Palynological record of the Carnian Pluvial Episode from the northwestern Sichuan Basin, SW China

Abstract

The prevailing arid Late Triassic climate was interrupted by a humid Carnian Pluvial Episode (CPE) during the mid-Carnian period. In this study, a palynological study was conducted for the Ma'antang Formation (Carnian) from the northwestern Sichuan Basin, SW China, in the eastern Tethys. The study reveals dominance of terrestrial palynomorphs, and two palynological assemblage zones were identified. Palynofloras are well-presented by dominant ferns (especially Dipteridaceae/Matoniaceae), with less abundant lycopsids, conifers, cycadophytes/ginkgophytes and seed ferns. Overwhelming predominance of wet Lowland SEG and hygrophyte elements, and increased Lowland/Hinterland as well as hygrophyte/xerophyte ratios observed in Units 2–4 of the Ma'antang Formation, suggesting intensified humidity during the Julian 2 in this area. This study presents the first palynological evidence for vegetation changes in South China during the CPE, and correlates well with observations from North China as well as western Tethys, thus further supports worldwide impact of humid climate associated with the CPE.