内蒙古二连盆地铀与油、煤的时空分布及铀的成矿作用     

李月湘  秦明宽  何中波 《国外铀金地质》2009,(1)

二连盆地是我国铀、石油和煤3种能源矿产共存的大型盆地之一,研究它们之间的时空和成因关系,对于盆地的综合找矿有着重要现实意义。研究结果表明,铀矿产于侏罗纪、白垩纪和古近纪的粗碎屑岩中,油气田主要产于侏罗纪、白垩纪的细碎屑岩中。产煤的小凹陷就是有利的产铀凹陷,产煤层位就是找铀的目的层位。石油、煤产生的还原性流体对砂岩型铀矿的成矿作用为:(1)还原性流体沿着断裂向上迁移扩散,对上部岩石产生了强烈的还原作用,大大增强了岩石的还原能力,铀在还原性的岩石中富集;(2)来自地表的含铀含氧水与来自下部上升的还原性流体相遇混合,使溶液中的U6+还原为U4+而沉淀;(3)深部还原性流体可携带一部分成矿物质进入容矿砂体而卸载,从而造成铀的初步富集或叠加富集。由于它们有空间上和成因上的联系,建议对于产有铀、石油和煤3种能源矿产的沉积盆地,需采用综合找矿的工作思路,充分挖掘石油、煤炭和铀矿3个部门已有的钻探资料和成果,进行二次开发,有利于快速开展盆地铀矿勘查和矿产资源评价。  相似文献   

海南乐东抱伦金矿金矿物的特征研究   总被引：1，自引：1，他引：0  

杨念  洪汉烈  张小文  向华  钟增球 《矿物岩石》2009,29(2)

通过光学显微镜观察、X射线衍射和电子探针分析,对海南乐东抱伦金矿金矿物的特征进行研究,结果表明：矿石中主要金属矿物为黄铁矿和磁黄铁矿,其次为黄铜矿、闪锌矿、毒砂、和方铅矿等;而脉石矿物则主要为石英、白云母和绢云母,其次为方解石、绿泥石和伊利石等。矿石中的金主要以自然金矿物形式产出,颗粒大小在1μm～35μm之间,多呈孤岛状及其他不规则形状,充填在石英以及黄铁矿等硫化物矿物颗粒之间,少量以包裹体形式包裹在硫化物、石英矿物晶体之中。金矿物化学组成分析结果表明,金的质量分数均在92％以上,其他元素含量甚微,其成色在942～978之间。根据自然金矿物的高成色特征可以推断,金矿物形成于较深的部位。此外,在与自然金矿物共生的黄铁矿中,含有较高的微量元素Co和Ni,且Co／Ni比值多大于1,说明成矿物质与深部岩浆作用有关。成矿物质与硫化物、二氧化硅等一同向上运移,当流体物理化学条件（如温度、压力）发生变化时而沉积富集,石英的结晶稍早于硫化物矿物,而硫化物矿物与金矿物的结晶基本上是同时的。  相似文献   

山东日照地区沿海海啸探析     

段家芬  尹茂仲  魏汝庆 《地震地磁观测与研究》2005,26(2):1-7

从概念上区分风暴潮和地震海啸,讨论风暴潮和地震海啸的形成、分布;通过对中国大陆沿海地震海啸和大陆架情况的分析,认为山东日照地区沿海既不具备形成地震海啸的条件,也不可能受非本地地震海啸的影响。日照沿海遭受的海洋灾害主要是风暴潮。  相似文献   

Discussion and Reply Llandovery‐Ludlow graptolites from central Victoria: New correlation perspectives of the major formations     

A. H. M. VandenBerg  A. C. Sandford  R. B. Rickards 《Australian Journal of Earth Sciences》2013,60(4):659-665

The Kambalda Ni province, located in the Archaean Norseman‐Wiluna greenstone belt of Western Australia, boasts the largest known concentration of komatiite‐associated magmatic Fe–Ni–Cu sulfide deposits. These are found as long, linear massive to disseminated bodies at the base of a thick komatiite sequence. The sulfide bodies are closely associated with, or contained within, trough structures at the contact with the underlying basaltic unit. In this study, the McComish Prospect, located 40 km south of Kambalda at Tramways, was studied to assess the relationships between volcanic facies, mineralisation and trough structures. The rocks in this region have variably experienced four phases of deformation, upper greenschist ‐ lower amphibolite facies metamorphism, granitoid intrusion, and subsequent alteration. Relict igneous textures are locally preserved at McComish, however, enabling the evaluation of existing geological models and interpretations. The McComish trough is considered to be entirely structural in origin and unrelated to primary volcanic processes (e.g. thermal erosion). The association of volcanic textural facies in individual flow units, and the distribution of flow units across the trough is more complex than predicted by prevailing models, suggesting an alternative komatiite lava emplacement mechanism. Results are consistent with the proposal that komatiites did not flow turbulently as widely accepted, nor did they cool by vigorous convection. Alternatively, the lavas were emplaced as inflated, lobate basalt pahoehoe‐like flows. Although Fe–Ni–Cu sulfide mineralisation at McComish is most likely volcanic in origin, its present distribution appears to be structurally controlled or modified. The zone of weakly to strongly disseminated sulfides at the base of the komatiite sequence is thickened adjacent to a major north‐northwest‐trending fault on the western margin of the trough. This fault is interpreted to have been a fluid conduit, remobilising the ore during metamorphism and deformation.  相似文献   

