OSL Dating of Paleo-Shorelines at Dagze Co, Central Tibetan Plateau

Well-preserved paleo-shoreline systems suggest lake shrinkage occurred in a vast region of the Tibetan Plateau, indicating dramatic paleo-environmental changes that linked closely to variations in Asian monsoon precipitation, glacial meltwater, and evaporation. The elevation and chronology of these...

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Bibliographic Details
Published in:Frontiers in Earth Science
Main Authors: Wu, Yang, Chen, Yiwei, Huang, Long, Ding, Ping, Cui, Hao, Wei, Gangjian
Format: Report
Language:English
Published: FRONTIERS MEDIA SA 2022
Subjects:
Geology
paleo-shoreline
OSL dating
Dagze Co
lake level change
Tibetan Plateau
Geosciences
Multidisciplinary
SUMMER MONSOON
ASIAN MONSOON
QINGHAI LAKE
BEACH RIDGES
TANGRA YUMCO
ICE CORE
HOLOCENE
LUMINESCENCE
CLIMATE
BASIN
Tangra
ice core
Online Access:http://ir.gig.ac.cn/handle/344008/68258
https://doi.org/10.3389/feart.2022.940013
Description
Summary:Well-preserved paleo-shoreline systems suggest lake shrinkage occurred in a vast region of the Tibetan Plateau, indicating dramatic paleo-environmental changes that linked closely to variations in Asian monsoon precipitation, glacial meltwater, and evaporation. The elevation and chronology of these shoreline features can be used to reconstruct lake level fluctuation history and regional paleo-climate. Here, we report optically stimulated luminescence (OSL) dating of 14 sediment samples from three of seven paleo-shorelines at south of Dagze Co, central Tibetan Plateau, using coarse-grained quartz and K-feldspar. Two fine grain silt samples were also measured. The results suggest the following: 1) The highest paleo-shoreline for Dagze Co has an elevation around 4,525 m (+55 m above modern lake). Its age is estimated to be 9.1 +/- 0.5 to 9.6 +/- 0.6 ka, suggesting a relative humid condition in the early Holocene. 2) After that, the lake level dropped similar to 20 m and remained relatively stable (+35 m) from similar to 8 to 5 ka, implying a dry condition with reduced runoff. Lake level further declined for similar to 40 m since about 5 ka. 3) The general trend of shrinkage for Dagze Co broadly matches studies from adjacent lakes, suggesting a common pattern of lake's evolution on the south/central plateau in the late Quaternary. The long-term decreasing trend of Asian monsoon precipitation should be the main reason.

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