Trace element variations across Middle–Upper Cambrian carbonates: Implications for the paleoenvironment of eastern Laurentia

Shembilu, Noel; Azmy, Karem

doi:10.1016/j.marpetgeo.2021.105385

Cited by 3 publications

(1 citation statement)

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“…Simultaneously, causal links between volcanic activity, biological crisis, climate change, and other geological events are still under discussion (Wignall et al, 2009;Bond et al, 2010;Cao et al, 2018;Chen and Xu, 2019;Zhang B. L. et al, 2021;Sun et al, 2022). Marine carbonate rocks usually have the original geochemical composition that can approximately represent the paleo-seawater, and record the paleoenvironmental information such as seawater temperature (Zhao et al, 2022), redox conditions (Wignall and Twitchett, 1996;Rimmer, 2004;Tribovillard et al, 2006;Scholz et al, 2011;Takahashi and AuthorAnonymous, 2014;Shembilu and Azmy, 2022) and primary productivity (Tribovillard et al, 2006;Schoepfer et al, 2015). Nevertheless, due to global extensive regression, most regions have transformed from marine strata to non-marine strata (Ross and Ross, 1987;Haq and Schutter, 2008;Shen et al, 2020).…”

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confidence: 99%

Late Guadalupian–early Lopingian marine geochemical records from the Upper Yangtze, South China: Implications for climate-biocrisis events

Sun²,

Xia³

et al. 2023

Front. Earth Sci.

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Major paleoenvironmental changes occurred during the Guadalupian-Lopingian boundary (GLB) transition, but the causative linkages among the Emeishan Large Igneous Province (LIP), end-Guadalupian crisis and climatic fluctuations are still in dispute. Variation of geochemical proxies preserved in the sedimentary records is important evidence in examining potential links between volcanisms and environmental changes. Herein, we carried out a comprehensive study of carbon/strontium isotope and trace element geochemistry at the Dukou section, northern margin of the Upper Yangtze. During the Late Guadalupian, the carbon isotope showed a negative drift, the marine primary productivity declined simultaneously, and redox proxies indicate the enhancement of ocean oxidation. It is worth noting that the δ13Ccarb turns into a rapid negative drift from a slow decline at approximately 260.55 Ma, which was almost synchronized with the latest reported eruption ages of Emeishan Large Igneous Province. This coincidence suggests that global volcanic-tectonic activity during the Late Guadalupian might have been the important factor in carbon-cycle perturbation. Subsequently, the δ13Ccarb presents a rapid positive shift at approximately 259.4 Ma, and climate transformed from interglacial to P4 glacial, indicating that the climate rapidly cooled before the Emeishan LIP completely ended, which may be due to carbon sinks caused by weathering of mafic rocks, and may also be associated with a significant reduction in global volcanic activity. Accompanied by sudden weathering attenuation, the 87Sr/86Sr ratios show a significant increase instead from the previous long-time low value, which only can be explained reasonably by the rapid decline in mantle-derived Sr flux associated with the weakening of volcanic activity and mafic weathering. Intergrated geochemical indices in this interval shows that there is a rapid climate perturbation associated with a significant δ13Ccarb negative shift at approximately 260.55 Ma ∼ 259.10 Ma, which may be related to the eruption surge of the Emeishan LIP, active volcanic arcs, and triggered the end-Guadalupian biocrisis.

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