Distinguishing the source of carbonates from lake sediments of Lake Chenghai, Yunnan Province

Abstract

碳酸盐是湖泊沉积物的组成部分,其碳、氧同位素组成是恢复湖区古气候/古环境的有效代用指标.沉积物碳酸盐包括物源区带来的外源碳酸盐和湖泊内生沉淀产生的自生碳酸盐,其中只有自生碳酸盐才具有古气候指示意义.故沉积物碳酸盐来源辨识是开展碳酸盐古环境记录研究的基础和前提.通过多种方法的综合判别,证明了程海沉积物碳酸盐主要是自生碳酸盐,为开展碳酸盐记录研究提供了可靠依据.程海是开展碳酸盐碳氧同位素与古气候研究的理想场所,尤其值得深入研究.;The research of stable carbon and oxygen isotope of Carbonate of lake sediments, is one of the most effective indices to reconstruct paleoclimatic and paleoenvironmental information. Sedimentary carbonate consists mainly of allochthonous carbonates produced by surface runoff and authigenic carbonates produced by inorganic precipitation. However, the authigenic carbonate has the paleoclimatic and paleoenvironmental meaning. Consequently, distinguishing the source of carbonate is the basis and premise for the research of sedimentary carbonates. This paper utilized various methods to prove that the carbonate in Lake Chenghai,Yunnan Province was authigenic, which provided the basis for the research of sedimentary carbonates. Lake Chenghai provides an ideal lacustrine setting for research of stable carbon and oxygen isotope to reconstruct paleoclimate, and the future research will be deserved.