industrial mineral resource assessment, mine development rock

1

Industrial Mineral Resource Assessment of Mine Development RockTimmins, Ontario

Ontario Geological SurveyMineral Deposits Circular 34

1997

ii

Northern OntarioDevelopment Agreement

Entente de développementdu nord de l'Ontario

CANADAONTARIO

M i n e r a l s • M i n é r a u xNO

DA

ED

NO

•

This publication was funded under the Minerals program of the Canada-Ontario Northern Ontario Development Agreement (NODA), a four year joint initiative signed November 4, 1991.

Ontario Geological SurveyMineral Deposits Circular 34

Staff of the Sedimentary Geoscience Section and Golder Associates Ltd.

1997


© Queen’s Printer for Ontario, 1997 ISSN 0706-4551ISBN 0-7729-7995-2

Publications of the Ontario Geological Survey and the Ministry of Northern Developmentand Mines are available from the following sources. Orders for publications should beaccompanied by cheque or money order payable to the Minister of Finance.

Reports, maps and price lists (personal shopping or mail order):Mines and Minerals Information CentreM2-17 Macdonald Block900 Bay StreetToronto, Ontario M7A 1C3Toll-free long distance, 1-800-665-4480 (within Ontario)

Reports, maps and price lists (personal shopping):Publication SalesMinistry of Northern Development and MinesWillet Green Miller CentreLevel B2, 933 Ramsey Lake RoadSudbury, Ontario P3E 6B5Telephone: (705) 670-5691Fax: (705) 670-5770E-mail: [email protected]

Canadian Cataloguing in Publication Data

Ontario Geological Survey and Golder Associates Ltd.

Industrial mineral resource assessment of mine development rock, Timmins, Ontario

(Ontario Geological Survey mineral deposits circular, ISSN 0706-4551 ; 34)ISBN 0-7729-7995-2

1. Aggregates (Building materials)–Ontario–Timmins Region. 2. Industrial minerals–Geology–Ontario–TimminsRegion. I. Golder Associates. II. Ontario. Sedimentary Geoscience Section. III. Ontario Geological Survey. IV.Series.

TN939.I52 1997 553.6’2’09713142 C96-964002-1

Every possible effort is made to ensure the accuracy of the information contained in thisreport, but the Ministry of Northern Development and Mines does not assume any liabilityfor errors that may occur. Source references are included in the report and users may wishto verify critical information.

If you wish to reproduce any of the text, tables or illustrations in this report, please writefor permission to the Manager, Publication Services Unit, Information Services Section,Ministry of Northern Development and Mines, Willet Green Miller Centre, 933 RamseyLake Road, Sudbury, Ontario P3E 6B5.

Cette publication est disponible en anglais seulement.

Parts of this publication may be quoted if credit is given. It is recommended that referencebe made in the following form:

Ontario Geological Survey and Golder Associates Ltd. 1997. Industrial mineral resourceassessment of mine development rock, Timmins, Ontario; Ontario Geological Survey,Mineral Deposits Circular 34, 31p.

Edited/Produced by: Geomatics International Inc.

ii

Resource Area Selection and Reporting........................................................................ 3Office and Field Procedure.................................................................................... 3

Sampling Procedure........................................................................................ 3Data Presentation and Interpretation...................................................................... 3

Resource Area Symbol.................................................................................... 3Site Selection Criteria............................................................................................ 5

Resource Size.................................................................................................. 5Aggregate Quality .......................................................................................... 5Location and Setting........................................................................................ 5

Regional Considerations........................................................................................ 5

Background.................................................................................................................... 8

Bedrock Geology.......................................................................................................... 9Broulan, Hoyle and Pamour Sites.......................................................................... 9Delnite Mine............................................................................................................ 9Dome Mine.............................................................................................................. 9

Selected Resource Areas................................................................................................ 11Broulan Mine Selected Resource Area.................................................................. 11Hoyle Mine Selected Resource Area...................................................................... 11Pamour Mine Selected Resource Area.................................................................. 15Delnite Mine Selected Resource Area.................................................................... 15Dome Mine Selected Resource Area...................................................................... 15

Potential Resource Areas.............................................................................................. 18

Aggregate Suitability, Testing and Processing.............................................................. 19Aggregate Suitability of Sampled Rock Units...................................................... 19

Broulan Mine Selected Resource Area............................................................ 19Hoyle Mine Selected Resource Area.............................................................. 19Pamour Mine Selected Resource Area............................................................ 19Delnite Mine Selected Resource Area............................................................ 20Dome Mine Selected Resource Area.............................................................. 20

Further Testing and Established Use...................................................................... 21Mill Abrasion Test.......................................................................................... 21Leachate Toxicity............................................................................................ 21Alkali Aggregate Reactivity............................................................................ 21Magnesium Sulphate Soundness and Freeze-Thaw Tests.............................. 21Field Performance Tests.................................................................................. 21

Processing and Operational Factors ...................................................................... 22

Summary........................................................................................................................ 23

References...................................................................................................................... 24

Metric Conversion Table................................................................................................ 31

iii

Contents

FIGURES1. Timmins mine development rock study area.......................................................... 42. Generalized bedrock geology of the Timmins area .............................................. 103. Broulan, Hoyle and Pamour sites.......................................................................... 124. Delnite site.............................................................................................................. 165. Dome site................................................................................................................ 17

TABLES1. Resource area symbol abbreviations...................................................................... 52. Physical requirements for coarse aggregate.......................................................... 63. Physical requirements for fine aggregate.............................................................. 74. Typical rock types found in the study area and their aggregate suitability .......... 85. Selected resource area summary............................................................................ 116. Aggregate suitability test results............................................................................ 137. Acid-base accounting ............................................................................................ 148. Summary of potential uses .................................................................................... 209. Recommended application-specific tests .............................................................. 21

APPENDIXESAppendix A—Sample Descriptions.............................................................................. 25Appendix B—Aggregate Quality Test Specifications.................................................. 26Appendix C—Glossary.................................................................................................. 27

iv

Depletion of traditional, high-quality aggregate resources in the Timmins region of north-eastern Ontario has generated interest in the potential usage of mine development rock asa possible replacement source. Mine development rock may be a potential source of high-specification aggregate products suitable for hot-mix asphalt and concrete applications.This report provides a partial inventory and preliminary assessment of the aggregateresource potential of mine development rock in the Timmins, Ontario, area.

The study area includes all or part of the following 6 townships: Hoyle, Mountjoy,Tisdale, Whitney, Ogden and Deloro. This report is based on data gathered by previousstudies in the area and a preliminary field assessment undertaken in the winter of 1994.The Ontario Geological Survey (1983) previously reported on the sand, gravel and bedrockaggregate resource potential for a large part of this study area.

Within the study area, 8 sites were identified as containing significant resources ofmine development rock. Of these, 5 were sampled and form the Selected Resource areas(SRAs). These SRAs include the mine development rock of the Broulan, Delnite, Hoyleand Pamour mines, operated by Royal Oak Mines Inc., and the Dome Mine, operated byPlacer Dome Canada. The existing mine development rock resources at these sites totalover 1.75 Mm3 or 3.5 Mt, with the bulk of these at the Dome Mine. Additional potentialresources are located at the Delnite Mine and Placer Dome Canada’s “super pit”, which iscurrently under development at the Dome Mine location. It is expected that the “super pit”development will produce at least an additional 170 Mt of mine development rock.

All of the sites are currently accessible by high-quality, all-weather mine roads and aregenerally within 1 km of a paved highway. Most sites have a rail line within 1 km as well.

At each of the 5 SRAs, samples of specific rock types were collected. Sixteen sampleswere collected and submitted to the Ontario Ministry of Transportation for aggregate suit-ability testing. The results varied widely, depending on rock type. The mixture of rocktypes within the existing mine development rock piles dictates that aggregate producedfrom them would be acceptable for only fairly undemanding applications. Several sites arecurrently being exploited for a limited number of aggregate uses, such as granular baseand subbase products. Upgrading the rock quality by sorting or processing is unlikely tobe successful. However, at sites where mining will continue, planned selective strippingand segregation of good quality rock units, of volcanic rocks in particular, could probablysustain the production of aggregates for all construction uses. Slates and slaty greywackes,in general, tested poorly and should be segregated during selective stripping.

Ontario Geological Survey and Golder Associates Ltd. 1997. Industrial mineral resource assessment ofmine development rock, Timmins, Ontario; Ontario Geological Survey, Mineral Deposits Circular 34, 31p.

v

Abstract

vii


Staff of the Sedimentary Geoscience Section and Golder Associates Ltd.

This report is published with the permission of the Senior Manager, OntarioGeological Survey, Sedimentary Geoscience Section.

The completion of this study has involved the assistance of numerous individualsat Golder Associates Ltd. (GA), the Ontario Ministry of Northern Developmentand Mines (MNDM), the Ontario Ministry of Transportation (MTO), Placer DomeCanada (PDC) and Royal Oak Mines Inc. (ROM). We would like to acknowledgethe contributions of B. Esford, S. Espinoza, P. Kresin, G.M.M. Ley, D. McPhedran,D. Vukov and R.J. Wortel, (GA); C.A. Kaszycki, R.I. Kelly and J. Norwood,(MNDM); B. Gorman and C.A. Rogers, (MTO); D. Ried and M. Kilbourne, (ROM);D. Gagnon and S. Kosowan, (PDC).

As the demand for aggregate resources continues toincrease in the Timmins area and the existing surficialaggregate resources become depleted and/or unavailablebecause of land use and environmental reasons, a newsource of aggregate will be required. Potentially, one suit-able source of aggregate may be mine development rockthat is stockpiled at many of the mines in the study area.Mine development rock is the rock excavated during min-ing in order to obtain access to ore. Mine developmentrock may also be generated during the development ofopen pit mines. In the Timmins area, some mine develop-ment rock has been used for mine backfill, tailingsembankment construction, erosion protection, and granularbase and subbase in road construction.

This project provides a base of information that canbe used to identify rock types that may be used as aggre-gate, thus outlining the economic potential for mine devel-opment rock. The study includes the results of the aggre-gate suitability testing from those sites having the highestpotential as aggregate resource producers.

OFFICE AND FIELD PROCEDURES

The methods used to prepare the report primarily involvedthe interpretation of published geological data, such asbedrock and surficial geology maps and reports, examina-tion of aerial photographs, and field investigation of poten-tial resource areas. Most observations were made at minerock piles identified by airphoto interpretation of the studyarea and from information provided by mining companies.Field work included the examination of the mine rock with-in operating pits and existing mine rock piles. Airphotos atvarious scales were used to evaluate the size of the resource,especially in areas where access was limited.

The preliminary assessment identified 8 sites within thestudy area thought to contain potentially significant sourcesof mine development rock. Upon further investigation, 3sites were eliminated from additional study because thepotential resource was too small. The 5 sites with potentialfor commercial extraction were studied in greater detailand are shown on Figure 1. Representative samples offresh material were taken at these mine rock piles and ana-lyzed for a suite of aggregate properties in the laboratoriesof the Soils and Aggregate Section, Engineering MaterialsOffice, Ontario Ministry of Transportation (MTO), Downs-view and for acid generating potential by the GeoscienceLaboratories of the Ontario Ministry of Northern Develop-ment and Mines (MNDM), Sudbury.

