria)appeared in 1976 (BoRSI et alii). This washelpful in the restoration of the evolutionof the Calabrian arc. The most importantresults were;

1) the occurrence of Hercynian andMesozoic ages for biotites (from bothplutonics and very high grade rocks),preferentially distributed, which have beenrelated~taking into account also the geo­logical data - to a first order tectoniccontact between twO different strucruralunits (Stilo and Polia-Copanello Units);

2) the proto-Alpine uplift of the formersection of the Palaeozoic lower continentalcrusr (Le. the very high grade rocks croppingout in the northern Scree);

3) the composite naruee of the plulonof the Scree displaying Sr isotopic ratioswhich do not plot along an isochrone.

43 A. PAGLIONICO

NORTHERN SECTOR OF THE GALABR/AN ARCcretaceous paleogenic alpine chain

%

~

~ -

I-I I

118 '24 130 131;1 1411 '48 154 180 m.a.

Fig. 3. - Oistribution of biotit( ages (Rh/Se) ofmetasediments of the former lower crust S('C{ionof Northern Serre (x = 136 ma; a = 12 ma; n :::17) (BoRSI et aI., 1976).

In 1979 Wieland reported the results ofradiometric data on muscovite and hiotiteof pIu tonics and metamorphics, as well ason whole rock of granites cropping out inthe Sila.

Whole rock data give an age of 284-±14 ma for the granitic intrusions. The valuesobtained for minerals, nothwithstanding thescattering, confirm also in Sita the effects ofa Mesozoic rejuvenation at around 170-180ma ago, as found in Southern Calabria.

SCHENK (1980) presents V/Ph and Rh/Seradiomettic data through a former sectionof lower crustal continuous sequence about7 Km thick (Polia-Copanello aucr).

On the hasis of the radiometric ages of

various minerals and of the PT path - de­duced petrologically - the author hypothe­sized that: 1) the primary crystallization ofa metabasic rock happened 450 ma ago;2) the granulite fades metamorphism endedat 295 ma and was followed by an upliftof the lower crustal rocks into intermediatecrustal levels, and by synchronous plutonicintrusions.

Accordingly this restoration appears to theauthor to be very similar to that inferredfor the Ivrea zone.

A contribution on the late alpine andapennine orogenic phases recorded in theCalabrian arc has been supplied by BECCA­LUVA et alii (1981).

On the basis of two K/Ar determinationson metabasites belonging to the ophioliti.ferous units outcropping in Northern Ca­labria the authors postulated an isotopicre-equilibration event in the Oligocene­Miocene·

A Rb/Sr radiometric srudy (DEL MOROet al., 1982) was carried on three peralumi.nous graniroid masses ourcropping in rheSouthern secror of the Calabrian Arc (fig. 4).

An age of 293 ± 9 ma was calculated bymeans of a whole rock isochron on samplesof Capo Rasocolmo mass (Southern sectorof the Calabrian Arc). Strontium isotopicdata ((srSr/86Sr)1 = 0.708] suggest a crustalorigin for all the studied granitoids origi­nating from an heterogeneous metasedimen­tacy source with a high pelitic content. Theages of micas ranging from 282-291 ma areconsistent with the calculated isochrone.

SOUTHERN SECTOR OF THE CALABRIAN ARC

%N

o MESOALOMINOUS SUITE

ITIID PERALOMINOUS SUITE

s

1 9 206 213 221 2 8 23S 2 2S0 2S1 264 272 279 286 294 rna.

Fig. 4. - Distribution of biolite ages (Rb/Sr) of plutoniles OUlcropping in Southern Serre, Aspromonteand Mt. Pdoritani (er = 29 ma; tI = 30) (HoRSI eta!., 1976; DEl. MORO et al., 1982).

%

RADIOMETRIC GEOCHRONO'LQGY IN THE CALABRIAN ARC; A REVIEW

GEOCHRONOLOGICAL EVENTS RECORDEDIN THE CALABRIAN ARC

D Rb/Sr blotite ages

• K/Ar muscovite and amphibole ages

o U/Pbzircon age

'9

16-18 29•

43-56 1211361' 16 '811 6211 2 6 241 2 6 2126301o450 m.a.

