摘要
兹格塘错是位于藏北高原腹地的封闭型湖泊,其变化过程可直接反映区域气候变化。对一支深727 cm沉积岩芯中介形虫进行了壳体同位素分析,发现介形虫壳体氧同位素变化主要取决于壳体形成时的湖水氧同位素组成和湖水温度的变化;封闭湖泊湖水的氧同位素组成主要取决于降水和蒸发比值的变化。兹格塘错介形虫壳体碳、氧同位素变化特征表明两者可能受控于不同的环境因子。介形虫壳体同位素记录反映了全新世气候环境变化的整体特征,同时对晚第四纪特征气候事件都有明确记录,包括8.2 ka冷事件、Roman暖期、中世纪暖期以及小冰期等,在响应全球气候变化的过程中又记录了区域间的差异响应。
Located in the hinterland of North Tibetan Plateau,Zigetang Lake is an enclosed lake with bad climate and little precipitation,the regional environment has always been faintly disturbed by human beings,with great evaporation and no glacier in the catchment,the main supply of water comes from surface runoff,and factors of water balance are simple. Thus Zigetang Lake is ideal for study on the climatic evolution of Tibetan Plateau. A 727 cm long core（ ZGT02） was obtained at water depth of 30 m in the west of Zigetang Lake,and its AMS age covers the whole Holocene. Ostracode shell stable isotopes analysis used to reconstruct paleoclimatic and environmental change. Limnocythere inopinata is the species for analysis; Results show that the δ18O of the shell is controlled by the δ18O and temperature of the lake water. In closed or semi-closed lake,δ18O is an indicator to effective moisture（ ratio of precipitation /evaporation） and mainly controlled by the temperature in arid and semi-arid area. High δ18O indicates high evaporation and low precipitation while low δ18O indicates the contrary ones. The curve of δ13C changed in-phase with that of δ18O would indicate that they were controlled by different factors. These environmental changes and the variations of the lake level reflected by the geochemical of Zigetang Lake sediments are wellsupported by other research results,at the same time,there are different as the different area.
出处
《山地学报》
CSCD
北大核心
2014年第3期373-379,共7页
Mountain Research
基金
国家自然科学基金项目"青藏高原全新世气候变化高分辨率湖泊沉积记录研究(40471001)~~
关键词
青藏高原
湖泊沉积
全新世环境
介形虫
壳体同位素
Tibetan Plateau
Lake sediments
Holocene environment
Ostracode shell
stable isotopes
作者简介
张宏亮（1970-），男，河南林州人，博士，副教授，主要从事湖泊资源与环境研究。Tel：0372-2900043：E-mail：phytolith@163．com
通信作者：李世杰，研究员，博士生导师，从事湖泊沉积与全球变化研究。E-mail；shjli@nighs．ac.cn
