OMINECA MINING DIVISION

Transcription

1 A GEOI'HYSICAL REPORT ON llfe NARY CLAIMS OMINECA MINING DIVISION

2 TABLE OF CONTENTS Page INTRODUC TION LOCATION 1969 FROGBAN AIRBORNE SURrn EQUIPMENT, RESULTS SURVEY AND DATA REDUCTION COBCLUSIONS AKD RECOPBENDATIONS t Department of Ikiiwes and Petrotsum Resaa~rces,- f- m WEPORT m a ASA~~~~~EI:ST 1 NO.... Zd23.p MA,... C ;_ SdiinEng R@cordarBs Office REGOWDEB _----

3 LIST ILLUSTRATIONS Page #\ (a) In Pbcket Helicopter ~ eo~h~sicaf Survey E,M, and Magnetic Contour Plan

4 I AIRBORNE HAG - E.M. PROFILES I1 DECLARATION OF EXPENDITURES

5 INTRODUC TION LOCATION The Mary claims are on Blunt Nountain about 30 miles north of Smithers, 3, C. and 7 miles east,of the C.N.R. line at a point about 15 miles southeast of Hazelton. Most of the claims are above timber line at elevations of 5,000 to 7,000 feet, Access is by helicopter from Smithers although there are existing roads to within 5 miles of the proper-by. An Upper Cretaceous granodiorite stock forms the core 0 ' of Blunt Mountain. There are several areas of known porphyry mineralization within the stock, was One of these known occurraces staked (the Mary claims) and the helicopter mounted magnetic and electromagnetic survey was conducted over a larger area of the stock in order to outline other areas of porphyry mineralization,

6 EQUIPNEMT, SURVEY ABD DATA REDUCTION On August kth, 1969, a 107 line mile airborne magnetic and electromagnetic survey of about 35 square miles was comp- leted. The survey area included the Mary group of mineral claims as shown on the accompanying rnap in the pocket of this report, The equipment and crew were supplied by Lockwood Survey Corporation Limited of Toronto, Readings of the in and.out of phase components of the resultant electromagnetic field plus a vertical magnetic intensity were taken from an ph-1100 helicopter platform. The equipment ixicluded a 4300 c,p.s, and a Gulf Mark I11 magnetometer, electromagnetic system The receiver coils and magnetometer head were carried in a 30 foot bird suspended beneath the helicopter on a 100 foot cable, Plying height 1 was maintained at about 220 feet above the ground asld the bird travelled at about 100 feet above the ground. Terrain clearance was measured by a Bonzar radio altimeter and recorded on the EeM. tapes. A Gulf recorder was used for the magnetom- eter and the EeMe system was linked to' a Taylor recorder in which the conductors were recorded in positive values. possible, Flight lines were oriented northwest-southeast where The lines were approximately 1500 feet apart.

7 C) However, the steep terrain made both line direction and terrain clearance difficult to maintain, Because the survey area is largely mountainous, the flight lines were "broken offt1 when the helicopte~ was unable "c continue climbing up the mountainside, Often the new line started after the aircraft had regained safe flying speed was not coincident the old one at the "break off" point, However, a continuous film record was kept of the flight lines so that they were easily plotted, The picking of the 8mm. film for location points,and the data reduction was done by Versatile Drafting Ltd,, 448 'Seymour Street, Vancouver, B, Ce The data was drafted at 1" = 1000' and a copy of the map is included in the pocket of this report, I - RESULTS Twenty-f our conductors were outlined by the survey. Pour of these are of primary interest and are coloured red i on the accompanying map, These conductors are number 2, number 7, and number 13, Eight conductors of secondary interest were outlined by the survey and are coloured green on the accompanying map. These conductors are numbers 1, 4, 10, 11, 15, 17, 18, 19, and 24, The remainder of the 24 conductors shown on the accompanying map are probably due

8 Conductor number 3. is a 35 ppm negative in phase anomaly with no out of phase response. It is nearly coincident with 3 a 1,000 gamma mag high, lplis conductor is probably due to injected magnetite, Conductor number 2 gave a 50 ppm in phase response and a I 25 ppm out of phase response which are on the flank of a, 300 gamma mag high, This anomaly may be due to porphyry mineralization and should be investigated, Conductor 4 is difficult to interpret because the in phase trace is coriplicated by a scale chagge, Elowever, it i I appears as though the in phase response is about -75 pprn and the out of phase response is about +30 ppm. The conductor is coincident with a 2,000 gamma mag high and so is quite probably 1 I an expression of conductive magnetite, Anomaly 7 is a negative 35 ppn in phase response and positive 20 ppm out of phase response which is not coincident with a strong magnetic feature. However, an adjacent 200 gamma mag peak suggests a conductor parallel to the flight line which may be related to porphyry mineralization, be investigated on the ground, This anomaly should Conductor LO gave a 50 ppm negative in phase response with no out of phase response, The conductor is coincident with about a 700 gamma mag high and is therefore probably due to

9 injected magnetite. Conductor 11 probably also reflects injected magnetite, The negative 50 pprn in phase response and zero out of phase response are adjacent to a mag high, Conductor 13 is a 40 ppm in phase and 70 pprn out of phase positive response which is adjacent to a very sharp and distinctive 400 gamma mag peak.!phis conductor may be a reflection of porphyry mineralization and should be investigated on the ground. Anomaly 15 is a 20 pprn in phase and 40 ppm out of phase response which is adjacent to a 200 gamma mag high. Although it probably is caused by a structural or fomational zone of conductivity it should be investigated on the ground. Conductor 17 is part of a large zone of conductivity which is probably fomational, However, an adjacent 200 ganma mag high suggests the possibility of porphyry mineralization, This area warrants ground investigation, Conductor 18 gave an 80 pprn in phase and 25 pprn out of phase response which is coincident with a 40 gamma positive mag feature. This conductor is also probably formational but should be investigated on the ground, C, Anomaly 19 is a 65 ppm in phase and 35 pprn out of phase which is coincident with a 40 gamma mag irregularity, This

10 anomaly is also probably due to a formational feature but warrants a brief ground examination, Conductor 24 is pr0ba.bl.y due to injected magnetite, The negative 75 ppn in phase response cad weak,out of phase response are coincident with a 300 gamma nag high,

11 CONCLUSIONS AND RECOPlfsiENDATIONS Three areas of possible porphyry mineralization are indicated by anomalies number 2, 7, 13. These areas should be investigated by ground geophysical aad rock geochemical surveys. In addition, 9 'areas of possible interest were outlined by aylomalies number 1, 4, 10, 11, 15, 17, 18$ 19, and 2k, Although these anomalies are probably of formational origin, they should be investigated by ground traverses. Respectfully submitted, R. We Woolverton, P. Eng.

12 AIRBORNE YAG - EM PROPIZES

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61 APPENDIX I1

62 Tae undersigned considers %he following costs to be applicable as zssessnen-k wo:k: 107 line miles of helicopter Nag-324 survey Q $55 per mile - 85,885 Re W, Woolverton, P, Eng.

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