巴什布拉克铀矿区褪色蚀变Quickbird高分图像地学分析   总被引：1，自引：0，他引：1  

叶发旺  刘德长 《地球信息科学学报》2012,14(1):123-127

 位于新疆塔里盆地西北缘的巴什布拉克铀矿床是与油气还原褪色蚀变密切相关的铀矿床,但有关油气还原褪色蚀变的依据大多是地质和地球化学方面的微观依据。本文在分析巴什布拉克铀矿化褪色蚀变岩石地质特征的基础上,根据Quickbird高空间分辨率卫星遥感数据的特点,开展了数据的增强处理,进一步提高了Quickbird数据对褪色蚀变岩石的分析和解译能力,并利用经过增强的Quickbird数据,对铀矿区出露的油气还原褪色蚀变岩石的空间形态和分布特征进行了分析:(1)从铀矿区及周围地区的较大视野,分析了油气还原褪色蚀变岩石的总体分布特征;(2)从整个铀矿区的尺度,分析了未发生褪色蚀变的紫红色砂岩残留体的形态特点、空间展布特征等;(3)从东矿区段更大尺度,分析了处于大片未蚀变紫红色砂岩内部的灰黄色褪色蚀变砂岩的形态特点和空间展布特征。上述分析,从正反两个方面,为铀矿化褪色砂岩的油气还原成因提供了大尺度的宏观依据,并为外围找矿提供了重要信息,充分展示出Quickbird高空间分辨率遥感技术在铀矿找矿中的应用潜力。  相似文献   

西藏冈底斯斑岩型铜钼矿床的Cu、Mo同位素组成及其意义   总被引：2，自引：0，他引：2       下载免费PDF全文

胡文峰  张烨恺  刘金华  郭亮  周炼 《地球科学》2019,44(6):1923-1934

选取西藏冈底斯成矿带的驱龙、达布斑岩型铜钼矿及鸡公村石英脉型钼矿为研究对象,分别挑选含矿斑岩和石英脉中的黄铜矿、辉钼矿进行Cu、Mo同位素测定.结果表明,西藏冈底斯斑岩型黄铜矿的δ^65/63Cu介于0.01‰~0.98‰,辉钼矿的δ^97/95Mo介于-0.34‰^-0.15‰,热液脉型矿床中辉钼矿的δ^97/95Mo介于-0.35‰^-0.23‰.形成于陆-陆碰撞造山后的冈底斯斑岩型铜钼矿床的Cu同位素与俯冲带产出的斑岩型矿床中的Cu同位素组成具有一定的相似性,均表现为单峰分布的特征.驱龙斑岩型矿床中热液脉与含矿斑岩中的δ^65/63Cu具有一致性,可能反映了二者在来源上具有一致性.在冈底斯斑岩型铜钼矿床中,不同蚀变带具有不同的Cu、Mo同位素组成,自蚀变中心向外,δ^65/63Cu与δ^97/95Mo表现出负相关趋势,可能与成矿流体的性质密切相关.冈底斯石英脉型钼矿较斑岩型铜钼矿δ^97/95Mo相对偏负,结合两类矿床的成矿年代,可能暗示两类矿床的成矿物质是同一源区连续演化的结果.  相似文献   

湖南锡矿山超大型锑矿床围岩蚀变元素迁移特征及定量计算研究     

弭希风  胡瑞忠  付山岭  彭建堂  骆金诚  陈应华 《矿物岩石地球化学通报》2019,(1):103-113

湖南锡矿山锑矿床是目前世界上已发现的最大的锑矿床,其硅化非常发育且与矿化关系密切,根据硅化蚀变程度的强弱,从围岩到矿石大致划分为4个带:灰岩→弱硅化灰岩→强硅化灰岩→矿石。为揭示锡矿山锑矿的成矿过程及成矿流体信息,利用Isocon标准化方法,以Al_2O_3为惰性组分,对各蚀变带围岩及矿石的主、微量元素进行质量平衡计算。结果表明,热液蚀变过程中,Si、Sb、Li和Bi等大量迁入,而Ca、Mg、Na和大离子亲石元素Sr、Ba、Rb等大量迁出;成矿热液呈酸性并富硅,其中Hg、As、Au、Tl等元素含量极低,这可能是导致锡矿山锑矿床矿种单一的原因之一。稀土元素除Eu外,其他元素未发生明显的活化迁移,水岩反应并未影响原岩的稀土元素配分模式;蚀变岩及矿石中的Eu负异常可能表明成矿过程是在相对还原的环境下进行的。  相似文献   

Two types of uranium mineralization in Gulcheru quartzite: Fracture-controlled in Ambakapalle area and litho-controlled in Tummalapalle area,Cuddapah Basin,Andhra Pradesh,India     

