北祁连东段冷龙岭—毛毛山地区 金矿化地质特征及找矿方向          下载免费PDF全文

王琦  安国堡 《甘肃地质》2006,15(1):53-57

冷龙岭—毛毛山地区位于北祁连东段。为揭示这一地区金成矿规律和控矿因素,从大地构造背景、含矿建造以及成矿构造等几个方面讨论了青分岭金矿床的成矿条件。通过对该区区域地质和构造特征以及金地球化学异常特征分析,提出了进一步找矿方向。  相似文献   

青海祁连两类火山成因硫化物矿化蚀变带地球化学特征及找矿标志          下载免费PDF全文

蒋敬业  李方林  王苹  陆建培 《地球科学》1999,8(3):304-307

研究区发育火山成因块状黄铁矿矿床和铅锌铜多金属硫化物矿床及其相应的两类矿化蚀变带．黄铁矿矿化蚀变带以亏损Ｐｂ,Ｚｎ,Ｃｕ,Ａｇ,Ｓｒ,Ｂａ,Ｍｎ及Ｋ,Ｎａ,Ｍｇ等元素,且多为负异常,元素无明显共生组合规律为特点;多金属矿化蚀变带则以富集多金属元素及伴生元素,富Ｋ,Ｍｇ,贫Ｎａ为特征,而且多元素共生组合好,异常强度高而宽度窄,下盘晕强于上盘晕．同时,总结了两类矿化蚀变带地球化学找矿标志,对区内主要蚀变带进行了含矿远景评价  相似文献   

扬子地块古生代大地构造演化及古地磁学研究综述   总被引：5，自引：0，他引：5  

白立新  朱日祥 《地球物理学进展》1996,11(3):109-116

本文简要地论述了扬子地块古生代大地构造研究现状，扬子与华夏地块之间的华南裂谷盆地于奥陶纪初发生收缩，直到加里东末期基本封闭，古生代扬子地块与华北地块之间的秦岭海槽以拉张为主，扬子地块西缘古生代期间处于相对稳定的构造环境，古生代末进入特提斯构造域，发生活化。  相似文献   

再论华南（东）晋宁－加里东海盆地形成、演化及封闭   总被引：3，自引：0，他引：3  

余达淦 《安徽地质》1994,(Z1)

华南（东）晋宁－加里东海盆地形成于青白口纪，经历了晋宁期，加里东早期及加里东晚期３个演化阶段。海盆地基底为陆壳，形成于拉伸的裂谷环境，海盆地的封闭以陆内俯冲及拼贴为主，具多阶段性。海盆地基底，特别是华夏地块基底高热值属性导致了加里东海盆地有湘桂海盆地和赣闽粤海盆地２种类型，后者位于华夏基底之上，活动性明显，形成数条陆内动力热流变质带。  相似文献   

祁连山冰川变化及其脆弱性     

CAI Xingran  LI Zhongqin  XU Chunhai 《地理学报(英文版)》2022,32(1):117-140

Glaciers are a reliable freshwater resource in arid regions of West China and the vulnerability of its changes is closely related to regional ecosystem services and economic sustainable development. Here, we took the Qilian Mountains as an example and analyzed the spatiotemporal characteristics of glacier changes from 1998 to 2018, based on remote sensing images and the Second Chinese Glacier Inventory. We estimated the basic organizational framework and evaluation index system of glacier change vulnerability from exposure, sensitivity and adaptability, which covered the factors of physical geography, population status and socio-economic level. We analyzed the spatial and temporal evolutions of glacier change vulnerability by using the vulnerability evaluation model. Our results suggested that:(1) Glacier area and volume decreased by 71.12±98.98 km² and 5.59±4.41 km³, respectively, over the recent two decades, which mainly occurred at the altitude below 4800 m, with an area shrinking rate of 2.5%. In addition, glaciers in the northern aspect(northwest, north and northeast) had the largest area reduction. Different counties exhibited remarkable discrepancies in glacier area reduction, Tianjuan and Minle presented the maximum and minimum decrease, respectively.(2) Glacier change vulnerability level showed a decreasing trend in space from the central to the northwestern and southeastern regions with remarkable differences. Vulnerability level had increased significantly over time and was mainly concentrated in moderate, high and extreme levels with typical characteristics of phases and regional complexity. Our study can not only help to understand and master the impacts of recent glacier changes on natural and social aspects but also be conducive to evaluate the influences of glacier retreat on socio-economic developments in the future, thus providing references for formulating relevant countermeasures to achieve regional sustainable development.  相似文献   