5 4 3AGES OLlGO-MIOCEN EOCENIC UPPER JURASSIC­

LOWER CRfTACfUS

2 1CARBONIFEROUS ORDOVlCIAN

PERMIAN

Fig. 5. - Geochronological evems recorded in the Calabrian arc (references in Ihe ton).

Few data are available relating to meta­morphic and plutonics dredged in the Tyr­rhenian sea (SARTORI, 1982). The plutonicsgive an isochron (Rb/Sr whole-rock-mineral)of 302 ma; whereas metamorphics give anisochrone (Rb/Sr whole rock-mineral) of69 ma. K/Ar (whole rock) of 47 ma and97 ma have also been determined on meta­morphics.

In 1983 the results of 40 K/Ar deter­minations on ophiolites and associated lowercontinental crust rocks outcropping atboundary between Calabria and Lucaniawere published (DELALOYE et aI., 1983) ina summary. The main results are as follows:merabasahs with monophase orogenic meta­morphism give total rock ages of 50 ma;metabasalts and metagabbros showing amultistage metamorphism give total rockages from 26 to 57 ma; recrystallizedamphibolites give ages of 55-90 ma andpoorly recrystallized amphibolites give agesof 81-223 ma. Interestingly, an isochron of210 ma has been calculated for amphibolesfrom amphibolites, and isochrons of 27-28ma have been calculated for blue amphiboles,and chlorites from blue schist ophiolites.

Recently (1984) a geochronological study(ZUPPETTA et alii, 1984) on the meta·basalts occurring in rhe Borghi Unit of theM. Peloritani area has been published. By

means of K/Ar methods on seven samplesan isochrone of 217 ± 3 ma was obtained.This age, according to the authors, points toa middle Triassic tectonic phase in the Pelo­ritani range.

Concluding remark8

From the geochronological review, itappears that the data available relating tothe Calabrian Arc ate still very ambiguous.Palaeozoic, Mesozoic and Tertiary gea­chronological events are recorded (fig. 5).

Palaeozoic ages seem to indicate: 1) theexistence of an Ordovician magmatic activityor of a pre- or eo-Hercynian metamorphism;2) the end of Hercynian metamorphism atabout 295 ma followed by intrusion ofhuge masses of granodiorite-granite-tonalitemostly between 295 and 275 ma. Someproblems arise when we consider somemineral ages ranging from 238-250 ma,whose significance is still obscure.

A lot of Giurassic-Cretaceous Rb-Srmineral ages have been determined bothin plutonics and in metamorphics croppingout north of Capo Vaticano-Soverato line.Interestingly similar ages have been de­termined on rocks dredged on the floor ofthe Tyrrhenian sea. The significance of these

50 A. PAGLlONICO

ages is still in debate. They might be dueto me cooling subsequent to the Hercynianuplift, otherwise they may reflect phenomenaconnected to Tethy's evolution.

Teniary mine~1 ages have been determinedin me AUSlCalpine nappes and in the ophioli­tiferous units; the events recorded in theformer are older than in the latter. Probablythey reflect, on the whole, isotopic resettingconsequent to the Alpine and Apenni~

orageneses.

It is worthy of note that Triassie ageshave been also determined. Whether or notthese are connected with Triassic conlinentalthinning and/or rifting needs deeper analysis.

On the other hand. the mesozoic andtertiary geochronological events need 10 bebetter fined inlQ the ge<XIynamic evolutionof the Calabrian arc.

Acknowl~dg".,tnl. - This research was supportedby M.P.L (40lj()).

TABLE I

V/Ph radiometric dl1/11

2

'"~2""'"

,..'"'"'"'"

'"'".'",'86

'"'"'"'"

'"'"m'"

'"'"'"'"

'"'"

,ss'"'"'"~,

,..'"m'"

lOSS 0.06630 .1'3901

2'I'Xl 0.05907 .mu5610 0.05631 .IW3

!1960 0.053~7 .300516950 o,osqq\ .5353

~870 0,05509 1.0qSO

5310 0,OS1l75 5.6870

16300 o.~ O.O':lll'5

382'>0 IO.or.sn i.lom~ :O.065'J8 .12115 I6030 :0.05651 ,05$6652 10.1'55&11 ,2151>0

1~20 0.05321 6.1Ii~6

lino 0.055635.8627lAI0 0.055625.lllII6

22110 0.05870 9018

3600 0.05623 .1~55

1(}q10 0.OS37•. 17.11

111.688~i.6

u3.l578.8

21.9

~.2

639.51l1.65&1.7

5'*i .1

...I'"~

."'"'"'"m211

."01'

