Abstract

The Boothia Uplift of the central Canadian Arctic Islands, located some 1200 km west of the Caledonian collision zone, is a "Laramide-type" basement-cored uplift that affected Precambrian crystalline basement and lower Paleozoic carbonate platform sequence. The two major segments of the Boothia Uplift, separated by the east-trending Barrow Strait, had different deformational histories. In the southern segment, uplift of the basement began in Late Silurian time, while in the northern segment, there was subsidence and platform drowning.In the northern segment, a thick sedimentary succession, containing numerous potential detachment surfaces, was involved in Early Devonian deformation. Folding of the cover along northerly trends resulted in the longitudinal infilling of two small, synclinal basins in the hanging wall of the uplift. The type of basin fill was dependent on source proximity and was influenced by contemporaneous flexure of the sedimentary cover. The western basin, the Grove Lake basin, received predominantly terrestrial sediments, and the eastern one, the Sutherland River basin, received mostly marine sediments, including a thick, possibly submarine, synsedimentary breccia that accumulated in response to tilting of partly lithified, carbonate strata. Southward-transported clastic sediments of the basin-fill sequence and contours showing the amount of pre-Emsian erosion suggest that a high-angle tear fault influenced sedimentation in the Grove Lake basin.The areally restricted and variably transported syntectonic clastics of the northern segment are different from coeval clastics of the southern segment. This is attributed to different deformational histories along the uplift and, in particular, to the deformation of a thick, locally anisotropic sedimentary cover sequence in the northern segment.A thick Emsian to early Eifelian carbonate platform sequence onlapped the eroded Boothia Uplift which had acted as a paleohigh for some 10–15 Ma. Early Devonian basement faults appear to have been reactivated as dextral wrench faults during Tertiary time.

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