Case Studies - Mineral Exploration

Black Dog Massive Sulphide Deposit, Rock and Roll Property, B.C.

Introduction

The survey area is located approximately 10 kilometres northwest of the Snip Mine in the Iskut River area of northwestern British Columbia. The Black Dog massive sulphide deposit is hosted by a sequence of volcanic and sedimentary rocks in the central portion of the Stikine Arch. Airborne multi-frequency electromagnetic geophysics, combined with follow-up ground surveys have delineated the Black Dog Horizon which hosts strata-controlled disseminated to well laminated semi-massive to massive sulphides.

The mineralisation strikes northwest-southeast, dips at 20-30 degrees to the southwest and has been drill tested over a strike length of 250 metres. Ground HLEM has traced the Black Dog Horizon over 1300 metres while airborne EM data suggests a minimum strike length of 7000 metres. The Black Dog Horizon has a thickness of approximately 25 metres within which numerous semi-massive to massive lenses occur over widths of up to 10 metres. Assay data representative of diamond drilling on the Black Dog is listed below.

The HEM airborne survey of this area was instrumental in the discovery of the Black Dog Horizon. The airborne data were collected by the Aerodat, now Fugro Airborne Surveys, helicopter electromagnetic (HEM) system towed 30 metres above terrain. Data were also recorded from a high sensitivity Scintrex cesium magnetometer and a two station Herz VLF-EM sensor, both towed at 50 metres above terrain. The Aerodat HEM unit is a four-frequency system consisting of two vertical coaxial coil pairs operating at 935 and 4600 Hz and two horizontal coplanar coil pairs operating at 4175 and 33,000 Hz. The coils are mounted in a Kevlar "bird" at a separation of 7 metres. The ground data was collected by Lloyd Geophysics utilising a Horizontal Loop Electromagnetic system operating at 880 Hz, 3520 Hz and 7040 Hz with a coil separation of 50 metres, and an Induced Polarisation system utilising a Pole-Dipole Array with an (a) spacing of 25 metres.

Helicopter EM Profiles Frequencies= 4600 Hz Coaxial, 4175 Hz Coplanar

Horizontal Loop EM Profiles Coil Separation= 50m; Frequencies= 3520 Hz, 7040 Hz

 

Airborne and Ground Depth Sections and Profiles

Drill Hole Cross Section- Line 5100

Conclusions

Acknowledgements

The comparison of HEM data with Ground Geophysics, Geology and Drill Hole cross section is presented courtesy of Prime Explorations, a division of Prime Equities Inc., Eurus Resource Corp. and Thios Resources Inc.