21~0

"SS2196n,

811"ZllU 2266

906

m'

10COOOS

K Al-110I Al·lt>8I Al·_8'lI Al-81~

K AI.-88}

K Al·l~1

K AI.·85K Al-90

I Al.·808

I Al.-80S

""-I Al.-I1OI A!.."20

l/IOLlTl

..JIIC.....StlTl

U·_lO&&I__ IT[

101.051'''' !H~l"Cn

•

• Sia~ fraction of the same sample. ** According to the nomcnc:laturc propelled by WlNII:1Ll 6: SDI"(I97J). ..* Acnudil!8 the ordtt of the rdefUlCCS.

RADIOMETRIC GEOCHRONOLQGY IN THE CALABRIAN ARC: A REVIEW 51

TABLE 2

KtAT radiometric data

F-r.,,,

10 .. oJ. ,,~ 'k''''......"". " ~.~, .. _.~.....,.,'..,,, '" • ,........ ...." •• ~"" ''''.l> •. ,""..." •• ,......... .~ ...... ".. ~.,....,..,..... rn • .." ...." •• _.., •• .. ,.. ... .,.".... ,,, M:", "., '.."....,.. '..... ... • • ...." ., ,wo

" " ..,.. ::1 ......... ,. ,.",~"

r'·'M " •• ... ".. ,,~.....,..,.. ,,, M " • 'N "., •••....,..,..", ,.\0 " " ..,,' .,.. =......,..,..", ." • " ....., >l.' •••" .. '.m •• .....- •• .~ .'".....,..,..", "', • •• ...." •• ...

" •• ..," 'H llU'

~-'''''' ''I' " •• ..", n .• ,.~,....,..,..", ". " •• ,..", •• ",.,......,.,'..... ,." " •• '."1 .. ''I''w"'...."..'" ". " ,." ..,,' •• ...i' ....,." ..". ~ " '. .~ •• ,,~.

~ ...."..,..... rn. " •• '.VI ... ,,,..~ :--..::::::, ,." • " '.", .,' ,..

" " ,....• "',..';1 ...._.,,'" " .' 'II~'

r'" " • ,.,-..,-,,, " " ••~-".--..,..-- ~ ....;;;; •• • •• ...." •• .,..,......., ,. • '. ..- " "

.,1'--"~"...."" ..., - • .." ,,,,, •

" '.O! ~.mm • ... ,.. •" '.n ~."u,,,,_., - " •• ... •

TABLE 3

KtAr radiometric data

....."'. .....". 10 .. 'O" ,,~ •• '..'-".......... -" - .. .. _.._"""'IJt!l.~_ .."n,

~. " •• U1'. •_'",n, ~. " " "'" •_ .."n,~. " ... .,,, •

F::"''' ~. " '.ll Ill" •""". ~. .' •• •• •

'"""""'....... ' ". • <.N ..,,, •• ~. •• ,......, ,,-. • •• ..", Ol.' - •, ,...,.., "..., • .~ ... ., _. •,.......' ,,- • ..,.. ..,,, "., "'" •e ,......, ,,-... • 1.>" •• •• 11... •..,......., ".", • '-1" ..." •• ,.. •li ..,......., "·111 • .W ..." ".. ~" •I~

•• • •• .- ,....., •..'....... ',.,....... ' ...., • '.11 ..- .... "j ,.,...,.., ...., • .." ..- "'.... "~ ..,...,.., , • " .- ' ....1 "r"' • • •• .- ,..... •i :::::: . • •• ..~ ,..... "Oil" • •• ..- ,..... "....,.. ' 0"" • ," ..- 1....' "

••u••"

TABLE 4Rb/Sr radiometric data

GEOLOGICA. I ANAL ynD e. s. 87 RB 87 SA 81SR AGE B1BLlOGRAPHIC

REfERENCESSAMPlES

PHASE (PP") (PP") "5. "5. "5. " SOURCES

",

RA.11E • ,'''"

h B, 2S~! 9 •"

B, 2821 8 •1. B, 2S1! 8 •,. B, 2S0! 9 •1. B, 287!10 ," B, 283! 8 ,

GNEISSIC ,. B, 167~ 6 ,IGRANOBLASTl H

lo B, Ill! 6 ," B, 205% 7 •l. B, 103! 3 •l. B. 181! 6 •" B, 210% fl •" B. In! ~ •l. B, 253: 8 •" B, 1l~: ~ •

ORlOGNEISS .. B, 229! 7 ,.. B" 2~6! 8 ,.,B" 2S0! 8 ,'R 250: 8 ,

•• '" 2~5! 8 ," 211! 9 ,

0, B, 183% 6 ," B, 56! 2 •

52 A. PAGLlONICO

TABLE 5

Rb/Sr radiometric data

u

fOlOGICAl NA.VHO ",.

