31M04SW0I86 63.1724 STRATHY010

REPORT GS VERTICAL MAGNETIC INTENSITY. ELECTROMAGNETIC AND GEOLOGICAL SURVETS OF THE KEEVIL CONSULTANTS LIMITED DORIS LAKE CLAIMS. STRATH! TOWNSHIP DISTRICT OF NIPISSING.______ONTARIO

INTRODUCTION

The initial tailings basin for the Sherman Mine at Timagami

will inundate portions of several claim groups adjacent to the eastern

half of Vermilion Lake. One of these groups is not controlled by

Cliffs of Canada, and the recorded holders do not want flooding to

occur until the mineral potential of the claims is ascertained.

Accordingly, during parts of March, April and May, 1965, three sep

arate magnetic, electromagnetic and geological surveys were carried

out to assess the possibility of mineral occurrences.

PROPERTY

The property consists of a group of six unpatented mining

claims in the Timiskaming Mining Division, numbered as follows:

T-52187 (1)T-52190 - 91 inclusive ( 2)T-53814 - 16 inclusive (3)

These claims are recorded in the name of T. G. Robinson,

of North Bay, who holds them in trust for Keevil Consultants Limited,

a member of Keevil Mining Group Limited.

LOCATION AND ACCESS

The claims are located in Strathy Township adjacent to the

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northeast end of Vermilion Lake, and north of it. Th* group lies

about 3Jj miles WNW of the village of Timagand, which is 65 miles

north of North Bay.

Easiest access is by float equipped aircraft from Timagand,

landing on Vermilion Lake. The trip takes less than five minutes.

A canoe route leads north from Lake Timagand via Turtle and Tetapaga

Lakes. A bush road westward from Goward, three miles north of

Timagand, passes close to the northwest corner of the group.

PREVIOUS WORK

Considerable trenching and test pitting was done in the

past. One diamond drill hole was found on claim T-52191. It is

located 300 feet south of baseline "B" and 20 feet east of cross

line 8400W (see plan SM-86c). The hole had apparently been drilled

northward. Some core remained at the site and sections containing

pyrite and pyrrhotite (apparently barren) were noted. During the

summer of 1964, self-potential and geological surveys of claims

T-52187, T-52190 and T-52191 were carried out by Geophysical

Engineering and Surveys Limited for Keevil Consultants Limited.

This work was submitted for assessment credit on September 16, 1964

and subsequently approved. The credit consisted of 43 assessment

days geophysical and 40 assessment days geological per claim, for

a total of 166 assessment days.

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TOPOGRAPHY

Doris Lake is about 55 feet above the level of Vermilion

Lake. Hills rise immediately west and south of Doris Lake to heights

of 115 and 150 feet respectively above Vermilion Lake. The highest

hill is on claim T-52191.

In general, the high ground contains numerous outcrops.

Overburden is shallow, but deepens where swampy ground occurs on

the west side of Doris Lake.

LINE CUTTING AND CHAINING

The line cutting and chaining on claims T-53814 - 16 inclus

ive was contracted to Simpson and Taylor, Ontario Land Surveyors, of

North Bay. A total of 7.25 miles of line, including baselines, were

cut with the cross lines at 200 foot intervals.

The two baselines already established on claims T-5218?

and T-52191 were extended westerly. The "A*1 or notfcbern baseline

was extended approximately 1,200 feet to cross claim T-53814, while

the WB" or southern line was lengthened 2,800 feet to cross claims

T-53815 and T-53816.

THE SURVEYS

The procedure and pertinent data of the three surveys are

described under separate headings. However, for clarity and conven

ience, the discussion and summary of all results are compiled under

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a common heading.

1) Magnetic Survey - The field work was carried out on March 8-10,

17-20 inclusive, 1965. The instrument used was Jalander No. 5768,

a fluxgate magnetometer measuring the vertical component of the

earth's magnetic field. The sensitivity is 10 gammas per scale

division. A total of 10.5 miles of line were traversed and 688

stations were occupied. Readings were normally taken at 100 foot

intervals but the distance was decreased to 50 feet where anomalous

conditions were encountered. The results of the survey are plotted

on map No. SM-S6A. The values are given in gammas. Assessment data

for the survey will be found in the Appendix.

2) Electromagnetic Survey - The field work was carried out on

March 31 and April 1-6 inclusive, 1965. Again all the claims were

covered by the survey and 10.5 miles of line were traversed with a

total of 748 readings recorded. In gffect, continuous readings were

made possible by observing the instrument scale while moving along

the picket lines. This is an innovation, since the survey was ac

complished using a very portable, light-weight instrument, the re

cently developed Ronka E.M.15. This instrument is very satisfactory

for light overburden. It has a maximum depth penetration of 30 feet,

sufficient for even the heavier overburden marsh area at Doris Lake.