Sampling Procedure

The sampling procedure involved the following steps ateach site:

1. review of site bedrock geology, with informationprovided by mine personnel

2. accessing of the mine development rock piles

3. determination of the constituent rock types

4. collection of 60 kg of fresh rock of each type, eitherfrom new development rock or by excavating withinthe piles

5. submission of the samples for testing to the appro-priate laboratory

The sampling program was designed to give basicinformation on potential aggregate suitability for each ofthe major rock types in the mine rock piles, so that mineoperators could assess the economic viability of maintainingsegregated rock piles.

A grab sample (sample no. PD-D-8) was collected atone site in order to determine the characteristics of theexisting unsorted mine development rock and to contrastthat with segregated resources. The grab sample was col-lected by randomly gathering approximately 60 kg of rockfrom several rock piles.

DATA PRESENTATION AND INTERPRETATION

Topographic maps of the Ontario Basic Mapping Program,at a scale of 1:20 000, were used as a compilation base forthe field and office data. Detailed resource location andsampling information was then transferred to maps providedby the mining companies.

Those sites that have the highest potential to produceaggregate have been designated as Selected Resource areas.

Resource Area Symbol

The characteristics of each SRA are summarized by meansof standardized descriptors, which are portrayed as“resource area symbols” (see “Selected Resource Areas”).The format of this symbol is similar to those commonlyfound in soil mapping and land classification systems usedin North America. Three components of the symbol indi-cate the potential resource size, existing access, and pro-cessing and environmental characteristics for eachresource area examined. The fourth component of thesymbol indicates the potential aggregate uses for a specificsample taken at a resource area. The composition of eachsample is outlined in Appendix A. The symbol componentsare illustrated by the following example:

3

Industrial Mineral Resource Assessment, Mine Development Rock

Resource Area Selection and Reporting

4

OGS Mineral Deposits Circular 34

Pamour

MURPHY

JESSOP

GOWAN

HOYLE

WHITNEY

TISDALEMOUNTJOY

DELORO

OGDEN

SHAW

WARK

Timmins

101

655

629

101

HoyleBroulan

Dome

Delnite

Figure 1. Timmins mine development rock study area.

SouthPorcupineSouthPorcupine

Porcupine

Back

Road

N

0 10 km5

ONTARIO

90°

80°

50°

TimminsTimmins

N

0 400 km

Legend

Selected Resource Area

Project Area

Township Boundary

Del

nite

Roa

d

Dome

RO-P-1

50 ALL

Rd MS, FP, NAG

Potential Resource Size

- 20 000 - 50 000 m3

Potential Aggregate Uses for Specific Sample

- suitable for all high-quality uses

Processing and Environmental

- rock is in a mixed rock pile, with fines present, and is non-acid generating

Existing Site Access

- all-weather road

Sample No.

The resource area symbol abbreviations are summarizedin Table 1. Each of the components are discussed below.

All SRA size estimates are based on tonnage values pro-vided by mining companies. The existing site access is iden-tified in broad terms; i.e., by road type and rail. Potentialaggregate uses were determined by comparing the results ofsuitability testing at the Ontario Ministry of Transportationto provincial performance standards (Tables 2 and 3). Theprocessing and environmental factors are summarized usinggeneral classification parameters, as defined in Table 1.

SITE SELECTION CRITERIA

Resource Size

Ideally, a selected resource area should contain avail-able bedrock resources large enough to support acommercial operation using a stationary or portableprocessing plant. In practice, much smaller resourcesmay be of significant value depending on the volume,quality and location of alternative reserves in the restof the municipality.

Aggregate Quality

The limitations of bedrock aggregates for various usesresult from variations in the type of the bedrock units.

Lithology provides an indicator of the quality of anaggregate. The unique physical and chemical properties ofeach rock type determine its value for use as a crushedrock product. The presence of objectionable mineral con-stituents, such as amorphous silica, soft minerals andmetal sulphides, even in relatively small amounts, canrestrict the potential aggregate uses, especially for rigor-ous applications such as concrete and asphalt. Similarly,highly weathered, very porous and friable rocks areunsuitable for aggregates. Samples known to containobjectionable constituents are indicated by an asterisk inthe Potential Aggregate Uses component of the resourcearea symbol.

Location and Setting

The location and setting of a resource has a direct influ-ence on its value for possible extraction. The selection of aresource includes an assessment of natural and manmadefactors that may limit or prohibit its extraction. In the caseof this study, constraints that would normally be considered,such as houses or roads for instance, have little or no impacton access to the resource. Consequently restraints related tolocation and setting are not considered further in this report.

REGIONAL CONSIDERATIONSIn selecting areas for resource development, it is importantto assess both the local and the regional resource base. Theoverall aggregate resources in the region surrounding amunicipality should be properly assessed in order to evaluateand compare specific alternative resources and to adoptoptimum resource management plans. Although an appre-ciation of the regional context is required to develop com-prehensive resource management techniques, such detailedevaluation is beyond the scope of this report. The selectionof resource areas made in this study is based primarily ongeological data and on the considerations outlined in pre-ceding sections.

5


Table 1. Resource area symbol abbreviations.

POTENTIAL RESOURCE POTENTIAL AGGREGATE SIZE USES

Symbol Range (m3) Symbol Potential Use

20 0 - 20 000 * Not suitable

50 20 000 - 50 000 AG Aggregates (granular)

200 50 000 - 200 000 CC Concrete

1000 200 000 - 1 000 000 ASP Asphalt

VL greater than 1 000 000 RR Riprap

RB Rail ballast

ALL All high-quality uses

Note: Potential uses are based ontest results. Additionaltesting will be required toconfirm specific uses.

EXISTING SITE ACCESS PROCESSING AND ENVIRONMENTAL

Symbol Description Symbol Description

Rd All-weather road MS Mixed rock pile

Hwy Paved highway SS Separated rock pile

RR Railway line PC Primary crushing required

MR Mine road FP Fines present

PAG Potentially acid generating

NAG Non-acid generating

6


Petrographic Number, Granular, Maximum

Petrographic Number, Hot-m

ix, Maximum

MgSO4 Soundness Loss,

Maximum %

Los Angeles A

brasion Loss,Maximum %

Micro-Deval Abrasion Loss,

Maximum %

Flat and Elongated Particles, Maximum %

24 Hour Water Absorption, Maximum %

Loss by Washing Pass 7

5 µm, Maximum % (gravel)

Loss by Washing Pass 7

5 µm, Maximum % (cr

ushed rock)

Percent Crushed, Minimum %

Two-Face Crushed, Minimum %

Freeze-Thaw Loss,Maximum %

Plasticity In

dex

Insoluble Resid

ue, Retained on 75 µm, Minimum %

Table 2. Physical requirements for coarse aggregate, Ontario Provincial Standard Specifications and MTO special provisions (MTO 1994).

Use Material

Base (OPSS1010)(SP110S07)

Granular A 200 - - 60 25 - - - - 50 - - crushed rock or crushed gravelGranular M 200 - - 60 25 - - - - 50 - - crushed rock or crushed gravelGranular O - 180 - 35 - - - - - 100 - 10 0 crushed rock

Subbase (OPSS1010)(SP110S07)

Granular B Type I 250 - - - - - - - - - - 0 crushed rock or gravelGranular B Type II 250 - - - - - - - 100 - - 0 crushed rock

Subgrade (OPSS1010)(SP110S07)

Select Subgrade Material 250 - - - 30 - - - - - - - 0 gravel(SSM)

OGDL (SP313F01)untreated - 160 15 35 - - - - - 100 - 10 crushed rockA.C. treated - 160 15 35 20 - - 1.3 2.0 100 - 10 crushed rockP.C. treated - 160 15 35 20 - - 1.3 2.0 100 - 10 crushed rock

Hot Mix (OPSS1003)Hot-laid (HL) 1gravel 120 5 - - 15 1.0 1.0 - 80 - - - -dolomitic sandstone 140 5 - - 15 1.0 - 1.0 - - - - 45trap rock 120 5 - - 15 1.0 - 1.0 - - - - -meta-arkose 145 5 - - 15 1.0 - 1.0 - - - - -

DFC (OPSS1149)gravel 120 5 - - 15 1.0 1.0 - 80 - - - -dolomitic sandstone 140 15 - - 15 1.0 - 1.0 - - - - 45trap rock 120 5 - - 15 1.0 - 1.0 - - - - -

OFC (OPSS1149)gravel 120 5 - - 20 1.6 1.0 - - 100 - - -dolomitic sandstone 140 15 - - 20 1.0 - 1.0 - - - - 45trap rock 140 5 - - 20 1.0 - 1.0 - - - - -

HL 3 135 12 35 - 20 1.75 1.3 2.0 60 - - - crushed rock or crushed gravelHL 4 (Surface) 160 12 35 - 20 - 1.3 2.0 60 - - - crushed rock or crushed gravelHL 4 & 8 (Binder) 160 15 35 - 20 2.0 1.3 2.0 60 - - - crushed rock or crushed gravelMedium Duty Binder 160 15 35 - 20 2.0 1.3 2.0 95 80 - - crushed rock or crushed gravelHeavy Duty Binder 160 15 35 - 20 2.0 - 2.0 100 - - - all crushed rock

Surface Treatment(OPSS304)

Class 1 & 5 135 12 35 - 20 1.75 - - 60 - - - crushed rock or crushed gravelClass 2 160 15 35 - 20 - - - 60 - - - crushed rock or crushed gravelClass 3 160 12 35 - 20 2.0 - - 60 - - - crushed rock or crushed gravel

Concrete (OPSS1002)structural/ 140 12 50 - 20 2.0 1.0 2.0 - - - - crushed rock or crushed gravelconcrete base must be chemically stable

pavement/exposed structure 125 12 35 - 20 2.0 1.0 2.0 - - - - as abovedeck

OGDL - Open Graded Drainage Layer DFC - Dense Friction Course OFC - Open Friction Course

7


MgS

O 4Sou

ndness L

oss

Max

imum

%

Micr

o-Dev

al Abra

sion

Loss,

Max

imum

%

Petrog

raphic

Exam

inat

ion

Organ

ic Im

purities

Max

imum

%

Sand A

ttriti

on L

oss

Max

imum

%

Pass 7

5 µm

% Plastic

ity

Index

Use Material

Hot Mix (OPSS1003)HL 1 16 20 * 0-5 0 natural sand, gravel, or crushed rockHL 2 20 25 3-8 0 screeningsHL 3 16 20 0-5 0 screeningsHL 4 (Surface) 20 20 0-7 0 screeningsHL 4 & 8 (Binder) 20 25 0-7 0 screeningsMedium Duty Binder 20 25 0 screeningsHeavy Duty Binder 20 25 0-7 0 crushed rock onlyOpen Friction Course 20 20 * 0-8 dolomitic sandstone, trap rockDense Friction Course 20 20 * 2-12 dolomitic sandstone, crushed bedrock,

trap rock, meta-arkose

Surface Treatment(OPSS304)

Class 4 20 0-7 0 natural sand or crushed rock screenings

Structural Concrete &Concrete Base 16 20 * 3 0-7 natural sand

(OPSS1002) 0-5 manufactured sand

Pavement Concrete &Exposed Structure 16 20 * 3 0-3 natural sandDeck (OPSS1002) 0-5 manufactured sand

Ice Control Sand 9 0-5 natural sand(OPSS1004) 14 0-3 manufactured sand

* Less than 5% shale, chert, or mica

Table 3. Physical requirements for fine aggregate, Ontario Provincial Standard Specifications and MTO special provisions (MTO 1994).

The study area encompasses all or part of 6 townshipswithin the city limits of Timmins (see Figure 1) includingmost of the mines and prospects associated with thePorcupine Gold Camp.

