Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction
The purpose of this study is to test models of millennial-scale climate response to hemispheric-scale drivers during the late Pleistocene in northwestern North America. Towards this end, a 12.5-10.5 mbgs section of the BB3-I core, spanning 38-35 ka in age and taken from Summer Lake Basin, Oregon, US...
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California State University, Bakersfield
2016
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ftcalifstateuniv:oai:scholarworks:7s75dg18n 2024-09-30T14:39:46+00:00 Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction Fetzer, Dawn A Negrini, Robert Lafever, Roy Jacobsen, Anna L. 2016 https://hdl.handle.net/20.500.12680/7s75dg18n English eng California State University, Bakersfield Natural Sciences, Mathematics, and Engineering Geological Sciences http://hdl.handle.net/20.500.12680/7s75dg18n http://rightsstatements.org/vocab/InC/1.0/?creator Geochemistry Paleoclimatology Paleoenvironment N-alkanes Masters Thesis 2016 ftcalifstateuniv https://doi.org/20.500.12680/7s75dg18n 2024-09-10T17:06:17Z The purpose of this study is to test models of millennial-scale climate response to hemispheric-scale drivers during the late Pleistocene in northwestern North America. Towards this end, a 12.5-10.5 mbgs section of the BB3-I core, spanning 38-35 ka in age and taken from Summer Lake Basin, Oregon, USA, was investigated using lipid molecular stratigraphy and compound specific carbon isotope analysis. Previous climate proxy studies on this core segment, including those based on Corg/N, ostracode taxonomy, palynology, and environmental magnetism, divided the core segment into four intervals of alternating warmer/wetter and cooler/drier climate corresponding to Dansgaard-Oeschger (D-O) Interstadials #8 and #7 and the successive stadials. Carbon isotope ratios ranged from -24.5 to -42.4 ‰ indicating that as expected, all plants represented by the leaf waxes followed the C3 photosynthetic pathway. ACL25-33 (Average Chain Length) and CPI23-35 (Carbon Preference Index) values in the sediment samples associated with the D-O interstadials were higher (30.31 -29.61) than the ACL values for the stadials, particularly the one that followed IS#7, indicating the dominance of terrestrial-sourced vegetation during interstadials and aquatic vegetation during stadials. Similarly, Paq values were lower during interstadials and vice-versa indicating an increased terrestrial component of organic matter rather than organics of strictly lacustrine origin. Furthermore, a preference for terrestrial origin in interstadial samples was found in the odd carbon-numbered, long-chain n-alkanes with the younger stadial sample identified to be exclusively aquatic/lacustrine. These results support the teleconnection hypothesis of climate response to late Pleistocene millennial-scale climate change in the North American Great Basin wherein warmer temperatures in the North Atlantic drive wetter, warmer Great Basin climates and vice-versa. Master Thesis North Atlantic Scholarworks from California State University |
institution |
Open Polar |
collection |
Scholarworks from California State University |
op_collection_id |
ftcalifstateuniv |
language |
English |
topic |
Geochemistry Paleoclimatology Paleoenvironment N-alkanes |
spellingShingle |
Geochemistry Paleoclimatology Paleoenvironment N-alkanes Fetzer, Dawn A Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction |
topic_facet |
Geochemistry Paleoclimatology Paleoenvironment N-alkanes |
description |
The purpose of this study is to test models of millennial-scale climate response to hemispheric-scale drivers during the late Pleistocene in northwestern North America. Towards this end, a 12.5-10.5 mbgs section of the BB3-I core, spanning 38-35 ka in age and taken from Summer Lake Basin, Oregon, USA, was investigated using lipid molecular stratigraphy and compound specific carbon isotope analysis. Previous climate proxy studies on this core segment, including those based on Corg/N, ostracode taxonomy, palynology, and environmental magnetism, divided the core segment into four intervals of alternating warmer/wetter and cooler/drier climate corresponding to Dansgaard-Oeschger (D-O) Interstadials #8 and #7 and the successive stadials. Carbon isotope ratios ranged from -24.5 to -42.4 ‰ indicating that as expected, all plants represented by the leaf waxes followed the C3 photosynthetic pathway. ACL25-33 (Average Chain Length) and CPI23-35 (Carbon Preference Index) values in the sediment samples associated with the D-O interstadials were higher (30.31 -29.61) than the ACL values for the stadials, particularly the one that followed IS#7, indicating the dominance of terrestrial-sourced vegetation during interstadials and aquatic vegetation during stadials. Similarly, Paq values were lower during interstadials and vice-versa indicating an increased terrestrial component of organic matter rather than organics of strictly lacustrine origin. Furthermore, a preference for terrestrial origin in interstadial samples was found in the odd carbon-numbered, long-chain n-alkanes with the younger stadial sample identified to be exclusively aquatic/lacustrine. These results support the teleconnection hypothesis of climate response to late Pleistocene millennial-scale climate change in the North American Great Basin wherein warmer temperatures in the North Atlantic drive wetter, warmer Great Basin climates and vice-versa. |
author2 |
Negrini, Robert Lafever, Roy Jacobsen, Anna L. |
format |
Master Thesis |
author |
Fetzer, Dawn A |
author_facet |
Fetzer, Dawn A |
author_sort |
Fetzer, Dawn A |
title |
Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction |
title_short |
Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction |
title_full |
Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction |
title_fullStr |
Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction |
title_full_unstemmed |
Study of Summer Lake, OR BB3-I core via biogeochemical molecular and isotopic analysis for Paleoclimate Reconstruction |
title_sort |
study of summer lake, or bb3-i core via biogeochemical molecular and isotopic analysis for paleoclimate reconstruction |
publisher |
California State University, Bakersfield |
publishDate |
2016 |
url |
https://hdl.handle.net/20.500.12680/7s75dg18n |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://hdl.handle.net/20.500.12680/7s75dg18n |
op_rights |
http://rightsstatements.org/vocab/InC/1.0/?creator |
op_doi |
https://doi.org/20.500.12680/7s75dg18n |
_version_ |
1811642366993367040 |