Dynamic Analysis of Deformational Structures of the Xianniishan Fault Zone in the Three Gorges of the Yangtze River

Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannushan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on these results, a 3-D deformational structure model of the fault was established and its geometrical and kinematic characteristics in two main deformational stages i.e. the main Yanshanian and Himalayan were discussed. The directions of principal and the differential stresses in these two stages were determined by using conjugate joints, striations of fault planes and microstructures of the fault zone. The direction of σI is N-S in direction with differential stresses of 150-250 MPa in the Yanshanian, and N70E with a differential stress ranging from 80-120 MPa in the Himalayan.     

Carboniferous Mixed Terrigenous Clastic, Carbonate and Sulphate Sediments in the Bachu Area, Xinjiang

The Carboniferous system in the Xiaohaizi area, Bachu County, Xinjiang Uygur Autonomous Region, composed of typical mixed terrigenous clastic, carbonate and sulphate sediments, was mainly deposited in the tidal flat and lagoon environments. The mixed sediments occur as the following eleven types: 1. limestone intercalated with siltstone; 2. interbeds of shale and limestone; 3. gypsolyte interbedded with limestone; 4. gypsolyte intercalated with siltstone; 5. gypsolyte interbedded with shale; 6. gypsolyte intercalated with siltstone, limestone and dolomite; 7. siltstone interbedded with gypsolyte and limestone; 8. terrigenous detritus scattered in carbonate matrix; 9. carbonate as cement in clastic rocks; 10. mixed sediments of carbonate and terrigenous mud; 11. mixed sediments of carbonate grains with terrigenous sand. Based on the analysis of the dynamic mechanism of mixed sediments, it is believed that these types of mixed sediments in the study area were controlled by climate, sea level change and so     

Chronostratigraphic Subdivision and Correlation of the Permian in China

Since the principle of multiple stratigraphic classification has been widely accepted by Chinese stratigraphers, various new Permian chronostratigraphic units have been proposed in China, and they need to be redefined. The establishment of a new global chronostratigraphic scheme of the Permian, compilation of Permian lithostratigraphic units and updating of Permian biostratigraphic sequences of China makes it possible to present a revised regional chronostratigraphic succession for the Permian System in China. This succession consists of three series and eight stages. The Chuanshanian Series includes two stages, the Zisongian and the Longlinian; the Yanghsinian (Yangxinian) Series is subdivided into the Chihsian (Qixiaan) and the Maokouan Subseries, of which the former comprises the Luodianian and the Xiangboan Stage, and the latter the Kufengian (Gufengian) and the Lengwuan Stage; the Lopingian (Lepingian) Series includes the Wuchiapingian (Wujiapingian) and the Changhsingian (Changxingian) Stage.     

Massive Sulphide Deposits Related to the Volcano-Passive Continental Margin in the Altay Region

The Devonian volcano-passive continental margin in southern Altay is a significant volcanogenic massive sulphide metallogenic belt. Acidic volcanism has been dominant on the inner side of the volcano-passive continental margin, i.e., near the old land, resulting in a Pb-Zn metallogenic sub-belt, in which the ore deposits are hosted by sedimentary rocks in volcanic series, as represented by the large Koktal Pb-Zn deposits. In the central part of the margin far away from the old land, bimodal volcanic formations are well developed, forming volcanics-hosted Cu-Zn metallogenic sub-belts, e.g., the large-scale Ashele Cu-Zn deposit. The Qiaoxiahala sub-belt on the outer side of the margin near the ocean ridge is located at the spreading central trough, where ophiolite suites are developed. This type of deposits is rich in gold and copper, similar to the Cyprus-type Fe-Cu-Au metallogenic sub-belt in metallogenic environment (represented by the Qiaoxiahala medium-scale Fe-Cu-Au deposit). From the old land to th     

浅谈对“混合土”的认识及其地基处理

“混合土”是一种特殊性土,成分复杂,粒径悬殊,力学性质变化较大。本文以株洲市南华花园地区“混合土”为例,剖析了勘察中应注意的事项,阐述了动力触探是对“混合土”勘察的有效手段,并结合工程实际情况,提出了相应的地基处理措施。     

卫星遥感信息处理与多元统计分析

本文针对遥感信息的数据特征探讨了卫星遥感信息处理与多元统计算法之间的关系,并从实际出发对最小二乘残差技术,目标模式识别,增强主成份分析等方法的应用作了介绍。     

湖南氧化金矿资源特征及其利用现状存在问题与对策

本文阐述了湖南氧化金矿资源的分布、矿床类型及其地质特征,总结了近年来我省氧化金矿资源勘查和利用方面所取得的成就,找出了其中存在的主要问题,探讨了加速勘查和开发氧化金矿资源的对策与措施。     

娄邵地区煤矿地质灾害

本文对娄邵地区煤矿地质灾害的地质背景,灾害特征进行了综合分析,在此基础上,作者认为煤矿开采与抽水使矿区构造应力场变化和重新分配,是产生地质灾害的基因,同时,提出了减灾措施。     

洞庭湖综合治理中根治“地质灾害”的重要性

本文从洞庭湖区环境地质条件入手,分析堤防失事及所存在的险工险段与地质缺陷的关系,指出地质灾害是造成防洪工程失事不可忽视的因素。在洞庭湖区综合治理过程中,应注重对地质缺陷的治理     

江垭库区人潮溪段公路边坡破坏机制及整治措施

通过实地勘察,本文分析了江垭库区人潮溪公路边坡,边坡破坏的形成条件、动态特征以及各类边坡的破坏机制,从而提出以加固临空面和采取排水防水为主的整治措施。