Contrast in Fluid M etallogeny between the Tianmashan Au-S Deposit and the Datuanshan Cu Deposit in Tongling, Anhui Province     

LEE Hyun Koo 《《地质学报》英文版》2003,77(1):116-124

A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion  相似文献   

甘肃夏河—合作地区金矿特征及找矿思路   总被引：2，自引：0，他引：2       下载免费PDF全文

周会武  王伟  张发荣 《甘肃地质》2003,12(1):63-69

本文对甘肃夏河—合作地区的地层、构造、岩浆岩等与成矿有关的因素进行了综述 ,主要对已发现的金矿的类型及其特征进行了总结。该地区金矿类型主要为构造蚀变岩型、微细浸染型 ,矿床严格受构造控制。提出了今后的找矿思路和方向  相似文献   

塔里木盆地塔中32井中上奥陶统内潮汐沉积   总被引：11，自引：1，他引：11       下载免费PDF全文

何幼斌  高振中  张兴阳  翟永红  旷红伟 《古地理学报》2003,5(4):414-425

塔里木盆地塔中32井的中、上奥陶统钻遇厚度为1 462 m。它是一套巨厚的深灰色泥岩、页岩与灰色砂岩、粉砂岩互层夹少量灰岩的地层。其中深灰色泥岩、页岩最多；砂岩和粉砂岩主要分布于上部和下部，中部砂岩和粉砂岩较少；鲕粒灰岩数量少，主要夹于深灰色泥页岩中。这些砂岩和鲕粒灰岩既可单独成层，但更常见它们与深灰色泥页岩组合成薄互层。薄互层中发育脉状、波状和透镜状层理，并普遍发育交错层理和双向交错纹理。这些特征表明砂岩和鲕粒灰岩为深水斜坡上的内潮汐沉积的产物。这些内潮汐沉积进一步划分为4种类型：双向交错纹理细砂岩型、单向交错层和双向交错纹理中-细砂岩型、韵律性砂泥岩薄互层型和鲕粒灰岩型。它们具有5种垂向沉积层序，在剖面上常形成多旋回韵律性沉积组合。  相似文献   

吉林省土壤中有效锰、铜、钼和锌含量的时空变化   总被引：5，自引：0，他引：5  

杨娟  王冬艳 《世界地质》2003,22(4):392-395

选择吉林省的五个大豆种植区(敦化、桦甸、榆树、农安、白城)、四个水稻种植区(白城、九台、延吉、梅河口)及3个草场分布区(镇赉、洮南、大安)，对其土壤中有效锰、铜、钼和锌的含量在过去20年的变化作了比较和分析。经研究表明：吉林省土壤中有效锰和有效铜含量较20年前有所增高，有效钼含量总体呈降低趋势，中部部分地区和东部地区土壤有效锌含量降低，其余地区含量增高。空间分布东部高于中西部。  相似文献   

新疆铜矿类型与找矿靶区   总被引：3，自引：2，他引：3  

陈哲夫 《新疆地质》2003,21(2):190-194

在分析研究新疆铜矿类型、地质特征、矿区地质构造及找铜潜力的基础上，对进一步的找铜靶区进行了初步预测．新疆铜矿工作程度总体较低，各构造成矿区和类型都有找铜前景，最具潜力和最有希望找到大型铜矿床的是阿尔泰，东、西天山和西昆仑地区斑岩型、海相火山沉积型、斑岩—夕卡岩复合型、海相沉积热液叠加型与铜镍矿化物型的成矿类型．  相似文献   

胶东金矿床碳酸盐矿物的碳-氧和锶-钕同位素地球化学研究   总被引：16，自引：8，他引：16  

刘建明 叶杰徐九华  孙景贵沈昆 《岩石学报》2003,19(4):775-784

对胶东四类金矿床(盆地边缘砾岩型、斑岩型-浅成热液型、石英脉型和破碎带蚀变岩型)矿石中的碳酸盐矿物开展了系统的碳-氧同位素和锶-钕同位素地球化学研究。研究结果表明，与宏观的成矿地质条件和矿床地质特征相对应，山东金矿床可能有亲岩浆岩和亲沉积盆地两个不同的成矿系统。前者包括斑岩型-浅成热液型、石英脉型和破碎带蚀变岩型三类金矿床，后者指盆地边缘砾岩型金矿床，二者具有不同的碳-氧和锶-钕同位素地球化学特征。山东亲岩浆岩系列的金矿床，其锶-钕同位素与同时代的幔源岩浆岩一致，碳同位素显示幔源碳和岩浆碳的特征，氧同位素则显示初生水与大气降水不同比例混合的可能性，因此有可能是以CO2为主、富合成矿金属的地幔流体与浅部下渗大气降水相互作用的结果。而与岩浆岩关系不密切、主要受盆地边缘断裂控制的盆地边缘砾岩型金矿床，其碳-氧和锶-钕同位素组成均较分散，可能主要与地壳浅部下渗大气降水对上地壳各种岩石淋滤萃取演化而成的成矿流体有关。  相似文献   

Exploration and discovery in Yellowstone Lake: results from high-resolution sonar imaging, seismic reflection profiling, and submersible studies     

L. A. Morgan  W. C. Shanks  III  D. A. Lovalvo  S. Y. Johnson  W. J. Stephenson  K. L. Pierce  S. S. Harlan  C. A. Finn  G. Lee  M. Webring  B. Schulze  J. Dühn  R. Sweeney  L. Balistrieri 《Journal of Volcanology and Geothermal Research》2003,122(3-4):221-242

