Arctic sediment routing during the Triassic: sinking the Arctic Atlantis

Abstract

Opening of the Arctic Ocean has been the subject of much debate, and the placement of terranes in the Early Mesozoic remains a crucial part of this important discussion. Several continental terranes complicate the palaeogeographical reconstruction. One such terrane is Crockerland, which has been inferred to explain sediment distribution in the Arctic throughout the Mesozoic. However, Triassic successions throughout the Arctic basins bear many similarities, and a common sedimentary source could offer a simpler explanation with fewer complications for the past configuration of the Arctic. The study’s goal is to test the hypothesis of long-distance sediment transport from a common source in present-day Russia to all Arctic basins in the Triassic, and to demonstrate how estimates of sediment routing distances can improve pre-break-up platetectonic reconstructions. Results confirm that (1) the Arctic basins were closely connected prior to break-up in the Mesozoic, (2) based on regional facies distribution, sediment budgets, sediment modelling and detrital zircon age spectra, the Crockerland terrane is unlikely to have existed as a major sediment supplying area, (3) the reconstructed Arctic sediment routing system can help to constrain plate-tectonic models, and (4) statistical estimation of sediment transport is a novel and potentially important tool for improving plate-tectonic and palaeogeographical reconstructions.