Simulation of Carbon Isotope Excursion Events at the Permian-Triassic Boundary Based on GEOCARB

• Published in: Open Geosciences
• Main Authors: Zhong Y. J., Huang K. K., Lan Y. F., Chen A. Q.
• Format: Article in Journal/Newspaper
• Language: English
• Published: De Gruyter 2018
• Subjects: permian-triassic boundary; carbonate; carbon isotope; geocarb; simulation; Geology; QE1-996.5; Methane hydrate
• Online Access: https://doi.org/10.1515/geo-2018-0034; https://doaj.org/article/ff0c00686a614dca85c45fcf273a0fd2

The biggest Phanerozoic mass extinctionoccurred at the Permian-Triassic boundary and resulted in the loss of about 95% or more of all marine species. For quite some time, many kinds of abnormal environmental events were adopted to explain the abnormal reduction of carbon isotope at the Permian-Triassic boundary, however there still has not been a unified opinion. In this paper, based on the carbon cycle balance model of the earth under a long-period scale, the contributions of possible cataclysm events at the Permian-Triassic boundary to the carbon isotope records in carbonates were quantitatively simulated. The results proved that a single event, such as volcanism, terrestrial ecosystem collapse or another factor, was not strong enough to lead to the negative bias of carbon isotope at the Permian-Triassic boundary. Even though the release of methane hydrate can result in a comparably large negative excursion of inorganic carbon, this explanation becomes unsuitable when both the shifting Permian-Triassic boundary and the fluctuation record of other inorganic carbon isotopes in the early Triassic as a whole are considered. Therefore, it is suggested that the dynamic equilibrium between inorganic carbon reserves and organic carbon reserves was possibly disturbed by a superimposed effect of multiple events.