" R. ~ISR I ~{SR "" Oll.IOGRAP"lC

RHERE"USSAMPLES

P"ASE (PP,.,) (PP") "S; ~" 8"6$. 1 "' SOURCES

O"GJ'.UCCOUNn-·-

G.ANITE KAW 1770 "" ll7 " 28511~ 15B, 151 7 ~2~tJ7

GRA~ITE KAW 1856 '" I" 17 26~!J~ 25B, 79 11 J~2tJ5

G..NIH KAW 1771 " 127 13 28~~13 25B, IBl 7 302t12

GRANllE KAW 1852 " IBO " 275!il 25B, 265 " 285tll

GRANIH KAW 1857 B, 170 7 270~1l 25

GRAN I lE KAW 1772 B, 12 " 800!750 25

G.ANITE KAW 1860 B, 116 "221! 9 25

IG"NIIE KAW 1861 B, 112 3 223! 9 15

TABLE 6

Rb/Sr radiometric data

fOLOG1CALt:L ¥ZED

., S• ".. "s. I "s. A.. BIBLIOG~APMIC

EFERENCE>SAMPLES

"" ( pp,,) (pp,.,) SOs; ~M "S; ,"' SOURCES

USIRoAVINEUNllS

(POi:!T"tOPA-NELLO UNII)

NElSSIC Ccz 111119 B, 231 7.5 139!13 5GRANOOLAS 1I lE

NEISSIC (cz11I350 B, 561 65 1~7! 6 5.ANOOLOSTIIE

UA.ZOOJOR11IC (ez 111 236 B, 3"" 12.6 lW16 5NE I SS

UAHOOlOOITle CczlII237 B, 299 "-l 152~ 7 5NE I SS

TONALllle CczIII238 B, l55 1.6 1~2~ " 5GNEISS

TONALITle (cz IJ I 2~5 B, )95 3.1 13~~ " SGNElSS

TONALITle (czI11247 B, 92S 3.2 137! • 5NElSS

TONALl11C Lell 21 B, 312 8.2 139!11 5NE I SS

RA"11010 (CAR 23 8, 39l 5.' B?! 5 5SIOTlTlC

NE I SS

OONITOIIl CczI1!5~ B, 300 11.0 137!}q 5101 I TleNE I SS

RANITOIO '" 18 B, 365 3.7 l~O! 5 510TIT1eNE 1SS

ONALlI E '" 22 B, 318 5.1 1~9! 7 SONALlTE czllI217 B, 931 9.S 149~ 9 5

RADIOMETRIC GEOCHRONOLOGY IN TIlE CALABRIAN ARC: A REVIEW 53

TA.BLE 7

Rh/Sp raJ;om~tric J a t arCll.O&ICAL ~TnD .. ," "',. So So

, IlL I0(;"'''' It

PHUU'CES S.......u ~.s£ {,,"l (" .. ) "$; "$;" "$;' M SOU'tH

S'lbO Y~!1

UNODIO"'E fCIIII2S1 B, '78 1.9 289!5 5

R.~OD1ORllE (Cl III X B, "5 S. " 26819 5

RONODIORIH reI 11 12S2 B, 330 '.5 278!8 5

UNODIORII! r" I2l B, "0 }.I 28]! 5 5

""OD I01111 t r11 111B, 361 2.5 210!5 5

~ U.o;(IOIDllllt CII 11 1313 B, ". .., 2Qu7 5~

ttl 1011.... I!l ,ultlll312 B, ,.. '.' 2~7,

• ,; JOI<.... IH ,[(llll 248 B, ,,, 2.6 211!~

~ 10l'l.... 1f( (llll 2~ B, ,,, L6 216U 5

BIO'IIIC Cl III 506 S, 56' ,.. 236t7 ,'O~PN"IH

K-FELOS'O'- Cl J 11 1", S, ". 1.6 203'~,

IlEGoC"SIaUNllt

K-'HOSPOR- ClIII 2", S, '" '.5 2oot 6 5EGOCRTSIR.N1H

-'HDSPOR- ClJ 11 lSS S, ". 6.' 2W8 5£GOCR1SIUNIl[

-flbDVOR- '" III B, ", '.S 261!5 5OOC,1SI

UNIH

-F(bDSP.oJt- '" '70 B, 680 6.' 2q3!6 ,&ACUS'

