The Double Ed deposit is located 3 kilometres west of Granby Bay on Observatory Inlet.
The region is underlain by a roof pendant, consisting of volcanic and sedimentary rocks, within the Eocene Coast Plutonic Complex. These pendant rocks have been correlated with Middle-Upper Jurassic Hazelton Group rocks and overlying upper Middle to Upper Jurassic Bowser Lake Group sedimentary rocks (Geological Survey of Canada Open File 3453). The Hazelton rocks consist of variably chloritized pillow and massive andesite and basalt with minor mafic tuffs. The overlying Bowser Lake sediments consist of argillite, siltstone and sandstone with minor chert and limestone. There are two observable phases of folding in the area, an initial north-northeast trending phase followed by a later east-northeast trending phase.
The deposit occurs in a sequence of chloritized pillow basalts, basaltic pyroclastics and minor pelitic to siliceous sediments near a major volcanic/sediment contact. The deposit comprises two distinct orebodies, the Number 1 and 2 bodies. The Number 1 deposit forms a tabular sheet 400 by 150 to 210, by 12 metres and is situated on the east limb of an anticline that plunges 70 degrees to the south. The Number 2 deposit occurs on the west limb of this same anticline, is more irregular in form, and extends downdip for 175 metres. The north ends of both deposits terminate against a northeast trending steeply dipping fault.
The mineralized horizon consists of volcanogenic, stratabound massive to banded to disseminated pyrite, pyrrhotite, minor chalcopyrite and sphalerite. Mineralization is hosted in basaltic tuffs and siliceous to pelitic sediments that have been altered to chlorite schist and quartzite to biotite schist, respectively. Gangue minerals consists of quartz and biotite, with subordinate chlorite, albite and magnetite.
The two zones combined show a drill indicated resource of 1,229,236 tonnes of 1.3 per cent copper and 0.6 per cent zinc; and a drill inferred resource of 748,430 tonnes of 1.3 per cent copper and 0.6 per cent zinc. The zones remain open to depth with scope for further limited tonnage of similar grade (Report by Taiga Consultants Ltd., 1992). This report and Assessment Report 23528 has a good summary and history of exploration in the Anyox area.
Work History
In 1952, Cominco Ltd. discovered the Double Ed deposits as a result of regional prospecting. The occurrence was explored by surface drilling (6400 metres in 25 holes) in 1953 and 1954, and by a crosscut adit and underground drilling (4300 metres in 33 holes) in 1959 and 1960. The portal is situated at approximately 150 metres elevation on the west bank of Bonanza Creek, approximately 3 kilometers upstream from where the creek enters Granby Bay. The portal measures 2.75 metres high by 2.75 metres wide and the workings total 870 metres in length. By the 1980’s, Cominco and various joint venture partners had completed 96 drill holes, totalling approximately 17000 metres, on the area along with numerous programs of geological mapping, geophysical surveys and geochemical sampling.
In 1990, Cominco sold their interests in the Anyox project area to Moss Management Ltd. and Boston Financial Corp. In 1992 and 1993, Taiga Consultants conducted exploration programs on the Hidden Creek area on the behalf of TVI Copper (TVI Pacific Inc.). In 1992, the two zones combined were reported to have a drill indicated resource of 1,229,236 tonnes of 1.3 per cent copper and 0.6 per cent zinc; and a drill inferred resource of 748,430 tonnes of 1.3 per cent copper and 0.6 per cent zinc. The zones remain open to depth with scope for further limited tonnage of similar grade (Report by Taiga Consultants Ltd., 1992). This report and Assessment Report 23528 has a good summary and history of exploration in the Anyox area.
In 2006, Kenrich-Eskay Mining Corp. completed 50 diamond drill holes, totalling 14275 metres, on the Coastal Copper project including 27 drill holes on the Double Ed area. Other exploration work included an airborne electromagnetic and magnetic survey, geological mapping and stream sediment sampling. At this time, an indicated resource of 1,850,000 tonnes grading 1.6 per cent copper, 1.0 per cent zinc and 15.1 grams per tonne silver was reported (Harrison, D., McKinley, S. (2007-06-18): Technical Report on the Coastal Copper Project, Anyox Area).
In 2007, Kenrich-Eskay Mining Corp. completed seven drill holes, totalling 2493 metres, located near the Double Ed showing, targeting extensions to the mineralized zone. Hole DE06-20x was drilled on the north end of the deposit. This hole was a continuation of hole DE06-20, which ended prematurely in 2006. The hole intersected stringer and massive sulphides grading 1.2 per cent copper over 4 metres and 1.0 per cent copper over 11 metres. This drilling helps to confirm the presence of a low-grade feeder zone to the north of the massive sulphide lens (Assessment Report 30152).
