5873 INDUCED POLAKIZATION SURVEY OVER THE BROOKS PROSPECT BROOKS PENINSULA AREA VANCOUVER ISLAND, B.C. NANAIMO AND ALBERNI MINING DIVISIONS BY Z. B. DOBORZYNSKI JANUARY, 1976 Department of Miner and Petroleum Resources ASSESSMENT REPORT t+o...&zz!. MAP.,-
c TABLE OF CONTENTS SUMMARY AND CONCLUSIONS 1 REASON FOR SURVEY 2 LOCATION AND ACCESS EQUIPMENT AND PROCEDURE RESULTS %, CONCLUSIONS
LIST OF ILLUSTRATIONS "' 1. Location Map of Brooks Prospect fj, 2. Claims Surveyed i,; 3. Dipole-Dipole Array & ''1 4. Pseudo Section - Line 28+00S., 0, 5. Pseudo Section - Line 32+00S *' 6. Pseudo Section - Line 36+00S 4 >' 7. Map (In Pocket) - Plan of Induced Polarization Survey # c 8. Location Map - No. 14 dated Jan. 1976
SUMMARY AND CONCLUSIONS A variable frequency induced polarization survey was carried out over a claim group southwest of Port Alice on Vancouver Island. One weak response was identified from the survey area. The cause may be an increase in fracturing of the rock. There are no indi- cations of concentrations of disseminated sulphide mineralization in 7 % excess of 2% in the survey area.
- 2 - REASON FOR SURVEY The Brooks prospect is being explored for porphyry copper mineralization. Three lines were surveyed with induced polarization to locate the copper mineralization or the pyrite halo believed to surround it. LOCATION AND ACCESS The property is located about eleven miles southwest of the village of Port Alice on Vancouver Island (Fig. 1). The claims (Fig. 2) 7 s straddle the rounded ridge separating the Little Klaskish river drainage to the north and the Nesparti River. Access to the property is by helicopter, either from the end of the road at Port Alice or from the helicopter charter base at Port Hardy, about 30 miles to the northwest. EQUIPMENT AND PROCEDURE A McPhar P670 variable frequency induced polarization unit was used. The maximum output of the transmitter was 2.5 KW at two frequen- cies: 0.3 and 5.0 Hz. The ground was energized by a pair of stainless steel electrodes, a distance of 200 feet apart. The resulting ground voltages were measured between a second pair of electrodes also 200 feet apart, and an integer number (n) times the electrode separation from the current electrodes. The electrode configuration is called the dipole-
i -3 3! 8
- 5 - dipole array and is illustrated in Fig. 3. The quantities recorded are the apparent resistivity at 0.3 Hz. (Pa/2'ii in ohm-meters) and the Frequency Effect (PFE), which is the percentage change in the resistivities at the two frequencies. Since the degree of polarization is related to the apparent resistivity, it is found that the Metal Factor (MF) is a useful parameter in determining the amount of polarization in a rock mass. This value is obtained by dividing the PFE by the corresponding apparent resistivity at 0.3 Hz. Measurements were taken for 4 values of (n) = 1, 2, 3 and 4, 7 s thereby increasing, in steps, the volume of rock sampled. The data are presented in a pseudo depth section format, illustrated in Fig. 3. It should be noted that the separation between the current and potential electrodes is only factor determining the depth of sampling. Therefore these plots are not true vertical sections of the electrical properties of rock below the survey line. The results are presented at a scale of 1" = 200' in pseudo sections (Figs. 4, 5 and 6) and plan view (Map 1). RESULTS A number of low resistivity zones were detected. Many of these may be caused by topography and/or changes in the level of the water table.
1,2-5,6-6 - c METHOO USED IN PLOTTING DIPOLE-DIPOLE INDUCE0 POLARIZATION AND RESISTIVITY RESULTS I 2 3 I I I 1 1 4 5 6 7 0 9 Stations on line x = Electrode spread length n = Electrode separation n - 4 P P P I,2-6,7. 2,3-7,8 3,4-8,9 n - 3 P P P P 1,2-5,6 2,3-6.7 3.4-7,8 4,5-8.9 Apparent Resistivity P P P P P n - 2 1,2-4,5 2,3-5,6 3,4-6,7 4,5-7,8 5,6-8,9 P P P P P P n - J L I a 9 \ / \ / \ / \ / \ / \ ' M.E M.F. M. F. M.E M.F. M. F n - l 1,2-3,4 23-43 3,4-5,6 4,5-6,? 5,6-7,8 6.7-8.9 M. F. M.F. M. F. M.F. M.F. n-2 1,2-4,5 22-5,6 3,4-6,7 4,5-7,0 5,6-8,9 M.E M.F M. F. M. F n - 3 ~ n - 4 1,2-6,7 2,3-7,8 3,4-8,9 2,3-6,7 3,4-7,8 4,5-8,9 Apparent Metal Factor M. F. M. F. M. E t I a 9 n - l I,2-3,4 2.3-4,s 3,4-5,6 4,5-6,7 5,6-7,8 6,7-8,9 F. E. F, E. F. L F.E. F. E. n - 2-1,Z-4,5 2.3-5,6 3,4-6,7 4,5-7,8 5,6-8,9 F. E. F. E. F.E. F. E. n - 3 1,2-5,6 2,3-6,7 3,4-7,8 42-8,9 Apparent Percent F. E. F. E. F. E. Frequency Effect n - 4 1,2-6,7 2,3-7,0 3.4-8.9