The region contains large areas of glacially derivedsurficial aggregate deposits. During the early developmentof the Timmins area, these deposits were extensivelyexploited. Today these sources continue to provide a majorpart of the region’s aggregate supply; however, somesources are nearing depletion and additional supplies willbe required to meet the future needs of the area.

Recently, several properties have opened surfaceoperations, which have in turn produced significant quan-tities of mine development rock. Mine development rockhas been utilized on a limited basis from Royal OakMines’ Delnite, Broulan and Pamour sites and, currently alocal contractor is processing rock generated by the devel-opment of the “super pit” at Placer Dome’s Dome Mine.Mine rock has been utilized on a limited scale for residentialdriveway fill, granular base and subbase for roads, erosioncontrol and mine backfill.

Mine development rock was commonly used as a rawconstruction material for the development of mine infra-

structures for the Porcupine Gold Camp. During shaft sinkingand mine development, significant amounts of mine wasterock were produced. This rock was then used to build rockpads for the construction of the mines and access roadsthrough the bush.

In 1983, the Ontario Geological Survey conducted anaggregate resources inventory of the central part of the cityof Timmins (OGS 1983). The 1983 study covered a largepart of the area of the current investigation. It focussed onsurficial and bedrock resources with an assessment of theirpotential suitability for aggregate. The rock types and theiraggregate suitability, as outlined in the aforementionedreport, are summarized in Table 4.

The report (OGS 1983) recommended felsic intrusiverocks as the most suitable bedrock type for potentialaggregate use. Several areas of this rock type were delin-eated and potential rock volumes were determined. Noneof these areas are located within the present study area.The report also noted that certain varieties of the felsicintrusive rocks, with high feldspar and quartz content, mayexperience stripping problems, that is, poor adhesion ofasphalt in mixes, although no test results on the materialswere presented.

8


Background

Table 4. Typical rock types found in the study area and their aggregate suitability (after OGS 1983).

Rock Type Aggregate Considerations

intermediate to mafic metavolcanic rocks frequently sheared and some varieties weather easily

metasedimentary rocks suitable for crushed stone; some varieties are chemically reactive

metaintrusive/metavolcanic rocks weather easily

intermediate to mafic intrusive rocks generally suitable

felsic intrusive rocks most suitable, hard and relatively homogeneous

mafic intrusive dike rocks non-olivine bearing variants are hard and massive, generally suitable

The study area lies within the Abitibi greenstone belt ofthe Canadian Shield. This region contains a variety ofvolcanic, intrusive and sedimentary rock types. Most ofthe rock types in this area are between 2 and 3 billionyears old, and have undergone varying degrees of meta-morphism associated with folding, faulting and intrusiveand volcanic activity throughout this long history. Thethick volcanic sequences in the Abitibi have also pro-vided the basis for localized metallic mineralizationthrough various mechanisms. One of the major econom-ic mineral deposits resulting from this is marked by thePorcupine Gold Camp, a region of structurally relatedgold deposits that runs through the study area fromsouthwest to northeast and has provided the impetus formuch of the socioeconomic development in this area.The bedrock geology of the study area has been outlinedby Pyke (1980, 1982) and Berger (1991). The general-ized bedrock geology for the study area is shown inFigure 2.

The specific bedrock geology of the SelectedResource areas is described in the following sections. Allof the primary rock types in this part of Ontario have beenmetamorphosed to varying degrees, due to the complexgeological history of the area. For the sake of brevity inthis report, the prefix “meta” will be assumed when dis-cussing rock types. In those cases where primary rocktypes have been obliterated, the appropriate metamorphicrock type name will be used.

BROULAN, HOYLE AND PAMOUR SITES

The Broulan, Hoyle and Pamour sites are locatedapproximately 19 km east of Timmins on Highway 101,in the Township of Whitney (see Figure 1). The localgeology has been described in a paper by Duff (1986).The stratigraphy at the 3 sites is fairly simple and wellunderstood. The sequence consists of a series of sedi-mentary rocks including conglomerate and greywackethat overlie volcanic rocks. An unconformity betweenthe sedimentary and volcanic rocks is marked by anagglomerate unit of chloritic rock that hosts clasts ofangular to subangular shape. All rocks have been foldedand are steeply dipping.

DELNITE MINE

The Delnite Mine, which lies approximately 7 km south ofTimmins (see Figure 1) is owned by Royal Oak MinesInc., which suspended mining operations in 1987 (D. Ried,Royal Oak Mines Inc., personal communication, 1994).

The geology of the Delnite property is similar to thatof many properties in the Porcupine Camp, that is, asequence of volcanic rocks underlying a sequence of sed-imentary rocks (Pyke 1982). These sequences have beenfolded and altered and are now steeply dipping. At theDelnite Mine, the metavolcanic rocks are carbonatizedNeoarchean basalts and serpentinized ultramafic flows.The clastic rocks are greywackes.

DOME MINE

The Dome Mine lies south-southeast of Timmins and approx-imately 3 km southwest of South Porcupine (see Figure 1)and is one of the original mines of the Porcupine Gold Camp.

The general geology of the site is as follows (PlacerDome Canada 1987). The Dome Mine lies on the southlimb of a large syncline. The sequence of rocks present atthe mine includes metavolcanic rocks overlain by a seriesof metasedimentary slates and conglomerates. The wholeassemblage is folded and plunges to the northeast.

South of the sedimentary rocks lies a zone of magne-sium-rich, metamorphosed and carbonatized rocks. Theserocks trend to the east-northeast and are presumed to occupya fault zone. To the west, this zone of highly altered andcarbonatized rocks passes between the 2 major porphyrybodies at the mine. To the east, within the carbonatized zone,are found lenses of porphyry-type rocks, similar lithologi-cally to the main porphyry bodies at the mine.

To the south of the highly altered porphyry-carbonaterock zone is a series of south-dipping, massive, mafic flows.

The existing open pit is also cut by a near vertical dia-base dike approximately 7 to 10 m in width. Also of noteis the presence of quartz veining associated with goldemplacement and faulting. Mineralization, in the form ofsulphide mineralization, is common in most of the ore andwaste rock that has been intersected in the open pit.

9


Bedrock Geology

10


��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

�

��

��

��

��

��

Tim

min

sT

imm

ins

Nig

ht H

awk

LakeF

rede

rick

H

ouse

Lak

e

Fig

ure

2. G

ener

aliz

ed b

edro

ck g

eolo

gy o

f th

e T

imm

ins

area

(af

ter

Ont

ario

Geo

logi

cal S

urve

y 19

91).

NM

afic

to u

ltram

afic

m

etav

olca

nic

rock

s

Fau

lt

Stu

dy a

rea

boun

dary

NE

O-

TO

ME

SO

AR

CH

EA

N (

2.5

to 3

.4 G

a)

Mas

sive

gra

nodi

orite

to g

rani

te a

nddi

orite

-mon

zoni

te-g

rano

dior

ite s

uite

Dio

rite-

mon

zoni

te-g

rano

dior

ite s

uite

Fol

iate

d to

nalit

e su

ite

Maf

ic a

nd u

ltram

afic

roc

ks

Coa

rse

clas

tic m

etas

edim

enta

ry r

ocks

Met

ased

imen

tary

roc

ks

Fel

sic

to in

term

edia

te m

etav

olca

nic

rock

s

Maf

ic to

inte

rmed

iate

met

avol

cani

c ro

cks

010

km

��

��

��

��

��

��

��

��

��

��

��

��

��

Within the Timmins study area, 5 sites were selected forsampling and analysis:

1. Broulan Mine (No. 5 pit)

2. Hoyle Mine (No. 2 pit)

3. Pamour Mine (No. 3 pit)

4. Delnite Mine

5. Dome Mine

These sites were selected based on accessibility and theexisting and potential resource size. Their locations areshown on Figure 1. Table 5 summarizes the access details,volume and tonnage estimates for each of the SelectedResource areas.

BROULAN MINE SELECTED RESOURCE AREA

The Broulan Mine Selected Resource Area lies northeast ofPorcupine and about 1.5 km north of Highway 101 (seeFigure 1). Details of the site are shown on Figure 3. Theresource consists of mine rock from the development of theNo. 5 pit. A generally unsorted pile situated south of theinactive pit contains greywacke, slate and metavolcanicrocks. The site can be accessed along mine access roadsfrom the Pamour Mine site or by the Hallnor Road fromHighway 101. A rail line passes within 200 m of the pile.

The pile was estimated to contain approximately26 600 m3 of rock, as listed in Table 5. Three rock sam-ples, RO-B-1, -2 and -3 were collected, one for each ofthe major rock types (i.e., slate, greywacke, and vol-canic rocks, respectively). The samples are describedin Appendix A. The results of physical testing by MTOare summarized in Table 6 and the results of MNDMtests for acid-generating potential are summarized inTable 7.

By averaging test results from each sample, a generalindication of potential uses for a mixed sample from theresource area may be obtained. The average PN valuesfor the Broulan samples do not meet hot-mix and con-crete aggregate standards, due to the deleterious effectsof the slate (Table 6). A mixed sample from this resourcearea would appear to be suitable primarily for granularuse. Production of rail ballast may also be possible. Apreponderance of thinly bedded rock types suggests thatan average sample would be unsuitable for the productionof riprap.

HOYLE MINE SELECTED RESOURCE AREA

The Hoyle Mine Selected Resource Area lies to thenortheast of the Broulan site and on the south side ofHighway 101 (see Figure 1). The resource lies to thesouth of the No. 2 pit, which is currently being used asan access point for a new decline. The rock pile containsa mixture of material generated from the developmentof the No. 2 pit and from ongoing underground excava-tion. Development rock derived from the No. 2 pit has amedian block size of 0.6 m, while the undergrounddevelopment rock generally has a median size of 0.2 m.Fines, material finer than 75 µm, are present in both.

The site is accessed from Highway 101 via a mineroad. The resource area outlined on Figure 3 consists of 80to 85% volcanic rocks and 15 to 20% sedimentary rocks.Two samples were collected. Sample RO-H-1 consisted ofslaty greywacke and sample RO-H-2 of altered pillowedbasalt and ultramafic rocks. The estimated total volume ofmaterial present is 22 200 m3. A description of the samplescollected is given in Appendix A, with the results of physicaland acid-generating tests summarized in Tables 6 and 7,respectively.

Aggregate uses of a mixed sample from this resourcearea are considered to be limited. The presence of slatygreywacke is deleterious to the overall quality of a mixedsample. The material is deemed suitable for granular prod-ucts, rail ballast and small sizes of riprap.

11


Selected Resource Areas

Table 5. Selected Resource Area summary (see Table 1 for access abbre-viations).

Selected Access Volume Tonnage Sample Resource (km) (m3) (tonne) Nos.