《China Geology》2019,2(2):142-156

The Cuddapah Basin in southern India has a potential for uranium mineralization due to some favorable factors such as its temporal, stratigraphic and tectonic settings. Systematic exploration program conducted by the Atomic Minerals Directorate for Exploration and Research (AMD) within the Cuddapah Basin resulting in the recognition of distinct types of uranium mineralization, viz., strata bound type, fracture/shear-controlled type and tabular type. The Gulcheru Formation which is the lowermost unit of the Cuddapah Basin is dominantly arenitic in nature. During the exploration works, a number of uranium anomalies were identified with dimensions ranging from 1 m to 1.5 km. Gulcheru quartzite hosted uranium mineralization is intermittent and inconsistent in nature. The anomalous outcrops are distributed over a strike length of ca. 60 km between Gandi in the SE and Ambakapallein the NW. Presently, two different types of uranium mineralization are characterized on the basis of field observations, mapping and structural interpretation, petro-mineralogy and geochemistry. Although the host rock is same for both types, the mechanism of uranium enrichment is totally different. The Ambakapalle uranium mineralization is controlled by fault zone and associated hydrothermal activity. Whereas, the Tummalapalle uranium mineralization is litho-controlled in nature influenced by suitable four ‘P’ factors, i.e., provenance, porosity-permeability, precipitation and preservation. The geochemical characterization of Gulcheru quartzite suggest a passive margin type of provenance setting. Petro-mineralogically the quartz arenite suggests enough textural as well as mineralogical maturity. Ambakapalle quartzite is slightly strained and deformed due to faulting. Analysis of selected samples recorded 0.01% to 0.048% U₃O₈ and <0.01% ThO₂. Petrographic observation revealed that the anomalies were appeared due to secondary uranium minerals occurring as surficial encrustations, fracture filling and lesser irregular patches. Structural analysis suggests the mineralization along E-W trace slip fault is possibly consistent in sub-surface. Tummalapalle quartzite is relatively less deformed arenitic in nature with significant enrichment in MREE. The genetic models for the two types of mineralization is totally different.© 2019 China Geology Editorial Office.  相似文献   

波浪对海洋上混合层温度变化的影响研究     

张晓爽  吴克俭 《中国海洋大学学报(自然科学版)》2012,(9):1-6

通过在海洋上混合层温度方程的平流输运项中加入Stokes漂的影响,定量计算了波浪Sokes漂对混合层温度变化的贡献,即Stokes漂对SST变化的影响。结果表明,波浪Stokes漂的平流输运作用对混合层温度变化的贡献与平均流的贡献在量值上处于可比的量级,二者全球平均比值为23.43%,最大比值达到70%。而对于SST变化率的影响也较为显著,加入Stokes漂影响后,SST变化率的最大变化值达到0.989×10-6℃/s,SST变化率的全球平均变化值为0.077 8×10-6℃/s,与SST变化率全球平均量值0.516 2×10-6℃/s相比达到15.07%,是不可忽略的。因此,在对于海洋混合层温度计算过程中,考虑波浪Stokes漂的作用是必要的。  相似文献   

内蒙古四子王旗夏尔楚鲁金矿床地质特征及成因     

李凤仁  张赋 《地质与资源》2012,21(4):350-353

夏尔楚鲁金矿床位于白乃庙-温都尔庙古陆块晚古生代活动陆缘带内.金矿围岩为白音宝拉格组变质岩系和早三叠世黑云母花岗岩,矿体赋存在断裂构造破碎带中,受近南北向断裂构造控制.金矿体为含金石英脉,具有膨大、分支、复合特征.系统总结了矿石矿物组成、结构构造特征,认为金属矿化与硅化、绢英岩化、黄铁矿化、辉钼矿化等蚀变作用有关.成矿作用发生在伸展地球动力学环境下,控矿构造具有多阶段活动的特点,矿床的成因类型为岩浆期后热液型金矿床.  相似文献   

遥感技术在矿产远景调查工作中的应用——以内蒙古莫力达瓦旗巴彦街地区为例     

江山  石绍山  时建民  姚远  王宇利 《地质与资源》2015,24(1):57-62

工作区所在的大兴安岭北段地区,由于地面披覆物的影响,地质体在遥感影像上的区分度降低,一般认为遥感技术难以发挥作用.但是对矿调工作来说,抓住与矿产分布最为密切的线、环形构造和遥感蚀变异常两方面的内容最为关键,而这两方面的内容受地面披覆物的影响相对较小.在巴彦街矿调项目中,首先对工作区进行不同尺度的线、环形构造解译,运用比值-主成分分析方法提取蚀变异常.综合两方面的内容,并结合化探异常圈定了重点工作区,经探槽工作验证,具有较好的找矿前景.  相似文献   

