The Cretaceous/Tertiary boundary event in Tibet

Abstract

The Cretaceous/Tertiary boundary in the Gamba and Tingri regions of Tibet occurs between the Zongshan and Jidula Formations. Arenaceous facies similar to those of the Jidula Formation are widespread in Tibet and Pakistan; collectively, these represent the diachronous deposits of the Latest Cretaceous-Early Tertiary regression. Major faunal changes took place in Tibet during the Late Cretaceous. Ali of the Cretaceous ammonoids, planktonic and benthonic foraminifera, rudistid and inoceramid bivalves became extinct over the Campanian Maastrichtian interval in a stepwise pattern, with abrupt Late Campanian and Late Maastrichtian extinction events (Tabs. 3, 4). A large number of new taxa appeared during the Danian (Tabs. 3, 4). These faunal changes in the shallow-water marine facies of Tibet demonstrate that this region was not isolated from major global faunal changes taking place in the Cretaceous/Tertiary boundary mass extinction interval.