| 摘要: |
| 1990年用铀系年代学及古地磁对昆特依盐湖沉积物进行年代测定，探讨该湖区地球化学演化与古气候变化关系。结果表明，该区最老的盐层形成于早更新世晚期（大于730ka），大量的盐类沉积则始于300ka左右；盐湖沉积物中元素含量变化主要受古盐度、矿物、类质同象和吸附控制；沉积物水溶F／Cl比值与古盐度成反比关系；该湖2000ka以来的古环境演变：盐层形成于干冷、偏酸性的氧化环境，泥岩层形成于温暖、偏碱性的还原环境。认为，昆特依盐湖730ka以来，有8次大的干湿与冷暖气候的波动。 |
| 关键词: 盐湖沉积物 元素垂直分布 古盐度指标 地球化学环境 第四纪古气候 昆依特盐湖 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，18975066号 |
附件 |
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| STUDY OF GEOCHEMICAL EVOLUTION AND PALAEOCLIMATIC F LUCTUATION OF KUNTEYI SALT LAKE IN THE QAIDAM BASIN, QINGHAI |
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Han Fengqing, Huang Qi, Wang Kejun, Wang Huaan, Yuan Li
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Institute of Salt Lakes, Academia Sinica, Xining 810008
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| Abstract: |
| In 1990 uranium series age, paleomagnetic and geochemical study of the sediment from Kunteyi Salt Lake in the Qaidam Basin were carried out to approach the relation between geochemical evolution and paleoclimatic evolution of the lake. The results show that the earliest salt layer was formed in the late of Lower Pleistocene (730 thousands years ago). Large scale halite precipitation began about 300 thousand years ago. The elemental content variations are controlled by salinity, mineral-forming, isomophic replacement and adsorption. Water soluable F/C1 ratio is an new indicator of palaeosalinity, the former is inversely proportional to the latter. Salt layers in the Kunteyi Salt Lake were formed in oxidation-subacid under dry-cold palaeoclimate, mud layers in reduction-subalkalinity under warm-moist palaeoclimate. On the basis of element geochemistry, palaeosalinity and sedimentology, authors suggest there have been 8 large palaeoclimate fluctuations (from the warm-moist to cold-dry) during the last 730 ka in the region of Kunteyi Salt Lake. |
| Key words: Salt lake sediments, Vertical distribution of elements, Indicator of palaeosalinity, Geochemical environments Quaternary palaeoclimate,
Kunteyi Salt Lake |
