Isotopic evidence from a Brazos River (Texas, USA) cretaceous/paleogene boundary section consistent with a pulse of greenhouse warming shortly after the Chicxulub impact

IF 4 1区地球科学 Q1 GEOGRAPHY, PHYSICAL

Global and Planetary Change Pub Date : 2025-06-10 DOI:10.1016/j.gloplacha.2025.104924

Kenneth G. MacLeod, Brian T. Huber, Clay Tabor, Siddhartha Mitra, Rachel Wheatley, Cheryl Harrison, Maya Tessler, Charles Bardeen, Nicole S. Lovenduski, Julio Sepúlveda, Joshua Coupe, Shixiong Hu

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Abstract

Stable isotopic analyses of individual specimens of the benthic foraminifera Lenticulina show an ~1 ‰ decrease in d18O values beginning 170 cm above the K/Pg boundary at the Brazos River ‘River Bank South’ Cretaceous/Paleogene (K/Pg) outcrop. This negative d18O shift is most rigorously documented by analyses of visually screened fragments of gently crushed specimens. Scanning electron microscope images of broken specimens confirm that excellent test preservation is present throughout the section. Parallel d18O analyses of other separates (specimens infilled with secondary carbonate, isolated secondary carbonate, and test fragments that failed visual screening) are offset by −1 ‰ to −3 ‰ from the clean fragments reinforcing arguments that clean foraminiferal fragments preserve depositional values.

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来自Brazos河（美国德克萨斯州）白垩纪/古近纪边界剖面的同位素证据与希克苏鲁伯撞击后不久的温室变暖脉冲一致

对底栖有孔虫Lenticulina个体标本的稳定同位素分析表明，在布拉索斯河“南岸”白垩系/古近系（K/Pg）露头处，从K/Pg边界上方170 cm处开始，d18O值下降了~1 ‰。这种负的d18O位移是最严格的记录，通过分析视觉筛选碎片轻压标本。破碎标本的扫描电子显微镜图像证实，在整个切片中存在良好的测试保存。平行d18O分析的其他分离物（充满次生碳酸盐的标本，分离的次生碳酸盐和未通过目测筛选的测试碎片）与清洁碎片抵消了−1 ‰至−3 ‰，加强了清洁有孔虫碎片保持沉积价值的论点。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Global and Planetary Change 地学天文-地球科学综合

CiteScore

7.40

自引率

10.30%

发文量

226

审稿时长

63 days

期刊介绍： The objective of the journal Global and Planetary Change is to provide a multi-disciplinary overview of the processes taking place in the Earth System and involved in planetary change over time. The journal focuses on records of the past and current state of the earth system, and future scenarios , and their link to global environmental change. Regional or process-oriented studies are welcome if they discuss global implications. Topics include, but are not limited to, changes in the dynamics and composition of the atmosphere, oceans and cryosphere, as well as climate change, sea level variation, observations/modelling of Earth processes from deep to (near-)surface and their coupling, global ecology, biogeography and the resilience/thresholds in ecosystems. Key criteria for the consideration of manuscripts are (a) the relevance for the global scientific community and/or (b) the wider implications for global scale problems, preferably combined with (c) having a significance beyond a single discipline. A clear focus on key processes associated with planetary scale change is strongly encouraged. Manuscripts can be submitted as either research contributions or as a review article. Every effort should be made towards the presentation of research outcomes in an understandable way for a broad readership.