Paleoclimate and growth rates of speleothems in the northwestern Iberian Peninsula over the last two glacial cycles
| Autor: | Montserrat Jiménez-Sánchez, Xianfeng Wang, Hai Cheng, Ana Moreno, R. Lawrence Edwards, Heather Stoll, Saúl González-Lemos, María José Domínguez-Cuesta, Ana Mendez-Vicente |
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| Rok vydání: | 2013 |
| Předmět: |
010506 paleontology
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Holocene climatic optimum Speleothem Stalagmite Monsoon 01 natural sciences Arts and Humanities (miscellaneous) Cave Climatology Paleoclimatology General Earth and Planetary Sciences Glacial period Physical geography Holocene Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Quaternary Research. 80:284-290 |
| ISSN: | 1096-0287 0033-5894 |
| Popis: | Speleothem growth requires humid climates sufficiently warm to stimulate soil CO2 production by plants. We compile 283 U/Th dates on 21 stalagmites from six cave systems in the NW coast of Spain to evaluate if there are patterns in stalagmite growth that are evidence of climatic forcing. In the oldest stalagmites, from marine oxygen isotope stage (MIS) 7–5, growth persists through the glacial period. Hiatuses and major reductions in growth rate occur during extreme minima in summer insolation. Stalagmites active during the last interglaciation cease growth at the MIS 5–4 boundary (74 ka), when regional sea-surface temperature cooled significantly. During MIS 3, only two stalagmites grew; rates were highest between 50 and 60 ka during the maximum in summer insolation. One stalagmite grew briefly at 41 ka, 36.5 and 28.6 ka, all during warm phases of the Dansgaard–Oeschger cycles. A pronounced Holocene optimum in stalagmite growth occurs from 9 to 6 ka. The cessation of most growth by 4.1 ka, coincident with broad increases in aridity over the Mediterranean and areas influenced by the North African Monsoon, suggest that regions such as NW Spain, with dominant Atlantic moisture sources, also experienced increased aridity at this time. |
| Databáze: | OpenAIRE |
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