中亚天山地区关键水文要素变化与水循环研究进展     

陈亚宁  李稚  方功焕 《干旱区地理》2022,45(1):1-8

天山地处欧亚大陆腹地,是丝绸之路经济带中段的重要水源地.天山地区的水循环系统具有时空差异性大、水源机制复杂、径流构成多元以及水系统脆弱等特点,水循环各环节受陆表格局和气候变化影响显著,水文要素对气候变化响应敏感,难以沿用现有的流域水循环模式阐述其内在机理.结合文献阅读和研究,系统分析了气候变化背景下天山地区关键水文要素...  相似文献   

Effective Elastic Thickness and Its Geological Significance In the Ordos Block and Adjacent Areas     

CHEN Qing  Franz NEUBAUER  DONG Yunpeng  HE Dengfeng  CHEN Hao 《《地质学报》英文版》2013,87(Z1):114-115

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黔东南重磁异常与金异常特征及找矿意义   总被引：1，自引：0，他引：1  

杨建辉  王亮  张家德  杨胜发 《物探与化探》2013,(5)

为了深入挖掘黔东南地区的找矿潜力,对黔东南地区区域重磁异常进行解释,研究东部地区的天锦黎金矿密集区及西部地区的金化探异常分布特征,发现金矿床（点）和金化探（元素、块体）异常的产出,同重、磁异常平面分布和推断的岩浆岩侵入体（基性岩类、酸性岩、构造蚀变岩）及区域性深大断裂构造（东西向、南北向）的分布,存在着空间、时间和成因上的联系,由此拓开了黔东南天锦黎金矿密集区及外围金矿地质找矿的新思路,不要只限于在相关地质层位里和北东向构造及伴生断裂（即“背斜加一刀”）交会处及其附近,来寻找变质碎屑岩中的脉型金矿。  相似文献   

资源三号数据在重力中区地形改正中的应用     

孙喜亮  刘召芹  刘斌  邸凯昌  张明华 《物探与化探》2013,(5):822-826

针对我国资源三号卫星立体影像数据,利用GPS控制点,结合前视、下视、后视区域网平差精化有理函数模型,探讨了资源三号卫星立体影像数据用于重力中区地形改正的高精度DEM生成方法。通过1：1万高精度DEM数据进行地改实验验证表明：资源三号卫星立体影像数据提取的DEM可以满足1：20万区域重力测量中区地改精度要求,为我国重力测量中区地形改正提供了一条有效途径,拓展了资源三号数据在区域重力测量中的应用。  相似文献   

Petrogenesis of the ü?kap?l? Granitoid and its Mafic Enclaves in Elmal? Area (Ni?de, Central Anatolia, Turkey)     

Hüseyin KURT  Kerim KO?AK  Kür?ad ASAN  Mustafa KARAKA? 《《地质学报》英文版》2013,87(3):738-748

The Late Cretaceous ükapili Granitoid including mafic microgranular enclaves intruded into metapelitic and metabasic rocks, and overlain unconformably by Neogene ignimbrites in the Ni de area of Turkey. It is mostly granite and minor granodiorite in composition, whereas its enclaves are dominantly gabbro with a few diorites in composition. The ükapili Granitoid is composed mainly of quartz, K-feldspar, plagioclase, biotite, muscovite and minor amphibole while its enclaves contain mostly plagioclase, amphibole, minor pyroxene and biotite. The ükapili Granitoid has calcalkaline and peraluminous (A/CNK= 1.0-1.3) geochemical characteristics. It is characterized by high LILE/HFSE and LREE/HREE ratios ((La/Lu) N = 3-33), and has negative Ba, Ta, Nb and Eu anomalies, resembling those of collision granitoids. The ükapili Granitoid has relatively high 87Sr/86Sr (i) ratios (0.711189-0.716061) and low εNd (t) values (-5.13 to -7.13), confirming crustal melting. In contrast, the enclaves are tholeiitic and metaluminous, and slightly enriched in LILEs (K, Rb) and Th, and have negative Ta, Nb and Ti anomalies; propose that they were derived from a subduction-modified mantle source. Based on mineral and whole rock chemistry data, the ükapili granitoid is H-(hybrid) type, post-collision granitoid developed by mixing/mingling processes between crustal melts and mantle-derived mafic magmas.  相似文献