This report on the Whitehorse Copper Belt is written by a geologist who was actively involved in mining and exploration in the district during the decade of the seventies. It includes a review of earlier data and compiles recent work, mining practice, geological concepts and constraints and problems in development and mining. Earlier reports on the district by McConnell and Kindle emphsized geology; this report concentrates on mining and development. The report was written when mining in the district was at its peak; it will be useful to those contemplating future development in the Copper Belt and for comparing the district to others. Mining in the Copper Belt may cease soon and the report was solicited by D.I.A.N.D. from Whitehorse Copper Mines as a record of mining practice and geological concepts.

Whitehorse Copper Mine, within the city limits of Whitehorse, produced about 10 million tons of fine-grained calc-silicate tailings before its closure in 1982. The tailings, now desiccated, do not support plants although some areas have been undisturbed for more than 20 years. Barren tailings have high pH and electrical conductivity (E.C.) but are otherwise non-toxic. The minimum requirements for sustainable plant growth are under study in a pilot project in which freely available compost from various sources was mixed with the uppermost tailings as a proto-soil. Six plots were initially treated with one dose of chemical fertilizer, regularly irrigated and protected from wind. Planted Yukon native grasses germinated and both transplanted trees and seeds in the compost survived. Grass growth was measured after 2 growing seasons and is directly related to the quantity and quality of the compost tilled into the upper 10 centimetres of the tailings. Soil texture, moisture retention and organic nutrients improved. Similar abandoned sites could benefit from the addition of readily available compost and the use of locally propagated seeds and native plants.

Geology of the Whitehorse Copper Belt (NTS 105 D/11), southern Yukon. A compilation including a 1:25 000-scale geological map with marginal notes on bedrock geology, mineral occurrences, mineral deposits and grades of some mineral deposits.

This report discusses the distribution of intrusion related and other mineral occurrences in the Whitehorse map-area, Yukon. Mineral occurrences recorded in the Archer, Cathro and Associates, Ltd., Northern Cordillera Mineral Inventory have been classified according to deposit type and principal commodities then plotted on a lithologic map (1:250 000 scale) which is in part an updated version of the Geological Survey of Canada four mile map for the Whitehorse map-area by Wheeler (1961). New information added to the map includes: geology and geochronology of the Bennett Lake cauldron subsidence complex; geology of the Atlin Terrane; reinterpreted geology of the adjacent Laberge map-area and part of the Bennett and Atlin map-areas; a reclassification of geologic units in southern Yukon; reconnaissance mapping, classification and geochronology of granitic rocks in the Whitehorse map-area; and detailed stratigraphy of the Upper Triassic Lewes River Group with special emphasis on the Whitehorse Copper Belt and the associated Cu-Fe skarn deposits.

The Whitehorse Copper Belt is a northwest-trending chain of copper-bearing skarn deposits, located four kilometres west of the city of Whitehorse (NTS 105 D). The belt extends parallel to the Alaska Highway for thirty kilometres, from the Crestview subdivision to the junction of the Alaska Highway and the South Klondike Highway. From the time Jack McIntyre staked the Copper King in 1898, the belt has been vigorously prospected and mined for its valuable copper, gold and silver metals.

This publication is a field guide to the geology and mining history of the Whitehorse Copper Belt. It is designed to assist Whitehorse residents and visitors in exploring this fascinating area. Sheet 1 is a geological map with a list of suggested stops, while sheet 2 provides specific descriptions of many mineral occurrences. Stops are numbered roughly from north to south on this map, and are grouped according to their geographic location and access routes on sheet 2.

In the first three decades of this century, $2,712,000 worth of copper ore came out of the copper belt (Johnston, 1975). The mines were only active, however, when copper prices were high. Ultimately, the drop in copper prices after the first World War, the discontinuous nature of the copper deposits, and the high cost of transport brought an end to production in the copper belt for half a century. In the 1960s and 1970s, modern mining technology made it profitable to mine copper ore on a large scale, an undertaking that had proven uneconomical in the early days. Nonetheless, New Imperial Mines Ltd., later Whitehorse Copper Mines Ltd., had much in common with those early mines. Transportation costs were still high, the extent of mining development depended on outside capital investment and world copper prices, and there was still a close connection with the nearby community of Whitehorse. A companion paper discusses the geology of the area as well as the historic and contemporary mining technology used in the copper mines. This document will address historic events and issues during 85 years of exploration, development and production in the copper belt (NTS 105 D).

Aggregate is an integral resource for the development of Whitehorse. The City of Whitehorse receives much of its gravel from private quarries located within city limits; this benefits the city by reducing the transportation costs associated with hauling aggregate from outside of the city. Anticipated growth and development places an increased demand on locally sourced aggregate required for construction. While new quarries are vital for growth, it is important that resource extraction be maximized near existing quarries in order to take advantage of existing infrastructure. The goal of this project is to gain a better estimate of the quality and quantity of aggregate at four sites in the vicinity of Whitehorse. Four locations in the Whitehorse area were investigated for their aggregate potential: 1) McLean Lake, 60°38’20.62”N 135°04’06.75” W; 2) km 196 North Klondike Highway (Takhini Bridge); 3) Haekle Hill/Alaska Highway (60°48’17.77N 135°13’36.95”W, 761 m asl); and 4) Long Lake (road site 60°45’26.19N 135°02’34.42”W, 723 m asl).

The objective of this investigation is to guide the exploration for and development of aggregate resources for the City of Whitehorse in accordance with its Official Community Plan. Four sites in the immediate Whitehorse vicinity were selected by the Yukon Geological Survey to be addressed within this study. Prospective exploration targets are evident in each site but additional ground-truthing is necessary to reliably confirm the presence or absence of aggregate material.

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