Area

Broulan MR, Rd, 26 600 53 200 R0-B-1, Mine RR (0.5), 2, 3

Hwy (2)

Hoyle MR, 22 200 44 400 R0-H-1,Mine Hwy (0.2), 2

RR (1)

Pamour MR, 187 750 375 500 R0-P-1, Mine Hwy (0.2), 2, 3

RR (0.5)

Delnite MR, 18 000 36 000 R0-D-1, Mine Rd (0.2), 2

RR (5)

Dome MR, 1 530 500 3 061 000 PD-D-1 Mine Hwy (0.3), to 8

RR (1)

12


��

��

��

��

��

��

��

��

��

��

��

��

��

Thr

eeN

atio

nsLa

ke

Pam

ou

rM

ine

Sel

ecte

d

Res

ou

rce

Are

a

Ho

yle

Min

eS

elec

ted

R

eso

urc

e A

rea

Bro

ula

n M

ine

Sel

ecte

d R

eso

urc

e A

rea

Hig

hway

101

Ontario N

orthland R

ailway

Leg

end

RO

-B-1

Roc

k sa

mpl

e si

te a

nd

num

ber

Tai

lings

are

a

Ope

n pi

t exc

avat

ion

Min

e ro

ck a

nd o

verb

urde

n

Min

e de

velo

pmen

t roc

k

��

��

�

RO

-P-2

200

AG

Hw

y, M

R, R

RM

S, P

C, N

AG

RO

-P-3

200

AL

L

Hw

y, M

R, R

RM

S, P

C, N

AG

RO

-P-1

200

AG

, AS

P, R

R, R

B

Hw

y, M

R, R

RM

S, P

C, N

AG

RO

-H-1

20A

G, R

R, R

B

Hw

y, M

RM

S, P

C, N

AG

, FP

RO

-H-2

20A

G, A

SP

, RR

, RB

Hw

y, M

RM

S, P

C, N

AG

, FP

RO

-B-3

50A

LL

Hw

y, M

R, R

RM

S, P

C, N

AG

RO

-B-2

50A

G, A

SP

, RR

, RB

Hw

y, M

R, R

RM

S, P

C, N

AG

RO

-B-1

50*

Hw

y, M

R, R

RM

S, P

C, N

AG

Pam

ou

rN

o. 1

Min

e

No

. 2 p

it

N

025

0 m

No

. 5 p

itN

o. 5

pit

Hal

lno

rM

ine

PorcupineRiver

Fig

ure

3. B

roul

an, H

oyle

and

Pam

our

site

s (d

eriv

ed f

rom

dra

win

g pr

ovid

ed b

y R

oyal

Oak

Min

es I

nc.)

. For

Res

ourc

e A

rea

Sym

bol c

ompo

nent

s se

e T

able

1.

R0-

B-1

R0-

B-3

R0-

H-1

R0-

P-1

R0-

P-3 R0-

P-2

R0-

H-2

R0-

B-2

No

. 3 p

it

R0-

B-1

R0-

B-3

R0-

H-1

R0-

P-1

R0-

P-3 R0-

P-2

R0-

H-2

R0-

B-2

No

. 3 p

it

13


Table 6. Aggregate suitability test results.

Sample Lab ID PN PN LA MDA Absn Bulk Apparent % Passing No. No. Hot Mix & Gran- Abrasion Loss, % Density Density 75 µm Sieve,

Concrete ular Loss, % % g/cm3 g/cm3 by washing

Broulan Mine Selected Resource Area

RO-B-1 16013 304 137.2 20.62 19.2 - - - 2.5

RO-B-2 16014 135.4 100 18.6 8.8 0.5 2.74 2.78 2.9

RO-B-3 16015 119.6 100.3 22.46 10.4 0.8 2.75 2.809 3.1

Average 186.3 112.5 20.56 12.8 0.65 2.8

Hoyle Mine Selected Resource Area

RO-H-1 16018 186.2 100 20.44 19 0.2 2.76 2.776 3.3

RO-H-2 16019 135.1 100 23.6 25.4 0.4 2.82 2.855 4.1

Average 160.7 100 22.02 22.2 0.3 3.7

Pamour Mine Selected Resource Area

RO-P-1 16020 133.3 100 30.14 11.6 0.33 2.72 2.749 3.3

RO-P-2 16021 177.8 100 32.7 19.1 0.4 2.73 2.757 3.1

RO-P-3 16022 107.9 100 30.64 12.1 0.27 2.85 2.875 3.7

Average 139.7 100 31.16 14.3 0.33 3.4

Delnite Mine Selected Resource Area

RO-D-1 16016 137.4 100 19.5 16.3 0.4 2.83 2.858 2.7

RO-D-2 16017 122 100 17.32 14.7 0.4 2.82 2.85 2.4

Average 129.7 100 18.41 15.5 0.4 2.81 2.827 2.6

Dome Mine Selected Resource Area

PD-D-1 16005 226.0 100.0 - 24.5 0.27 2.972 2.996 3.4

PD-D-2 16006 152.3 100.0 17.54 14.7 0.30 2.704 2.727 3.7

PD-D-3 16007 167.8 100.0 22.24 25.1 0.23 2.808 2.827 4.8

PD-D-4 16008 114.2 100.0 18.62 10.9 0.30 2.793 2.817 3.1

PD-D-5 16009 161 100 18.92 13.3 0.47 2.78 2.816 3.1

PD-D-6 16010 119.3 100 9.92 7.7 - - - 2.5

PD-D-7 16011 156.7 100 17.1 10.7 0.3 2.86 2.886 2.5

PD-D-8 16012 126.1 101.4 22.68 7.9 0.37 2.8 2.828 2.6

Average 152.9 100.2 18.15 14.4 0.32 3.2

PN Petrographic Number LA Los Angeles

MDA Micro-Deval Abrasion Absn Absorption

14

OGS Mineral Deposits Circular 34Ta

ble

7. A

cid-

base

acc

ount

ing,

bas

ed o

n th

e M

EN

D a

cid-

base

pro

toco

l (E

MR

199

1).

Sam

ple

Lab

ID

Fiz

z H

Cl

HC

lN

aOH

NaO

HSa

mpl

eTo

tal

NP

AP

NP

/AP

Net

NP

No.

No.

Rat

ing

xa

yb

Wei

ght

Sulp

hur

Obs

erve

dc

(%)

RO

-B-1

1601

3sl

ight

40.0

0.10

028

.25

0.09

72

0.15

831

.494

4.93

86.

378

26.5

56

RO

-B-2

1601

4st

rong

40.0

1.00

036

.23

1.00

02

0.29

794

.250

9.28

110

.155

84.9

69

RO

-B-3

1601

5st

rong

40.0

1.00

020

.88

1.00

02

0.14

647

8.00

04.

563

104.

767

473.

438

RO

-D-1

1601

6st

rong

40.0

1.00

023

.73

1.00

02

0.07

740

6.75

02.

397

169.

700

404.

353

RO

-D-2

1601

7st

rong

40.0

1.00

025

.72

1.00

02

0.23

735

7.00

07.

406

48.2

0334

9.59

4

RO

-H-1

1601

8st

rong

40.0

1.00

033

.37

1.00

02

0.16

916

5.75

05.

281

31.3

8616

0.46

9

RO

-H-2

1601

9st

rong

40.0

1.00

024

.49

1.00

02

0.16

538

7.75

05.

156

75.2

0038

2.59

4

RO

-P-1

1602

0st

rong

40.0

1.00

033

.16

1.00

02

0.28

017

1.00

08.

750

19.5

4316

2.25

0

RO

-P-2

1602

1m

oder

ate

20.0

1.00

016

.68

1.00

02

0.17

083

.000

5.31

315

.624

77.6

88

RO

-P-3

1602

2st

rong

40.0

1.00

018

.69

1.00

02

0.03

953

2.75

01.

213

439.

381

531.

538

PD-D

-116

005

stro

ng40

.01.

000

34.0

11.

000

22.

290

149.

750

71.5

632.

093

78.1

88

PD-D

-216

006

stro

ng40

.01.

000

35.6

41.

000

20.

341

109.

000

10.6

5610

.229

98.3

44

PD-D

-316

007

stro

ng40

.01.

000

28.1

51.

000

20.

117

296.

250

3.65

681

.026

292.

594

PD-D

-416

008

stro

ng40

.01.

000

28.8

01.

000

21.

150

280.

000

35.9

387.

791

244.

083

PD-D

-516

009

stro

ng40

.01.

000

28.0

51.

000

20.

154

298.

750

4.81

362

.078

293.

938

PD-D

-616

010

none

20.0

0.10

016

.75

0.09

72

0.02

29.

381

0.67

513

.898

8.70

6

PD-D

-716

011

stro

ng40

.01.

000

32.3

51.

000

20.

575

191.

250

17.9

6910

.643

173.

281

PD-D

-816

012

stro

ng40

.01.

000

32.4

91.

000

20.

479

187.

750

14.9

6912

.543

172.

781

NP

= n

eutr

aliz

atio

n po

tent

ial i

n to

nnes

CaC

O3

equi

vale

nt,

calc

ulat

ed a

s 50

a (

x-{b

/a}y

)/c

AP

= a

cid

pote

ntia

l, ca

lcul

ated

as

31.2

5(%

sul

phur

)

Net

NP

= N

P- A

P

a =

nor

mal

ity o

f H

Cl (

g/l)

b =

nor

mal

ity o

f N

aOH

(g/

l)

c =

sam

ple

wei

ght (

g)

x =

vol

ume

of H

Cl a

dded

to

reac

h pH

7.0

(m

l)

y =

vol

ume

of N

aOH

add

ed to

re

ach

pH 7

.0 (

ml)

PAMOUR MINE SELECTED RESOURCE AREA

The Pamour Mine Selected Resource Area, which is situatedimmediately west of the Hoyle site, is outlined on Figure 3.The resource consists of material derived from the devel-opment of the No. 3 pit. Two piles of the mine developmentrock are located to the northeast of that pit. Extraction fromthe pit is expected to produce an estimated 0.5 Mt of minedevelopment rock by 1997. The piles were found to contain3 different rock types—greywacke, slate and volcanicrocks—in various amounts and generally unsorted by rocktype. The material contained in the piles ranges in size from0.6 m to fines. The piles are accessible by good qualitymine roads and lie within 100 m of Highway 101.

The resource areas identified on Figure 3 contain anestimated 190 000 m3 of rock. Samples RO-P-1, -2 and -3were collected from the 2 piles and contained greywacke,slate and volcanic rocks, respectively. The sample descrip-tions are given in Appendix A and the results of laborato-ry testing are summarized in Tables 6 and 7.

The potential uses of a mixed rock sample from thisresource area may be considerable. A mixed sampleappears suitable for granular products, riprap and rail bal-last. Production of some hot-mix and possibly concreteaggregate may also be possible from a mixed sample;however, these uses are likely dependent to a large degreeon the percentage of slate and slaty greywacke present.

DELNITE MINE SELECTED RESOURCE AREA

The Delnite Mine Selected Resource Area is locatedapproximately 5 km to the southeast of Timmins and isaccessible from the “Back Road” by the Delnite PropertyRoad (see Figure 1). The mine site, which is now aban-doned, is located at the southern end of the Delnite Road.The resource area at the mine lies some 200 m from theDelnite Road, along a disused mine road of uncertain con-dition. The site contains 2 piles of mine development rock(Figure 4). The pile that lies to the southeast of the openpit contains 2 different rock types, both of which weresampled. This pile was noted to contain fines as well asseveral pockets of overburden. A second pile lies adjacentto the No. 2 shaft and is discussed under the potential addi-tional resources section.

The resource area is estimated to contain 18 000 m3 ofrock and is outlined on Figure 4. Two samples, RO-D-1and RO-D-2, were collected at the site and are describedin Appendix A. Laboratory testing results are summarizedin Tables 6 and 7.

The average test values suggest that a mixed sampleof mine development rock from the Delnite Mine site maybe suitable for a wide range of aggregate uses includinggranular, riprap, rail ballast and some hot-mix and con-crete products. Although the material appears suitable forsome high-specification uses, further application-specifictesting should be performed prior to usage.

DOME MINE SELECTED RESOURCE AREA

The Dome Mine Selected Resource Area lies approximately3 km to the southwest of South Porcupine (see Figure 1)and is accessed from the Back Road. At the time of inves-tigation, the east waste dump (Figure 5) consisted of minedevelopment rock that had been derived primarily from anopen pit mining operation.