'ONlll

TA.8LE 8Rh/Sp TaJiom~tTic J Q t a

lOl.OGIC.... """lYlUI .. '" ".. So "S. ~, OI ... IOG....PNIC

'(OU!NCts SAAIobts PNOS! (",,) (,,,.) "$; ~" BOS;' M SllI,I'C!S

"uSI.OObPIN!UNIH

G••NOL IlE KAL-l~7 wo 97,6 167.5 1.69 .72349 0.702107 108t 1 22B, 85.7 '.0 '56 .26881"- 19.1 116.9 0,313 . 72091 0.72026 147t7 22X-HlO 30.4 366.7 1.82 .72405

G....OI.I1E Al.-80s WO~1'

150.6 }'58 .72140 0.71867 1I4!1 '2., 7.1 '.7 ". .()/l1l0

"- ,I:" 101.9 O.lOS .11980 0.1183 lq4t9 22K-'Elo 5.0 lO'l.l 2.07 .1231l1

'"0/00l1 lE f.o..81 ...;l:1

161.9 U, .lI':I61 0.11769 1I2!1 22., .7 B.' ". .03111"- 22.1 180.9 0.354 .lI815 0.117Qo loU9 "K-HbD 10.0 1153.6 1.35 .72010

GKlllSlC ~-310 " 81.0 110.6 2.2. .13018 0.1'219 "'I "_.ITE ., 31.1 B.' '" .011561

6N£11S1C AI.-657 " 19.0 314.4 0.732 .lI6D.5 O.lI54 10l!1 "~.. B, 25.3 ••• m .ss'"1Il'0·_10- AI. _94 " ~'

199.0 1.13 .11S01 O.lI290 B5!1 22~....o .,. B, .1 '.0 36' .41104• liE p, .., "'.. O.O~ .71239 0.11227 116!5 22K-fEbll n.lI 393.7 2.02 .71734

54 A. PAGLlONICO

TABLE 9

Rh/S, radiometric dala

GEOLOGIC~L AtlALYIeD R, S. S7Rs 87S~ 87S~,,, BIBLIOGRAPHIC

SAMPLES PHASE (PPH) (PPM)REFERENCES SOS; sos;;H B'55;1 " SOURCES

AUSTROALPltlEONi Is

GNElSSlC KAl.-170 " 127 ,0 12U 2.92 a,n01l6 0.7250 B2!1 22GRlIlOBlAST lIE B, 503.7 ., l15 1.35316

GIIE I ss le KAL-168 >' 61.0 211.1 0.8390.72261 0.72101 134~1 11GRANOBlASTI1E B, 496.l! '.3 138 1.17526

MUlE KAL-l!91 '0 154.3 IIlO,I! 3.18 0.71298 0.7038 203t lj 11p, B.l lIS.6 0.03690.70390 0.7039 lllj!l 11B, 371. 4 5.5 103 1.03193

GNEISS]C KAL-879 p, 1.J 13.5 0.00&10.71274 0.71273 13lj~l 11GRANOBLAST1TE B, 309.4 B.1 111 0.92657

QUARZOOIOR1TIC KAL-887 p, O.B 39,3 0.00950.71136 0,71135 SS!} 22GNEISS B, 272.3 18.1 lIS.9 O,761103

TOt/AUTE KAl-730 >' 81.9 85.1 0.8320.713l!6 0.7119 133!1 22B, m.7 1.J 80l 2.22801

lCASCHIST KAl-l!2 '0 532.0 75.2 20.7 0.79609 0.7170 2681lj 22>' 623,3 Bl!,4 9.83 0.75457 0.7485 4311 11B, 667.7 17.7 179 0.91987

