Postglacial alluvial fan dynamics in the Cordillera Oriental, Peru, and palaeoclimatic implications
| العنوان: | Postglacial alluvial fan dynamics in the Cordillera Oriental, Peru, and palaeoclimatic implications |
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| المؤلفون: | Ralf Hetzel, Matthias Hinderer, Andrea Hampel, Kevin Ratnayaka, Manfred Frechen, Jens Hornung |
| المصدر: | Quaternary Research 91 (2019), Nr. 1 Quaternary Research |
| بيانات النشر: | Cambridge University Press (CUP), 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften, 010506 paleontology, Alluvial fan, 010504 meteorology & atmospheric sciences, Sedimentation rate, Andes, 14C dating, Climate history, 01 natural sciences, Deposition (geology), law.invention, 10Be exposure dating, Arts and Humanities (miscellaneous), law, Peru, ddc:550, Precipitation, Radiocarbon dating, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, Sediment, Sedimentation, Erosion, General Earth and Planetary Sciences, Physical geography, Geology |
| الوصف: | Alluvial fans record climate-driven erosion and sediment-transport processes and allow reconstructing past environmental conditions. Here we investigate the sedimentation history of two alluvial fans located in formerly glaciated valleys of the Cordillera Oriental, Peru.10Be exposure ages from the fan surfaces and radiocarbon ages from the fan interiors constrain the final stages of fan formation. The10Be and14C ages cluster mainly between 13.3–9.3 ka and 11,500–9700 cal yr BP, respectively. Our age data set indicates that—after deglaciation—large amounts of fan sediment were deposited until ∼10 ka, when sedimentation rates declined rather abruptly. This pattern is supported by10Be erosion rates for the fan catchments, because under the assumption of constant erosion the time needed to erode the material stored in the fans significantly exceeds their age. Correlating our ages with regional climate records indicates that precipitation exerts the primary control on fan sedimentation. Two periods with elevated lake levels and increased precipitation between 18 and 14.5 ka and from 13 to 11.5 ka resulted in rapid deposition of large fan lobes. Subsequently, lower precipitation rates decreased erosion in the catchments and sediment delivery to the fans, which have remained largely inactive since ∼9.5 ka. |
| تدمد: | 1096-0287 0033-5894 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2ebe5ab3b14f343e63fa61ff486db63a https://doi.org/10.1017/qua.2018.106 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....2ebe5ab3b14f343e63fa61ff486db63a |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 10960287 00335894 |
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