A high-resolution temporal record of environmental changes in the Eastern Caribbean (Guadeloupe) from 40 to 10 ka BP

QUATERNARY SCIENCE REVIEWS

卷:155

Article

Royer, Aurelien¹  Malaize, Bruno²  Lecuyer, Christophe^3,4  Queffelec, Alain¹  Charlier, Karine²  Caley, Thibaut²  Lenoble, Arnaud¹ 

[1] Univ Bordeaux, CNRS UMR PACEA 5199, Batiment B18,Allee Geoffroy St Hilaire,CS 50023, F-33615 Pessac, France

[2] Univ Bordeaux, CNRS UMR EPOC 5805, Batiment B18,Allee Geoffroy St Hilaire,CS 50023, F-33615 Pessac, France

[3] Univ Lyon 1, Lab Geol Lyon, Ecole Normale Super Lyon, CNRS UMR 5276, F-69622 Villeurbanne, France

[4] Inst Univ France, Paris, France

关键词: Caribbean Basin;    Last Glacial;    Guano;    Carbon isotope;    Nitrogen isotope;   

DOI  :  10.1016/j.quascirev.2016.11.010

来源: Elsevier

【 摘 要 】

In neotropical regions, fossil bat guano accumulated over time as laminated layers in caves, hence providing a high-resolution temporal record of terrestrial environmental changes. Additionally, cave settings have the property to preserve such organic sediments from processes triggered by winds (deflation, abrasion and sandblasting) and intense rainfall (leaching away). This study reports both stable carbon and nitrogen isotope compositions of frugivorous bat guano deposited in a well-preserved stratigraphic succession of Blanchard Cave on Marie-Galante, Guadeloupe. These isotopic data are discussed with regard to climate changes and its specific impact on Eastern Caribbean vegetation during the Late Pleistocene from 40 to 10 ka cal. BP. Guano delta C-13 values are higher than modern ones, suggesting noticeable vegetation changes. This provides also evidence for overall drier environmental conditions during the Pleistocene compared to today. Meanwhile, within this generally drier climate, shifts between wetter and drier conditions can be observed. Large temporal amplitudes in both delta C-13 and delta N-15 variations reaching up to 5.9 parts per thousand and 16.8 parts per thousand), respectively, also indicate these oceanic tropical environments have been highly sensitive to regional or global climatic forcing. Stable isotope compositions of bat guano deposited from 40 to 35 ka BP, the Last Glacial Maximum and the Younger-Dryas reveal relatively wet environmental conditions whereas, at least from the end of the Heinrich event 1 and the Bolling period the region experienced drier environmental conditions. Nevertheless, when considering uncertainties in the model age, the isotopic record of Blanchard Cave show relatively similar variations with known proxy records from the northern South America and Central America, suggesting thus that the Blanchard Cave record is a robust proxy of past ITCZ migration. Teleconnections through global atmospheric pattern suggest that islands of the eastern Caribbean Basin could be also under the influence of a bipolar temperature gradients that impact the mean location of the ITCZ, with a Southern Hemisphere imprint during the glacial period and a more significant role of Northern Hemisphere during the last deglaciation. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

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