Comment on cp-2021-104

doi:10.5194/cp-2021-104-rc2

Abstract

Abstract. Paleotemperature reconstructions of the end-Cretaceous interval document local and global climate trends, some driven by greenhouse gas emissions from Deccan Traps volcanism and associated feedbacks. Here, we present a new clumped-isotope-based paleotemperature record derived from fossil bivalves from the Maastrichtian type region in southeastern Netherlands and northeastern Belgium. Clumped isotope data document a mean temperature of 20.4Â±3.8ââC, consistent with other Maastrichtian temperature estimates, and an average seawater Î´18OÂ value of 0.2Â±0.8ââ° VSMOW for the region during the latest Cretaceous (67.1â66.0âMa). A notable temperature increase at â¼66.4âMa is interpreted to be a regional manifestation of the globally defined Late Maastrichtian Warming Event, linking Deccan Traps volcanic CO2 emissions to climate change in the Maastricht region. Fluctuating seawater Î´18O 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.

Highlights

During the Late Maastrichtian, greenhouse gas emissions from the emplacement of the vast Deccan Traps large igneous province (LIP) on the Indian subcontinent resulted in global warming
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 10 during a key interval of geologic history
20 1 Introduction During the Late Maastrichtian, greenhouse gas emissions from the emplacement of the vast Deccan Traps large igneous province (LIP) on the Indian subcontinent resulted in global warming

Summary

Introduction

During the Late Maastrichtian, greenhouse gas emissions from the emplacement of the vast Deccan Traps large igneous province (LIP) on the Indian subcontinent resulted in global warming (see Hull et al, 2020 and references therein). This warming event (termed the Late Maastrichtian Warm Event or LMWE; Woelders et al, 2018) has been observed in multiple locations and has been dated to approximately coincide with the onset of major Deccan volcanism (66.413 ± 0.067 Ma; 25 Sprain et al, 2019). Deccan Traps volcanism and associated feedbacks and the Chicxulub bolide impact create a complex record of paleoenvironmental disturbances through the end-Cretaceous, leading to the rapid extinction of ~70 % of species on Earth (Schulte et al, 2010)

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