摘要
大柴旦盐湖因蕴藏固体和液体硼矿资源成为柴达木盆地诸多盐湖中最早被关注和开发的盐湖之一。然而,对其常年水体底部沉积剖面的相关研究工作却几乎没有开展。报道了该盐湖中央湖底硼矿层以上连续沉积剖面的加速器质谱计(AMS)14C年代学和矿物学研究结果,首次揭示湖底硼矿层形成于约3600 a BP之前;剖面的岩性与矿物组成标示了晚全新世以来该盐湖水化学演化的3个主要阶段;受降水量主控的入湖径流量决定了盐湖水位和卤水水化学的阶段性演化特征,以及各阶段中十年级和百年级的水化学变动。研究结果为探讨柴达木盆地北部晚全新世以来水文气候的演变历史提供了代理记录。
Da Qaidam Salt Lake is known for its both liquid and solid boron resource. The exploitation of the boron deposits and related geological studies started since 1950s. Little attention has been paid, however, to the study of sedimentary records from the salt lake as regarding to brine evolution and environmental change. Here we report the result of AMS 14C dating and mineralogical investigation on a subbottom sediment section from the central area of the saline water-body. The result reveals that the subbottom pinnoite deposit was formed before 3600 a BP, and that the lake underwent three stages of lake levels and brine evolution in the late Holocene, which were determined mainly by precipitation-controlled catchment inflow. The mineralogical records also depict fluctuations in lake-levels and water chemistry on decadal and centennial scales. The data provide a proxy record for the reconstruction of the late-Holocene hydro-climate change on the northern Qaidam Basin.
出处
《地球化学》
CAS
CSCD
北大核心
2011年第2期156-162,共7页
Geochimica
基金
国家自然科学基金(4057117340871008)
兰州大学西部环境教育部重点实验室开放基金
关键词
湖底沉积剖面
矿物学记录
卤水演变
环境变化
大柴旦盐湖
subbottom sediment profile
mineralogical record
brine evolution
environmental change
Da Qaidam Salt Lake