NEISS KAl-51 >R 194.5 69.9 8.09 0.75183 0.7272 21412 11'0 604.6 26.8 fi6.7 ll.93003

TABLE 10Rh/Sr radiomefric data

EOlO~IC~l l\N~lYZEO .. ,. "., " s. "S. "" OIBlIO~UP"IC

PHERENCESS~~PlES

PHASE ( pp,,) (pp,,) "So 86"$,;" 8SS; I .. SOURCES... ASOCOl-~O MASS--LEUCOIIONZO- P 80-1 .. I" 177 1.1~ 0.715~ S~RANI1E

P 80-2 "" III no 1,70 0.717~ S· P 80-2 B, '" 5.6 50ll,18 2.5457 256~~ B· P 80-2 <, 262 '" 2,07 0.7190 B· P 80-2 p, la 165 0,18 O.71B BLEUCOIONAll H P 80-3 " S6 616 0.26 0.7111 B

· P 80-3 B, ". S.O 232.98 1.56~8 258:~ 6· P 80-3 ,. 160 55.7 8.35 0.7~~1 28?!£> BlEUC010N~C I lE P 80-4 .. 66 528 0.36 0,7W B

LEUCOMON1O- 80-5 " 167 67 7.8~ 0.7~2U BGUNITE

P 80-5 B, 1011 2 , 1?61.oo 7.0209 252!~ 8· t 80-5 '0 J9B , B 156.57 1. 3~98 287!5 SGR~NOO'O.'IE P 80-6 .. ., 02£ 0.67 0.712~ S

· P 80-8 .. 110 m 0.97 0.71~1 S· P 80-8 S, '" J.5 736.98 3.71~6 287!S 8LEUCOGUNOO'Q- P 9 .. 9B l61 0.78 0.7125 8OIT E · ",. .. 115 1SI 2.22 0.7198 S

I· P185 .. 50 ''1 0.31 0.7ll6 S· P19~ .. Jl3 190 1.68 0.7169 S

RADIOMETRIC GEOCHRQNQLOGY IN THE CALABRIAN ARC: A REVIEW

TABLE 11

Rh/Sr radiometric data

55

EOlOGICOl NOly/fO " I" ~.. ",. ",. m ~1!lloG"'.IC

~HUt.(£SS...,'U '.OSE (,,~) ("M) w,; w,;. ~ ~ 50u~CU,

pTA.On

-~

G.O.OOIO"I'E C 80-10 ~ 95 m 0./3 0.7112 •LEUCOG~A.O- ( 80-11 ~ 151 '"' I. ~q 0.7m •DIORllE

., 95B 5.' 5R~6 ~,0896 0.7077 2'llt~

"' s.. 22.5 63.10 0.9697 0.7078 289tS"".IO.l'IC ( 80-12 ~ m Ul 1.63 0.7If>4 •OPlllE

6U.OD'O.ITE ( SO-l~ ~ '00 3ll l.30 O.71oS •B, m '9 S~).ll ~.)31S 0.70':16 2S~~5

" m S% 1.8~ 0.7169

" 91 ~, om 0.71001'\o.10.lllC ( 80-15 .. '"0 66 ,.". 0.7~lS 0A'" lE "'

,,. S.5 S69.)~ 3.()/J63 0.709~ 2S8!~

"".IO...Hllt ( 80-16 .. ISl 1lS 2,0~ 0.7203 0GU.ODIO"llt ( 80-17 .. '" '" 0,8l 0.7116 0LIUCO>OONIO- C SO-IS .. 161 W. 2,36 o,nl~ 0o~O.I't

""NlO.U."[ C 80-19 .. ISl ll8 139 0,1B8 •GOA.OD'OOlll C 80-20 BB 15 '" 0.57 0,7103 0., 98' ,.0 ~03.82 2,3687 0.7080 2SSt5Llucoou.o- C 80-21 ~ 181 1.. 2.13 0,72\)2 •OIO~"E

l'UCOO.A.O- '" • .. 110 138 ~.~3 o,n12 •0100' It· Gf 72 .. m 50 12.22 0.7609 •· CNI20 .. 10' ., 0.S6 O. ?115 •· (N176 .. 111 % 6.~6 O. 7~39 •

