Cryogenic wedges and cryoturbations on the Ordos Plateau in North China since 50 ka BP and their paleoenvironmental implications

During the last 50 ka, cryogenic wedges on the Ordos Plateau formed during three major periods: (i) early local Last Glaciation, ca. 50 ka BP; (iii) local Last Permafrost Maximum(local LPM), 25–19 ka BP; and (v) post-local LPM, 16–9 ka BP. Cryoturbations mainly formed in the following periods: (ii)...

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Bibliographic Details
Published in:Permafrost and Periglacial Processes
Main Authors: He, Ruixia, Jin, Huijun, French, Hugh M., Vandenberghe, Jef, Li, Xiaoying, Li, Fang, Jiang, Guanli, Zhang, Ze, Chen, Xuemei, Serban, Raul D., Wang, Shaoling, Guo, Dongxin
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
Last Glacial Maximum
Last Permafrost Maximum
Ordos Plateau
cryogenic wedges
cryoturbations
permafrost
Permafrost and Periglacial Processes
wedge*
Online Access:https://research.vu.nl/en/publications/2125dead-8f87-4755-900a-348ae0fe173a
https://doi.org/10.1002/ppp.2084
https://hdl.handle.net/1871.1/2125dead-8f87-4755-900a-348ae0fe173a
https://research.vu.nl/ws/files/224586919/Cryogenic_wedges_and_cryoturbations_on_the_Ordos_Plateau_in_North_China_since_50_ka_BP_and_their_paleoenvironmental_implications.pdf
https://www.mendeley.com/catalogue/af89fea9-aa2f-37cd-93d4-7f157537f4c0/
Description
Summary:During the last 50 ka, cryogenic wedges on the Ordos Plateau formed during three major periods: (i) early local Last Glaciation, ca. 50 ka BP; (iii) local Last Permafrost Maximum(local LPM), 25–19 ka BP; and (v) post-local LPM, 16–9 ka BP. Cryoturbations mainly formed in the following periods: (ii) pre-local LPM, 45–30 ka BP and (iv) ~ 20 ka BP. The coldest periods with well-developed permafrost (i and iii) were most conducive for forming cryogenic wedges. The following periods of warming climate and degrading permafrost favored the formation of cryoturbations. During the local LPM, sand wedges and polygons were well developed and widely distributed on the Ordos Plateau when mean annual air temperatures (MAATs) were approximately 12°C lower than that at present. At ~30 ka BP, MAAT was 6–7°C lower than that at present. Paleoclimate conditions on the Ordos Plateau were reconstructed since 50 ka BP as follows: cold (ca. 50 ka BP) → cool (45–30 ka BP) → very cold (25–19 ka BP) → cool (19–9 ka BP) → intermittent warming until the present day. The amount of precipitation fluctuated, but with a general trend of drying since 50 ka BP. Under the next generally warming climate (after 9 ka BP), permafrost gradually degraded and eventually disappeared from the Ordos Plateau.

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