The mine site contains a diverse suite of rock typesincluding greywacke, volcanic rocks, and diabase. Theeast waste dump is accessed from the Back Road, along ashort (less than 500 m) section of mine road. An OntarioNorthland Railway (ONR) rail line spur runs into theDome property from the main line to the north.

During the study, 7 different rock units were sampled(samples PD-D-1 to PD-D-7). An eighth sample (PD-D-8)was collected from the existing mine development rockpile to reflect the variance within the pile. A description ofthe samples collected is given in Appendix A. At the timeof investigation, the east waste dump was estimated tocontain 3 Mt of rock, which translates to a volume ofapproximately 1.5 Mm3. Tables 6 and 7 summarize theresults of laboratory testing.

A grab sample of several rock types, sample PD-D-8,performed well in tests and may be suitable for many high-quality aggregate uses, including structural concreteaggregate. Averaged test results for individual samplesprovide somewhat different values than those for the grabsample PD-D-8; however, the range of potential usesremains wide. Potential uses include granular products,riprap and rail ballast. Limited hot-mix usage may also bepossible.

Since the time of the original sampling program,Placer Dome Canada has proceeded with a significantexpansion of the open pit mine operation. The ongoingexpansion of the original pit into what is now termed the“super pit” has and is generating significant tonnages ofmine development rock. The original east waste dump hasbeen greatly expanded and a new south waste dump sitehas been established (see Figure 5). The potential of thisadditional mine development rock is discussed under“Potential Resource Areas”.

15


16


��

��

LegendRO-D-1

Rock sample site and number

Open pit excavation

Mine development rock

��

RO-D-2

20 ALL

Rd, MR MS, PC, FP, NAG

RO-D-1

20 ALL

Rd, MR MS, PC, FP, NAG

RO-D-2

RO-D-1

open pit

Potential Resource

Area

Delnite MineSelected Resource Area

RO-D-2

RO-D-1

open pit

No. 1 Shaft

No. 2 Shaft

Potential Resource

Area

Delnite Mine

Delnite MineSelected Resource Area

N

0 500 m

Figure 4. Delnite site (derived from drawing provided by Watts, Griffis & McOuat Limited, and Ministry of Natural Resources). For Resource AreaSymbol components see Table 1.

17


��

��

��

��

��

��

��

��

��

appr

oxim

ate

nort

hern

lim

it of

roc

k pi

le a

t tim

e of

sam

plin

g

“su

per

pit

”P

D-D

-1 t

o P

D-D

-8“s

up

er p

it”

east

was

ted

um

p

sou

th w

aste

du

mp

Bac

k R

oad

Ont

ario

Nor

thla

nd R

ailw

ay

Fig

ure

5. D

ome

site

(de

rive

d fr

om d

raw

ings

pro

vide

d by

Pla

cer

Dom

e C

anad

a).

N

060

0 m

PD

-D-1

to

PD

-D-8

Leg

end

PD

-D-1

Roc

k sa

mpl

e si

te a

nd

num

ber

Tai

lings

are

a

Ope

n pi

t exc

avat

ion

Min

e de

velo

pmen

t roc

k��

��

Do

me

Min

e S

elec

ted

R

eso

urc

e A

rea

Within the study area, additional piles of mine develop-ment rock are present that may provide potentially suitablesources of aggregate. Sampling and testing of materialfrom these sites was not completed as part of this study.The additional potential sites are discussed below.

At the Delnite Mine, 2 piles of mine developmentrock are present. One pile lies southeast of the open pit andhas been discussed in “Selected Resource Areas”. The sec-ond pile lies adjacent to the No. 2 shaft and was most like-ly derived from underground development. This pile wasnot sampled; however, it is identified as a potential addi-tional resource area (see Figure 4). If the rock types aresimilar to those present in the sampled pile then a mixedsample of mine development rock may be suitable for awide range of aggregate uses, including granular, riprap,rail ballast and some hot-mix and concrete products.Application-specific testing would need to be performed

on any material obtained from this pile prior to use. Thepotential resources from this site are estimated to beapproximately 20 000 m3 of rock.

Since the time of the original investigation, PlacerDome Canada has embarked on a major expansion of theopen pit mine located at the Dome Mine site (see Figure 5).This expansion, known as the “super pit” project, has andwill continue to produce significant tonnages of mine devel-opment rock. It is expected that at least 170 Mt of materialwill be produced in the very near future, making it thelargest potential source of mine development rock in thearea. At the time of writing, a local contractor had enteredinto an agreement with Placer Dome Canada to utilize themine development rock. The contractor has been able toproduce a variety of aggregate products from the material,including: Granular A, modified Granular B, riprap, gabionstone, pit run, and various sizes of clear stone.

18


Potential Resource Areas

AGGREGATE SUITABILITY OF SAM-PLED ROCK UNITS

The laboratory testing results (see Table 6) were comparedto current Ontario Provincial Standards for coarse and fineaggregates (see Tables 2 and 3) in order to provide anassessment of potential aggregate suitability. The suitabilityof the samples for other uses such as riprap/armourstoneand rail ballast was assessed based on the lithological exam-ination of the samples. A summary of aggregate quality testspecifications is provided in Appendix B.

In addition to physical testing, acid-base accounting(chemical) tests were carried out to determine the acidgenerating potential of each sample (see Table 7). Thetests compare the neutralization potential (NP) of eachsample with its acid potential (AP). Where the NP:APratio is less than 3:1, the sample is considered potentiallyacid generating. The testing protocol was developed toassess the likelihood of acid being generated from minerock stockpiles or impounded tailings. Acid-generatingpotential is related to the presence of sulphide minerals.Certain sulphides are reactive in mortar and concrete, pro-ducing brown staining and pop-outs, and acidic drainagefrom unbonded granular materials could potentially affectwater courses. Mine development rock that is shown to bepotentially acid generating is therefore not recommendedfor aggregate uses.

A summary of the potential uses of each sample isincluded in the resource area symbols on Figures 3 to 5and in Table 8. The potential uses listed for each sampleare generally conservative and a broader range of appli-cations may be possible. Since the suite of laboratorytests performed was not completely application-specific,further testing would be required in most cases to con-firm suitability for a specific use. Additional testing isdiscussed in “Further Testing and Established Use”.

In general, test results indicate that volcanic rockshave the best potential to supply a wide range of products,including higher specification products such as hot-mix orconcrete aggregate. Greywackes are generally suitable forall granular base and subbase products as well as riprapand rail ballast applications. Use as hot-mix and concreteaggregate is limited. Slates generally provided poor testresults and are limited at best to some granular base orsubbase uses.


In spite of its reasonably good results in the durability tests,the slate (sample RO-B-1) is not recommended for anyhigh-quality aggregate use. Very thinly bedded or laminat-ed rock may produce excessive amounts of undesirable flat

and elongated particles upon processing. The hot-mixand concrete petrographic number (PN) for this sampleis excessive for these applications; however, the granu-lar PN indicates suitability for granular base and sub-base use.

The greywacke of sample RO-B-2 has been designat-ed as suitable for most aggregate uses, except for concrete.Because this rock unit is thinly bedded (60 to 200 mm), itmay not be possible to produce the full range of conven-tional riprap sizes.

The fine-grained volcanic rocks of sample RO-B-3are considered potentially suitable for all high-qualityaggregate uses. This material does not meet the lowabsorption requirement for all categories of rail ballast,although it may be used on branch lines and secondarymain lines. Further application-specific testing should beperformed to confirm its suitability.


Sample RO-H-1, consisting of slaty greywacke, doesnot meet the minimum PN requirements for asphalt orconcrete aggregate, but should be suitable for low-specification aggregate uses. As in the case of sampleRO-D-1, riprap produced from this rock unit may notinclude the full range of sizes since the rock is thinlybedded.

A sample of altered basalts and ultramafic rocks, sampleRO-H-2, meets the requirements for many uses, includingmost granular base and subbase uses, structural/concretebase aggregate, riprap and rail ballast. It also marginallymeets the requirements for use as asphalt aggregateincluding hot-laid (HL) 3.


Three samples were taken at the Pamour site. SampleRO-P-1, a greywacke, performed well. It is suitable forgranular base and subbase applications, some hot-mix usesand structural/concrete base aggregate.

The slaty greywacke and slate of sample RO-P-2 maybe suitable for use as granular material. However, theserock types are very thinly bedded and may produce exces-sive amounts of undesirable flat and elongated particlesupon processing, limiting its use even further.

Sample RO-P-3, consisting of volcanic rocks, per-formed very well in testing, and may be suitable for allhigh-quality aggregate uses, provided that further applica-tion-specific tests confirm this.

19


Aggregate Suitability, Testing and Processing


The 2 rock types sampled at this site were of high qualityand performed well in physical tests. Sample RO-D-1 wasa mixed sample of volcanic and sedimentary rocks, bothfine grained and foliated. The sample meets the aggregatequality requirements of many asphalt mixes, surface treat-ment and concrete base; however, it does not meet the rig-orous requirements of HL 3 asphalt, Class 1 and 5 surfacetreatment or concrete pavement.

The second sample taken at this site, RO-D-2, was asample of volcanic rocks which performed well in testingand may be considered for high-quality aggregate uses.


The Dome Mine site is the largest of the 5 sites sampledand exhibits the greatest variation in rock types. SamplePD-D-1 is a slate to slaty greywacke. Its physical charac-teristics limit its use as an aggregate to granular base andsubbase applications; however, its potential for acid gen-eration may limit even these uses.

While sample PD-D-2, a siliceous porphyry, is notsuitable for use as concrete aggregate, it is probably suit-able for granular and some hot-mix aggregates, riprap andrail ballast. Although it is unsuitable for use as HL 3asphalt aggregate, it does meet the requirements for theother asphalt classes.

Sample PD-D-3, a chloritic greenstone (volcanic rock),is not suitable for any use other than granular material. Whilethe durability test results are mixed, with the Los AngelesAbrasion loss being acceptable and the Micro-DevalAbrasion loss being marginally unacceptable, this rock typeis probably unsuitable for use as riprap or rail ballast becauseof the presence of chlorite, which may reduce its resistanceto self-abrasion.

Sample PD-D-4, referred to by mine geologists as agreenstone xenolith, meets the durability requirements for allhigh-quality uses, including concrete aggregate. It is, how-ever, a poor candidate as architectural concrete aggregatedue to its relatively high pyrite content of 1 to 2%. The oxi-dation of pyrite in aggregate near the surface of concretemay cause surface staining and pop-outs.

Sample PD-D-5, a siliceous volcanic rock, is suitablefor use as granular material, riprap and rail ballast, but notfor higher quality aggregate uses.

A diabase sample, PD-D-6, performed well in labora-tory tests and meets the requirements for all high-qualityuses. Application-specific testing would need to be per-formed to confirm its suitability.

Sample PD-D-7, a greenstone (volcanic flow rock)may be suitable as aggregate for a variety of high-qualityuses, excluding concrete and HL 3 aggregate.

20


Table 8. Summary of potential uses.

