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

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.

Source‐to‐sink mass‐balance analysis of an ancient wave‐influenced sediment routing system: Middle Jurassic Brent Delta, Northern North Sea, offshore UK and Norway

“…Recent studies have shown that applying the BQART model to source regions can provide reasonable predictions of sediment flux that are consistent, within one order of magnitude, when compared to estimated sediment budget in the downsystem stratigraphic record in sub‐modern (Watkins et al, 2018) and ancient depositional sinks (Brewer et al, 2020; Gilmullina et al, 2022; Lyster et al, 2020; Zhang et al, 2018). However, our analysis of the Brent Delta system suggests that the mapped net‐depositional sediment budget (2.0–2.8 Mt/year, median estimate: 2.3 Mt/year) is about an order of magnitude less than the total BQART‐predicted sediment budget from the three source regions (13.9–23.0 Mt/year, median estimate: 17.4 Mt/year; Figure 15).…”

“…However, the extent to which sediment mass‐balance is feasible, even in data‐rich and structurally‐confined depositional sinks, is often not well evaluated, as net‐export or net‐import of sediment (e.g., by marine transport processes as outlined above) and intrabasinal sediment sourcing are usually not accounted for in these supposedly closed systems. This raises concerns as to how practicable it is to balance erosional and depositional sediment budgets, particularly in leaky or open sediment routing systems, which are significantly more common in the geological record (Gilmullina et al, 2022; Weltje & Brommer, 2011).…”

Placing constraints on the nature of short‐term eustatic curves

“…Large changes in hinterland relief and the resulting size of drainage basins can also show dramatic changes over the timeframes analysed here (e.g. Braun et al, 2014;Gilmullina et al, 2021). Therefore, the approach outlined here should be used with caution in settings where large changes in sediment supply are likely to occur, including localised autocyclic effects.…”

Changing provenance and stratigraphic signatures across the Triassic–Jurassic boundary in eastern Spitsbergen and the subsurface Barents Sea

“…The stratigraphy investigated in eastern Spitsbergen when compared to the Barents Sea, shows the variable magnitude of uplift and erosion at the Triassic-Jurassic boundary. It seems reasonable to assume that the De Geerdalen and Flatsalen formations originally had similar development as elsewhere in the western part of the Svalbard Platform, Svalbard and the Barents Sea, and that many hundreds of meters of strata is missing below the Jurassic unconformity (Müller et al, 2019;Gilmullina et al, 2021b). This erosion is the source for sediments with young detrital zircon age spectrum in the Jurassic succession.…”