The L Lake (Electrum Northwest) occurrence is located north of the informally named L Lake on a south-southeast–facing slope, northwest of the Finlay River and approximately 7.5 kilometres northeast of the river's junction with the Firesteel River.

The region is situated at the southern end of the Toodoggone Gold Camp, which lies within the eastern margin of the Intermontane Belt and is underlain by a northwest-trending belt of Paleozoic to Neogene sediments, volcanics and intrusions. The Electrum prospect is situated within a Mesozoic volcanic arc assemblage bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins.

Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Takla Group andesite flows and pyroclastic rocks. These Takla rocks have been intruded by plutons and other bodies of the mainly granodiorite to quartz monzonite Early Jurassic Black Lake Suite and are in turn unconformably overlain by or faulted against Lower Jurassic calc-alkaline volcanics of the Toodoggone Formation (Hazelton Group).

The dominant structures in the area are steeply dipping faults that define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high-angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively, these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.

The occurrence area is underlain by Toodoggone Formation grey, orange and green andesite, and quartz-eye andesite crystal and crystal lapilli tuff. The contact between these two units is faulted. Lesser red, hematitic ash-fall tuffs interbedded with crystal tuffs also occur. These are variably chlorite and epidote altered. To the southeast, outcrops consist of Takla Group andesitic flows and volcanic tuff. The quartz monzonite to granodiorite Black Lake stock lies immediately to the west and intrudes Takla Group volcanics.

Locally, Takla Group volcanic rocks hosting quartz-carbonate breccia veins, 1.0 to 2.0-metres wide, with pyrite, sphalerite, galena and chalcopyrite mineralization are associated with a fault zone.

This mineralized zone is on strike to the northwest of the Electrum (MINFILE 094E 125) occurrence. The nature and distribution of quartz-chalcedony veins with minor adularia selvages, alteration and presence of fine sulphosalts with low base-metal concentrations suggests a higher elevation of an epithermal system with potential for an en echelon system along strike and at depth for high-grade gold and silver bonanza zones.

In 2003, rock samples yielded values of up to 0.72 gram per tonne gold, 204.4 grams per tonne silver, 0.999 per cent lead, 1.348 per cent zinc and 1.242 per cent copper (Assessment Report 27429).

Work History

The area has been explored in conjunction with the nearby Grace 1 (MINFILE 094E 129) and Electrum (MINFILE 094E 125) occurrences and a complete exploration history can be found there.