Sample No. Potential Uses1,2


RO-B-1 Not suitable

RO-B-2 Most coarse and fine aggregates; riprap (small sizes);rail ballast

RO-B-3 All high-quality uses

Average3 Granular aggregates; rail ballast


RO-D-1 Granular; marginal for hot-mix, concrete; riprap; railballast

RO-D-2 All high-quality uses

Average All high-quality uses


RO-H-1 Granular; riprap (small sizes); rail ballast

RO-H-2 Some granular, hot-mix and concrete; riprap; rail ballast

Average Granular; riprap (small sizes); rail ballast


RO-P-1 Granular; some hot-mix and concrete aggregates; riprap; rail ballast

RO-P-2 Granular aggregates only

RO-P-3 All high-quality uses

Average Granular; some hot-mix, concrete aggregates; riprap; rail ballast


PD-D-1 Not suitable

PD-D-2 Granular and some hot-mix aggregates; riprap; rail ballast

PD-D-3 Granular aggregates only

PD-D-4 All high-quality uses

PD-D-5 Granular aggregate, riprap; rail ballast

PD-D-6 All high-quality uses

PD-D-7 Granular; some hot-mix, concrete aggregates; riprap;rail ballast

PD-D-8 Granular; some hot-mix, concrete aggregates; riprap;rail ballast

Average Granular; some hot-mix, concrete aggregates; riprap; rail ballast

1 The potential uses have been established by comparing limited testresults (see Table 6) with Ontario specifications (see Tables 2 and 3).Additional testing, and/or evidence of past satisfactory performance,will be required to confirm specific uses.

2 Loss by washing results for all samples exceed the recommendedlimits as outlined on Table 6, however, these results have not been con-sidered in assessing potential uses, because they are influenced byaggregate processing and handling.

3 Suggested potential uses for the average sample from each site are basedon average values from Table 6. The final use designation for mixed aggre-gate from each site is not predictable with certainty and will be influencedby: relative proportions of rock types, variations within individual rocktypes, and the degree of upgrading during processing.

FURTHER TESTING AND ESTABLISHED USE

The sampling and testing reported here has been in thenature of a preliminary or reconnaissance study. Theassessment of the potential aggregate uses of each of therock units sampled has been done by comparing the resultsof a limited range of tests (see Table 6) with current Ontariospecifications for construction aggregates (see Tables 2and 3) and by considering lithological data (Appendix A)in conjunction with the test results to determine additionaluses such as riprap/armourstone and rail ballast. To firmlyestablish that the rock units are suitable for the suggestedgranular aggregate and other applications, a more compre-hensive testing program would be appropriate; this wouldinvolve a larger number of samples from the identifiedresource areas and additions to the range of tests applied.Some specific recommendations for additional tests aresummarized in Table 9 and discussed below.

Mill Abrasion Test

Canadian Pacific Railway requires that material pass thistest, which reflects the demands placed on rail ballast.Unlike the Micro-Deval Abrasion test, which this testresembles, no steel shot is included with the sample and theabrasion component measured is essentially self-abrasion.Aggregate designated for use as railway ballast will berequired to withstand self-abrasion, and display an elevatedlevel of resistance to impact. Los Angeles Abrasion valuespermit the evaluation of the resistance to impact.

Leachate Toxicity

Under the Environmental Protection Act, Regulation 347of Revised Regulations of Ontario, 1990, mine rock maybe considered to be a leachate toxic waste if leachate pro-duced from the material contains contaminants that exceedprescribed levels. Leachate that contains any of the conta-minants listed in Schedule 4 of Regulation 347 at a con-centration in excess of one hundred times the specifiedlevels is considered to be a leachate toxic waste. Materialsthat produce leachate levels of 10 to 100 times the criteriaare considered registerable solids.

Contaminant concentrations are determined throughthe use of an approved leachate extraction procedure.Under this procedure a sample of mine rock is subjected toa weak acid treatment using acetic acid. The leachate thatis obtained is analyzed for elements such as arsenic, silver,lead and mercury. If any mine rock is found to producecontaminants at the levels specified for leachate toxicmaterials or registerable solids, the material is considereda waste and cannot be used in any construction activities.

Alkali Aggregate Reactivity

Some of the metasedimentary and metavolcanic rocks ofnorthern Ontario have been identified as alkali-silica reactivein concrete. When reactive aggregates are used, a reactionbetween certain siliceous components of a rock and the alkalihydroxides of cement paste produces an expansive silica gelwhich can cause expansion and cracking in concrete. Thecracking makes the structure more vulnerable to attack byfreeze-thaw cycles and to corrosion by winter de-icing salts.

In the geological context of this study, the rocks that arecandidates for reactivity are those which contain secondary,microcrystalline quartz (resulting from metamorphism),cryptocrystalline silica (i.e., jasper) or a devitrified ground-mass (i.e., as in some metavolcanic rocks). There is signifi-cant potential for reactivity in the rock suite studied, withthe exception of the diabase dike sample (PD-D-6), whichhas low-potential reactivity.

In the case of many metamorphic rock types, the stan-dard rapid alkali aggregate tests do not consistently reflectfield behaviour; therefore, any information that can begathered from records of field performance is extremelyvaluable. Otherwise, a one- or two-year laboratory test maybe required.

Magnesium Sulphate Soundnessand Freeze-Thaw Tests

Resistance to freeze-thaw cylces is a critical durabilityparameter, and both the magnesium sulphate soundnessand freeze-thaw tests reflect resistance to freeze-thawcycles. The samples from the project area gave low waterabsorption test results, which often correlates to goodfreeze-thaw resistance. However, the proportion of platyminerals present and their distribution within some of therock units will affect the resistance of the aggregate tofreeze-thaw cycles; thus, it is recommended that at leastone of the magnesium sulphate soundness or freeze-thawtests should be performed.

Field Performance Tests

The assessment of physical properties by tests in the labora-tory is not an absolute indicator of the quality of an aggregate.Sometimes the laboratory tests do not adequately reflect

21


Table 9. Recommended application-specific tests.

Recommended Test Application

Mill Abrasion rail ballast

Alkali Aggregate Reactivity concrete

Magnesium Sulphate Soundness concrete, hot-mix asphalt, rail ballast

Freeze-Thaw Granular O, open gradeddrainage layer

field requirements. It is possible for a material that per-forms well under field conditions to show poorly underlaboratory testing. If a long-term history of satisfactoryfield performance can be documented, it is possible toestablish the suitability of an aggregate for a similar purpose,under similar exposure conditions, in spite of the laboratorytest results. As an example, many acceptably performinggranites suffer high losses and fail to meet the specifica-tions of the Los Angeles Abrasion test. It is recognized thatthe elevated losses are a function of texture, grain size,mineral cleavage and lack of elasticity due to the narrowhardness range of constituent minerals. All of these workagainst granites during the laboratory test because the testdoes not measure only abrasion resistance, but also resis-tance to impact. Since high-level impact resistance is not acommon functional requirement of aggregate, with theexception of rail ballast, granite aggregates are frequentlyapproved for use as granular materials, hot-mix asphaltaggregate or concrete aggregate based on documented pre-vious field performance rather than laboratory test results.

An evaluation of the current state and past performanceof any construction work carried out with aggregates pro-duced from the identified resource areas would contributetowards an overall appreciation of their aggregate potential.

PROCESSING AND OPERATIONALFACTORS

In outline, the processing arrangements required to pro-duce construction aggregates would include the recoveryof feed stone from existing mine rock piles, probably byan intermediate capacity wheeled excavator loading itdirectly into a multiple-stage crushing and screening plant.Stockpiles of individual sizes of crushed product would bemaintained for direct shipment or blending.

In a mixed rock pile, some rock types will obviouslybe stronger and more durable than others. During excavationand handling, weaker rock types may break down intosmaller fragments or generate fines. Consequently, thelarger fragments should be more durable and enhancementor beneficiation of aggregate quality may be possible byselectively reclaiming only the larger rock fragments frommine rock piles and/or removing fines prior to crushing.The crushing process may also effect some upgrading ofthe material if significant contrasts in abrasion and impactresistance exist between high- and low-quality rock units.Excessive fines, produced from poorer quality rocks, wouldbe removed in this process. Washing the crushed productsduring or after screening will help increase the quality, andis certain to be required for producing aggregates forasphalt and concrete applications, in order to ensure 75 µmwashing losses are within specification (see Table 2).

Given the significant range of rock qualities present inthe mine rock piles, it is considered unlikely that sufficientupgrading in the overall quality could be maintained con-sistently enough to allow the production of aggregates forall high-demand applications. Production from existingmine rock piles is likely, therefore, to be suitable principallyfor granular materials, possibly including some asphaltproducts and riprap.

At sites where further mining is planned, it may bepossible to define the distribution of rock types withinthe stripping area and to plan for selective stripping andsegregated stockpiling of the most durable rock unit(s)to allow for ongoing production of high-quality aggre-gates. This approach is most applicable at the Domesite, where the scale and duration of mining operationswill be greatest. The operational and cost implicationsof selective stripping and segregated stockpiling are notknown.

22


This report provides an evaluation of the aggregate resourcepotential of mine development rock in the Timmins area.Depletion of traditional, high-quality aggregate resourcesin the Timmins region of northeastern Ontario has gener-ated interest in the potential use of mine developmentrock as a possible replacement. Mine development rockmay be a potential source of higher-specification aggre-gate products suitable for hot-mix asphalt and concreteapplications.

The study identified 5 sites that form the SelectedResource areas (SRAs). These SRAs include the minedevelopment rock of the Broulan, Delnite, Hoyle andPamour mines, operated by Royal Oak Mines Inc., and theDome Mine, operated by Placer Dome Canada. The exist-ing mine development rock resources at these sites totalover 1.75 Mm3 or 3.5 Mt, with the bulk of these at theDome Mine. Additional potentially suitable sources ofmine development rock are present at the Delnite andDome mine sites. The Delnite potential resource area iscalculated to contain approximately 20 000 m3 of rock,while at the Dome site ongoing development of the “superpit” open pit mine is expected to produce at least 170 Mtof material.

The aggregate suitability of mine development rockwas assessed through the testing of representative samplescollected at each of the 5 SRAs. In general, the volcanicrocks are suitable for a wide range of products, including

those of higher specification such as hot-mix or concreteaggregate. Greywackes are generally suitable for all gran-ular base and subbase products as well as riprap and railballast applications; hot-mix and concrete aggregate appli-cations are limited. Slates generally provided poor testresults and at best are limited to some granular base or sub-base applications.

Upgrading the rock quality by sorting or processing isunlikely to be successful given the significant range ofrock types present in the mine rock piles. Production fromexisting mine rock piles is likely, therefore, to be suitableprincipally for granular materials, possibly including someasphalt products and riprap. At sites where further miningis planned, however, it may be possible to define the dis-tribution of rock types within the stripping area and to planfor selective stripping and segregated stockpiling of themost durable rock unit(s), to allow the ongoing productionof high-quality aggregates.

Enquiries regarding the industrial minerals resourceassessment of mine development rock of the Timmins areashould be directed to the Sedimentary Geoscience Section,Ontario Geological Survey, Ontario Ministry of NorthernDevelopment and Mines, 7th floor, 933 Ramsey LakeRoad, Sudbury, Ontario P3E 6B5 (Tel: (705) 670-5904),or to the Resident Geologist, Porcupine District, Ministryof Northern Development and Mines, 60 Wilson Ave.,Timmins, Ontario P4N 2S7 (Tel: (705) 360-8350).

23


Summary

Berger, B.R. 1991. Geology of Hoyle and Gowan townships; OntarioGeological Survey, Open File Map 175, scale 1:20 000.

Department of Energy, Mines and Resources 1991. Acid rock drainageprediction manual; Department of Energy, Mines and Resources,MEND Project No. 1.16.1.

Duff, D. 1986. Pamour no. 1 mine; Gold ‘86 Excursion Guidebook, 1.Abitibi Belt, Timmins to Larder Lake, Section 1.6, p.27-29.

