The Chef (Icefall) showing consists of two mineralized zones situated on both sides of a precipitous cliff topped by an icefall, between the Taku and Tulsequah rivers, approximately 81 kilometres south of Atlin, B.C.
The Icefall (Chef) area consists of Lower Jurassic Laberge Group finely bedded sediments (locally graphitic argillite to wackes) and lesser volcanic sediments, Paleozoic tuffs, flows and sediments and Upper Triassic Stuhini flows, tuffs, and sediments. The area is overlain by Eocene Sloko Group volcanic rocks (flow, tuff, debris, flows) and intruded by Sloko-Hyder Plutonic Suite felsic to intermediate dykes and other Lower Jurassic monzonites and quartz monzonites of the Aishihik Plutonic Suite.
Copper-lead-zinc mineralization was seen in outcrop and in highly mineralized float boulders on the lower section of ice. Pyrite, pyrrhotite, chalcopyrite, galena, and sphalerite (with malachite and azurite oxidation minerals) occur massively or as disseminations within silicified and/or clay altered tuff and sediments.
The Icefall prospect consists of two mineralized areas separated by an inaccessible icefall, which, on the basis of mineralized float, probably masks continuity between the two showings. On the west side of the icefall, mineralization consists of pyrite plus/minus quartz veins hosted by argillites of the Laberge or Stuhini groups. This style of mineralization grades eastward into a zone of green to white (bleached) weathering rocks, apparently of volcanic origin. Float from this relatively inaccessible area contains abundant disseminated sulphides, primarily pyrite, and several zones of copper staining were observed in the cliff face. Boulder trains on the glacier approximately 1 kilometre south of the cliff contain abundant mineralized detritus, including bleached lapilli tuff, felsic intrusive, quartz-eye porphyry and rocks of uncertain protolith, containing disseminated and semimassive pyrite and sphalerite, with minor galena and chalcopyrite.
Work History
The Icefall was discovered and mapped by BC Geological Survey Branch geologists in 1993. The CST 1, 2, 3 claims were staked by Ecstall Mining Corporation in 1994 to cover the Icefall and Stoker (104K 126) polymetallic sulfide mineral occurrences. Exploration work on the CST claim claims by Ecstall in 1994 consisted of soil sampling (41 samples), silt sampling (5 samples), prospecting and rock sampling (23 samples). At the time, analytical results were considered encouraging.
In 2007, Saturn Mineral's personnel conducted reconnaissance prospecting and rock sampling programs accompanied by lithological and structural observations on the Pete-ME property. In 2007, 86 rock samples were collected in the vicinity of the Icefall and Stoker showings
It was concluded that the showings documented in 2007 and discovered on the property before do not form any consistent zone of any considerable width, length and grade. Several gossans encountered along the surveyed valleys of the Icefall and Stoker drainages, do display signs of strong alteration, but they are accompanied by only very low-grade mineralization.
In 2008 MMI (mobile metal ion) soil sampling along with grid emplacement was carried out on the western part of the Pete-Me Property in the vicinity of the Icefall showing (104K 130). A total of 27 soil samples over 625 meters were collected. Multispectral analysis images for the entire claim area are given. These show iron oxide with lineaments, illite/sericite with lineaments; kaolinite/alunite with lineaments; and siliceous rocks with lineament. Several shaded-relief maps with lineaments are also given Assessment Report 30456).
