NORTH FORK CLAIMS. Si)!cm north of Ilsrrison Hot Sp5-lgs, 3.c. 50' 121' PW

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1 GEOPHYSICAL/GEOCHEMICAL REPORT ON.? ELECTROMAGNETIC, SELF POTENTIAL Ai'iD SOIL GEOC:iE?;l STRY SURVEYS OVER NORTH FORK CLAIMS NECi rjjestminster MINING DIVISION BRITISH COLUMBIA NORTH FORK CLAIMS Si)!cm north of Ilsrrison Hot Sp5-lgs, 3.c. 50' 121' PW \JR ITTEN FOX SILVEX STANDAX;;) PIINES LTiI Sesc :idstings Street Vancouver, B. C. V6iZ 3V4 3. M. Anderson, Geophysicist GEOTRONICS SURVEYS LTI) Mesic Pender Street Vancouver, B.C., V6C DATED Novernber 9, 1981 Engineering 8 Mining Geophywxts VANCOUVER, CANADA

2 .I I I [l::::, SUMMARY CONCLUSIONS RECOMMENDATIONS i i ii INTRODUCTION PROPERTY AND OWNERSHIP... 2 LOCATION AND ACCESS... 2 GEOLOGY... INSTRUMENTATION AND THEORY... Electromagnetic... Self Potential... FIELD PROCEDURE... RESULTS... 5 Geochemistry... 5 Electromagnetic... 6 Self Potential... 6 SELECTED BIBLIOGRAPHY... 8 GEOPHYSICIST S CERTIFICATE... 9 AFFIDAVIT OF EXPENSES... 10

3 t LIST OF ILLUSTRATIONS FIGURES At Back of Report Location Plan Claim Map FIGURE 1 2 DRAWINGS In Pocket SHEET Copper and Zinc Geochemistry Electromagnetic Profiles Self Potential Profiles

4 i SUMMARY In October, 1981, soil geochemistry (Cu and Zn) and geophysical surveys (horizontal loop EM and self potential) were carried out over part of the North Fork Claims. The surveys were designed to trace the extent of a massive sulphide vein that had been exposed by road construction activities. The geochemistry showed strongly anomalous values in the vicinity of the showing, and isolated anomalies elsewhere. Both geophysical techniques detected a linear anomaly passing through the showing. CONCLUSIONS (1) Both EM and SP appear to be successful in locating the massive vein-type sulphide deposits seen in the road cutting. (2) There is reasonable coincidence of EM and SP anomalies on lines 0+50N, O+OO and 0+50S, considering the resolution obtained from the reading interval. The EM anomaly on the road is slightly more removed from the SP anomaly, however, the former is very weak in comparison and hence its location is not very accurate. (3) The EM results suggest that the lens is steeply dipping. [?ore closely spaced readings would be necessary to obtain a quantitative dip estimate.

5 ii (4) The trend of the geophysical anomalies is NNW-SSE. Although there is a strong geochemical anomaly associated with the showing, the anomaly does not continue to South Road along this trend. The most obvious explanation is that the mineralization is deeper in this area. RECOMMENDATIONS (1) The geophysics suggests that the sulphide vein continues for a strike length of at least 250 m. Diamond drilling is therefore justified to investigate the geometry and mineral content of the vein at depth. A series of angled holes could be drilled from the road to intersect the anomaly revealed on lines 0+50N, O+OO and 0+50S. A further one or two holes should be drilled into the anomaly on South Road. (2) If the drilling proves successful, consideration should be given to carrying out further geophysical work on the property. Infill lines are needed between South Road and line 0+50S, plus lines to the south of the road. Sefore any EM work is commissioned, it is essential that the survey lines be properly cleared, to permit accurate cable distances to be maintained.

6 GEOPHYSICAL/GEOCHEMICAL REPORT 8. ON ELECTROMAGNETIC, SELF POTENTIAL & SOIL GEOCHEMICAL SURVEYS OVER NORTH FORK CLAIMS NEW WESTMINSTER MINING DIVISION BRITISH COLUMBIA 4 ~~ J INTRODUCTION Soil sampling, horizontal loop electromagnetic and self potential surveys were carried out over part of the North Fork Claims, near Harrison Lake, B.C. A road cutting through the claims has exposed a vein of massive sulphide mineralization; the purpose of the geochemical and geophysical work was to trace the extent of this vein and locate any similar occurrences elsewhere on the property. The geochemical work was undertaken by Silver Standard Mines Ltd.; the geophysical surveys were completed by Geotronics Surveys Ltd. during the period October 17th to 24th, 1981 by a two-man crew led by Rolf Krawinkel, geophysicis:.

