Environmental Conditions and Events Prior to the Permian-Triassic Boundary at Meishan Section, China

摘要

INTRODUCTION Extensive investigations have been conducted on the Permian-Triassic (P-T) boundary mass extinction and environmental changes. Previous studies focus on the records of paleontology (Jin et al., 2000), carbon isotope composition (Xie et al., 2007; Yin et al., 2001), platinum-group elements (Xu et al., 2007), zircon chronology (Mundil et al., 2004; Bowring et al., 1998), and organic geochemistry (Xie et al., 2005) in a relatively large stratigraphical interval at the Meishan Section. Under the mind of high-resolution "post-stratotype" research, the microfacies sequence in the key interval of Beds 24-29 at the Meishan Section was recently examined to highlight the events and depositional conditions during the P-T boundary (Cao and Zheng, 2009). Here, we present a preliminary study on the observation of 1 cm thick continuous strata just below event Bed 25 (including pyrite crust and the upper most layer of Bed 24e).