The palynology of the Permian succession in the CSDP-2 Well, South Yellow Sea, China

Abstract

The fully cored CSDP-2 Well, drilled in the central uplift region of the South Yellow Sea, China, provides indispensable and very significant research opportunities to understand the evolution of life, paleoclimate, paleogeography, and tectonics during the Permian in the South Yellow Sea area of the Yangtze paleoblock. We here analyze 118 samples from 893.7 to 1798.8 m depth of the CSDP-2 borehole core and recognize three Permian palynological assemblages, Laevigatosporites minimus – Florinites florini (MF) for the Kungurian mid-lower Qixia Formation, Crucisaccites quadratoides – Limitisporites rhombicorpus (QR) for the Capitanian lower Longtan Formation and Macrotoispora media – Anticapipollis tornatilis (MT) for the Wuchiapingian upper Longtan Formation, in an ascending order. These palynological assemblages indicate a warm and semi-humid rainforest paleoenvironment and a drying tendency of the paleoclimate. The present study area belongs to the Yangtze paleoblock in paleogeography and is a part of the Cathaysia flora based on mega-plant fossil records. However, our palynological assemblages show similarities to those of both South China and North China subzones and, especially, their pollen contents with arid coniferous affinities highly similar to those in the north part of the South China subzone. The presence of conifers might suggest a more arid climate in the North China subzone had started to affect the Yellow Sea area in the Lopingian (Permian).