Ontario Geological Survey 1983. Aggregate resources inventory ofthe central part of the city of Timmins, Cochrane District;Ontario Geological Survey, Aggregate Resources InventoryPaper 89, 49p.

Ontario Geological Survey 1991. Bedrock geology of Ontario, east-centralsheet; Ontario Geological Survey, Map 2543, scale 1:1 000 000.

Ontario Ministry of Transportation 1994. Ontario Provincial StandardSpecifications and Special Provisions; OPSS 1002, 1003, 1004, 1010,1149 and SP110S07, 313F01.

Placer Dome Canada 1987. Dome mine, mine geology informationpaper; unpublished report, Placer Dome Canada, 4p.

Pyke, D.R., 1980. Geology of the Timmins area, District of Cochrane;Ontario Geological Survey, Open File Report 5281, 396p.

——— 1982. Geology of the Timmins area, District of Cochrane; OntarioGeological Survey, Report 219, 141p.

24


References


RO-B-1 Slate: fine grained, very thinly bedded, dark green, pyritic.

RO-B-2 Greywacke: medium to fine grained, thinly bedded, dark green, pyritic.

RO-B-3 Basalt: fine grained, quartz veining, iron-carbonate rich.


RO-H-1 Slaty greywacke: thinly bedded, fine to very fine grained.

RO-H-2 Altered pillowed basalt and altered ultramafic rocks.


RO-P-1 Greywacke: fresh, medium grained, medium to thickly bedded, pyritic, minor quartz veining.

RO-P-2 Slaty greywacke and slate: fresh, very thinly bedded, fine to very fine grained, pyritic.

RO-P-3 Basalt: medium grained, crystalline, silicitized with quartz veining.


RO-D-1 Sample from waste pile, fine-grained sedimentary rocks and fine-grained volcanic rocks, both units foliated.

RO-D-2 Sample of mostly fine-grained, dark green volcanic rocks.


PD-D-1 Slate, slaty greywacke: thin to very thinly bedded, fine to very fine grained, pyritic; sample may be higher insulphide content than would generally be encountered.

PD-D-2 Paymaster Porphyry (mine terminology): highly siliceous, sericitic, fine grained, crystalline, foliated, minor pyrite.

PD-D-3 Southern Greenstones (mine terminology): chloritic, fine grained, dark green, minor pyrite.

PD-D-4 Greenstone xenolith (mine terminology): fine to very fine grained, minor quartz veining, 1 to 2% pyrite content.

PD-D-5 Carbonate rock (mine terminology): highly metamorphosed volcanic rock, carbonatized, siliceous, low sulphidecontent, high quartz content, some fuchsite.

PD-D-6 Diabase dike: massive, medium to fine grained, crystalline.

PD-D-7 Greenstone flows (mine terminology): fine grained, dark green to dark grey, foliated, some pyrite.

PD-D-8 Grab sample from waste pile at several sites: includes several representative rock types.

25


Appendix A—Sample Descriptions

Various aggregate quality tests are often conducted on samples to indicate their potential suitability for various uses. Adescription and the specification limits for each test are included in this appendix. Although a specific sample meets ordoes not meet the specification limits for a certain product, it may or may not be acceptable for that use based on fieldperformance. Additional quality tests other than the tests listed in this appendix can be used to determine the suitabilityof an aggregate.

Related to the porosity of the rock types of which an aggregate is composed. Porous rocksare subject to disintegration when absorbed liquids freeze and thaw, thus decreasing thestrength of the aggregate. This test is conducted in conjunction with the determination of thesample’s relative density.

Acid-base accounting involves chemical tests to determine the neutralizing potential and theacid potential of a granular material. If the NP:AP ratio is less than 3, the material has thepotential to become acid generating when exposed to air.

Also related to porosity and the presence of swelling minerals, this test indicates the resis-tance to disintegration of an aggregate subjected to freezing and thawing. Samples are sub-jected to 5 cycles of freezing and thawing in a sodium chloride solution. A weight loss inexcess of 10% indicates potential problems in some granular aggregate uses.

This test measures the resistance to abrasion and the impact strength of aggregate. Thisgives an idea of the breakdown that can be expected to occur when an aggregate is stock-piled, transported and placed. Values less than about 35% indicate potentially satisfactoryperformance for most concrete and asphalt uses. Values of more than 45% indicate that theaggregate may be susceptible to excessive breakdown during handling and placing.

This test is designed to simulate the action of freezing and thawing on aggregate. Those aggre-gates which are susceptible will usually break down and give high losses in this test. Valuesgreater than about 12 to 15% indicate potential problems for concrete and asphalt coarseaggregate.

The Micro-Deval Abrasion test is an accurate measure of the amount of hard, durable materi-als in sand-sized particles. This abrasion test is quick, cheap and more precise than the fineaggregate magnesium sulphate soundness test that suffers from a wide multilaboratory vari-ation. The maximum loss for HL 1, HL 3, HL 4 (surface), Open Friction Course (OFC), andDense Friction Course (DFC) is 20%. Structural and pavement concrete also allow a loss of20%. For HL 2, HL 4 (binder) and HL 8 the maximum allowed loss is 25%.

This is a rapid test for detecting alkali-silica reactive aggregates. It involves the crushing ofthe aggregate and the creation of standard mortar bars. For coarse and fine aggregates, sug-gested expansion limits of 0.10% to 0.15% are indicated for innocuous aggregates. Greaterthan 0.10% but less than 0.20% indicates that it is unknown whether a potentially deleteriousreaction will occur, and greater than 0.20% indicates that the aggregate is probably reactiveand should not be used for Portland cement concrete. If the expansion limit exceeds 0.10%for coarse and fine aggregates, it is recommended that supplementary information be devel-oped to confirm that the expansion is actually because of alkali-reactivity. If confirmed dele-teriously reactive, the material should not be used for Portland cement concrete unless cor-rective measures are undertaken, such as the use of low or reduced alkali cement.

Individual aggregate particles in a sample are divided into the categories good, fair, poor anddeleterious, based on their rock type (petrography) and knowledge of past field performance.A petrographic number (PN) is calculated. The higher the PN, the lower the quality of theaggregate.

26


Appendix B—Aggregate Quality Test Specifications

Absorption Capacity

Acid-Base Accounting

Freeze-Thaw Loss

Los Angeles Abrasionand Impact Test

Magnesium SulphateSoundness Test

Micro-Deval AbrasionTest

Mortar Bar AcceleratedExpansion Test

PetrographicExamination

Abrasion resistance: Tests such as the Los Angeles Abrasion test are used to measure the ability of aggregate to resistcrushing and pulverizing under conditions similar to those encountered in processing and use. Measuring resistance isan important component in the evaluation of the quality and prospective uses of aggregate. Hard, durable material is preferredfor road building.

Absorption capacity: Related to the porosity of the rock types of which an aggregate is composed. Porous rocks aresubject to disintegration when absorbed liquids freeze and thaw, thus decreasing the strength of the aggregate.

Aggregate: Any hard, inert, construction material (sand, gravel, shells, slag, crushed stone or other mineral material) invarious-sized fragments used for mixing with a cement or bituminous material to form concrete, mortar, etc., or usedalone for road building or other construction. Synonyms include mineral aggregate and granular material.

Aggregate Abrasion Value: This test directly measures the resistance of aggregate to abrasion with silica sand and asteel disk. The higher the value, the lower the resistance to abrasion. For high-quality asphalt surface course uses, valuesof less than 6 are desirable.

Alkali-aggregate reaction: A chemical reaction between the alkalis of Portland cement and certain minerals found inrocks used for aggregate. Alkali-aggregate reactions are undesirable because they can cause expansion and cracking ofconcrete. Although perfectly suitable for building stone and asphalt applications, alkali-reactive aggregates should beavoided for structural concrete uses.

Archean: A division of the Precambrian covering the period of time from 2 500 to >3 400 million years before pre-sent (Ma). The Archean has been subdivided into 3 eras known as the Neoarchean (2 500 to 2 900 Ma), the Mesoarchean(2 900 to 3 400 Ma) and the Paleoarchean (>3 400 Ma).

Armourstone: Large angular blocks of quarry stone, up to approximately 10 tonnes in weight, that are placed and fittedon the base of a dike, breakwater or pier.

Basalt: A dark-coloured, extrusive (or locally intrusive), fine-grained rock. Basalt is rich in ferromagnesian mineralsand labradorite feldspar. Pillowed basalt is characterized by a series of discontinuous pillow-shaped masses formed byunderwater extrusion of the lava.

Beneficiation: Beneficiation of aggregates is a process or combination of processes which improves the quality(physical properties) of a mineral aggregate and is not part of the normal processing for a particular use, such as routinecrushing, screening, washing, or classification. Heavy media separation, jigging, or application of special crushers(e.g., cage mill) are usually considered processes of beneficiation.

Blending: Required in cases of extreme coarseness, fineness, or other irregularities in the gradation of unprocessedaggregate. Blending is done with approved sand-sized aggregate in order to satisfy the gradation requirements of the material.

Bulk relative density: The density of a material relative to water at 4° C and atmospheric pressure at sea level. An aggre-gate with low relative density is lighter in weight than one with a high relative density. Low relative density aggregates(less than about 2.5) are often non-durable for many aggregate uses.

Carbonatization: An alteration process involving the transformation of minerals containing calcium, magnesium,potassium, sodium, and iron into carbonates or bicarbonates of these metals. Also, the introduction of, or replacementby, carbonates.

Chert: Amorphous silica that often occurs as irregular masses or lenses but can also occur finely disseminated throughlimestones and in association with iron formations. It has a deleterious affect on aggregates used in Portland cement con-crete, due to its reactivity with alkalis in Portland cement.

Clast: An individual constituent, grain or fragment of a sediment or rock, produced by the mechanical weathering of alarger rock mass. Synonyms include particle and fragment.

Conglomerate: Sedimentary rock composed of rounded fragments varying in size from pebble to boulder in a fine-grained matrix of sand or silt, usually cemented together by calcium carbonate, silica, or hardened clay.

27


Appendix C—Glossary

Crushable aggregate: Unprocessed gravel containing a minimum of 35% coarse aggregate larger than the No. 4 sieve(4.75 mm) as well as a minimum of 20% greater than the 26.5 mm sieve.

Deleterious rock type: A general term used to designate those rock types which are chemically or physically unsuitedfor use as construction or road-building aggregates. Such rocks as chert, shale, siltstone and sandstone may deterioraterapidly when exposed to traffic and other environmental conditions.

Dense Friction Course: A premium surface paving course with high frictional resistance. Aggregates have an identicalgradation to HL 1 aggregates, although the physical properties of both the fine and coarse aggregates are superior.

Devitrified groundmass: Material between the phenocrysts (crystals) in an igneous rock that has been converted fromglass to crystalline material.

Diabase: An igneous rock of basaltic composition, consisting essentially of labradorite (feldspar), pyroxene, olivine andhornblende. The texture of the rock is generally medium grained.

Dolostone: A carbonate sedimentary rock consisting chiefly of the mineral dolomite and containing relatively little calcite(dolostone is also known as dolomite).

Drift: A general term for all unconsolidated rock debris transported from one place and deposited in another, distin-guished from underlying bedrock. In North America, glacial activity has been the dominant mode of transport and depositionof drift. Synonyms include overburden and surficial deposit.

Felsic: Said of an igneous rock having abundant light-coloured minerals (quartz, feldspar, feldspathoids and muscovite mica).

