全新世安固里淖易溶盐沉积及其环境意义

内陆湖泊沉积物的易溶盐含量与湖水化学组成密切相关，因此通过测试沉积物钻心的易溶盐含量可以重建古湖水化学演化过程。在安固里淖湖心区钻取沉积剖面，以1cm为间隔分样，测试剖面八大离子的含量（即K+、Na+、Ca₂+、Mg2+、CO₃₂-、HCO₃-、Cl-和SO₄₂-）和其他有关的地球化学特征，并且对各项离子含量进行相关分析，得到剖面易溶盐组成变化曲线和和易溶盐指标变化曲线。根据易溶盐曲线变化情况，结合钻心纹层纪年得到的的纹层年代，将安固里淖8507aB.P.以来的湖水化学演化过程分为以下几个阶段：8507~7600aB.P.，湖水化学类型为Na+-Cl- 型，盐度较高；7600~4724aB.P.，湖水化学类型为Na+-Cl--SO₄₂- 型，盐度最高；4724~3057aB.P., 湖水化学类型为Na+-Cl- 型，3057~574a B.P湖水化学类型为Na+-CO₃₂--HCO₃-，盐度较低；574aB.P.以来湖水化学类型为Na+-Cl- 型，盐度较低但是呈现快速增加趋势。同钻心的粒度分析结果相比较，易溶盐变化曲线的转折早于粒度变化曲线，反映易溶盐沉积对气候变化的反应比粒度特征更敏感，是一个较好的反映气候变化的替代性指标，有待于推广应用。

HOLOCENE SOLUBLE SALT SEDIMENTS OF ANGULINAO LAKE AND ITS ENVIRONMENT

The distribution of soluble salt in sediments of in_land lake is close with the hydrochemical feature of lake water, so we can reconstruction the process of hydrochemical evolution of the lake by analyzing the lake's soluble salt deposition. Through coring in the lacuster of Angulinao Lake, testing the eight kinds of ions( K+、Na+、Ca₂+、Mg2+、CO₃₂-、HCO₃-、Cl- and SO₄₂- ) and other related geochemical features, and analyzing the correlation among the ions, the author has drawn the curves of soluble salt distribution and soluble salt indictor. According to the variation of curves of soluble salt, and combining with the varve chronology, the hydrochemical evolution of Angulinao Lake is speculated from the soluble salt distribution of  the core: During 8507~7600 yr B.P., the lake is abundant in Na+ and Cl-, its saltness is high; in 7600~4724 yr B.P., the water is abundant in Na+, Cl- and SO₄₂-, its saltness is very high; in 4724~574 yr B.P., the water is abundant in Na+, CO₃₂- and HCO₃-, its saltness is a little low; since 574 yr B.P., the lake is abundant in Na+ and Cl-, the saltness is low and going up. Comparing with the curves of grain size, the turning points of curves of soluble salt are earlier than curves of grain size, therefore the soluble salt depositon is more sensible to fluctuation of environment , it's a good indictor and should be extended to apply.