In:
The Holocene, SAGE Publications, Vol. 30, No. 12 ( 2020-12), p. 1741-1751
Abstract:
Palaeohydrochemical and palaeohydrological changes of lakes have seldom been reconstructed from the fossil shells of the gasropod Radix auricularia, which is a new, and potentially high-resolution environnmental archive. We conducted a geochemical and stable isotope study of the shells of Radix from the exposed fluvio-lacustrine sediments near Lake Yamdrok Yumtso in the southern Tibetan Plateau. Our aims were to determine the sedimentary environment, palaeo-lake hydrochemistry and hydrological status. AMS 14 C and OSL dating indicates that a lake-level stage of Yamdrok Yumtso higher than that of today occurred during ~4.7–1.2 cal. kyr BP. Results of Sr/Ca, δ 13 C and δ 18 O analysis of the fossil shells of Radix auricularia indicate that the lake-level fluctuations were mainly controlled by changes of the Indian Summer Monsoon; decreasing evaporation during the mid- to late-Holocene was also responsible. In addition, based on the geochemical relationship between Radix sp. shells and the ambient water in lakes, the values of δ 18 O Palaeo-water and Sr/Ca Palaeo-water reconstructed using the fossil shells of Radix auricularia are −8.2‰ to −5.1‰ and 0.0012 to 0.0057, respectively. Further, based on the values of δ 18 O shell , together with geomorphological evidence, we infer that Yamdrok Yumtso was a closed lake system, and we estimate its possible extent during the interval of high lake-level. In addition, we speculate that the water level of Yamdrok Yumtso at this time exceeded 4448.9 m a.s.l., but was less than 4451 m a.s.l., and that the major separation of various components of the Yamdrok Yumtso system occurred after 1.2 kyr BP.
Type of Medium:
Online Resource
ISSN:
0959-6836
,
1477-0911
DOI:
10.1177/0959683620950426
Language:
English
Publisher:
SAGE Publications
Publication Date:
2020
detail.hit.zdb_id:
2027956-5
SSG:
14
SSG:
3,4
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