GEOL GCHEM & GEOPH RPT ON THE BROWN MCDADE · PDF file In 1983, Hollinger Argus Limited...

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Transcript of GEOL GCHEM & GEOPH RPT ON THE BROWN MCDADE · PDF file In 1983, Hollinger Argus Limited...

  • DENTON 010





    JUM -

    Submitted by,

    R.A. Archer Project Geologist May, 1987

  • 42Aesseei32 2.i ei ea DENTON


    Introduction Property Location, Access and Description Recorded Holder Submitting Party Acknowledgements Previous Work Regional Geology Lithogeochemistry and Property Geology Electromagnetic Survey Discussion References




    2 2 2 3 4 6 8

    11 12 13


    1. List of Claims - Brown McDade Project


    1. Property Location Map 2. Topography of Claim No. P.568473 3. Geological Compilation of Brown-McDade Option 4. Electromagnetic Profiles for 444 Hz Frequency 5. Electromagnetic Profiles for 1777 Hz Frequency

    2. 3.


    Assay Results of Hollinger-Argus Drilling Program - 1983 Lithogeochemical Results of Newmont Sampling - 1986 Invoices for Assaying Expenditures, & Geotechnical Data Statement


    In October, 1986, Newmont Mines Limited entered into an

    agreement with Brown-McDade Resources Ltd. to option the

    latter's 12-claim property in Denton Twp ., 30 km

    southwest of Timmins, Ontario.

    The property is located in the western Abitibi Belt and

    is underlain by mafic and felsic metavolcanics intruded

    by a granodiorite body. Gold mineralization occurs at

    the contact between the intrusive and the basalts and is

    associated with pyrrhotite in quartz veins within zones

    of intense carbonatization, sodium depletion and

    potassium enrichment . Approximately 1000 tons of this

    material grading O .14 oz Au/ton was mined by Brown-

    McDade in 1982. Eleven of the twelve claims have 200

    days assessment credit and one (P .554599) has been

    brought to lease. The twelfth claim, however, (P.568473)

    requires 100 days to bring it up to the 200 day maximum.

    In September of 1986, Newmont conducted a program of

    lithogeochemical sampling of outcrops and older diamond

    drill core to aid in the interpretation of the property

    geology. In addition, a horizontal loop electromagnetic

    survey was carried out on claim no . P .568473 for

    assessment credits . The results of these surveys and

    the subsequent geological interpretation are discussed

    herein, with specific reference to claim number


  • -2-


    The Brown-McDade Option consists of 12 contiguous claims

    located in the northwest quarter of Denton Township,

    about 30 kilometres southwest of the City of Timmins

    (Fig. 1, Table 1). The property straddles Highway 101

    and is further accessed by several logging roads and an

    all-weather gravel road. One of the claims, P.554599*

    has been brought to lease and ten others have 200 days

    assessment credit. Claim no. P.568473 has only 100 days

    assessment credit, however, and is the subject of this


    There is approximately 10# outcrop on the property as-

    indicated in Fig . 3 . The remainder of the area is

    overlain by a thin sheet of glacial debris and surficial

    vegetation . The latter consists mainly of spruce,

    poplar and jackpine with alders, cedar and some tamarack

    near Cripple Creek (Fig's. 2 A 3).


    The recorded holder of the claims is Newmont Mines

    Limited, Suite 900, 808 West Hastings Street, Vancouver,



  • -3-

    The submitting party is Newmont Exploration of Canada

    Ltd., 637 Algonquin Blvd. East, Timmins, Ont., license

    number A37767 . All work described herein was done by

    Newmont personnel or by companies contracted by Newmont.

    The submitting author was directly involved in the

    program and takes full responsibility for this report.


    Guy Thibault Exploration Services of Timmins carried out

    both the linecutting and the Max-Min II electromagnetic

    survey on claim no. P.568473* including drafting of the

    profiles. Lithogeochemical sampling was conducted by the

    author and R . Norman of Shear Exploration Ltd . The

    interpretation of geology and geophysics was carried out

    by the author. Rock samples were analysed by Technical

    Service Laboratories of Toronto.


