Summary Interpretation Report of Low Power

GM 53358 SUMMARY INTERPRETATION REPORT OF LOW POWER BOREHOLE TRANSIENT EM SURVEYS, CHIBOUGAMAU 11-1119 PROJECT SUMMARY INTERPRETATION REPORT of LOW POWER BOREHOLE TRANSIENT EM SURVEYS over the CHIBOUGAMAU 11-1119 PROJECT near CHIBOUGAMAU, QUÉBEC for SOCIÉTÉ QUÉBÉCOISE d'EXPLORATION MINIÉRE (SOQUEM) CHIBOUGAMAU, QUÉBEC MRN - S.I.S.E.M. 1995/10 GM 53358 Timmins, Canada Brendan Light March, 1994 David J.W. Dawson, B.Sc. QCI Project: C-258 Quantec Consulting Inc. Quantec ~6156 si001 4V2 9 TABLE OF CONTENTS 1.0 INTRODUCTION 3 2.0 GENERAL SURVEY DETAILS 4 2.1 Location and Access 4 2.2 Survey Drill Holes 4 3.0 SURVEY WORK UNDERTAKEN 5 3.1 Generalities 5 3.2 Survey Personnel 5 3.3 Equipment and Survey Procedure 5 3.4 Difficulties encountered and accuracy of measurements 8 3.5 Data Reduction and Presentation of Results 8 4.0 SUMMARY INTERPRETATION AND RECOMMENDATIONS 10 4.1 DDH 1119-94-04 10 4.2 DDH 1119-94-06 10 4.3 DDH 1119-94-07 11 4.4 DDH 1119-94-08 11 4.5 DDH 1119-94-09 12 4.6 DDH 1119-94-10 12 4.7 DDH 1119-94-12 13 APPENDIX A: STATEMENT OF QUALIFICATIONS APPENDIX B: LOOP LOCATIONS FOR CHIBOUGAMAU 11-1119 PROJECT APPENDIX C: DAILY PRODUCTION REPORT APPENDIX D: LIST OF MAPS APPENDIX E: INSTRUMENTATION SPECIFICATION APPENDIX F: TEM PROFILES APPENDIX H: BOREHOLE LOCATION MAPS APPENDIX I: SURVEY LOCATION MAP ii Quantec 1.0 INTRODUCTION During the period of February 1 to February 28, 1994, Quantec Consulting Inc. of Porcupine, Ontario conducted Low Power Transient Electromagnetic (LPTEM) borehole surveys over the Chibougamau 11-1119 Project property located in Obalski and Lemoine Townships, southeast of Chibougamau ,Quebec .. The surveys were performed on behalf of Société Québecoise d'Exploration Miniére (SOQUEM) of Chibougamau, Quebec. The project was carried out under the direction of Marc Boivin of SOQUEM. The objective of the downhole surveys was to define the downhole geophysical picture by energizing conductors associated with possible massive sulfides, which may not have been fully examined by the drilling. The work follows previous Horizontal Loop Electromagnetic (HLEM or "Maxmin") and Induced Polarization (IP) geophysical surveys. The drill holes surveyed had been positioned to test conductors located from the results of the previous surveys. The present survey was undertaken concurrently with the diamond drilling program, and served to assist in targeting follow-up DDH's. The following report describes the instrumentation used, presents the LPTEM borehole survey results, includes a summary/preliminary interpretation, and offers brief recommendations for future work. It is not intended to represent a complete analysis of the BHTEM data collected at Chibougamau 11-1119. CANT ON MchE1V7.IE CHtBOUGaMAu OCALiSAL1OCiDES LEWES PULSE-17d EFFECiUES FAH QUAR2EC- 1994 IPOI[f ^CFÜBOIIGAMAV• 11-1119 Fiqure 1: General location map showing the Chibouqamau 11-1119 Project. 4 2.0 GENERAL SURVEY DETAILS 2.1 Location and Access The Chibougamau 11-1119 Project property is located approximately 25 km southeast of Chibougamau ,Quebec, in Obalski and Lemoine Townships, on Lake Chibou- gamau (see Figure 1 and Appendix H). The area is easily accessible by vehicle by traveling east from town along a secondary highway to Lake Chibougamau. The crew was based in Chibougamau throughout the course of the survey. Access to the diamond drill holes on the property was facilitated by 4wd truck and snowmobile . 2.2 Survey Drill Holes Seven (7) drill holes were targeted for BHTEM surveying. Each of the drill holes was surveyed using three to five (3-5) transmit loops, whose position and orientation were prede- termined by David Dawson of Quantec and Marc Boivin of SOQUEM. The NS and EW (meters) positions for all the profiles presently shown are referenced to the existing coordi- nate systems. The position of the transmitting loops and the holes surveyed from each are listed in Appendix B. CHIBOUGAMAU 11-1119 PROJECT LPTEM BOREHOLE SURVEY OLE AZIMUTH. TOTAL:DE DÉPTH (rrij:;' LOGGED :(m ) 1119-94-4 N360° / -45° 145 Collar, South, East 435 1119-94-6 N360°/-45° 340 Collar, North, East, West, South 1700 1119-94-7 N360° / -53° 368 Collar, North, East, West, South 1840 1119-94-8 N360° / -56° 250 Collar, South, West 750 1119-94-9 N360° / -60° 279 Collar, North, East, West, South 1395 1119-01 10 N360°/-45° 741 Collar, North, East, West, South 1150 1119-01 12 N360° / -450 397 Collar, North, East, West, South 1985 TOTAL 9.255 km Table I: Borehole Survey Coverage at the Chibougamau 11-1119 Project 4 3.0 SURVEY WORK UNDERTAKEN 3.1 Generalities The geophysical program over the Chibougamau 11-1119 Project was undertaken between February 1st to 28th, 1994. Seven (7) boreholes were surveyed, typically using 5 loops each, totaling nine thousand, two hundred and fifty-five (9,255m) meters. Measure- ments were acquired at 10 meter intervals, with the spacing reduced to 5 m in anomalous zones. Each measurement consists of 20 time channel readings of the transient electromagnetic field, using a single-frequency (30 Hz) time-base, in the axial component direction parallel and positive up the borehole (Hz). 