The transmitter has an operating frequency of 16,000 cycles

per second. Both transmitter and receiver coils are tilted at 35

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from the vertical. A slightly different measuring system must be

used since neither dip angle nor in-phase, out-of-phase readings

are entirely applicable. The secondary signals from the series-

tuned receiving coil are amplified and fed to a syncronous detec

tor. The detector output, in fractions of milliamps, is read on

a centre-zero meter calibrated - 10 divisions. The sensitivity

is such that a secondary field of about 30 parts per million of

the primary field at the receiving coil, if parallel with the

receiving coil axis and in-phase with the primary field, will

give one small division deflection on the output indicator. De

flections indicate the magnitude of magnetic intensity of the

distorted primary field.

Signal components in parallel to the coll axis, opposite

in-phase to the primary field (1800 phase shift) are indicated

towards the red scale of the meter (-) to indicate a conductive

object. A magnetic non-conductive object is indicated on the blue

scale C+) in similar circumstances. The survey results are plotted

on map No. SM-86B. The information is presented as profiles along

the picket lines. The positive peaks are interpreted as represent

ing a zone of magnetic permeability; negative peaks indicate con

ductive zones. The profiles were corrected for slight temperature

effects. The readings are given in parts per million or fractions

of milliamperes. Assessment data for the survey will be found in

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the Appendix.

3) Geological Survey - The following is a report on the geologic

mapping on the portion of the property not previously mapped by

Keevil Consultants Limited. The area is included in claims No.

T-53814, T-53815 and T-53816. The field work was carried out on

May 20-26, 1965.

PREVIOUS MAPPING

The area was included in the geological mapping by

W. W. Moorhouse, reported in O.D.M. Annual Report Vol. 51* part

6 (1942). As previously mentioned, three claims of the group,

T-52187, T-52190 and T-52191, had been mapped in detail during

1964.

GENERAL GEOLOGY

TABLE OF FORMATIONS

- Precambrian

Keewatin: - Rhyolite, acid agglomerates,carbonate and sericite schists.

- Andesite, tuff.- Basalt, tuff.

- - - - - intrusive contact - - - - -

Keweenawan:- Olivine diabase dikes.

- Quaternary

Pleistocene: Boulder-gravel overburden with a thin Recent layer of sand, gravel and peat.

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GEOLOGY

The Keewatin volcanics in the area are chiefly acidic

excepting in the northwest corners of claims T-53814 and T-53816

where andesites are present.

In general the acidic volcanics are made up of rhyolitic

flows and carbonate and sericite schists. This member varies from

massive lava type to pyroclastic and is not uniform in composition.

The degree of dynamic metamorphism greatly affects the lithology.

The rhyolite where massive exhibits a rusty weathered

surface but is quite resistant to weathering. Where it has been

sheared, however, the rhyolite has been deeply weathered. On the

accompanying map (SM-86c) the massive and lightly sheared rhyolites

are shown separately, but the highly sheared and/or altered rhyolites

are shewn as part of the schistose volcanics. The rhyolite is any

where from grey to greenish in colour and sometimes tends to be

slightly porphyritic with quartz being the phenocrysts.

Carbonate and sericite schists form the larger part of

the volcanic complex. They are principally highly altered rhyolite.

In places the schist contains blocks of massive relatively unaltered

rhyolite and these occurrences have been mapped as rhyolite breccia.

In places the altered flows are interbedded with agglomerate. The

schist is generally deeply weathered and very rusty, and varies in

colour from a very light brown to a dark grey.

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The basis volcanics, andesite and basalt, are massive,

fine-grained and in places tuffaceous.

The Keweenawan olivine diabase occurs as two roughly

parallel dikes which strike approximately NSO0^ and dip very

steeply towards the south. Their contacts are irregular and have

the characteristic chilled zone. The diabase away from the con

tact is coarser-grained, lighter in colour and more magnetic than

the chilled zone.

Near the diabase contact the volcanics are usually darker

in colour due to a "baked" contact.

STRUCTURE

The only structural feature noted during the field mapping,

other than some jointing in the diabase, is the shearing. It strikes

just south of west, dipping steeply to the south.

MINERALIZATION

Sulfide mineralization occurs sporadically throughout the

volcanics in the form of dissemination of pyrite. This was the only

type of sulfide noted. Mineralization is somewhat more concentrated

at or near the diabase contacts. The best occurrence noted is 200

feet north of baseline "B" on line 0+00 where the sulfides accounted

for less than 1^ of the host volcanics.

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RESUETS OF THE SURVEY

CORRELATION AND DISCUSSION OF THE GEOPHYSICS AND GEOLOGY

The magnetic survey indicated two parallel anomalous

magnetic lows trending about west by northwest across the property

and approximately 900 feet apart. The southern anomaly crosses

claims T-53815 and T-53816, while the northern anomaly crosses

claims T-52191 and T-53814. The electromagnetic survey indicated

the same two parallel anomalies and showed them to be zones of

greater permeability. It was suspected that these anomalies are

caused by the diabase dikes as shown on Moorhouse 1 s map No, 51e,

and the geological survey showed this assumption to be true.

The weak magnetic anomaly in the southeast corner of

claim T-52191 is probably due to the narrow iron formation mention

ed by Moorhouse in his report.

