西藏特提斯喜马拉雅早-中侏罗世岩石薄片偏光显微图像数据集

A photomicrograph dataset of Early-Middle Jurassic rocks in the Tibetan Tethys Himalaya

中国西藏自治区南部特提斯喜马拉雅出露完整的侏罗系,是研究侏罗纪东特提斯古海洋、古环境和古地理演化的重要场所,也是探索冈瓦纳大陆裂解、洋中脊扩张、大火成岩作用和温室地球气候间相互作用的重要载体。定日和聂拉木地区的下-中侏罗统以碳酸盐岩为主,同时还发育碎屑岩和混积岩,由老到新划分为扎木热组、普普嘎组、聂聂雄拉组。迄今,藏南侏罗系研究程度不高,且地层存在重复或缺失等问题,不同研究区地层划分和对比仍存在较大困难。为了更好地服务今后的研究,如准确进行区域地层对比、避免重复的岩石学工作并高效利用已有研究成果等,本数据集利用偏光显微镜,对采集自定日卧龙剖面和聂拉木年多剖面的494个岩石薄片进行了单偏光和正交偏光两种形式的显微照片采集。本数据集详细介绍了这两个剖面的大地构造背景、古地理位置、采样位置、地层时代、岩石名称等信息。本数据集可以直接服务基础地质学研究,可大大提高研究人员的效率,同时可以依靠深时数字地球(DDE)平台,进行数据整合应用,从更广的空间和时间尺度解决重大科学问题,也可以服务找矿、找油、建筑、教学与科普等。

Well exposed in the Tethys Himalaya of southern Tibet,China,the Jurassic is important for studying the evolution of paleo-ocean,paleoenvironment and paleogeography in the eastern Tethys.It is also important for us to understand the interaction between Gondwana rifting,mid-ocean ridge expansion,large igneous province,and Earth’s greenhouse climate.The Lower-Middle Jurassic in Tingri and Nyalam is dominated by carbonate rocks,together with siliciclastic and mixed carbonate-siliciclastic rocks.It consists of the Zhamure,Pupuga,and Niexiongla formations from bottom to top.To date,the Jurassic in southern Tibet remains less understood.Due to repeated and incomplete stratigraphic records,it is still difficult to accurately identify the strata through comparison of their lithologic units.This study was initiated to better serve future research on,for example,accurate regional stratigraphic comparison,and to avoid repetitive petrological work.Micrographs of 494 thin sections were collected from the Wölong(Tingri)and Nianduo(Nyalam)sections using microscopes under single polarized and orthogonal light,respectively.This dataset includes such information as tectonic setting,paleo-geographic location,sampling sites,stratigraphic age,and rock name of these two sections.It can be used to support geological research and to improve the work efficiency.When integrated with other data at the deep-time digital earth(DDE)platform,the dataset has the potential to help unpack major scientific issues on a wider space and time scale.In addition,it can also be used for mine and oil exploration,construction,teaching and general science popularization.