Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records.
Long sediment cores (12.5 and 13.5 m) from two lakes in Yunnan Province were used to infer the paleoclimate of southwest China over the past 50,000 yr. During the Holocene and marine isotope stage (MIS 3), bio-induced carbonate precipitation and organic matter (OM) production was high, suggesting wa...
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ftusouthflorida:oai:digitalcommons.usf.edu:fac_publications-3441 2023-07-30T04:04:14+02:00 Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. Hodell, David A. Brenner, Mark Kanfoush, Sharon L. Curtis, Jason H. Stoner, Joseph S. Xueliang, Song Yuan, Wu Whitmore, Thomas J. 1999-01-01T08:00:00Z https://digitalcommons.usf.edu/fac_publications/2446 https://login.ezproxy.lib.usf.edu/login?url=http://www.sciencedirect.com/science/article/pii/S0033589499920720# unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/fac_publications/2446 https://login.ezproxy.lib.usf.edu/login?url=http://www.sciencedirect.com/science/article/pii/S0033589499920720# http://creativecommons.org/licenses/by-nc-nd/4.0/ USF St. Petersburg campus Faculty Publications Paleoclimate Stable isotopes China Biology text 1999 ftusouthflorida 2023-07-13T21:50:32Z Long sediment cores (12.5 and 13.5 m) from two lakes in Yunnan Province were used to infer the paleoclimate of southwest China over the past 50,000 yr. During the Holocene and marine isotope stage (MIS 3), bio-induced carbonate precipitation and organic matter (OM) production was high, suggesting warm temperatures and high primary productivity. In contrast, sediment inorganic carbon (IC) and organic carbon (OC) concentrations were low in last glacial deposits from 38,000 to 12,000 cal yr B.P., indicating cool temperatures and low productivity. The 50,000-yr record has alternating peaks of carbonate and coarse-grain (>38 μm) quartz that reflect warm, moist interglacial or interstadial conditions alternating with cold, dry glacial or stadial conditions, respectively. Spectral analysis of the carbonate and quartz signals reveals power concentrated at periods of 7200 and 8900 cal yr, respectively, that may reflect a nonlinear climate response to precessional forcing at a time of reduced eccentricity modulation (McIntyre and Molfino, 1996). Oxygen isotope values of calcite from Yunnan lake cores indicate the summer monsoon was weak during the last glaciation from 50,000 to 12,000 cal yr B.P. The summer monsoon intensified between 12,000 and 8000 cal yr B.P., but weakened gradually in response to insolation forcing during the mid-to-late Holocene. Our results support the Overpeck et al. (1996) model that posits a weak summer monsoon during the last glaciation that responded nonlinearly to insolation forcing when its intensity was affected by Eurasian snow cover and ice-sheet extent. The summer monsoon intensified and responded linearly to seasonal insolation forcing in the Holocene when ice volume diminished. Text Ice Sheet University of South Florida St. Petersburg: Digital USFSP McIntyre ENVELOPE(-153.000,-153.000,-87.283,-87.283) |
institution |
Open Polar |
collection |
University of South Florida St. Petersburg: Digital USFSP |
op_collection_id |
ftusouthflorida |
language |
unknown |
topic |
Paleoclimate Stable isotopes China Biology |
spellingShingle |
Paleoclimate Stable isotopes China Biology Hodell, David A. Brenner, Mark Kanfoush, Sharon L. Curtis, Jason H. Stoner, Joseph S. Xueliang, Song Yuan, Wu Whitmore, Thomas J. Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. |
topic_facet |
Paleoclimate Stable isotopes China Biology |
description |
Long sediment cores (12.5 and 13.5 m) from two lakes in Yunnan Province were used to infer the paleoclimate of southwest China over the past 50,000 yr. During the Holocene and marine isotope stage (MIS 3), bio-induced carbonate precipitation and organic matter (OM) production was high, suggesting warm temperatures and high primary productivity. In contrast, sediment inorganic carbon (IC) and organic carbon (OC) concentrations were low in last glacial deposits from 38,000 to 12,000 cal yr B.P., indicating cool temperatures and low productivity. The 50,000-yr record has alternating peaks of carbonate and coarse-grain (>38 μm) quartz that reflect warm, moist interglacial or interstadial conditions alternating with cold, dry glacial or stadial conditions, respectively. Spectral analysis of the carbonate and quartz signals reveals power concentrated at periods of 7200 and 8900 cal yr, respectively, that may reflect a nonlinear climate response to precessional forcing at a time of reduced eccentricity modulation (McIntyre and Molfino, 1996). Oxygen isotope values of calcite from Yunnan lake cores indicate the summer monsoon was weak during the last glaciation from 50,000 to 12,000 cal yr B.P. The summer monsoon intensified between 12,000 and 8000 cal yr B.P., but weakened gradually in response to insolation forcing during the mid-to-late Holocene. Our results support the Overpeck et al. (1996) model that posits a weak summer monsoon during the last glaciation that responded nonlinearly to insolation forcing when its intensity was affected by Eurasian snow cover and ice-sheet extent. The summer monsoon intensified and responded linearly to seasonal insolation forcing in the Holocene when ice volume diminished. |
format |
Text |
author |
Hodell, David A. Brenner, Mark Kanfoush, Sharon L. Curtis, Jason H. Stoner, Joseph S. Xueliang, Song Yuan, Wu Whitmore, Thomas J. |
author_facet |
Hodell, David A. Brenner, Mark Kanfoush, Sharon L. Curtis, Jason H. Stoner, Joseph S. Xueliang, Song Yuan, Wu Whitmore, Thomas J. |
author_sort |
Hodell, David A. |
title |
Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. |
title_short |
Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. |
title_full |
Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. |
title_fullStr |
Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. |
title_full_unstemmed |
Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. |
title_sort |
paleoclimate of southwestern china for the past 50,000 yr inferred from lake sediment records. |
publisher |
Digital Commons @ University of South Florida |
publishDate |
1999 |
url |
https://digitalcommons.usf.edu/fac_publications/2446 https://login.ezproxy.lib.usf.edu/login?url=http://www.sciencedirect.com/science/article/pii/S0033589499920720# |
long_lat |
ENVELOPE(-153.000,-153.000,-87.283,-87.283) |
geographic |
McIntyre |
geographic_facet |
McIntyre |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
USF St. Petersburg campus Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/fac_publications/2446 https://login.ezproxy.lib.usf.edu/login?url=http://www.sciencedirect.com/science/article/pii/S0033589499920720# |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
_version_ |
1772815504440819712 |