摘要
湖泊碳酸盐的形成与湖水物理化学性质以及气候环境密切相关,是记录湖泊环境信息的重要载体。以巴丹吉林沙漠腹地6个湖泊中2种类型的碳酸盐(钙华、湖泊沉积物碳酸盐)为研究对象,基于稳定碳、氧以及团簇同位素(Δ_(47))指标,对比分析了2种碳酸盐的沉淀过程及其所揭示的环境信息。研究表明:(1)巴丹吉林沙漠6个湖泊中钙华与沉积物2种碳酸盐的碳、氧同位素特征显著不同,钙华沉积的氧同位素显著较湖泊沉积物碳酸盐偏负。(2)湖泊沉积物碳酸盐的团簇同位素温度[T(Δ_(47))]与区域夏季温度接近;而钙华碳酸盐的T(Δ_(47))低于湖泊沉积物碳酸盐。(3)基于氧同位素和T(Δ_(47))估算的碳酸盐沉淀水体δ^(18)O显示,形成钙华碳酸盐的水体δ^(18)O记录了泉水与湖水混合的信号。研究结果初步揭示了巴丹吉林沙漠腹地盐湖碳酸盐的环境指示意义,为长时间尺度上揭示沙漠湖泊的水文演化提供了数据支撑。
The formation of lake carbonate is closely associated with the physical and chemical properties of lake water and the climatic environment,serving as an essential carrier of lake environmental information.This study examines two types of carbonates(tufa and lake sediment carbonate)from six lakes in the hinterland of the Badain Jaran Desert,Inner Mongolia,China.The precipitation processes of these carbonates and their environmental implications were analyzed using stable carbon,oxygen,and clumped isotope(Δ_(47))indices.The results indicate the following:(1)The carbon and oxygen isotope characteristics of tufas and lake sediment carbonates from the six lakes differ significantly,with the oxygen isotope values of tufa deposits being notably more negative than those of lake sediment carbonates.(2)The clumped isotope temperatures[T(Δ_(47))]of lake sediment carbonates are consistent and approximate the regional summer temperature,whereas the T(Δ_(47))of tufas are lower.(3)Based on oxygen isotope values and T(Δ_(47)),the estimatedδ^(18)O composition of the water in which the tufas precipitated suggests that the tufas capture a mixed signal from spring water and lake water.These findings provide preliminary insights into the environmental significance of salt lake carbonates in the hinterland of the Badain Jaran Desert and offer data to support long-term investigations into the hydrological evolution of desert lakes.
作者
李全聪
雷国良
赵晖
朱芸
孙婉婷
于源
江戈平
LI Quancong;LEI Guoliang;ZHAO Hui;ZHU Yun;SUN Wanting;YU Yuan;JIANG Geping(Key Laboratory of Humid Subtropical Eco-geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350117,Fujian,China;School of Geographical Science and School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,Fujian,China;Institute of Geography,Fujian Normal University,Fuzhou 350117,Fujian,China;Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China)
出处
《干旱区地理》
北大核心
2025年第2期247-256,共10页
Arid Land Geography
基金
国家自然科学基金青年科学基金(41977390)
第二次青藏高原综合科学考察研究(2019QZKK0202)
云南省高原地理过程与环境变化重点实验开放基金项目(PGPEC201801)
福建师范大学地理研究所公益类科研院所专项(2024R1002005)资助。
