Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments
Laguna Piuray is a carbonate lake in the Urubammba Province of southern Peru. The lake is formed in a glacial valley and surrounding the present-day shoreline are deposits ~4 m thick of calcite (CaCO3) rich sediments (marl) that record an interval of higher than present lake levels in the past. An i...
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ftunioncollege:oai:digitalworks.union.edu:theses-2384 2023-05-15T13:43:58+02:00 Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments White, Eric B 2010-06-01T07:00:00Z application/pdf https://digitalworks.union.edu/theses/1244 https://digitalworks.union.edu/cgi/viewcontent.cgi?article=2384&context=theses English eng Union | Digital Works https://digitalworks.union.edu/theses/1244 https://digitalworks.union.edu/cgi/viewcontent.cgi?article=2384&context=theses Honors Theses Peru geology sediment isotope record enrichment text 2010 ftunioncollege 2022-03-30T09:50:50Z Laguna Piuray is a carbonate lake in the Urubammba Province of southern Peru. The lake is formed in a glacial valley and surrounding the present-day shoreline are deposits ~4 m thick of calcite (CaCO3) rich sediments (marl) that record an interval of higher than present lake levels in the past. An intact 3.2 meter-long sample of the lake sediments was taken in 2008. Charcoal subsamples were obtained from the sediments and used for radiocarbon dating. The results indicate that the sediments contain an ~14.2 kyrs record, which includes the late-glacial; a period of dramatic climate change in Peru and globally. The sample was further subsampled every 0.5 cm and the resultant sediment samples were analyzed for organic and inorganic carbon, and sieved to isolate the <75 µm fraction what contains the authigenic calcite that precipitated in equilibrium with the lake water. The oxygen stable isotope composition shows highly depleted values from 14.2-11.3 kyrs BP including a small depletion coeval with the onset of the north Atlantic Younger Dryas (YD). A rapid 5‰ enrichment event, identical in magnitude to other regional isotope records, occurred 11.3 kyrs BP and indicates the climate became warmer and dryer from the end of the YD to the early Holocene. This shows the YD was felt in the southern tropics. On comparison with Antarctic and Greenland isotope records the Piuray archive, and a few other tropical isotope records, seem to indicate the southern tropics to have experienced bipolar climatic forcing associated with polar climate oscillations. This is evident in the Piuray isotope record, which seems to indicate the region to be following an Antarctic signal prior to the start of the YD. Text Antarc* Antarctic Greenland North Atlantic Union College: Digital Works Antarctic Greenland |
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Peru geology sediment isotope record enrichment |
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Peru geology sediment isotope record enrichment White, Eric B Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments |
topic_facet |
Peru geology sediment isotope record enrichment |
description |
Laguna Piuray is a carbonate lake in the Urubammba Province of southern Peru. The lake is formed in a glacial valley and surrounding the present-day shoreline are deposits ~4 m thick of calcite (CaCO3) rich sediments (marl) that record an interval of higher than present lake levels in the past. An intact 3.2 meter-long sample of the lake sediments was taken in 2008. Charcoal subsamples were obtained from the sediments and used for radiocarbon dating. The results indicate that the sediments contain an ~14.2 kyrs record, which includes the late-glacial; a period of dramatic climate change in Peru and globally. The sample was further subsampled every 0.5 cm and the resultant sediment samples were analyzed for organic and inorganic carbon, and sieved to isolate the <75 µm fraction what contains the authigenic calcite that precipitated in equilibrium with the lake water. The oxygen stable isotope composition shows highly depleted values from 14.2-11.3 kyrs BP including a small depletion coeval with the onset of the north Atlantic Younger Dryas (YD). A rapid 5‰ enrichment event, identical in magnitude to other regional isotope records, occurred 11.3 kyrs BP and indicates the climate became warmer and dryer from the end of the YD to the early Holocene. This shows the YD was felt in the southern tropics. On comparison with Antarctic and Greenland isotope records the Piuray archive, and a few other tropical isotope records, seem to indicate the southern tropics to have experienced bipolar climatic forcing associated with polar climate oscillations. This is evident in the Piuray isotope record, which seems to indicate the region to be following an Antarctic signal prior to the start of the YD. |
format |
Text |
author |
White, Eric B |
author_facet |
White, Eric B |
author_sort |
White, Eric B |
title |
Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments |
title_short |
Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments |
title_full |
Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments |
title_fullStr |
Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments |
title_full_unstemmed |
Late-glacial climate of the southern Peruvian Andes identified using stable isotopes from carbonate lacustrine sediments |
title_sort |
late-glacial climate of the southern peruvian andes identified using stable isotopes from carbonate lacustrine sediments |
publisher |
Union | Digital Works |
publishDate |
2010 |
url |
https://digitalworks.union.edu/theses/1244 https://digitalworks.union.edu/cgi/viewcontent.cgi?article=2384&context=theses |
geographic |
Antarctic Greenland |
geographic_facet |
Antarctic Greenland |
genre |
Antarc* Antarctic Greenland North Atlantic |
genre_facet |
Antarc* Antarctic Greenland North Atlantic |
op_source |
Honors Theses |
op_relation |
https://digitalworks.union.edu/theses/1244 https://digitalworks.union.edu/cgi/viewcontent.cgi?article=2384&context=theses |
_version_ |
1766195505189093376 |