Affiliation:
1. School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
Abstract
Abstract
Large magnitude and rapid negative carbon isotope (δ
13
C) excursions in the Triassic–Jurassic boundary (TJB) interval have been proposed as critical evidence for the hypothesis that the emplacement of the Central Atlantic Magmatic Province (CAMP) triggered global carbon cycle perturbations and the end-Triassic mass extinction (ETE). However, the pattern and timing of δ
13
C variations during the ETE remain poorly constrained. Here I present high-resolution organic carbon isotope (δ
13
C
org
) records from a terrestrial TJB succession continuously exposed along the Haojiagou valley on the southern margin of the Junggar Basin, northwestern China. The δ
13
C chemostratigraphic correlations, combined with the palynological data, indicate that the position of the TJB should be placed at the base of bed 53. Importantly, the results show that two rapid negative carbon isotope excursions at the end Triassic roughly coincide with two episodes of variations in the palynological records. This observation supports the hypothesis that two pulses of biotic crisis during the ETE may have been triggered by two major episodes of CAMP magmatic activity. In addition, the data in this study support an early start for CAMP magmatic activity in the early Rhaetian, which may have led to a global carbon cycle perturbation and the related biotic crisis or turnover.
Funder
national natural science foundation of china
chinese academy of geological sciences and national committee of stratigraphy of china
ministry of science and technology of the people's republic of china
unesco-iugs
Publisher
Geological Society of London
Subject
Geology,Ocean Engineering,Water Science and Technology