A Late Triassic vegetation record from the Huangshanjie Formation, Junggar Basin, China: possible evidence for the Carnian Pluvial Episode

The Carnian Pluvial Episode (CPE; c. 234–232 million years ago) is characterized by an accelerated hydrological cycle, global warming and a period of elevated biotic turnover. Using spores and pollen, we reconstruct vegetation and climate changes through a Carnian–Norian (Upper Triassic) interval of the Huangshanjie Formation from the Junggar Basin, China. Four palynofloras were identified, representing distinct vegetation communities. Among these palynofloras, we observed a prominent shift from a conifer-dominated climax forest community, with common ginkgophytes and bennettites, to a fern-dominated community, suggestive of an environmental perturbation. We interpret this change as a regional shift in vegetation, likely caused by increased humidity, consistent with the CPE. Our records represent the first indication of a possible CPE-induced vegetation response in the Junggar Basin and highlight how this event likely affected floral communities of inland Laurasia.This research was supported by the National Natural Sciences Foundation of China (NSFC 42002003) and the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS) (20182110) for J.P., the Swedish Research Council (VR) (grant no. 2019-04524 for S.S. and 2019-4061 for V.V.) and the Carl Tryggers Foundation (grant no. 19:380).