Continuous Wavelet Analysis on Ce/La and Magnetic Susceptibility Records in Permian-Triassic Dongpan Section in South China

摘要

INTRODUCTION The Permian-Triassic (P-T) mass extinction event (251.4±0.3 Ma) was the largest one in the Phanerozoic (Erwin, 1994). Establishing a high-precision chronostratigraphic framework is fundamental for a better understanding of the global climate change across the PermianTriassic. Owing to the general limitations of chronostratigraphy inferred from radiometric ages and paleontological records, the astronomical time scale (ATS), established by tuning astronomical forcing signals recorded in sedimentary strata, plays critical roles on defining and correlating the P-T mass extinction event (Rampino and Adler, 1998). In the last two decades, refinement of Quaternary to Paleogene chronostratigraphy by astronomical tuning to calculated orbital variations has allowed a more detailed understanding of the relationship between the sedimentary record and orbital cycles (Hilgen et al., 1999, 1995; Shackleton et al., 1999).