斑岩铜矿系统     

刘洪卫  张善明  冯罡  张建  刘雅峰 《地质与资源》2013,22(5):388

从区域尺度和矿床尺度两个方面论述了斑岩铜矿系统的特点.区域尺度上：1）斑岩铜矿多呈矿带或成矿域出现,带内众多斑岩铜矿呈簇或组合呈线状产出,这是构造作用控制下不连续岩株呈线状侵入就位的表现; 2）主要产于俯冲作用形成的岛弧和陆缘环境,构造应力属挤压但与中等拉张作用也有关,最近的研究证实大陆碰撞造山带也是斑岩型矿床产出的重要环境;3）其形成是通过具氧化性,S饱和,富含金属的岩浆熔体侵入所致,岩浆侵入作用为成矿提供了物质来源; 4）围岩的物理性质以及化学组成对矿床的规模、品位以及矿化类型具有极强的控制作用,碳酸盐岩围岩主要赋存近源Cu-Au夕卡岩矿床,少量远程Zn-Pb或Au夕卡岩矿床,在夕卡岩前缘还形成交代型Cu和Zn-Pb-Ag±Au矿床.矿床尺度上：1）含矿斑岩与斑岩型矿床时空相依,成因相联,是斑岩铜矿重要的含矿母岩和金属-S的可能载体;2）火山角砾岩筒在深部与矿化体平行或斜交,其与围岩的接触带,一般也是富硫金成矿带的一部分;3）与矿化有关的斑岩成矿系统内的角砾岩主要有爆发角砾岩、侵入角砾岩、爆发侵入角砾岩、热液角砾岩和热液卵石脉;4）斑岩铜矿系统中的热液蚀变自下而上可分为不含矿的早期钠质-钙质蚀变→含矿的钾化→绿泥石化-绢云母化→绢云母化→高级泥化,热液蚀变互相套合,矿化互相叠加;5）岩帽是斑岩型热液-成矿活动-蚀变体系的重要组成部分,是重要的找矿标志.  相似文献   

Assessment of a hydrologic model's reliability in simulating flow regime alterations in a changing climate   总被引：1，自引：0，他引：1       下载免费PDF全文

Rajesh R. Shrestha  Markus A. Schnorbus  Daniel L. Peters 《水文研究》2016,30(15):2628-2643

It is a common practice to employ hydrologic models for assessing present and future states of watersheds and assess the degree of alterations for a range of hydrologic indicators. Previous studies indicate that the hydrologic model may not be able to replicate some of the indicators of interest, which raises questions on the reliability of model simulated changes. Hence, we initiated a study to evaluate the replicability of the streamflow changes by employing the widely used variable infiltration capacity hydrologic model for sub‐basins and mainstem of the Fraser River Basin, Canada. Given that the hydrologic regime of the region is known to be influenced by teleconnections to the Pacific Decadal Oscillation (PDO) and El Niño–Southern Oscillation (ENSO), we used hydrologic responses to the PDO and ENSO states as analogues for evaluating the model's ability to simulate climate‐induced changes. The results revealed that the qualitative patterns of response, such as lower flows for the warm PDO state compared to the cool state, and progressively higher flows for the warm, neutral and cool ENSO states, were generally well reproduced for most hydrologic indicators. Additionally, while the directions of change between the different PDO and ENSO states were mostly well replicated, the magnitude of change for some of the indicators showed considerable differences. Hence, replicability of both magnitude and direction of change need to be carefully examined before using the simulated indicators for assessing future hydrologic changes, and a reliable replication increases the confidence of projected changes. Copyright © 2016 Her Majesty the Queen in Right of Canada. Hydrological Processes. © 2016 John Wiley & Sons, Ltd.  相似文献   

某水电站地下厂房围岩稳定性分析研究     

孔祥福  李景龙  李嘉春  王刚 《岩土力学》2006,27(Z1):296-299

某抽水蓄能水电站地下厂房洞室群所处地带围岩为新鲜的混合花岗岩及少量后期侵入的岩脉,岩石坚硬完整。采用新奥法施工,安装埋设了大量的观测仪器,准确地反馈安全监测数据对保障施工安全有不可替代的作用。通过整理分析该水电站完整的变形监测资料,证明了开挖对围岩变形的影响不大,除个别断层外,施工期和运行期的地下厂房整体上是稳定的。另外,还对地下厂房进行了数值模拟,采用有限差分法对模型进行非线性弹塑性计算分析,准确地预测了围岩动态变化过程,得出了洞室围岩位移和应力的变化规律,并与监测结果进行了对比,可为类似地下工程围岩稳定性分析提供借鉴。  相似文献