Storms and deforestation prior to Triassic – Jurassic Boundary? Evidence from woody fossils at upmost Xujiahe Formation, Southwestern China

Abstract

Abstract Global climate and environmental changes were the main causes of the end-Triassic mass extinction. However, direct sedimentological evidence of environmental catastrophes is rare in Triassic – Jurassic interval, especially in the eastern Tethys region. The newly discovered in-situ trunk fossils in paleosol surface and a set of unique branch-supported sandstones below may record the environmental disaster at the Triassic-Jurassic interval in the northern Sichuan Basin. Sedimentological data showed the strong storm prevalent induced the lodging direction of in-situ trunks is opposite to the direction of paleocurrent. Enhancement of large-scale runoff along with the dramatic increase of woody detrital input may indicate the deforesting at the Triassic -Jurassic boundary in eastern Tethys, Sichuan Basin.