A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico
Bog deposits in the Winsor Creek drainage basin, southern Sangre de Cristo Mountains, New Mexico contain a high-resolution record of Pleistocene to Holocene glacial activity. Sediment cores were recovered from an alpine bog (elevation 3,100 m) behind a Pinedale age moraine, 2 km from a high-elevatio...
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ftunvnewmexicoir:oai:digitalrepository.unm.edu:eps_etds-1315 2023-05-15T17:36:26+02:00 A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico Armour, Jake 2002-03-31T08:00:00Z application/pdf https://digitalrepository.unm.edu/eps_etds/291 https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1315&context=eps_etds English eng UNM Digital Repository https://digitalrepository.unm.edu/eps_etds/291 https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1315&context=eps_etds Earth and Planetary Sciences ETDs Geology text 2002 ftunvnewmexicoir 2023-02-02T22:16:32Z Bog deposits in the Winsor Creek drainage basin, southern Sangre de Cristo Mountains, New Mexico contain a high-resolution record of Pleistocene to Holocene glacial activity. Sediment cores were recovered from an alpine bog (elevation 3,100 m) behind a Pinedale age moraine, 2 km from a high-elevation (-3600 m) cirque. Three cores reached glacial talus and consist of -6 meters of finely laminated to coarsely laminated lake clays, grading into gyttja. Superimposed on this long-term, lake-bog transition record are many distinct coarse-grained detrital packages punctuating times of rapid environmental change. Accelerator mass spectrometry (AMS) carbon dating, sedimentology, variations in rock magnetic properties of the sediment, and organic carbon properties reveal six distinct periods of glacial/ periglacial activity often correlative with detrital sand deposition. These include a late Pleistocene Pinedale glacial termination (> 12,120 14C yr 14 B.P.), a Younger Dryas cirque glaciation (-10,100 C yr B.P.), an early Neoglacial periglacial event (-4,900 14C yr B.P.), a middle Neoglacial cirque glaciation (3,700 14C yr B.P.), and periglacial activity during late Neoglacial (2,800 14C yr B.P.) and Little Ice Age time (-120 14C yr B.P.). The age model from these cores indicates an increase in depositional rates immediately following glacial events, and a prolonged period of reduced deposition rates during the mid-Holocene warm period. Cold events documented in these cores correlate with times of reduced ice rafting events in the North Atlantic Ocean suggesting that these climatic changes were likely hemispheric in their extent. The extreme southern position of this glaciated range and the absence of correlative glacial conditions in the more northerly, higher elevation, San Juan Mountains of Colorado suggest a climatic discontinuity exists. Modern differential effects of summertime land surface heating on atmospheric temperatures could explain this apparent paradox. A similar strong climatic gradient during the late ... Text North Atlantic UNM Digital Repository (The University of New Mexico) San Juan |
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Open Polar |
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UNM Digital Repository (The University of New Mexico) |
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ftunvnewmexicoir |
language |
English |
topic |
Geology |
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Geology Armour, Jake A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico |
topic_facet |
Geology |
description |
Bog deposits in the Winsor Creek drainage basin, southern Sangre de Cristo Mountains, New Mexico contain a high-resolution record of Pleistocene to Holocene glacial activity. Sediment cores were recovered from an alpine bog (elevation 3,100 m) behind a Pinedale age moraine, 2 km from a high-elevation (-3600 m) cirque. Three cores reached glacial talus and consist of -6 meters of finely laminated to coarsely laminated lake clays, grading into gyttja. Superimposed on this long-term, lake-bog transition record are many distinct coarse-grained detrital packages punctuating times of rapid environmental change. Accelerator mass spectrometry (AMS) carbon dating, sedimentology, variations in rock magnetic properties of the sediment, and organic carbon properties reveal six distinct periods of glacial/ periglacial activity often correlative with detrital sand deposition. These include a late Pleistocene Pinedale glacial termination (> 12,120 14C yr 14 B.P.), a Younger Dryas cirque glaciation (-10,100 C yr B.P.), an early Neoglacial periglacial event (-4,900 14C yr B.P.), a middle Neoglacial cirque glaciation (3,700 14C yr B.P.), and periglacial activity during late Neoglacial (2,800 14C yr B.P.) and Little Ice Age time (-120 14C yr B.P.). The age model from these cores indicates an increase in depositional rates immediately following glacial events, and a prolonged period of reduced deposition rates during the mid-Holocene warm period. Cold events documented in these cores correlate with times of reduced ice rafting events in the North Atlantic Ocean suggesting that these climatic changes were likely hemispheric in their extent. The extreme southern position of this glaciated range and the absence of correlative glacial conditions in the more northerly, higher elevation, San Juan Mountains of Colorado suggest a climatic discontinuity exists. Modern differential effects of summertime land surface heating on atmospheric temperatures could explain this apparent paradox. A similar strong climatic gradient during the late ... |
format |
Text |
author |
Armour, Jake |
author_facet |
Armour, Jake |
author_sort |
Armour, Jake |
title |
A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico |
title_short |
A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico |
title_full |
A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico |
title_fullStr |
A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico |
title_full_unstemmed |
A Late Pleistocene and Holocene High-Resolution Glacial and Paleoclimate Record from the Southern Sangre de Cristo Mountains, Northern New Mexico |
title_sort |
late pleistocene and holocene high-resolution glacial and paleoclimate record from the southern sangre de cristo mountains, northern new mexico |
publisher |
UNM Digital Repository |
publishDate |
2002 |
url |
https://digitalrepository.unm.edu/eps_etds/291 https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1315&context=eps_etds |
geographic |
San Juan |
geographic_facet |
San Juan |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Earth and Planetary Sciences ETDs |
op_relation |
https://digitalrepository.unm.edu/eps_etds/291 https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1315&context=eps_etds |
_version_ |
1766135908080287744 |