Pre-mississippian rocks of Nansen sound area, District of Franklin

A reconnaissance of parts of the Lower Palaeozoic Franklinian eugeosyncline and the Lower Cambrian or older Cape Columbia Group has been carried out. The Cape Columbia Group consists of argillaceous, quartzose, and calcareous sediments showing low grade regional metamorphism. The pre-Silurian succession of the eugeos yncline is incomplete, strongly faulted, and not fossiliferous. A thick sequence of slate, phyllite, sandstone, ribbon chert, dolomite, limestone and volcanic rocks has been assigned to the Rens Fiord Complex. The area probably contains the most complete Silurian and Devonian section of the eugeosyncline. The Lower Silurian and (?) older Imina Group, composed chiefly of lithic arenite and siltstone, was derived from metamorphic rocks and limestone off the north coast of Ellesmere Island. The Middle and Upper Silurian strata of Ellesmere Island - more than 10, OOO feet thick - consist of slaty siltstone and shale with quartzose sandstone, volcanic rocks and some conglomerate in the Upper Silurian. Devonian strata preserved only in Axel Heiberg Island comprise 12, OOO feet of largely non-marine elastic sediments (Stall worthy Formation) overlain by 10, 500 feet of turbidites and volcanic rocks, (Svartevaeg Formation). There is evidence for several pre-Silurian orogenies. Caledonian movements - probably confined mainly to Axel Heiberg Island - took place between Middle Silurian and Middle Devonian time with intermittent tectonism and keratophyric volcanism in the late Middle and early Upper Silurian. Strong Mid-Palaeozoic movements affected the whole area between Lower Devonian and Upper Mississippian time and probably culminated in Upper Devonian(?) granitic intrusions.