乌恰县贝壳山:塔里木盆地西部沧海桑田的见证者  

The transition from sea to land of the western Tarim Basin:Evidence from Shell Mountain of Wuqia County

作　　者：杨婉舒 熊昕 席党鹏[1] 万晓樵[1] YANG Wanshu;XIONG Xin;XI Dangpeng;WAN Xiaoqiao(State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质大学(北京)生物地质与环境地质国家重点实验室,北京100083

出　　处：《自然杂志》2023年第2期148-154,共7页Chinese Journal of Nature

基　　金：国家重点研发计划(2022YFF0800800);国家自然科学基金面上项目(41872009、42288201)。

摘　　要：塔里木盆地西部位于亚洲大陆内部,远离海洋,气候极为干旱,以荒漠为主,但在3400万年前这里曾是一片充满生机的汪洋大海。位于塔里木盆地西端乌恰县的著名景观“贝壳山”,则是塔里木盆地西部沧海桑田的见证者。文章通过贝壳山的地层及所含化石的详细观察和考证,尝试重现塔里木盆地西部如何从“沧海”变为“桑田”的过程。贝壳山的组成为始新世中期(距今~4600万年)的浅海相牡蛎化石,表明在始新世中期,塔里木盆地西部还是一片属于新特提斯洋东北缘的海湾,气候温暖,水体清澈,发育了丰富的以牡蛎为代表的海洋生物,堆积了一套厚厚的贝壳层,即卡拉塔尔组。至始新世晚期—渐新世早期,海水逐步退出塔里木盆地西部地区,之后随着天山和昆仑山的不断隆升,原来埋藏在地下的贝壳层逐渐出露,形成如今的贝壳山。The western Tarim Basin,located in the interior of the Asian continent and far away from the ocean,is a typical arid desert landscape.However,the western Tarim Basin was marine environment before 34 Ma.The famous“Shell Mountain”in Wuqia County provides the direct evidence of the transition from sea to land in the western Tarim Basin.Based on the detailed study on the strata and fossils of the“Shell Mountain”,the process of how the western Tarim Basin changed from sea to land are carried out.The“Shell Mountain”is composed of marine oyster fossils in the middle Eocene(~46 Ma),indicating that the western Tarim Basin was a gulf in the northeastern margin of the Neotethys Ocean,with warm climate,shallow water,and rich in marine organisms represented by oysters.As a result,a set of thick shell layers,namely,the Karatal Formation,is deposited.During the late Eocene to early Oligocene,the sea gradually retreated from the western Tarim Basin.With the continuous uplift of the Tianshan Mountains and Kunlun Mountains since the late Oligocene,the previously buried shell layers are re-exposed,forming the present Shell Mountain.

关 键 词：塔里木盆地 双壳类 特提斯 古近纪 贝壳山 

分 类 号：P542[天文地球—构造地质学] P535[天文地球—地质学]