Deforestation,biomass and carbon finance in Amazonia     

《Climate Policy》2013,13(1):7-22

Biomass dynamics in Amazonia are quantified and the value that carbon finance could deliver from slowing deforestation is assessed. Above-ground forest biomass in the Legal Amazon shrank from 90 Pg to 76 Pg between 1978 and 2004. An average decrease of 0.64 Pg (standard error 0.38 Pg) per year was estimated for primary and econdary vegetation. For an improved, spatially and temporally explicit estimation, a time series of remote-sensing results and a model of secondary forest area and age distribution was combined with a large-scale forest-growth model. The observed trend of biomass decline is continuous and defines a baseline that the avoidance of deforestation could be measured against. Based on scenario calculations, the emission reductions from slightly reduced deforestation rates could be valued in the range of €1 billion annually. Carbon finance for reducing emissions from deforestation (‘avoided deforestation’), which is being discussed as an additional mechanism under the UN Framework Convention on Climate Change and its Kyoto Protocol, has the potential to alter the economic logic driving forest conversion.  相似文献   

以秸秆为微生物碳源的尾矿原位修复:动态实验的初步分析     

张楠  陈天虎  周跃飞  王进  金杰  黎少杰 《矿物岩石地球化学通报》2011,30(3):334-340

对铜陵相思谷尾矿砂中的重金属在生物和非生物条件下的淋滤行为进行了研究。设置两个动态反应柱进行实验(实验柱填充尾矿砂+污泥+秸秆,对照柱仅填充尾矿砂,进水SO42-1000 mg/L,pH 7.5)。结果表明,实验初期(0~20 d)实验柱出水重金属浓度明显高于对照柱,归因于柱内微生物加速了矿物分解和重金属的淋滤;此后实验柱出水SO42-浓度逐渐降低,同时Cu2+、Cd2+、Zn2+、总Fe浓度分别降至0.1 mg/L、0.1 mg/L0、.4 mg/L和1 mg/L以下。据此推测,实验柱中出现了微生物作用下的硫酸盐还原作用,生成了可以吸持重金属的硫化物沉淀。研究结果表明,以稻草为碳源、污泥为微生物接种源构建尾矿砂-微生物体系,能够有效还原硫酸盐并去除重金属,该方法可以用于矿山尾矿的原位修复。  相似文献   

硫酸盐还原菌对热镀锌钢材氢渗透行为的影响          下载免费PDF全文

张玉志  张大磊  李焰 《海洋科学》2011,35(1):48-53

采用Devanathan-Stachurski 双面电解池检测氢渗透电流技术和扫描电镜分析, 研究了热镀锌钢材在灭菌海水、灭菌培养基和接种了硫酸盐还原菌(SRB)的培养基等3 种介质中的氢渗透行为。氢渗透电流检测结果表明, 培养基的部分组分对热镀锌钢材的氢渗透行为有促进作用, 试样在灭菌培养基中的氢渗透电流密度的平均值比在灭菌海水中提高了约6 倍。尽管活性SRB 代谢产生的S^2?和HS^?能够促进热镀锌钢材的氢渗透行为, 但是, 由SRB 及其代谢产物和它们所黏附的腐蚀产物所形成的致密微生物膜减少了氢的析出和试样对氢的吸收量, 导致热镀锌钢材氢渗透行为最终被抑制, 因此, 试样在接菌培养基中的氢渗透电流密度的平均值比其在灭菌培养基中降低77%。扫描电镜分析表明, 热镀锌钢材在灭菌海水中能够形成腐蚀产物膜, 而暴露于灭菌培养基中的试样表面未形成明显的腐蚀产物膜, 但在接菌培养基中试样表面能形成黏附了腐蚀产物的致密微生物膜的附着, 表明热镀锌钢材表面的微生物膜与其氢渗透行为之间存在明显的相关性。  相似文献   

开发科技档案信息资源为辽宁省防震减灾事业服务     

高静 《东北地震研究》1995,(2)

在总结辽宁省地震科技档案工作的基础上，就档案工作的意义、重要性、辽宁省地震科技档案工作的特点和今后工作展望等问题作了叙述。  相似文献   

黄河凌汛及其预报研究   总被引：8，自引：0，他引：8  

宫德吉  白美兰  王秋晨 《气象》2001,27(5):38-42

分析了黄河内蒙古段凌汛的特点及凌灾的成因，指出黄河凌险与黄河中上游的降水状况、冬季结冰状况及开春后的融冰速度有密切关系。依据成灾物理因素，给出了判定河套凌险状况的凌险指数，据此可对黄河凌险进行预警。确定了黄河封河的临界温度指标，得出了制作黄河开河日预报的技术方法。  相似文献   

直接蒸发单颗粒锆石测定~(207)Pb/~(206)Pb年龄的方法   总被引：1，自引：0，他引：1  

王林森 《地球科学》1992,(5)

在双带源热离子发射质谱计上,用Kober,B.(1987)建立的方法直接蒸发锆石测定~(207)Pb/~(206)Pb表面年龄。4件已知年龄的锆石样品测定结果表明,用该方法测定的年龄值与常规锆石U-Pb一致曲线的上交点年龄一致。使用腈基丙烯酸酯粘合剂,使得装样简单、可靠,并可增加铅离子流强度。文中首次报道了湖北广水蔡家河小河岩体、黄土寨岩体中锆石的形成年龄。  相似文献