Stratigraphic development of the Permian to Triassic of East Greenland: An expanded and complete P-T boundary succession?

The Permian-Triassic boundary contains a record of Earth’s greatest mass extinction event. Sections through which this extinction event can be examined are rare, and are often condensed resulting in a poor resolution of the timing of its various component stages. Spectacular exposures through an expanded Permian-Triassic succession exist in East Greenland, however the completeness of these records has been a matter of considerable debate. To address this issue a regional synthesis has been undertaken, incorporating newly collected data with previously published work.

Following a Late Permian transgression, carbonate reef development accentuated pre-existing basin topography. Continued transgression led to the deposition of organic rich mudstones. During the latest Permian fluctuating sea level resulted in the localised erosion of the carbonate reefs which still formed bathymetric highs within the basin. At this time clastic systems also began to prograde in to the basin resulting in turbidite deposition in offshore regions. Erosion and shallow water deposition was focussed around the basin margins where carbonate reef development had been most extensive. The Early Triassic is marked by transgression and the blanketing of the region with mudstones and fine grained turbidite sandstones.

This study demonstrates the localised nature of erosion during the Permian-Triassic transition in East Greenland. Continuous offshore mudstone and turbidite deposition is recognised across the boundary were examined only a short distance from the basin margin and around areas of inherited basin topography. The synthesis undertaken provides a stratigraphic framework for further research on this important interval.