The Liupanshui area of the Upper Yangtze block is located in the joint action of Coastal Pacific tectonic and Tethys tectonic domain in the Meso-Cenozoic.Under the action of different tectonic stress in two directions,the original rock strata underwent extremely complex structural deformation.In order to correctly a-nalyze the complex structural traces in various directions in the region and reshape a reasonable structural evo-lution history,this paper studies the geometric characteristics,combination characteristics,and involvement of the fold combination in various directions in the region based on the data obtained from the regional geological survey.Combined with the dynamic background of regional tectonics,the genetic background,sequence,and mutual superimposition and transformation relationships of fold combinations in various directions in the region are discussed.It is concluded that there are three groups in the area:northeast linear folds,northwest linear folds and no specific axial folds.The north-east trending linear fold combination is the product of the interaction between the Kura-Pacific plate and the South China plate in the coastal Pacific tectonic domain.It is probably a fold combination of the foreland on the northwest side of the Changle-Nan'ao tectonic belt in the Yanshan period.The northwest linear fold is the product of the interaction between the Gangdese middle plate of the Tethyan tectonic domain and the Indian plate,which is the foreland fold combination on the northeast side of the Sanjiang composite orogenic belt.The combination of non-specific axial folds is formed by cross-axis super-position of north-west linear folds to transform north-east linear folds.There is a widespread phenomenon of cross-axis fold stacking in this area.This article provides new ideas for rationally analyzing the complex struc-tural deformation in the region and reshaping the correct structural evolution history.It provides a rare research base for the study of the'cross-axis fold stacking'model.
本文对产于贵州兴义乌沙地区上三叠统卡尼阶法郎组瓦窑段中的 17 件鱼龙标本进行研究,认为本次研究标本均为Qianichthyosaurus zhoui.通过对其肢骨的定性及定量分析认为,Qianichthyosaurus zhoui在后肢形态上存在性双形现象.暨雄性后肢外形窄长,雌性后肢则相对宽短;雄性的股骨比肱骨长度略长,而雌性的股骨与肱骨长度相当;雄性股骨近端和远端相较于雌性更为膨大股骨远端宽度为中轴宽度的2.5 3 倍,股骨长与股骨中轴的比值较大,通常大于3.5;雌性股骨近端和远端相较于雄性较小股骨远端宽度一般为中轴宽度的 2 倍左右,股骨长与股骨中轴的比例较小,比值约为3 左右雌性第一跖骨面积较小且具有凹缺,雄性第一跖骨面积较大不具凹缺.
在工业固废堆场及垃圾填埋场的整治前,需要查明堆、填物的空间分布,为开展挖掘清理工程提供技术依据.根据场地的基本情况分析勘察目标物理性质条件,选择地球物理勘探方法中的高密度电阻率法、高精度磁测法进行室内模拟,开展可行性研究.在实验场地进行现场勘察,了解填埋物异常反映特征,并推断其空间分布;经开挖验证地球物理勘探方法取得良好效果.
本文以新场河水库滑坡为研究对象,在野外勘查、探明滑坡地质条件和变形特征的基础上,对新场河水库滑坡的成因进行了分析,根据土体压缩特性和固结原理,参照地基变形计算方法,对滑坡稳定性及未来的变形发展趋势进行了评价.研究表明,具备顺层地质条件的库岸斜坡,在库水位升降和降雨联合作用下,即使没有很好的临空滑移条件,斜坡体也会产生蠕滑变形,其变形量的大小与坡体组成物质的压缩性有关.分析研究可为同类水库滑坡防治及安全运行提供借鉴.
根据《锂(Li)地球化学图》(贵州省地球化学图集,冯济舟等,2008)显示,晴隆县城北侧一带、普安青山一带、兴义万屯一带、安龙县城北侧一带均有较好的锂(Li)异常显示.经研究选取了普安青山一带开展了少量地质工作,发现锂(Li)异常层位主要为第四系(Q)残坡积松散黏土层,含锂(Li)黏土基底为强风化白云岩,下部为杂色黏土夹少量强风化白云岩碎块,中下部为土黄色、浅紫色黏土,中部及上部为褐红色黏土.经地表及浅井工程采集样品检测,基底白云岩含锂(Li)14.4 ug/g,黏土中锂(Li)含量最高达303 ug/g,平均含量 200 ug/g,超过锂(Li)元素在地壳中克拉克值的10 倍.经初步分析,本次研究工作显示了黔西南锂(Li)异常区具备一定的研究价值和找矿潜力.
