Lithostratigraphy, mineralogy and the boron-bearing brine evolution of DaQaidam Salt Lake in Qaidam Basin since Holocene period, northern Qinghai-Tibet Plateau

Chunliang Gao,Junqing Yu,Aiying Cheng,Xiuyun Min,G Yang,M Ziegler

doi:10.1051/e3sconf/202019804038

Abstract

Little attention has been paid to the study of sedimentary records from DaQaidam Salt Lake regarding brine evolution and hydro-climate change. Here we report the results of AMS 14C dating and mineralogical investigation on a sediment profile D4 from the south central of perennial saline water-body. The result revealed that pinnoite deposit in the lakebed was formed in early Holocene, the lake underwent three stages of lake-level and brine evolution in Holocene period, which were determined mainly by precipitation-controlled catchment inflow. The mineralogical records also depicted fluctuations in lake level and hydrochemistry on decadal and centennial scales.

Highlights

DaQaidam Salt Lake is known for its both liquid and solid boron resource in Qaidam Basin, and the exploitation in DaQaidam Salt Lake had started since 1950s, related geological, geochemical and chemical studies focused on the distribution, sedimentary characteristics and material sources of borate minerals in onshore sites [1-4]
We report the results of sediment profile D4 from DaQaidam Salt Lake in Qaidam Basin, including the lithostratigraphic and mineralogical records, as well as AMS 14C dating
The sediment profile D4 is located in the south central of DaQaidam Salt Lake, pinnoite deposits ranged from 549 to 735 cm, and the sediments above 549 cm represented a series of successive sedimentary sequence in perennial water-body since early Holocene

Summary

Introduction

DaQaidam Salt Lake is known for its both liquid and solid boron resource in Qaidam Basin, and the exploitation in DaQaidam Salt Lake had started since 1950s, related geological, geochemical and chemical studies focused on the distribution, sedimentary characteristics and material sources of borate minerals in onshore sites [1-4]. Little attention has been paid to the brine evolution and hydroclimate change correlated with the formation of pinnoite deposit [6-8]. We report the results of sediment profile D4 from DaQaidam Salt Lake in Qaidam Basin, including the lithostratigraphic and mineralogical records, as well as AMS 14C dating. The study aims to discuss the brine evolution and hydro-climate change correlated with the formation of pinnoite deposit since Holocene period

Sample descriptions

Mineralogical and lithostratigraphic records

Evaporite minerals

Findings

Conclusions