Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin
The extensive loess deposits of the Eurasian mid-latitudes provide important terrestrial archives of Quaternary climatic change. As yet, however, loess records in Central Asia are poorly understood. Here we investigate the grain size and magnetic characteristics of loess from the Nilka (NLK) section...
Published in: | Climate of the Past |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/cp-14-271-2018 https://www.clim-past.net/14/271/2018/cp-14-271-2018.pdf https://doaj.org/article/6d952dec6ce244a689b43271dc8d0cfd |
id |
fttriple:oai:gotriple.eu:oai:doaj.org/article:6d952dec6ce244a689b43271dc8d0cfd |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:oai:doaj.org/article:6d952dec6ce244a689b43271dc8d0cfd 2023-05-15T17:36:26+02:00 Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin Y. Li Y. Song K. E. Fitzsimmons H. Chang R. Orozbaev X. Li 2018-03-01 https://doi.org/10.5194/cp-14-271-2018 https://www.clim-past.net/14/271/2018/cp-14-271-2018.pdf https://doaj.org/article/6d952dec6ce244a689b43271dc8d0cfd en eng Copernicus Publications doi:10.5194/cp-14-271-2018 1814-9324 1814-9332 https://www.clim-past.net/14/271/2018/cp-14-271-2018.pdf https://doaj.org/article/6d952dec6ce244a689b43271dc8d0cfd undefined Climate of the Past, Vol 14, Pp 271-286 (2018) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/cp-14-271-2018 2023-01-22T17:52:59Z The extensive loess deposits of the Eurasian mid-latitudes provide important terrestrial archives of Quaternary climatic change. As yet, however, loess records in Central Asia are poorly understood. Here we investigate the grain size and magnetic characteristics of loess from the Nilka (NLK) section in the Ili Basin of eastern Central Asia. Weak pedogenesis suggested by frequency-dependent magnetic susceptibility (χfd%) and magnetic susceptibility (MS) peaks in primary loess suggest that MS is more strongly influenced by allogenetic magnetic minerals than pedogenesis, and may therefore be used to indicate wind strength. This is supported by the close correlation between variations in MS and proportions of the sand-sized fraction. To further explore the temporal variability in dust transport patterns, we identified three grain size end-members (EM1, mode size 47.5 µm; EM2, 33.6 µm; EM3, 18.9 µm) which represent distinct aerodynamic environments. EM1 and EM2 are inferred to represent grain size fractions transported from proximal sources in short-term, near-surface suspension during dust outbreaks. EM3 appears to represent a continuous background dust fraction under non-dust storm conditions. Of the three end-members, EM1 is most likely the most sensitive recorder of wind strength. We compare our EM1 proportions with mean grain size from the Jingyuan section in the Chinese loess plateau, and assess these in the context of modern and Holocene climate data. Our research suggests that the Siberian High pressure system is the dominant influence on wind dynamics, resulting in loess deposition in the eastern Ili Basin. Six millennial-scale cooling (Heinrich) events can be identified in the NLK loess records. Our grain size data support the hypothesis that the Siberian High acts as teleconnection between the climatic systems of the North Atlantic and East Asia in the high northern latitudes, but not for the mid-latitude westerlies. Article in Journal/Newspaper North Atlantic Unknown Climate of the Past 14 3 271 286 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
envir geo |
spellingShingle |
envir geo Y. Li Y. Song K. E. Fitzsimmons H. Chang R. Orozbaev X. Li Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin |
topic_facet |
envir geo |
description |
The extensive loess deposits of the Eurasian mid-latitudes provide important terrestrial archives of Quaternary climatic change. As yet, however, loess records in Central Asia are poorly understood. Here we investigate the grain size and magnetic characteristics of loess from the Nilka (NLK) section in the Ili Basin of eastern Central Asia. Weak pedogenesis suggested by frequency-dependent magnetic susceptibility (χfd%) and magnetic susceptibility (MS) peaks in primary loess suggest that MS is more strongly influenced by allogenetic magnetic minerals than pedogenesis, and may therefore be used to indicate wind strength. This is supported by the close correlation between variations in MS and proportions of the sand-sized fraction. To further explore the temporal variability in dust transport patterns, we identified three grain size end-members (EM1, mode size 47.5 µm; EM2, 33.6 µm; EM3, 18.9 µm) which represent distinct aerodynamic environments. EM1 and EM2 are inferred to represent grain size fractions transported from proximal sources in short-term, near-surface suspension during dust outbreaks. EM3 appears to represent a continuous background dust fraction under non-dust storm conditions. Of the three end-members, EM1 is most likely the most sensitive recorder of wind strength. We compare our EM1 proportions with mean grain size from the Jingyuan section in the Chinese loess plateau, and assess these in the context of modern and Holocene climate data. Our research suggests that the Siberian High pressure system is the dominant influence on wind dynamics, resulting in loess deposition in the eastern Ili Basin. Six millennial-scale cooling (Heinrich) events can be identified in the NLK loess records. Our grain size data support the hypothesis that the Siberian High acts as teleconnection between the climatic systems of the North Atlantic and East Asia in the high northern latitudes, but not for the mid-latitude westerlies. |
format |
Article in Journal/Newspaper |
author |
Y. Li Y. Song K. E. Fitzsimmons H. Chang R. Orozbaev X. Li |
author_facet |
Y. Li Y. Song K. E. Fitzsimmons H. Chang R. Orozbaev X. Li |
author_sort |
Y. Li |
title |
Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin |
title_short |
Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin |
title_full |
Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin |
title_fullStr |
Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin |
title_full_unstemmed |
Eolian dust dispersal patterns since the last glacial period in eastern Central Asia: insights from a loess-paleosol sequence in the Ili Basin |
title_sort |
eolian dust dispersal patterns since the last glacial period in eastern central asia: insights from a loess-paleosol sequence in the ili basin |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-14-271-2018 https://www.clim-past.net/14/271/2018/cp-14-271-2018.pdf https://doaj.org/article/6d952dec6ce244a689b43271dc8d0cfd |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Climate of the Past, Vol 14, Pp 271-286 (2018) |
op_relation |
doi:10.5194/cp-14-271-2018 1814-9324 1814-9332 https://www.clim-past.net/14/271/2018/cp-14-271-2018.pdf https://doaj.org/article/6d952dec6ce244a689b43271dc8d0cfd |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-14-271-2018 |
container_title |
Climate of the Past |
container_volume |
14 |
container_issue |
3 |
container_start_page |
271 |
op_container_end_page |
286 |
_version_ |
1766135917418905600 |