TABLE 12Rh/Sr radiometric data

(OlOGlCA' NAlVIED • • •• 5• 5. " 010lIOG"P.,(S......15

"tH.tNCH '.An ('PM) ('PM) w,; ~. w,; , ~ SOu~ClS

,,<0 0'-I 10.0.NI .ASS

'Ltucoou.oo,o- ( 80-1 .. IOS 118 0.95 0,7142 0./103 286t~ 0""l 0, 71. '.9 337.81 2.0835IIoNlOGU.llIC ( SO-2 .. 185 55 7.63 O. 7~29 0A'UII 0, '66 , .1 m.GO ]. 717~ 195:3

" .11 , .1 ISQ.~6 1.4621 0.7119 286:6LIUCOGUNOOIO- ( SO-3 .. 111 325 1.08 O. 7l~8 ••,n

( SO-. .. 100 m 1.23 0.7158 S., 681 1.• 12QO.Si> ). /()fi~ 0.11OS 2S3!~

"' 215 151 4, IS 0.1W 0.710£> 2%!7

" m ." 1.~1 U.12S2

" 12 155 0.36 0.7J2~

1 C 80-5 .. " "9 o.oy O,111S •I ( SO-6 .. m 119 1,08 0.71~9 •6.,"001001" C SO-7 .. ,0< lB' 0,80 0,713S S

C SO-8 .. " ,.. 0,82 0.7132 •11Io5COVl l IC C SO-9 S, '" 59 ~5S.28 2.5783 0.71S3 285t4 •P£G.olllE "' .IS 17. 3 78.70 J.O~SO 0.1194 282:4

" 150 '"' U6 0.7249LfUCOO.O.ODIO- (AI ~3 .. 111 1&9 US 0.720) •~ If E · (AI 6~ .. 156 111 2.65 0.7223 S

I· CAIl31 ~ 65 'SO 0.39 0.71IS S· CAI261 .. 101 195 1.00 0.7I~3 S

A. PAGLIONICO

REFERENCES

AMODIO MORIlLLi 1., BoNARDI G., CoLONNA V.,Dn:TRlCH D., GIUNTA G., IpPQuTo F., LIGUo­RI V., LoRENZONI S., PAGUONICO A., PERRONE V.,PICCARRETA G., Russo M., SCANooNE P., ZANET­TIN LoRENZONI E., ZUPPETTA A. (1976) - L'Ar­CQ Calabro-Pelori!fmo nel/'orogene Appenninico­Maghrebide. Mem. Soc. GeoJ. It., 17, 1-60.

BECCALUVA 1., CHIESA S., DELALOYE M. (1981) ­K/Ar age determinations on some Tethyan ophio­lites. Rend. Soc. It. Miner. Pelrol., 37, 869-880.

BoNARDI G., GJUNTA G., PEIUIONE V., Russo M.,ZUPPEl1A A., CIAMPO G. (1980) Osservazionisulf'evoluzone del/'Arco Calabro-Pe!oritano ne!Miocene inleriore: la lormazione di Stilo-Capod'Orlando. Boil. Soc. Geol. Ita!', 89, 36~·393.

BoRSI S., DUBOIS R. (1968) - Dannies gerxhrano­logiques sur I'hisloire hercynienne et alpine dela Calabre Centrale. Compt. Rend. Acad. Sei.Paris, 0266-72.

BoRSI S., HIEKE MERLIN 0., LoRENWNI S., PA­GUONICO A., ZANEl1lN LoaENzoNI E. (1976) ­Stilo Unit and .. dioritic-kinzigitic,. unit in LeSerre (Calabria, Italy). Geological, petrological,geochronological characters. Boil. Soc. Gool. h.,95, 1·26.

CIVETTA L., CoRTIi'll M., GUPAUNI P. (1973) _Interpretation of a.discordant K-Ar age pattern(Capo Vaticano, Calabria). Earth and Planet. Se.[.en., 20, 113-118.

DEULOYE M., FONTIGN1E D., SPADEA P. (1983) ­Radiometric dates of Calabria·Lucania ophiolires(Southern Italy) and associated continenlal rocks.Ophioliles, 8.

DEL MORO A., PARDINI G., MACCARRONE E., ROT­TURA A. (1982) - Studio radiometrico RbSr di!.ranitoidi peraluminosi deWarco calabro-peloritano.Rend. Soc. It. Miner. PetroL 38, 1015-1026.

