Revision mapping of the Yukon-Tanana and equivalent terranes in northern British Columbia and southern Yukon Territory between 131° and 132°W

The northern half of the Jennings River (104-O) and southern half of the Wolf Lake (105 B) map areas include multiply deformed and metamorphosed rocks of the eastern Big Salmon Complex (Yukon Tanana Terrane) and a succession of mostly Paleozoic rock assemblages whose terrane affinity is in question. Hazel Ridge, on the west side of the area, reveals folded mafic metavolcanic rock, piedmontite chert, and marble in a series of overturned isoclinal folds. This consistent stratigraphic succession is overlain by metagreywacke on a possible unconformity. In the northeast, siliceous gritty and mafic metavolcanic rocks of the Dorsey assemblage are intruded by orthogneiss. These are overlain on a probable detachment fault by thin mafic volcanic rock and limestone ((?)Klinkit assemblage) and by dark phyllitic rocks and quartzite (Swift River assemblage). Both Hazel Ridge and the Dorsey assemblage contain several quartz±feldspar-phyric siliceous layers that suggest volcanogenic massive-sulphide potential.