‘No portion of the American continent is perhaps so rich in wonders as the Yellow Stone’ (F.V. Hayden, September 2, 1874)Discoveries from multi-beam sonar mapping and seismic reflection surveys of the northern, central, and West Thumb basins of Yellowstone Lake provide new insight into the extent of post-collapse volcanism and active hydrothermal processes occurring in a large lake environment above a large magma chamber. Yellowstone Lake has an irregular bottom covered with dozens of features directly related to hydrothermal, tectonic, volcanic, and sedimentary processes. Detailed bathymetric, seismic reflection, and magnetic evidence reveals that rhyolitic lava flows underlie much of Yellowstone Lake and exert fundamental control on lake bathymetry and localization of hydrothermal activity. Many previously unknown features have been identified and include over 250 hydrothermal vents, several very large (>500 m diameter) hydrothermal explosion craters, many small hydrothermal vent craters (1–200 m diameter), domed lacustrine sediments related to hydrothermal activity, elongate fissures cutting post-glacial sediments, siliceous hydrothermal spire structures, sublacustrine landslide deposits, submerged former shorelines, and a recently active graben. Sampling and observations with a submersible remotely operated vehicle confirm and extend our understanding of the identified features. Faults, fissures, hydrothermally inflated domal structures, hydrothermal explosion craters, and sublacustrine landslides constitute potentially significant geologic hazards. Toxic elements derived from hydrothermal processes also may significantly affect the Yellowstone ecosystem.  相似文献   

浙江桐庐晚奥陶世晚期沉积层序和沉积环境分析   总被引：3，自引：0，他引：3  

范代读  李从先  蔡进功  邓兵  罗璋 《沉积学报》2003,21(2):247-254

文昌组上段顶部是一套潮汐层理非常发育的泥质砂岩或砂质泥岩,存在双向交错层理,层面有雨痕,应为潮坪沉积。潮坪沉积由小型层序构成,小型层序又是由砂、泥质单层组成。砂质单层底部通常为岩性突变面或侵蚀面,砂质纹层较厚,其中可见对称波痕或泥砾;向上砂质纹层变薄,过渡到泥质单层。砂质单层形成于暴风浪时期,泥质单层是风浪衰减后恢复正常的潮汐沉积。因此,小型层序从成因上说是一风暴层序。碎屑成份、砾石成份分析表明沉积物均来自华夏古陆的沉积岩和变质岩基底。物源一致,岩层产状变化不大,反映文昌组沉积环境稳定。岩性、粒度分析表明文昌组是一向上变细、由浅海高能环境向近岸低能环境过渡的沉积层序。文昌组下段为浅海砂岩沉积,上段顶部为潮坪沉积。二者之间是一套夹砾岩透镜体的泥质粉细砂岩,其沉积环境应介于浅海和滨岸之间,为水下岸坡沉积。砾岩层只是大的沉积旋回中出现的事件性水下冲积物。  相似文献   

Lithology and palynology of Neogene sediments on the narrow edge of the Kitakami Massif (basement rocks), northeast Japan: Significant change for depositional environments as a result of plate tectonics     

Koji Yagishita  Akiko Obuse  Hiroshi Kurita 《Island Arc》2003,12(3):268-280

Abstract A controversial stratigraphic section, the Taneichi Formation, is exposed along the Pacific Coast of northeastern Honshu, the main island of the Japanese Archipelago. Although most sediments of the formation have long been dated as late Cretaceous, the northern section of it has been assigned to (i) the Upper Cretaceous; (ii) the Paleogene; or (iii) the Neogene. In the present report, we present the data of palynological and sedimentological studies, showing that the northern section should be assigned to the Neogene. A more important point in the present study is that we invoke some basic principles of fluvial sedimentology to resolve this stratigraphic subject. The lignite layers full of Paleogene–Miocene dinoflagellate cysts and pollen assemblages drape over the boulder‐sized (>40 cm in diameter) clasts in the northern section. However, the layers totally consist of aggregates of small lignite chips, indicating that the lignites are allochthonous materials. The mega‐clasts with derived microfossils in the lignites are thought to have been deposited as Neogene fluvial (flood) sediments in the newly formed Japanese Archipelago. Prior to the Miocene, the northern Honshu was part of the Eurasian Plate, thus the boulder‐sized clasts cannot be envisaged as long river flood deposits along the continental Paleogene Pacific Coast. Instead, the mega‐clasts with the draping lignites were probably derived from nearby Miocene highlands in the newly born island arc.  相似文献   

Sea-level changes and hydrothermal sedimentary mineralization of large-superlarge ore deposits among Sinian to Triassic in South China   总被引：2，自引：0，他引：2  

陈多福  陈先沛  陈光谦 《中国科学D辑(英文版)》2003,46(Z1)

Among the Sinian to Triassic strata in South China, the stratiform, quasi-stratiform and lenticular metallic deposits in association with hydrothermal sedimentation mainly occur in the four periods: (1) the Sinian Datangpo interglacial period, (2) the early period of Early Cambrian, (3) the late period of Middle Devonian to early period of Late Devonian,and (4) the late period of Early Permian. The four mineralization periods all happened around the maximum flooding period in the third-order seal-level cycle during the ascending stage in the first-order sea-level cycle. The deep seawater layer, starved and non-compensatory basin, low sedimentary rate, and low energy and anoxic environment during the maximum flooding period are very suitable for the formation and preservation of large to superlarge hydrothermal sedimentary deposits. The maximum flooding period also coincided with the intensified regional tectonism, extensive deep magmatism and hydrothermal sedimentation, which provide, for the formation of large to superlarge hydrothermal sedimentary deposits through the rapid accumulation of hydrothermal sediments, the needed dynamics, ore-forming materials and favorable passway for hydrothermal fluids to enter the basin.  相似文献