Abstract

The main source terrains for the Sverdrup Basin of Arctic Canada lay to the south and east and comprised the extensive Canadian and Greenland cratons which were mainly covered by Devonian siliciclastic strata. From Carboniferous to mid-Jurassic, the basin also received sediment from a northern source area, named Crockerland.

The Triassic-Jurassic succession of northernmost Axel Heiberg Island was examined to document the facies and stratigraphic distribution of Crockerland-derived sandstones in the succession. Such sandstones were identified by documenting a southward facies change to offshore siltstone and shale. Northerly-derived sandstones were found to be common in the Lower Triassic, Upper Triassic and lower Middle Jurassic portions of the succession. Their presence in the sandstone-dominant, uppermost Triassic–Lower Jurassic succession was not determined due to difficulties in differentiating northerly-derived sediments from those derived from the south and east.

All three Lower Triassic sequences contain sandstones of shallow to offshore shelf origin. Sandstone units are up to 45 m thick and the sandstone facies tract for each sequence is estimated to have been about 100 km wide. Thick intervals of beach to offshore shelf sandstones occur in two Carnian (Upper Triassic) sequences and the sandstones of the upper sequence are truncated northward by a major unconformity. This indicates that in late Carnian the Crockerland shoreline was well south of the northern tip of Axel Heiberg Island. Northerly-derived, Middle Jurassic (Aalenian) sandstones are preserved at only two localities. They are extensively burrowed and are of middle to outer shelf origin.

On the basis of the amount, composition and grain size of the sediment derived from Crockerland, it appears that low-lying, sedimentary strata characterized this source terrain. If Triassic to mid-Jurassic strata are preserved below the Cretaceous-Tertiary continental terrace wedge on the inner portion of the continental shelf north and west of Axel Heiberg, the succession may contain shallow shelf to beach sandstones which have the potential to act as reservoirs for petroleum.

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