There are a few indications of minor conductors within

the anomalous zones where small negative depressions occur in the

electromagnetic profiles. The most interesting occur on lines

16+OOW, 0400 and 2+OOW, baseline "B" at the south arm of Doris Lake,

and indicate a conductive zone possibly up to 500 feet long. The

geology suggests that this is caused by water-filled fractures with

in the diabase dike, caused by the presence of the lake.

Other scattered conductor indications are observed on

line 10400W, claim T-52191; on line 6+OOW, claims T-53814 and T-53815;

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en line 1OKXM, claim T-53814; on line 24"KX)W, claim T-53816.

Since the indications follow the strikes of the diabase dikes,

they are probably caused by structural irregularities in those

dikes rather than sulfide concentrations.

The scarcity of outcrop in the most western part of

claim T-53816 frustrated attempts to discover the reason for the

split in the geophysical anomaly, but it is probably due to a

branching of the diabase dike.

CONCLUSION

From the extensive trenching done in previous years it

would appear that the area has been well prospected for mineral

occurrences. The main geophysical anomalies represent the diabase

dikes. No metalliferous mineralization, other than the scattered

pyrites, was encountered during the mapping. These observations

indicate that there are no zones large enough to be of economic

value.

Respectfully submitted,

Port Arthur, Ontario August 5, 1965

LEGEND a SYMBOLS T. 5381

KEEWATIN ACIDIC SCHISTS AND AGGLOMERATE a A GGLOMERATE b R HYOLITE BRECCIA h A LTERED RHYOLITE 5 CARBONATE AND SERICITE SCHIST

MAINLY MASSIVE, GREY TO GREENISH RHYOLITE

ANDESITE t T UFF

BASALT t T UFF

KEWEENAWAN OLIVINE DIABASE

T. 52403T. 52186

T. 52190

STRIKE AND DIP OF SCHISTOSITY

DORISSTRIKE AND DIP OF OBSERVED CONTACT

SULFIDE MINERALIZATION (PRINCIPALLY PYRITE)

52191\ \

ASSUMED GEOLOGIC BOUNDARY

W.D. 267ASSUMED GEOLOGIC BOUNDARY FROM GEOPHYSICS

T. 53816

CLIFFS OF CANADA LIMITEDPORT ARTHUR. ONTARIO

KEEVIL GROUPVERMILIONT. RT. 4621 CLAIMS

GEOLOGYDATA FROM MAY 1965 FIELD

WORK BY E.GROOTENBOER. DATE MAY 31, 1965

DRAWING NO. SM - 86 CSCALE : l = 200

31M04SWOie6 63.1724 STRATHY 200

T. 52403NOTES 1. (O INSTRUMENT USED. JALANDER NO. 5 768

T. 52186(2) READINGS SHOWN ARE THE CONVERTED

INSTRUMENT VALUES, CORRECTED FOR

DIURNAL VARIATIONS, IN GAMMAS. T. 53811(3) DATA FROM MARCH 1965 FIELD WORK.

T. 52190

T. 52\I87

DORIS

W.D 267

T. 5 \38I6 \.."

CLIFFS OF CANADA LIMITEDPORT ARTHUR, ONTARIO

KEEVIL GROUPT. R.T. 4621 VERMILION

CLAIMS

DATE : APRIL 14, 1965MAGNETIC SURVEYSCALE: i" s 200'CONT. INT. 1OOO GAMMAS

63. I724 STRATHY

NOTES; to INSTRUMENT USED: RONKA E.M.IS.

(2) DATA FROM APRIL 1965 FIELD WORK.

(3) THE PROFILES HAVE BEEN CORRECTED FOR SLIGHT TEMPERATURE VARIATIONS

AND ARE PLOTTED FROM AN ESTIMATED, COMMON GRAPHIC BASE, I.E. THE

LINE OF TRAVERSE IS GRAPHIC ZERO. THE CORRECTED READINGS SHOWN ARE

THEREFORE INSTRUMENT SCALE DIVISIONS OF POSITIVE OR NEGATIVE CHANGE,

A POSITIVE CHANGE (PROFILE PEAK) INDICATING GREATER PERMEABILITY AND

VICE VERSA GREATER CONDUCTIVITY.

INSTRUMENT SCALE DIVISIONS REPRESENT FRACTIONS OF MlLLIAtdPS.

14) VERT. SCALE PROFILES IS l" - 20 INSTRUMENT SCALE DIVISIONS.

T. 52403T. 5 Z l 8 6

5 3 811

t! - Ha

•'T. 52190T. 5 a\l 8 7

T.\ 53814\ \ i.f \

W.D. 267

T. 5 \3 8 l 6 T. 5 381

REVISIONS

DATE i BYCLIFFS OF CANADA LIMITEDPORT ARTHUR, ONTARIO

KEEVIL GROUPT. RT. 4621 VERMILION

CLAIMSDATE ftPRlL 15, 1965ELECTROMAGNETIC SURVEYDRAWING NO. SM-86 BSCALE: l = 200

31M045W0106 63.1724 STRATHY 220