Late Cretaceous palynofloras from the southern Laurasian margin in the Xigaze region, Xizang (Tibet)

Palaeontology plays an indispensable role in interpreting the sedimentary and tectonic history of the convergence of India and Laurasia and its consequences. Hitherto, spores and pollen grains have not been used very much in this connection. In this paper, we consider the palynology of two sedimentary successions in Xizang (Tibet) that reflect the early stages of this convergence. One of these is near the town of Xigaze, in Xigaze County (the eastern site), and the other is in Zhongba County (the western site). The palynomorph assemblages from these sites are broadly comparable in being dominated by gymnosperm pollen taxa, especially Classopollis and Exesipollenites. Angiosperm pollen grains are more common at the eastern site, especially representatives of the genus Proteacidites. The assemblages are considered to be late Late Cretaceous (Santonian–Maastrichtian) in age and, in common with the lithologies from which they were recovered, reflect a hot, arid or semi-arid climate comparable to that prevailing in South China during this period.