- 7 - The drop in resistivity with depth on line 32+00S between 3+00E and lwooe is more regular in response and may be related to an increase in fracturing. CONCLUSIONS The induced polarization survey did not delineate any zones which can be attributed to concentrations of sulphide mineralization in excess of 2%. The lower resistances with depth on line 32+00S between 3+00E and IWOOE may be caused by an increase in fracturing. Z.B. Doborzynski Geophysicist
ASSESSMENT DETAILS PROPERTY Brooks Prospect - Lois Claim Group MINING DIVISION Nanaimo and Alberni LOCATION Port Alice, Vancouver Island, B.C. TYPE OF SURVEY Induced Polarization DATE STARTED July 24, 1975 7 1 DATE FINISHED August 7, 1975 OPERATING MAN DAYS 90 DRAUGHTING MAN DAYS 2 CONSULTING MAN DAYS 2 FIELD TECHNICIANS G. Dunn $ 50/day F. Shulist $ 50/day HELPERS R. Marguordt D. Bawol G. Wilson R. Simmons CONSULTANT 2. Doborzynski $150/day
_---------- CERTIFICATE I, Zbigniew B. Doborzynski, of the City of Toronto, in the Province of Ontario, hereby certify: 1. I am a geophysicist with a business address at 1235 Bay St., Toronto, Ontario. - 3 2. 3. 4. 5. I have been ernployed as a geophysicist for 2 years. I am a graduate of McGill University with a B. Eng. (1971) in Mining Engineering and Applied Geophysics and an M. Sc. (1974) in Applied Geophysics. I am an associate member of the Society of Exploration Geophysicist. The statements made in this report are based on a study of unpublished geological reports. @+@A Z.B. Doborzynski Dated - February 4, 1976
~~ COST STATEMENT FOR INDUCED POLARIZATION SURVEY LOIS 1-36 MINERAL CLAIMS VANCOUVER ISLAND, B.C. NANAIMO & ALBERNI MINING DIVISIONS Dane A. Bridge June, 1976 Department of Miner and Petroleum Resources ASSESSMENT REPORT
INTRODUCTION This cost statement for assessment work is to accompany a report titled: Induced Polarization Survey over the Brooks Penninsula Area, Vancouver Island, B.C., Nanaimo and Alberni Mining Divisions, by Z. B. Doborzynski, January, 1975. COST STATEMENT?I The following statement of costs applies to an Induced Polarization survey conducted on the Lois 1-36 mineral claims during the period July 24, 1975 and August 7, 1975. Labour G. Dunn (Technologist) July 24-Aug. 7/75 15 days @ $50/day $750.00 F. Schulist (Geophysical Operator) July 24-Aug. 7/75 15 days @ $5O/day 750.00 R. Somerville (P.Eng. Supervisor) July 25-Aug. 7/75 15 days (3 $96/day 1,440.00 R. Symons (Assistant-First Aid Attendant) July 24-Aug. 7/75 15 days @ $44/day 660.00 G. Wilson (Assistant) July 24-Aug. 7/75 15 days @ $3l/day 465.00
Cost Statement 2. Labour (cont'd.) D. Bawal (Assistant) July 24-Aug. 7/75 @ $3l/day 15 days $465.OO R. Marquardt (Assistant) July 24-Aug. 7/75 15 days @ $3l/day 465.00 Z. Doborzynski (Consultant Geophysicist) Jan. and Feb. /I6 4 days @ $150/day 600.00 Subtotal - Labour $ 5,595.00 Camp Costs Cost to erect camp (applicable to I.P. survey) 285.50 Food, lodging, hardware, misc. supplies and equipment, misc. ground transportation. 7 men x 15 days at average cost $20.20 2,121.00 Subtotal - Camp Costs 2.406.50 Technical Expenses Rental of I.P. Instrument McPhar Instrument Corp. 700.00 Repairs to I.P. Instrument McPhar Instrument Corp. 275-04 Subtotal - Technical Expenses 975.04 Services Contract Line cutting Darma Explorations Ltd. Invoice July 15, 1975 3,000.00 Misc: B.C. Tel,Reproduction,etc. 30.08 Subtotal - Services 3,030.08
Cost Statement 3. Transpo rat ion Air Fares - Vancouver to Pt.Hardy and return via PWA Air Freight via PWA Helicopter Support Van. Is. Helicopters 8.7 hrs. @ $292.50/hr $456-66 330-51 2,544.75 Miscellaneous Subtotal - Transportation $ 3,331.92 Office and Secretarial Costs 1 day @ $50 50.00 $ 50.00 TOTAL COSTS $15,388.54 I' I certify that the above costs are correct to the best of my knowledge. D. Bridge
STATEMENT OF QUALIFICATIONS I, Dane A. Bridge, of West Vancouver, British Columbia, hereby certify the following qualifications: (a) I obtained a B.Sc. Hons., in 1969, and a M.Sc., in 1972, in geology from the University of Manitoba, Winnipeg, Manitoba (b) I have been practising my profession as a geologist in Canada for seven years.,dane A. Bridge Geologist Imperial Oil Limited