新疆巴里坤湖9.0 cal ka BP以来沉积物地球化学元素分布特征与古气候环境演化

根据中国西北干旱区巴里坤湖BLK-1剖面沉积物的地化元素分析,采用SPSS因子分析法提取了对沉积环境变化敏感的地化元素和氧化物组分.在R、Q型因子分析的基础上,结合沉积物的硅铁铝率(SiO2/(Al2O3+Fe2O3))、淋失系数(SiO2/(MgO+K2O))、CaO/MgO以及腐殖化度等指标,提取出古气候环境信息.初步研究结果表明:近9.0 cal ka BP以来,巴里坤湖地区气候环境仍以干旱化为主,全新世期间出现过多次不同程度的干湿变化,经历了5个气候阶段:9.0—7.5 cal ka BP期间,气候干旱;7.5—5.8 cal ka BP期间,气候温暖湿润,为研究区全新世最佳适宜期;5.8—3.0 cal ka BP期间,气候干旱;3.0—1.0 cal ka BP期间,气候湿润;1.0—0 cal ka BP期间,气候干旱.

Study on the Characteristics of the Geochemical Elements and Paleoclimate Changes in Lake Barkol, Xinjiang Since About 9.0 cal ka BP

Geochemical elements analysis of BLK-1,retrieved from Lake Barkol,NW China,was carried out by using SPSS,and envoronmentally geochemical elements components can be easily identified according to the variations in the Load of R(Q)-type factors.In addition,we used some other proxies as the auxiliary factors in the analysis process.The results have shown that the paleoclimate of Lake Barkol has a drought trend overall,although it has experienced an alternating climate process(cold-moisture and warm-dry)since 9.0cal ka BP,and the history of paleoclimatic changes was reconstructed as follows:(1)9.0-7.0 cal ka BP,the palaeoclimate was dry;(2)7.5-5.8 cal ka BP,the palaeoclimate was warm and humid,we suggested it’s the Holocene Optimum period of study area;(3)5.8-3.0 cal ka BP,the palaeoclimate was dry;(4)3.0-1.0 cal ka BP,the palaeoclimate was warm and humid;(5)1.0-0 cal ka BP,the palaeoclimate was dry.