The EVA prospect is located in the South Chilcotin Mountains, on the north side of Tyaughton Creek, approximately 19 kilometres north-northwest of Gold Bridge, B.C.
The region in which the Eva prospect occurs is underlain by mainly sedimentary rocks of the Upper Triassic Tyaughton Group, intruded by felsic rocks of the Jurassic to Tertiary Coast Plutonic Complex.
The Eva showing itself occurs within a sequence of polymictic conglomerate, sandstone and siltstone cut by a swarm of feldspar porphyry dikes. The sedimentary rocks contain patchy skarn alteration consisting of the mineral assemblage calcite-diopside- epidote-quartz-chlorite-vesuvianite-pyrite-hematite associated with abundant calcite veinlets. The pyrite forms ubiquitous stringers, blebs and disseminations. The relationship between skarn alteration and gold-sulphide mineralization is unclear.
In 1980, Pan Ocean Oil carried out detailed mapping and sampling in the area, followed by Placer Development Ltd. who conducted programs of soil, talus fines, stream sediment and rock sampling in 1981, as well as ground magnetometer and VLF-EM surveys in 1983. In 1985, Hillside Energy Corporation and Claymore Resources Ltd. conducted a program of soil and rock sampling followed by geological mapping. In 1996, a drill hole was set up one hundred and twenty metres to the northwest of the Eva showing. The drill hole intersected a 1.2-metre wide shear zone with quartz veinlets and disseminated pyrite, stibnite and arsenopyrite within a steeply dipping feldspar porphyry dike striking at about 145 degrees. This zone contained 1.7 grams per tonne gold.
In 1987, Searchlight Resources Inc. carried out geological mapping and sampling in the area. The main vein comprises calcite, quartz, pyrite, bismuthinite, stibnite, arsenopyrite, specular hematite and minor chalcopyrite, with the stibnite occurring as disseminations and massive bands. Outcrop of the vein contains up to 6.51 grams per tonne over 0.23 metre. Results of this program directed Millenium Resources Inc. to drill 3 holes at the EVA showing, in 1988. The highest gold values obtained were 1.17 grams per tonne over 0.4 metre and 1.5 metre intersections (Assessment Report 18056).