    Gold was first discovered on what is now the Brown-

    McDade claim group in 1910 (Harding and Berry, 1938) .

    Two small shafts were sunk on the showings and, in 1935,

    several diamond drill holes were completed with

    apparently erratic results.

    In 1945, twelve diamond drill holes, totalling 4,250

    feet, were completed by Wakemac Denton Gold Mines Ltd.

    to test two shear zones trending north 70 east about 200

    and 400 metres south of the southwest block of the

    Brown-McDade property. Weak gold mineralization (up to

    0.17 oz/ton- over 2.8 feet) associated with arsenopyrite

    in quartz-carbonate stringers was intersected in the

    northernmost shear, however, no significant assays were

    obtained from the southern structure. The last of the

    twelve holes was drilled north of the shear zones on

    what is now claim no. P.554601 of the Brown-McDade group

    and was designed to test the continuity of a surface

    showing which assayed 0.19 oz Au/ton in a grab sample,

    While a few specks of visible gold were noted in a half-

    inch wide quartz stringer, this section was excluded

    from assaying and all other core samples assayed nil .

    No further work was recorded in the area until Brown-

    McDade Mines Ltd . staked the present claim group in

    1979-80. Subsequent linecutting, magnetic and V .L .P.

    surveys were carried out followed by power stripping and

  • -5-

    plugger work on claim nos . P .554599 and P.567640 and

    diamond drilling on claim no. P.554599- All field work

    was performed by J-Dex Mining and Exploration Ltd . on

    behalf of Brown-McDade. The drilling consisted of 422.5

    feet in 8 holes and was designed to test a zone of gold

    mineralization associated with pyrrhotite in

    carbonatized basalts at the contact with a granitic

    intrusion. Approximately 1000 tons of ore grading 0.14

    oz Au/ton were subsequently mined from two pits at this

    location in the summer of 1982.

    In 1983, Hollinger Argus Limited optioned eleven of the

    Brown-McDade claims and carried out geological,

    magnetic, electromagnetic, and limited induced

    polarization surveys . Sixteen diamond drill holes

    totalling 3965 feet were drilled by Hollinger in late

    1983 and early 1984 to test several targets outlined by

    the ground surveys and to determine the extent of the

    known gold mineralization . Several holes intersected

    ore grade gold values, the best being a 17 foot section

    assaying 0.146 oz Au/ton, however, an apparent lack of

    continuity was sufficient reason for Hollinger to

    terminate their option at this time. A complete list of

    all core assays greater than 0.01 oz Au/ton is given as

    Appendix 1.


    The property lies at the western end of the Abitibi

    greenstone belt near the Timmins gold camp. The regional

    geology of the Timmins area is well documented and is

    described by Pyke (1982) to consist predominantly of two

    major cycles of Archean volcanic rocks unconformably

    overlain by a thick sequence of epiclastic sediments,

    all of which are complexly folded, faulted and cut by

    younger diabase dykes.

    The oldest of the volcanic cycles, the Deloro Group, is

    composed predominantly of calc-alkaline basalt and

    andesite near the base with dacitic to rhyolitic flows

    and pyroclastics in the upper part, locally capped by

    iron formation . The younger Tisdale Group consists of

    ultramafic flows and basaltic komatiites overlain by a

    thick sequence of tholeiitic basalts. These are in turn

    overlain by volcaniclastic calc-alkaline dacites.

    The Porcupine Group metasediments are largely turbiditic

    in nature with conglomerates common near the base of the

    sequence. They are locally observed to lie unconformably

    on top of the Tisdale and Deloro Group volcanics and are

    proposed by Pyke to be contemporaneous with the Tisdale


    A few, small felsic porphyries intrude the Tisdale Group

    rocks and may be synvolcanic in origin . These are

    spatially, ' and possibly temporally, related to gold

  • -7-

    mineralization at the Hollinger, Mcintyre and Dome

    Mines, the three largest gold producers in the Timmins

    c amp.

    All rock types are cut by north-south trending diabase

    dykes of Matachewan age.

    The structure of the Timmins area is complex and the

    number and sequence of deformational phases is unclear.

    Possibly the best known structural feature is the