3.2 Survey Personnel David J.W. Dawson Crew Leader/ Geophysicist (QC!) Porcupine, ON. Zachary Thompson Field Technician (SOQUEM) Chibougamau, QC. 3.3 Equipment and Survey Procedure The survey implemented a low power (0.6 kVA) TEM system manufacture by Geon- ics Ltd. of Mississauga, Ontario. The EM-37 receiver is a variable-gain, single-channel, back-pack portable, analog data acquisition system weighing approximately 45 lb. and powered by Gel-Cel type batteries. The Rx unit measures the primary pulse and the time rate of decay of the magnetic flux across 20 time-gates (80 microseconds to 80 millisecond delay time) during the "off-time" using a pulse repetition frequency (time base) of 3, 7.5 or 30 Hz. The CPU is synchronized to the transmitter either via quartz clock synchronization, hard-wire or radio reference link. The TEM-57 low power (0.6 kVA/120V) transient electromagnetic transmitter was used in conjunction with a portable, 2 HP Honda gas powered generator and single-phase/60 Hz Geonics/Georator alternator weighing approximately 35 kg combined. Synchronization is through quartz crystal or reference cable. The Tx produces a 3, 7.5 or 30 Hz, bipolar rec- tangular current wave form (50% duty cycle) with turn-off times ranging between 20-450 µ sec, depending on the size, current and number of turns in the transmitter loop. The MD conversion and digital data storage were performed using the DAS 54P Polycorder manufactured by Omnidata, Inc., North Logan, Utah. The magnetic field sensor was a Geonics BH-43 single component borehole sensor/probe, which is a cylindrical (3.2 x 212 cm) air-core coil having an effective area of 64 metres2 weighing 15 lb. and measuring the time-rate of change of the magnetic flux across a 26 kHz bandwidth. The sensor consists of a separate antenna and pre-amplifications section. 5 Quantec To ensure optimum anomaly resolution and noise suppression, the following system parameters were selected for the Chibougamau 11-1119 Project fixed-loop LPTEM borehole profiling surveys: EM 57 Pulse repetition frequency: 30Hz Gain: 6-8 Integration number 8 (256 integrations) Loop sizes: 100 m by 100m 200 m by 200 m Current: 7 - 10 amperes Turn-off time: 75µs+12µs for reference cable correction Gate positions 78-6280 µs @ 0 turn-off Synchronization mode: reference cable Table II: System parameters for LPTEM surveys over Chibouqamau 11-11119 Project. The survey procedure is shown schematically in figures 2-3. The current in the loop produces a primary magnetic field (H) both inside and outside the loop (fig. 3). This primary field induces a vortex current pattern which energizes conductors which in turn create their own secondary magnetic field (Bs). In the case of the borehole survey, the rate of change of the secondary magnetic flux (dBs/dt) is measured as the axial down- the-hole component by the borehole probe (figure 2). These analog voltage measurements are recorded over 20 channels in the receiver, transferred to the Polycorder unit where they are digitized and stored in solid state memory in voltage units. The stored data is later transferred to a micro- computer where it is corrected for the turn-off time, current, and system gain, producing units in nanovolts per meter squared. The borehole survey is particularly useful to determine the geometrical relationship between a conductor or a complex swarm of conductors and the drill hole. Of particular im- portance is its application in cases where drilling is believed to have missed the target of in- terest. A borehole survey can effectively determine the direction and distance from the drill hole to the conductor by comparing the results of logs from several loops positioned around the hole, or by comparing the response from hole-to-hole. Additionally, conductors located below the end of a drill hole, which either may be too deep and/or have gone previously un- detected from surface, may be discovered during the course of a borehole survey. 6 +Hz Positive Hz=up borehole South Loop Collar Loop North Loop RX t Tx Loop Perimeters 5 to 10m Sample Interval xia Isolated Hole Survey Procedure Figure 2: Loop configurations and polarity conventions for fixed loop borehole profiling. In keeping with the industry standard, the primary field was considered positive up inside the loop and negative down outside (see figure 3). Similarly, the receiver orientations were recorded using HZ positive as vertical-up and parallel-to-borehole. Primary Field Sign Convention Survey Line \\ 11J~ i +111JIJJ Transmit Loop / Negative Down Outside ii%%%/ %%i%l! !;'/!/ / — -~~~-i/%Î1 / / 1 ------'7/'// Positive Up Inside \ \ ~~~~~~ --~iii,•/// ~\\ ~~ ~~~— ------,7,-//////:f1 \\ \\\\\\~,-...,»—_.—_— —~//i//.'%%///: \ \\\\\\\\\\\~--__—__ /////////1/1 '; i \\\\\\\\\\\\ ----~//,'i///////l11 1 \\\\\\\\\N,.....,,„\---~— ---///,'///////Ilt' 1 \\\\\\\\\\\\\~\\ --W//,//////////tf 1 \\\\\\\\\\\\\\~\—~ —/////;;;//////1!lf \\\\\\\\\\\\\,.\\,-^ ~—~-/.."//////,'/////f ~ 1\\\\\\\\\\\\\\~~ .

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