罗布泊地区晚第四系介形类分布特征及环境分析  

Late Quaternary Ostracods distribution and environmental analysis of Lop Nur Region

作　　者：王建中[1] 杨振京[1] 林防[1] 毕志伟[1] 林景星[2] 张冰[1] 刘畅[1,3] 

机构地区：[1]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [2]中国地质科学院地质研究所,北京100037 [3]石家庄经济学院,河北石家庄050031

出　　处：《干旱区地理》2015年第1期90-94,共5页Arid Land Geography

基　　金：国土资源大调查地质调查项目(200312300002);国家自然科学基金项目(40972212)

摘　　要：通过对新疆罗布泊地区地层剖面中的介形类分布及其组合特征的分析,在剖面中发现有14属31种介形类化石,划分出两个化石组合层段。第一层段以Limnocythere sanciti-patricii为组合特征,代表沉积环境为湖相,根据^14C年龄,此层段的沉积年龄在20 870-14 770 a BP。第二层段以Cyprideis littoralis和Darwinula stevensoni为组合特征,代表咸水—半咸水湖相沉积环境,根据^14C测年,地层沉积年龄约30 000 a BP。The ideal indexes to analyze paleoenvironment that reflect the environmental changes are the abundance and variation of differentiation degree of ostracods in the strata. If the climatic environment is warm and the temperature and depth of water are suitable,the abundance and variation of differentiation degree of ostracods are higher. On the contrary,if the climatic is cold and the environment of the water is bad,the abundance and variation of differentiation degree of ostracods are lower. Besides,some ostracods themselves are good facies fossil,for example,some ostracods are halo tolerant,some are euryhaline and some ostracods could not live in salt water. Therefore,on the basis of the distribution features of the ostracods in the stratigraphic section the conjecture to sedimentary environment of the time is viable. Through the analysis of ostracoda distribution and combination feature in Lop Nor stratigraphic section,in the stratigraphic section found 14 Genus 31 species of ostracoda fossils,divided into two fossil assemblage zones. The first zone is characterized by Limnocythere sanciti-patricii,representatives of the lacustrine sedimentary environment. According to^14 C age,the age of this zone is deposited in 20 870-14 770 a BP. The second zone is characterized by Cyprideis littoralis-Darwinula stevensoni,representatives of salt water-brackish lake sedimentary environment. According to14 C dating,the age of this zone is about 30 000 a BP.

关 键 词：罗布泊 晚第四系 介形类 环境信息 

分 类 号：Q913[天文地球—古生物学与地层学]