Linking sediment supply variations and tectonic evolution in deep time, source-to-sink systems—The Triassic Greater Barents Sea Basin

Albina Gilmullina,Christian Haug Eide,Anthony George Doré,Tore Grane Klausen,Anna Suslova,Valentina Marzia Rossi

doi:10.1130/b36090.1

Abstract

Abstract Triassic strata in the Greater Barents Sea Basin are important records of geodynamic activity in the surrounding catchments and sediment transport in the Arctic basins. This study is the first attempt to investigate the evolution of these source areas through time. Our analysis of sediment budgets from subsurface data in the Greater Barents Sea Basin and application of the BQART approach to estimate catchment properties shows that (1) during the Lower Triassic, sediment supply was at its peak in the basin and comparable to that of the biggest modern-day river systems, which are supplied by tectonically active orogens; (2) the Middle Triassic sediment load was significantly lower but still comparable to that of the top 10 largest modern rivers; (3) during the Upper Triassic, sediment load increased again in the Carnian; and (4) there is a large mismatch (70%) between the modeled and estimated sediment load of the Carnian. These results are consistent with the Triassic Greater Barents Sea Basin succession being deposited under the influence of the largest volcanic event ever at the Permian-Triassic boundary (Siberian Traps) and concurrent with the climatic changes of the Carnian Pluvial Event and the final stages of the Northern Ural orogeny. They also provide a better understanding of geodynamic impacts on sedimentary systems and improve our knowledge of continental-scale sediment transport. Finally, the study demonstrates bypass of sediment from the Ural Mountains and West Siberia into the adjacent Arctic Sverdrup, Chukotka, and Alaska Basins in Late Carnian and Late Norian time.

Highlights

Variations in amounts of sediment supplied to sedimentary basins and continental margins through geological time reflect variations in source-area tectonics and climate (Fig. 1) (Galloway et al, 2011; Braun et al, 2014)
Our analysis of sediment budgets from subsurface data in the Greater Barents Sea Basin and application of the BQART approach to estimate catchment properties shows that (1) during the Lower Triassic, sediment supply was at its peak in the basin and comparable to that of the biggest modern-day river systems, which are supplied by tectonically active orogens; (2) the Middle Triassic sediment load was significantly lower but still comparable to that of the top 10 largest modern rivers; (3) during the Upper Triassic, sediment load increased again in the Carnian; and (4) there is a large mismatch (70%) between the modeled and estimated sediment load of the Carnian
The LQART model accounts for the suspended sediment load (Syvitski and Milliman, 2007); bed load is an integral part of transported sediments, which can be up to 5–6% of total sediment supply (Alexandrov et al, 2009), and represents uncertainty in our models

Summary

Introduction

Variations in amounts of sediment supplied to sedimentary basins and continental margins through geological time reflect variations in source-area tectonics and climate (Fig. 1) (Galloway et al, 2011; Braun et al, 2014). Sediment supply rates in ancient sedimentary basins can be determined using, e.g., seismic data, well control, and biostratigraphic dating. These data are often used to constrain tectonic, climatic, and sedimentary evolution of the sedimentary basin and its hinterland. Sediments from the Urals, West Siberia, or Taimyr are thought to have been transported long distances across the Arctic in the Late Triassic (Miller et al, 2018; Sømme et al, 2018), but the tectonic evolution in the source area, the location of sediment sources, and the mechanism of sediment transport across vast distances remains unclear

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