Carboniferous and Permian subsurface stratigraphy, Prince Patrick Island, Northwest Territories, Canadian Arctic

Abstract

The Carboniferous and Permian succession of the Sverdrup Basin is extensive in the subsurface of northern Prince Patrick Island of the Canadian Arctic Archipelago, Northwest Territories. The succession is known from a series of seismic profiles and four exploratory wells drilled during the early 1970s. Upper Paleozoic strata are characterized by two broad packages. The lower package comprises Carboniferous to Lower Permian clastic and carbonate rocks truncated by a number of northwest southeast-trending synsedimentary normal faults. The upper package is composed of Middle Permian (Guadalupian) clastic rocks that were deposited during a regime of passive subsidence following the cessation of faulting. These strata are separated from the underlying Lower Permian and Carboniferous succession by a widespread and locally angular unconformity. Eleven upper Paleozoic formations have been identified on Prince Patrick Island: Borup Fiord, Canyon Fiord, Belcher Channel, Nansen, Raanes, Hare Fiord, 'unnamed clastics', Trappers Cove, Sabine Bay, van Hauen, and Trold Fiord. The succession contains eight major unconformities that can be correlated over a significant area. Five of these unconformities were encountered in three of the drilled wells. Three additional unconformities were observed on seismic profiles only. The eight unconformities and the seven transgressive regressive sequences between them have been traced seismically using a series of profiles. The ages of these sequences are Serpukhovian(?), Bashkirian Kasimovian, Gzhelian Sakmarian, Sakmarian Artinskian, Kungurian, Roadian Wordian and Capitanian(?). The Carboniferous and Permian geological history of Prince Patrick Island includes a complex succession of events whereby tectonic pulses, as evidenced by brittle deformation, alternated with episodes of tectonic quiescence and passive subsidence. Climatic conditions evolved from warm and relatively arid during the Bashkirian Sakmarian interval to increasingly cooler during the Artinskian Capitanian(?). More humid conditions were also established during the Kungurian. A major river system fed the Prince Patrick area with large amounts of clastic material during the Artinksian Guadalupian interval. The current geological setting of the area suggests the presence of many unexplored oil and gas plays. Unfortunately, the succession lies too deeply in the subsurface to envision any mineral exploration effort in the future.