7 2 PROPERTY AND OWNERSHIP The property is currently leased to Silver Standard Mines Ltd., by the owners, Dale McCallum, Hank Nickel and Don Crowhurst. The claims are as follows: i b Claim Name No. of Units Record No. Expiry Date North Fork July, 1982 North Fork Aug., 1982 LOCATION AND ACCESS The claims lie to the north of the first north fork of Cogburn Creek, on the eastern side of Harrison Lakes. Access is via logging road from Harrison Hot Springs, some 55 km distant. The road continues through part of the claim in a series of switchbacks. At an average elevation of about 1,000 in a.s.l., the steep terrain is covered in hemlock and cedar forest, making access along survey lines difficult. GEOLOGY The property is underlain by steeply dipping metamorphic rocks, probably Palaeozoic in age. These schists and amphibolites may be bounded near the east of the claim boundary by Upper Cretaceous quartz diorite. A 1.2 m wide band of massive sulphides is visible in the greenstone schist along the road in the surveyed area. This showing dips near-vertically and trends 342O, and comprises pyritepyrrhotite with chalcopyrite and minor sphalerite.

8 3 A more complete description of the geology of the claims has been given by Beaton. (1) INSTRUMENTATION AND THEORY Electromagnetic A MaxMin I1 portable two-man electromagnetorneter, manufactured by Apex Parametrics Ltd. of Toronto, was used to try to locate anomalous conducting zones in the sub-surface. The system comprises a transmitter coil and a receiver coil separated by a reference cable of any one of six lengths (25, 50, 100, 150, 200 and 250 m), to permit varying depth penetration of the electromagnetic signal. Further flexibility is achieved by a choice of operating frequencies (222, 444, 888, 1777 and 3555 Hz). For this survey the coils were orientated horizontally, at a separation of 50 m; measurements were taken at all five frequencies. In all induced-field electromagnetic surveying, a transmitter produces an alternating electromagnetic field (called the primary field), by passing a strong current through a coil of wire. The field propagates outwards in all directions and if it encounters a conductive body (e.g. a metallic sulphide body), it induces an electric current, with associated magnetic field. The receiver coil defects and measures the amplitude and phase of the total field, primary plus secondary. This is expressed as an in-phase (or real) component, and an outof-phase (or quadrature) component, both as percentage deviation from what the total field would be in the absence of any conductors. The fields rapidly lose strength with distance from the transmitter, hence a deep conductor has less of an effect than a close one. Better depth penetration is achieved with the lower transmitted frequencies, as the

9 4 signal is attenuated more rapidly the higher the frequency. If a line of EM readings crosses a dipping conductive sheet, the theoretical response in bozh real and quadrature components is a negative trough flanked on both sides by smaller positive peaks. The relative strengths of real and quadrature minima can be used to get a qualitative idea of the conductivity of the causative body. Provided the anomaly curves are well defined, they can be compared with published theoretical curves, to obtain estimates for the depth and dip of the causative body, plus its conductivity-thickness product. I Po I 111 I I Y Self Potential A Micronta Digital Multimeter was used to take measurements of the spontaneous potentfa1 difference between a pair of non-polarizing porous pot electrodes. The self potential effect is believed to be caused by the vertical gradient in Eh (oxidation potential) usually present in the ground. Any strong conductor (e.g. metallic sulphides or graphite), especially if it intersects the water table, will provide a medium for electron transfer from deeper layers to the surface. The current circuit is conpleted by ionic conduction through pore water surrounding the conductor. The surface manifestation of this phenomenon is a negative potential above the conductor; this is generally of the order mv, although higher values have been reported. The overall ground potential pattern may be complicated by the topographic effect (increasing negative values going up-hill), the effect of telluric currents, and contact voltages between pots and ground in different moisture conditions. Nevertheless the presence of sizeable ground potentials is a good indicator ml

10 1 5 of massive deposits of such minerals as pyrite, pyrrhotite, chalcopyrite, chalcocite, covellite, graphite, anthracite, pyrolusite and psilomelane. FIELD PROCEDURE The soil samples were taken by Silver Standard Mines Ltd., and analyzed for Cu and Zn content by Chemex Labs Ltd. I The MaxMin EM survey was carried out along four of the more accessible lines on the property, and along part of the logging road running east from the switchback near the intersection of lines 2+00W and 0+50S. The readings were taken every 25 my with a constant 50 m interval between transmitter and receiver, measured by the reference cable between the two units. While this distance was easy to maintain along the road, the timber, scrub and deadfall along the other lines probably resulted in chainage errors of up to 1.5 m. Dip angle measurements were taken with a hand-held inclinometer to enable the coils to be orientated in the same plane. The EM readings were then made at each of the five instrumental frequencies, 222, 444, 888, 1777 and 3555 Hz. Because of the rough terrain, the SP survey was conducted with a gradient array. The two pots were advanced at a spacing of 25 my along the survey lines, and readings of potential difference taken every 25 m. RESULTS Geochemistry The results of the Cu and Zn geochemistry study, undertaken by Silver Standard Mines Ltd., have been presented on Sheet 1, P

