Sedimentary facies and mineral provenance of Upper Triassic sandstones offshore Kvitøya, Svalbard: implications for palaeogeographic interpretations in the northern Barents Shelf area

Abstract

Upper Triassic (Carnian) sandstones of the De Geerdalen Formation cored south of the island of Kvitøya (80°N), north-easternmost Svalbard, are described in terms of sedimentary facies and petrography and compared regionally in the northern Barents Shelf. The succession off Kvitøya is characterized by its great thickness and is dominated by deltaic deposits with high sand content of lithic–feldspathic compositions. Comparison of sediment facies and sandstone compositions with adjacent areas suggest that the succession off Kvitøya is part of a larger delta system with its main sediment source from the east. The delta sedimentation was terminated by marine transgression in the earliest Norian. The sandstone compositions off Kvitøya differ from nearby locations by the higher content of cherty rock fragments and reworked volcanic debris in the Kvitøya sandstone, which is most distinct in the lower part of the succession. Provenance signatures are investigated by mineral–chemical analysis of detrital feldspars, rock fragments, garnet and Cr-spinel, characterizing a wide variety of igneous, metamorphic and sedimentary terranes, including palaeo-Urals and areas farther to east. Additional, more proximal sediment source areas may also have existed that could explain the increased sediment thickness and the mineralogical immature sandstone compositions of the Carnian sediments off Kvitøya.

Keywords

• de geerdalen formation
• carnian
• deltaic sedimentation
• feldspar compositions
• garnet
• cr-spinel