The Appalachian area as a tectonostratigraphic analogue for the Barents Sea shelf

Abstract

The US Appalachian Basin and the Arctic Norwegian and Russian Barents Sea shelf (BSS) areas are two strategic provinces for the energy industry. The Appalachian Basin is a well-studied, mature, onshore basin, whereas the offshore BSS is still considered a frontier area. This study suggests that the Appalachian Basin may be an appropriate analogue for understanding the BSS and contribute to development of a tectonostratigraphic framework for the area. Although the Appalachian and BSS areas reflect different times and settings, both areas began as passive margins that were subsequently subjected to subduction and continent collision associated with the closure of an adjacent ocean basin. As a result, both areas exhibited multi-phase subduction-type orogenies, a rising hinterland that sourced sediments, and a foreland-basin sedimentary system that periodically overflowed onto an adjacent intracratonic area of basins and platforms with underlying basement structures. Foreland-basin sedimentary systems in the Mid-to-Late Palaeozoic Appalachian Basin are composed of unconformity-bound cycles related to specific orogenic pulses called tectophases. Each tectophase gave rise to a distinct sequence of lithologies related to flexural events in the orogen. In this study, similar sequences are recognised in both BSS foreland-basin and adjacent intracratonic sedimentary sequences that formed in response to the Late Palaeozoic–Mesozoic Uralian–Pai–Khoi–Novaya Zemlya Orogeny, suggesting that the processes generating the sequences are analogous to the tectophase cycles in the Appalachian Basin. Hence, this pioneering use of the Appalachian area and its succession as large-scale tectonostratigraphic analogues for the BSS may further enhance understanding of Upper Palaeozoic to Middle Jurassic stratigraphy across the BSS