CANADA DEPARTMENT OF MINES AND RESOURCES MINES AND GEOLOGY BRANCH GEOLOGICAL SURVEY BULLETIN No. 5 GEOLOGY AND MINERAL DEPOSITS OF NORTHERN BRITISH COLUMBIA WEST OF THE ROCKY MOUNTAINS BY J. E. Armstrong OTTAWA EDMOND CLOUTIER PRINTER TO THE KING'S MOST EXCELLENT MAJESTY 1946 Price, 25 cents CANADA DEPARTMENT OF MINES AND RESOURCES MINES AND GEOLOGY BRANCH GEOLOGICAL SURVEY BULLETIN No. 5 GEOLOGY AND MINERAL DEPOSITS OF NORTHERN BRITISH COLUMBIA WEST OF THE ROCKY MOUNTAINS BY J. E. Armstrong OTTAWA EDMOND CLOUTIER PRINTER TO THE KING'S MOST EXCELLENT MAJESTY 1946 Price, 25 cents CONTENTS Page Preface............ .................... .......................... ...... ........................................................ .... .. ........... v Introduction........... h····················································· ···············.- ··············· ·· ········ ··· ··················· 1 Physiography. .............. .. ............ ... ......................... ·... ............. ....................... .......................... .... 3 General geology.. ........ ....................................................................... .... .. ... ...... ....... .. .... .... .. .. .. 6 Precambr ian........................................................................................... .... .. ....................... 6 Palreozoic................ .. .... .. .. ....... ................. ... ... ...... ................ ......... .... ... ... ...... .. .. .. ... .. .... ....... 7 Mesozoic.......................... .......... ..................................................... ...................................... 8 Cenozoic... ........... ... ........ ........................................................................................ .. ............ 10 Tertiary. ............ ............................ ... ... ...................... ............................ ....................... 10 Quaternary.. .............. ................................ ..... ................ .. ...... ...... ... ............. ............... 11 Intrusive rocks................. .. ........... ................ ................ .... .... ........... ... ............................... 11 Structural geology................................................................. .. ....... ......................... .................. 13 History of mining...................... .................................... ................... ........................... ............. 14 Economic geology ............... ..................................................................... .................... .. ............ 16 Summary of economic geology......... ..... .. ........................................................................ 16 Relation of metalliferous deposits to intrusions ............... .................... .. ............. 16 Relation of metalliferous deposits to structure. ...... ........ .. ........................... ........ 17 Mineral deposits..................... ...................................... .. ......................................... .. ......... 18 Placer gold................. ............................................................... ......... ..................... .. .. 18 Lode gold.................... ....... .... ... .. ............. .. ...... ......................................... ........ ........... 22 Atli? and ~t~kine .m.ii:ing divisions ................. ......... ............................. .... .. .... 22 8~~7~~~a rr::ir~r;g d<lY~~~?~;; .-.-:::.- .·.- .- .-.· : .-.- .-:.-.-::.·.-::.·:.-: : .- .- .·.-:: .-.-.- : .-.-:.·::.- :: :: :::::::::: ::: ::::: ::::::::::: ::: ~~ Portland Canal mining division .... ....... .. .... .. ................................... ............ .. .. 24 Queen Ch:i-r_lotte .m.ii;ing division............................ ...... .... ... ............. .............. 25 Skeena mm1ng d1v1s1on ......................... ... ............................... ... ............ ........... 25 Silver-lead-zinc .............. ..... .. ...... .. .............................................................................. 25 Portland Canal area ..................................................... :........ ................. .. ......... 26 Quartz veins containing one or more of the metals, silver, lead, and zinc .. ......... .... .. ....................... ........ ............ 26 ·silver-barite-jasper deposits ................................................................... 26 Silver-lead deposits ........... .. ............ ........... ........................ ..... .................. 27 Hazelton-Smithers area ............ .. ................. ..... ......... .. .. .... ... ... ........................ 27 Canadian National Railway belt from. Houston to Burns Lake.................................. ... ................. .. ......................................... 27 Ingenika River .................................... .................... ................ .... ... .................... 28 Copper... ........................................ ...... ... ... .. ...... ........................................................... 28 Mercury. ................................................ ... ..................................... .................... ........... 29 Tungsten..... ............ : ...... .. ... .. ... .. .. ........... .. ... ........................ .. ...................................... 30 Molybdenum ........... ... .. ........... .. ............ ... ...................... ............ ............... : ............ .. .... 31 Antimony..... .. .............. ................. ......................... .. ........ .... ..................................... ... 31 Manganese......... .... .................................. .................................................................... 31 Chromium............ ... ............... .. .. ... ... .... ...................................... .. ... .. .. ..... ....... .. .... .. .... 31 Mica.. .... .. ......... ... ..... ...................................... ............. .. ... ... .. ................. .. .. ............ ....... 32 Iron ............................... ................................. .............. .. .. .. .... ... ........................ ...... ...... 32 Pyrite.......... .... .. .................................. .. ................. ........................ .. ............................. 32 Coal. ........... .. ........ ............................... .... .... ............. ... ..... ..... ............... ......................... 32 Jurassic or Lower Cretaceous coal.. ......... .... .. ................. .............. ........ .......... 32 Tertiary coal.......................... ................................ .. ........................................... 33 Bibliography.. .... .. ............. .... .. ................. .... .......... ... .. .... ...... ......... ............. ........ .......... ............... 35 Illustrations Figure 1. Physiographic divisions.... ................ .. .. .............. .. ...................... .......................... 2 2. Geology............ .... .. ............................. ....................................................... ............... 5 3. Gold placers and coal fields .............................. .. .. .... .. ...................... ................... 19 4. Productive mines ..... .................... .................. ............................. ..... .. .. ... ............... 21 5. Map index .. .................................... ....... ......................... .... ... ·· ·· ······················· :· ·· ··· 34 v PREFACE North of the fifty-third parallel and west of the Rocky ]\fountains, British Columbia embraces a metalliferous region of some 130,000 square miles, much of which is essentially unprospected and its geology unknown in any but the most general terms. Much of it is difficult of access, far from main transportation routes, and virtually uninhabited. And yet in its comparatively brief recorded history a rather astonishing amount of information has accumulated on its better known parts, due in the main to activities connected with mining, prospecting, and geological exploration. In the present bulletin the author has endeavoured to assemble and correlate the more salient features of the geology, mineral occurrences, and mining history of this broad region, based on several consecutive years of field work and also on the numerous published accounts that have appeared in the past 70 years. An extensive bibliography and accompany­ ing index of geological maps should prove of special interest to those who wish further details on specific parts of the region. GEORGE HANSON, Chief Geologist, Geological Survey OTTAWA, December 4, 1945 GEOLOGY AND MINERAL DEPOSITS OF NORTHERN BRITISH COLUMBIA WEST OF THE ROCKY MOUNTAINS INTRODUCTION The part of British Columbia under consideration lies west of the Rocky Mountains, north of latitude 53 degrees, and covers about 130,000 square miles. The Canadian National Railway traverses the southern part of this region and much of the area lying between latitudes 53 and 56 degrees is readily accessible from the railway by roads and trails. Farther north communications are maintained by aeroplane or by long and arduous trips by river-boat and pack-horse. In this report the writer has attempted to correlate and summarize the geological information on northern British Columbia west of the Rocky Mountains, both published and unpublished, gathered by members of the Geological Survey during