LGM and Late Glacial glacier advances in the Cordillera Real and Cochabamba (Bolivia) deduced from 10Be surface exposure dating

Zech, Roland; Kull, Christoph; Kubik, Peter; Veit, Heinz (2007). LGM and Late Glacial glacier advances in the Cordillera Real and Cochabamba (Bolivia) deduced from 10Be surface exposure dating. Climate of the past, 3(4), pp. 623-635. Göttingen: Copernicus Publications 10.5194/cp-3-623-2007

[img]
Preview
Text
cp-3-623-2007.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (1MB) | Preview

Surface exposure dating (SED) is an innovative tool already being widely applied for moraine dating and for Late Quaternary glacier and climate reconstruction. Here we present exposure ages of 28 boulders from the Cordillera Real and the Cordillera Cochabamba, Bolivia. Our results indicate that the local Last Glacial Maximum (LGM) in the Eastern Cordilleras occurred at ~22–25 ka and was thus synchronous to the global temperature minimum. We were also able to date several Late Glacial moraines to ~11–13 ka, which likely document lower temperatures and increased precipitation ("Coipasa" humid phase). Additionally, we recognize the existence of older Late Glacial moraines re-calculated to ~15 ka from published cosmogenic nuclide data. Those may coincide with the cold Heinrich 1 event in the North Atlantic region and the pronounced "Tauca" humid phase. We conclude that (i) exposure ages in the tropical Andes may have been overestimated so far due to methodological uncertainties, and (ii) although precipitation plays an important role for glacier mass balances in the tropical Andes, it becomes the dominant forcing for glaciation only in the drier and thus more precipitation-sensitive regions farther west and south.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography > Physical Geography > Unit Biogeochemistry and Paleoclimate
08 Faculty of Science > Institute of Geography > Physical Geography > Unit Paleo-Geoecology
08 Faculty of Science > Institute of Geography

UniBE Contributor:

Zech, Roland; Kull, Christoph and Veit, Heinz

Subjects:

900 History > 910 Geography & travel

ISSN:

1814-9324

Publisher:

Copernicus Publications

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:59

Last Modified:

29 Sep 2015 16:46

Publisher DOI:

10.5194/cp-3-623-2007

Web of Science ID:

000251998800005

BORIS DOI:

10.7892/boris.25570

URI:

https://boris.unibe.ch/id/eprint/25570 (FactScience: 59203)

Actions (login required)

Edit item Edit item
Provide Feedback