Clumped-isotope-derived climate trends leading up to the end-Cretaceous mass extinction in northwest Europe
Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology or Earth and Environmental Sciences, Department of Earth and Environmental Sciences : Paleotemperature reconstructions linked to Deccan traps volcanic greenhouse gas emissions and associated fe...
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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My University
2021
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| Online Access: | https://dx.doi.org/10.7302/4001 http://deepblue.lib.umich.edu/handle/2027.42/171489 |
| Summary: | Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology or Earth and Environmental Sciences, Department of Earth and Environmental Sciences : Paleotemperature reconstructions linked to Deccan traps volcanic greenhouse gas emissions and associated feedbacks in the lead-up to the end-Cretaceous meteorite impact and extinction document local and global climate trends during a key interval of geologic history. Here, we present a new clumped-isotope-based paleotemperature record derived from fossil bivalves from the Maastrichtian type region, in southeast Netherlands and northeast Belgium. Clumped isotope data documents a mean temperature of 19.2 3.8 C, consistent with other Maastrichtian temperature estimates, and an average seawater δ18O value of -0.2 0.9‰ VSMOW for the region during the latest Cretaceous (67.1–66.0 Ma). A notable temperature increase at ~66.4 Ma is interpreted to be a regional manifestation of the globally-defined Late Maastrichtian Warming Event, linking Deccan Traps volcanic CO2 emissions prior to the end-Cretaceous extinction to climate change in the Maastricht region. Fluctuating seawater δ18O values coinciding with temperature changes suggest alternating influences of warm, salty southern-sourced waters and cooler, fresher northern-sourced waters from the Arctic Ocean. This new paleotemperature record contributes to the understanding of regional and global climate response to large-scale volcanism and ocean circulation changes leading up to a catastrophic mass extinction. |
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