DEL MORO A., PAGLIONICO A., PICCARRETA G., ROT­TUIlA A. (1985) - Tectonic structure and post­Hercynian evolution 0/ the Serre, Calabrian Arc,Southern Italy. Geologicul, petrological and ra­diometric evidences (in prep.).

FERU P., LoRENZONI S., ZANETTIN LoRENZONI E.(1982) - Geolo!.ical constitution and evolutionof Ihe Calabro-Peloritan Hercynian range. Rend.Soc. Miner. Petr., 38. 951·962.

FERRARA G .. IPPQLITO F., STAUFFER H., TONGIOIl­GI E. (1959) - Determinazione con metodi del!>iombo delf'ela di un /ifone 'pegmalilico preJsoDelianuova (Aspromonte,. Calabria). BoIl. Soc.GooL It., 78, 21'.

FEIlIlARA G., LoNGINELLI A. /1960\ _ Eta di duerocee 1!,ranitiche della zona delle Serrein Calabria.Boil. Soc. GeoL It .. SO. 2'.

HACCARO D.. laRENZ c.. GRAND,JACQUET C. (1972) .Essai sur J'ivalution lecloginelique de la.liason

Alpes-Appenniner (d~ la Uguri~ a la Calabre).Mem. Soc. Gool. It., 11, 309-341-

l.oRENZONI S., ZANEl1lN l.oaENzONI E. (1983) ­Nole illustrative del/a carta geologica delta Sila.Mem. Se. Gool., XXXIV, 317-342.

MOREsl M., PAGUONICO A., PICCARRETA G., ROT­TUIlA A. (1978) - The deep cruff in Calabria(Polia-Copanello Unit): a comparison with thelvreu-Verbano Zone. Mem. Soc. GooJ, Padova,33, 233·242.

NICOLEl1l M. (1970) - Eta di una raccia graniticadi Capo Vaticano (Calabria) ottenula con il me­lodo K·Ar. Per. Miner., pp. 39·159.

PAGLlONICQ A., ROTTUItA A. (1979) - Variscanmagmatism in the Calabro·Peloritan Arc, inSASSI F.P. (ed.), IGCP Projecl 5, Newsletler,1, 83-92.

PlEllAl1lNI D., ScANDONI!. P., CoRTIi'll M. (1975) ­Eta di messa in poslo ed ela di melamor{ismodelle .limburgili» nord-culabresi. nolI. Soc. Geol.It., 94, 367-376.

SARTORl R. (1982) - L'Arco Calabro-Peloritano.Aspelli di geologia marina. Rend. Soc. Miner.Petr., 38, 941-950.

SCANDONE P. (1979) - Origin of the Tyrrhenian Seaand Calabrian Arc (Southern Italy). Boil. Soc.Gool. It., 98, 27·34.

SeANooNE P. (1983) StrUClure and evolution 01the Calabrian Arc. Earth Evolution Sciences, Ill.

SeHENK V. (1980) - U-Pb and RbSr radiometricdates and their correlalion with metamorphicevents in Ihe granulite-facies baument of theSerre, Southern Calabria (Italy). Contrib. Mineral.Petrol., 73, 23·38.

SCHENK V. (1981) - Synchronous uplift of thelower crust 01 Ihe lvrea zone and of SouthernCalabria and itf passible conuquencer for theHercynian orogeny in Southern Europe. EarthPlanet. Sei. Leuers, 56, 305·320.

TORTORlcI 1. (1982·1983) - Lineamenti geologico­strufturaJi dell'Arco calabro-pelorilano. Rend. Soc.11. Miner. Peltol., 38, 927-940.

\'\7IEUND B. (1979) Age determinations in theLon!.obucco unil, Calabria, Italy. Manuscriptinedited.

WINKLEIl H.G.F., SEN S.K, (1973) - Nomenclature01 granulites and other high trade rocks. N. lb.Miner. Mh., 9, 393-401.

ZANEITIN LoIlENZONI E. (1982) - Relationships ofmain SlrUClural elements of Calabria (SouthernIlaly). N. lb. Gool. Paliiont. Mh., 7, 403-418.

ZUPPEl1A A., Russo M., CAPALDI G., TUCCILLO L.(1984) - Eflidenu di un evento rettonico lrias­sico nellVnila dei Borghi (Monti PeloritaniSicilia). Boil. Soc. Geol. It., 103, 87·9'.