干旱区湖泊沉积物腐殖化度的古气候指示意义--以新疆巴里坤湖为例  

The indicative significance of paleoclimate as indicated by humification of lacustrine sediment:a case on Lake Barkol,northeastern Xinjiang

作　　者：蔡颖[1] 钟巍[1,2,3] 薛积彬[1] 徐华君[2] 

机构地区：[1]华南师范大学地理科学学院,广州510631 [2]新疆大学教育部绿洲生态重点实验室,乌鲁木齐830046 [3]兰州大学西部环境教育部重点实验室,兰州730000

出　　处：《湖泊科学》2009年第1期69-76,共8页Journal of Lake Sciences

基　　金：新疆大学绿洲生态教育部重点实验室项目(XJDX0201-2008-02);兰州大学西部环境教育部重点实验室开放基金联合资助．

摘　　要：腐殖质具有对气候环境变化响应敏感的特点,已经展示出了作为古气候演变研究载体的重要潜力和优势.当前,腐殖化度对气候环境变化指示意义的研究主要应用于泥炭沉积上,而对于湖泊沉积物中腐殖化度气候环境变化的研究,至今尚未见到报道.根据新疆东疆北部巴里坤湖湖泊沉积物腐殖化度的分析,同时结合年代学、有机质含量、总有机碳、自生碳酸盐δ^(13)C,δ^(18)O的分析结果,认为该湖泊沉积物中腐殖化度可以较为敏感地反映气候环境变化的相关消息.较高的腐殖化度,指示气候相对湿润,而较低的腐殖化度值,指示气候相对干燥.在此基础上,结合多指标变化,初步划分了巴里坤湖地区近9.4cal kaBP以来经历了干(9.4-7.5cal kaBP)-湿(7.5-5.8cal kaBP)-干(5.8-3.0 cal kaBP)-湿(3.0-1.0cal kaBP)-干(1.0-0cal kaBP)五个阶段.The humification of peat deposits has been reported as a useful proxy to indicate paleoclimatic changes, but there is no reports focusing on lacustrine sediments. On the basis of analyses of the humification of lacustrine sediment in Lake Barkol, northeastern Xinjiang, and by comparing with results of multi-proxies such as OM, TOC, carbon and oxygen isotopes of carbonate, we considered that higher humification of lacustrine sediment value indicates relatively humid climate, whereas lower humification of lacustrine sediment indicates relatively dry condition. Based on humification proxy and other proxies, the paleoclimate of Lake Barkol could be divided initially into five phases： early Holocene （9.4-7.5cal kaBP）, climate is relative cold and dry; mid-Holocene （7.5-5.8cal kaBP）, relatively warm and humid climate prevailed, and then climate turned into warm and dry during 5.8-3.3cal kaBP; in late Holocene, climate became cold and dry; in 1.0-0.0cal kaBP from previous relatively cold and wet period lasting from 3.3 to 1.0cal kaBP.

关 键 词：巴里坤湖 腐殖化度 气候意义 

分 类 号：P532[天文地球—古生物学与地层学]