11 6 for comparison with the geophysical results. The main anomalous area coincides with the massive sulphide vein along the road cutting. Other anomalous values were found along South Road. Electromaenetic The EM results are shown on Sheet 2. Two frequencies, one high and one low, were selected for presentation. The data along lines 0+50N, O+OO, 0+50S and l+oos, all through bushland along only partly-cleared lines, will be seen to be much noisier than the results along the road. This effect is almost certainly caused by the difficulty of obtaining the correct separation between transmitter and receiver cotls in thick undergrowth and areas of steep topography. Nevertheless, a significant anomaly can be seen, associated with the sulphide showing; this feature can be traced to the lines on either side, i.e. 0+50N and 0+50S. It shows up more clearly on the higher frequency, 3555 Hz. It is considered that the anomaly curves are not well-enough defined to permit meaningful quantitative analysis, that is curve matching. However, it can be concluded that the causative body is steeply dipping, and has some depth extent. Due to the low noise level in the road data, much smaller amplitude anomalies can be identified, for example at chainage 300 m. No other significant anomalies are apparent elsewhere in the surveyed area. Self Potential The SP results are shown on Sheet 3. As with the EM, the road traverse is much quieter, presumably due to tne more variable grounding conditions for the pots along the bush lines. A

12 7 Q pronounced anomaly is associated with the showing, and a similar anomalous feature is seen on lines 0+50N, 0+50S and on the road line where it is particularly strong. There are some isolated anomalies on other lines, however they cannot be easily traced to adjacent lines. For ease of reference the interpreted SP and EM anoinalies have been plotted on the Copper Geochemistry results (Sheet 1). Respectfully submitted, eophysicist

13 8 SELECTED BIBLIOGRAPHY (1) Beaton, R.H. Property Examination for North Fork Claim. Silver Standard Nines Ltd., 1981 (2) Ketola, M., and Puranen, M. Type Curves for the Intermetation of Slingram (horizontal 100~) Anomalies over Tabular 3odies. Geological Survey of Finland 1967

14 GEOPHYSICIST'S CERTIFICATE m rir L m I r J I I in the Province of British Columbia, do hereby certify: That I am a Consulting Geophysicist of Geotronics Surveys Ltd., with offices at # West Pender Street, Vancouver, Sritish Columbia. I further certify: 1. That I am a graduate of the University of Tasmania (1971), and hold a B.Sc. degree in Geophysics. 2. That I have been praceising my profession for the past ten years. 3. This report is compiled from geochemical data obtained by Silver Standard Mines Ltd., and geophysical data taken by Rolf Krawinkel, Geophysicist in October, I have no direct or indirect interest in Che North Fork Claims, nor in Silver Standard Mines Ltd., nor do I expect to receive any interest as a result of writing this report. <y*. M. Anderson

15 10 AFFIDAVIT OF EXPENSES This is to certify that MaxMin EM and Self Potential surveys were carried out on the North Fork Claims from October 17th to October 24th, 1981 to the value of the following: FIELD: 2 Geophysical technicians, 70 hours at $40/hour Room and board, 8 days at $90/day 4-Wheel drive truck rental and gas, 9 days at $80/day Survey supplies Instrument rentals $2, , OFFICE: Geophysicist, 24.5 hours at $40/hour Geophysical technician, 22 hours at $25/hour Drafting and printing Typing, photocopying and compilation $ ,306.OO TOTAL $6, Respectfully submitted, Manager November 9, 1981

16 r.. TO ACCOMPANY REPORT BY J.M. ANDERSON,Geophysicist. GEOTRONICS SURVEYS LTD SILVER STANDARD MINES LTD. NORTH FORK CLAIMS NEW WESTMINSTER MD, B.C HORIZON TAL LOOP L CTROMAGN TlC SURVEY AND SP SURVEY LOCA TlON PLAN SCALE JOB No FIGURE ALTAIR drafflng services Itd

17 SURVEY / AREA 1 ir n I NOR% FORK l8l a mi II 49O 30' HA RRI SON LAKE I \ TO ACCOMPANY REPORT BY J M ANDERSON,Geophyslclst GEOTRONICS SURVEYS LTD SILVER STANDARD MINES LTD. NORTH FORK CLAIMS NEW WESTMINSTER MD, BC HORIZONTAL LOOP ELECTROMAGNENC SURVEY AND SP SURVEY CLAIM MAP SCALE DATE JOB No FIGURE 150,000 NOV

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