Fines: A general term used to describe the size fraction of an aggregate which passes (is finer than) the 0.075 mm sieve.Also described informally as “dirt”, these particles are in the silt and clay size range.

Gabion stone: Durable broken rock or concrete fragments graded in size from 75 to 200 mm, used to fill wire basketsfor erosion protection works and fortification of slopes and banks.

Gneiss: A generally coarse- or medium-textured metamorphic rock with the minerals arranged in parallel streaks orbands. Gneiss is relatively rich in feldspar. Other minerals commonly occurring in this rock include quartz, mica, amphiboleand garnet.

Gradation: The proportion of material of each particle size, or the frequency distribution of the various sizes whichconstitute a sediment. The strength, durability, permeability and stability of an aggregate depend to a great extent onits gradation. The size limits for different particles are as follows:

boulder more than 200 mm coarse sand 2 to 4.75 mmcobbles 75 to 200 mm medium sand 0.425 to 2 mmcoarse gravel 26.5 to 75 mm fine sand 0.075 to 0.425 mmfine gravel 4.75 to 26.5 mm silt, clay less than 0.075 mm

Granite: A generally medium- to coarse-grained, light-coloured rock that ordinarily has an even texture and is composedof quartz and feldspar with either mica, hornblende or both.

Granular Base and Subbase: Components of a pavement structure of a road, which are placed on the subgrade and aredesigned to provide strength, stability and drainage, as well as support for surfacing materials. Four types have beendefined: Granular A consists of crushed and processed aggregate and has relatively stringent quality standards incomparison to Granular B, which is usually pit-run or other unprocessed aggregate; Granular M is a shouldering andsurface dressing material with quality requirements similar to Granular A; and Select Subgrade Material has similarquality requirements to Granular B and it provides a stable platform for the overlying pavement structure. (For morespecific information the reader is referred to Ontario Provincial Standard Specification OPSS 1010).

Greywacke: A dark grey, indurated, coarse-grained sandstone that consists of poorly sorted, angular to subangulargrains of quartz and feldspar, with a variety of other dark rock and mineral fragments embedded in a compact, clay-rich matrix.

Greenstone: A term applied to any compact, dark green, altered or metamorphosed mafic volcanic or igneous rock(e.g., basalt, gabbro) that owes its colour to the presence of the secondary minerals chlorite, epidote or actinolite.

28


Greenstone belt: An elongate or beltlike region within continental Precambrian shields that is characterized by abundantgreenstone. An individual belt may contain the deformed and metamorphosed rocks of one or more sedimentary-volcanicsequences, within which there is generally a trend from mafic to felsic volcanic rocks.

Heavy Duty Binder: Second layer from the top of a hot-mix asphalt pavement. It is used on heavily travelled (especiallyby trucks) expressways such as Highway 401. Coarse and fine aggregates are to be produced from high-quality bedrockquarries, except when gravel is permitted by special provisions.

Hot-laid (or asphaltic) aggregate: Bituminous cemented aggregates used in the construction of pavements either assurface or bearing course (HL 1, 3 and 4), or as binder course (HL 2, 4 and 8) used to bind the surface course to theunderlying granular base.

Leachate: Soluble constituents from a rock or soil mass that have been removed by the action of percolating water.

Limestone: A carbonate sedimentary rock consisting chiefly of the mineral calcite. It may also contain up to 40% dolomite.

Lithology: The description of rocks on the basis of such characteristics as colour, structure, mineralogic compositionand grain size. Generally, the description of the physical character of a rock.

Los Angeles Abrasion and Impact Test: This test measures the resistance to abrasion and the impact strength ofaggregate. This gives an idea of the breakdown that can be expected to occur when an aggregate is stockpiled, trans-ported and placed. Values less than about 35% indicate potentially satisfactory performance for most concrete andasphalt uses. Values of more than 45% indicate that the aggregate may be susceptible to excessive breakdown duringhandling and placing.

Mafic: Said of an igneous or volcanic rock composed chiefly of one or more dark-coloured, ferromagnesian minerals.

Magnesium Sulphate Soundness Test: This test is designed to simulate the action of freezing and thawing on aggregates.Those aggregates which are susceptible to freezing and thawing will usually break down and give high losses in thistest. Values greater than about 12 to 15% indicate potential problems for concrete and asphalt coarse aggregate.

Medium Duty Binder: Second layer from the top of a hot-mix asphalt pavement. It is used on heavily travelled roads,usually four-lane provincial highways and municipal arterial roads. It may be constructed with high-quality quarriedrock or high-quality gravel with a high percentage of crushed faces, or with polymer-modified asphalt cements.

Meta-arkose: A feldspar-rich sandstone, pinkish or reddish in colour, that has been recrystallized by metamorphism sothat it resembles a granite.

Mill Abrasion Test: In this test, required by the CP Rail Ballast specifications, an aggregate sample is tumbled in a rotatingsteel drum to measure its resistance to self-abrasion and impact damage.

Mine development rock: The material excavated during mining in order to obtain access to ore.

Open Friction Course: An open-graded surface paving course that requires superior quality aggregates. The mix isused in place of Dense Friction Course (DFC) on highways with heavy traffic where low tire noise is required. OpenFriction Course (OFC) is free draining and has good frictional resistance.

Open Graded Drainage Layer: An open-textured permeable course that is covered either by a concrete pavement oran asphaltic binder, and overlies a granular base course. An Open Graded Drainage Layer (OGDL) is used in expresswayconstruction to provide rapid removal of water from the pavement structure into drainage ditches.

Petrographic examination: An aggregate quality test based on known field performance of various rock types. InOntario the test result is a Petrographic Number (PN). The higher the PN, the lower the quality of the aggregate.

Pit run: The unprocessed material obtained from deposits of sand or gravel, talus rock, quarries, slag, mine waste orother suitable granular material.

Plasticity index: The numerical difference between the liquid and plastic limits of a soil, representing the range of moisturecontents at which a soil is plastic. Together with the liquid limit, it gives an indication of the sensitivity of the soil tochanges in moisture conditions.

29


Polished Stone Value: This test measures the frictional properties of aggregates after 6 hours of abrasion and polishingwith an emery abrasive. The higher the PSV, the higher the frictional properties of the aggregate. Values less than 45indicate marginal frictional properties, while values greater than 55 indicate excellent frictional properties.

Porphyry: An igneous rock of any composition that contains conspicuous crystals in a fine-grained groundmass.

Possible resource: Reserve estimates based largely on broad knowledge of the geological character of the deposit andfor which there are few, if any, samples or measurements. The estimates are based on assumed continuity or repetitionfor which there are reasonable geological indications.

Precambrian: The earliest geological period extending from the consolidation of the earth’s crust to the beginning ofthe Cambrian Period (approximately 570 Ma).

Rail ballast: Crushed stone or gravel used to stabilize a railroad bed. Provides a firm base for the rail ties, distributingthe load, holding the track in line, and facilitating drainage.

Riprap: A layer, facing, or protective mound of stone of sound quality and well-graded in size from 75 to 500 mm.

Sandstone: A clastic sedimentary rock consisting chiefly of sand-size particles of quartz and minor amounts of feldspar,cemented together by calcareous minerals (calcite or dolomite) or by silica.

Screenings: Any fine-grained byproduct, including dust, that is generated during the processes of crushing and particle sizing.

Serpentinization: The process of hydrothermal alteration by which magnesium-rich silicate minerals (e.g., olivine,pyroxene and/or amphibole) are converted into or replaced by serpentine minerals.

Shale: A fine-grained, sedimentary rock formed by the consolidation of clay or mud and characterized by well-developedbedding planes, along which the rock breaks readily into thin layers. The term shale is also commonly used for fissileclaystone, siltstone and mudstone.

Slate: A low-grade, regionally metamorphosed clay- and silt-rich rock which has developed a well-marked cleavage buthas undergone little recrystallization, so that the rock is still very fine grained.

Soundness: The ability of the components of an aggregate to withstand the effects of various weathering processes andagents. Unsound rock types are subject to disintegration caused by the expansion of absorbed solutions. This may seriouslyimpair the performance of road-building and construction aggregates.

Syncline: A concave-upward fold containing stratigraphically younger rocks in the core.

Tailings: That portion of milled or washed ore that is regarded as too depleted to be treated further.

Till: Unsorted and unstratified rock debris, deposited directly by glaciers, and ranging in size from clay to large boulders.

Trap rock: Any dark-coloured, fine-grained, non-granitic intrusive or extrusive rock, such as basalt, diabase or fine-grained gabbro, used in road surfacing.

Ultramafic: Said of an igneous or volcanic rock composed of greater than 90% dark-coloured ferromagnesian minerals.

30


31


CONVERSION FACTORS FOR MEASUREMENTS IN ONTARIO GEOLOGICAL SURVEY PUBLICATIONS

Conversion from SI to Imperial Conversion from Imperial to SI

SI Unit Multiplied by Gives Imperial Unit Multiplied by Gives

LENGTH1 mm 0.039 37 inches 1 inch 25.4 mm1 cm 0.393 70 inches 1 inch 2.54 cm1 m 3.280 84 feet 1 foot 0.304 8 m1 m 0.049 709 7 chains 1 chain 20.116 8 m1 km 0.621 371 miles (statute) 1 mile (statute) 1.609 344 km

AREA1 cm2 0.155 square inches 1 square inch 6.451 6 cm2

1 m2 10.763 9 square feet 1 square foot 0.092 903 04 m2

1 km2 0.386 10 square miles 1 square mile 2.589 988 km2

1 ha 2.471 054 acres 1 acre 0.404 658 6 ha

VOLUME1 cm3 0.061 02 cubic inches 1 cubic inch 16.387 064 cm3

1 m3 35.134 7 cubic feet 1 cubic foot 0.028 316 85 m3

1 m3 1.308 0 cubic yards 1 cubic yard 0.764 555 m3

CAPACITY1 L 1.759 755 pints 1 pint 0.568 261 L1 L 0.879 877 quarts 1 quart 1.136 552 L1 L 0.219 969 gallons 1 gallon 4.546 090 L

MASS1 g 0.035 273 96 ounces (avdp) 1 ounce (advp) 28.349 523 g1 g 0.032 150 75 ounces (troy) 1 ounce (troy) 31.103 476 8 g1 kg 2.204 62 pounds (avdp) 1 pound (avdp) 0.453 592 37 kg1 kg 0.001 102 3 tons (short) 1 ton (short) 907.184 74 kg1 t 1.102 311 tons (short) 1 ton (short) 0.907 184 74 t1 kg 0.000 984 21 tons (long) 1 ton (long) 1016.046 908 8 kg1 t 0.984 206 5 tons (long) 1 ton (long) 1.016 046 908 8 t

CONCENTRATION1 g/t 0.029 166 6 ounce(troy)/ 1 ounce(troy)/ 34.285 714 2 g/t

ton(short) ton(short) 1 g/t 0.583 333 33 pennyweights/ 1 pennyweight/ 1.714 285 7 g/t

ton(short) ton(short)

OTHER USEFUL CONVERSION FACTORS

Multiplied by1 ounce(troy) per ton (short) 20.0 pennyweights per ton (short)

1 pennyweight per ton (short) 0.05 ounces (troy) per ton (short)

Note: Conversion factors which are in bold type are exact. The converion factors have been taken from or have been derived from factors given in theMetric Practice Guide for the Canadian Mining and Metallurgical Industries, published by the Mining Association of Canada in co-operation with theCoal Association of Canada.

Metric Conversion Table

32


ISSN 0706-4551ISBN 0-7729-7995-2

industrial mineral resource assessment, mine development rock

Documents