Major geological events in the late Guadalupian and carbon–strontium isotope responses in the Yangtze platform, South China

Abstract

Two sections of marine carbonate strata, Podu and Lengshuixi, from the Yangtze platform, South China, are investigated in terms of major geological events and carbon–strontium isotope responses. The results show a large-scale regression and a Large Igneous Province (LIP) event occurred in succession in the short interval of the late Guadalupian, inducing a biodiversity crisis. The regression event, marked by an increase in the 87Sr/86Sr ratio, is observed in the Jinogondolella postserrata Zone. It contributed significantly to the reduction in species habitat, leading to notable losses within the shallow-water species assemblage. A subsequent LIP event occurred after the appearance of Jinogondolella altudaensis, releasing CO2 and numerous other deleterious gases that further amplified the crisis in shallow-water to deep-sea environments. The corresponding decline in Sr and C isotopes could have been a response to the basaltic eruption (relative increase from mantle-derived Sr) and release of 12C-enriched CO2. During the process of creation of the LIP, the decline in δ13Ccarb was mainly associated with 12C-enriched CO2 release from organic matter in sedimentary strata, and high-temperature isotope fractionation during the volcanic eruption stage (exceeding 1200 °C). This study could further provide valuable clues regarding the development process of the major geological events and the causes of the biodiversity crisis.

Middle Permian organic carbon isotope stratigraphy and the origin of the Kamura Event

“…The composite geological time is based on Kametaka et al (2009), Gradstein et al (2012), Wu et al (2017) and Zhang et al (2019). The lithology legend is shown in Naqing section (Buggisch et al, 2011), Gou Chang section (Wignall et al, 2009;Bond et al, 2010b), Xiongjiachang section (Wignall et al, 2009;Bond et al, 2010b), Houchang section (Bond et al, 2010b), Rencunping section (Cao et al, 2018), Penglaitan (Wang et al, 2004), Tieqiao section (Yan et al, 2013), Kamura section (Isozaki et al, 2007a, b), Dukou section (Shen et al, 2013), Xikou section (Cheng et al, 2019), Shangsi section (Shen et al, 2013), Podu section (Shi et al, 2017), Lengshuixi section (Shi et al, 2017), and Palmar River section (Laya et al, 2013). The δ 13 C org records are from Kapp Starostin section (Bond et al, 2015), Gongchuan section (Liu et al, 2018), Tieqiao section (Yan et al, 2013), Sydney basin (Birgenheier et al, 2010), and Gujo-hachiman section (Nishikane et al, 2014) Fig.…”

Early–Middle Permian strontium isotope stratigraphy of marine carbonates from the northern marginal areas of South China: Controlling factors and implications

“…The 87 Sr/ 86 Sr minimum of the Capitanian is one of the most significant features in the Phanerozoic seawater 87 Sr/ 86 Sr history (Kani et al, 2008(Kani et al, , 2013Korte et al, 2006;McArthur et al, 2012;Veizer et al, 1999), and this extremely low Sr-isotope value naturally reflects a minimum flux from continental crust with respect to that from mid-oceanic ridges. Various global events such as orogenic events, glacial activities, and changes in sea-level, climate, weathering rates, oceanic crustal growth rates as well as mid-oceanic ridge hydrothermal systems are all important controlling factors for the components and evolution of Sr-isotope in Permian seawater (Chen, Joachimski, Sun, Shen, & Lai, 2011;Garbelli et al, 2019;Huang, Hou, Qing, et al, 2019;Isozaki, 2009;Kani et al, 2008Kani et al, , 2013Korte et al, 2006;Qu et al, 2020;Shi et al, 2017;Wang et al, 2018).…”