泥盆纪海相碳酸盐岩碳同位素组成及演变   总被引：4，自引：0，他引：4       下载免费PDF全文

陈代钊  陈其英  江茂生 《沉积与特提斯地质》1995,(5):22-28

根据对六景泥盆系碳酸盐岩碳同位素组成的系统分析表明：从落霍柯夫期到布拉格期海洋中的δ~１３Ｃ是逐渐变重，埃姆斯期明显变轻．艾菲尔期又开始变重，特别是基维特期有较明显的正向偏移，并继续向上变重，至弗拉斯期与法门期之交达到最大，尔后逐渐变轻，反映了泥盆纪海洋碳同位素组成的演变趋势．这和泥盆纪（二级）海平面的变化趋势是基本一致的，反映海洋碳同位素组成与海平面变化及相关的气候和海洋、大气中ＣＯ_２含量的成因联系。弗拉斯阶－法门阶界线附近δ~１３Ｃ的变化型式表明其间发生的生物绝灭事件是海平面升降和缺氧环境的周期性扩展等因素的累积效应的结果．  相似文献   

水洞岭地段应用铅同位素方法找矿评价的研究     

俸月星 《矿产与地质》1995,9(5):379-383

应用铅同位素方法，对水洞岭和桑树坪区段的铅同位素特征与桐柏大河铜锌矿床进行对比，认为水洞岭地段寻找优地槽块状硫化物层控型矿床有利，深部找铜矿有一定希望。  相似文献   

变质岩型铜矿床稳定同位素地球化学特征及成矿机理     

郭新生  陈民扬 《矿产与地质》1995,9(5):375-378

我国主要的变质岩型铜矿床Ｈ、Ｏ、Ｓ、Ｃ、Ｐｂ同位素研究结果表明，成矿热液具热卤水和地热水特征，成矿物质属深部来源，此外，不同程度的区域变质作用对变质岩型铜矿床的同位素的组成和分布亦产生一定的影响。总的来看，我国主要的变质岩型铜矿床与裂谷坳陷带大型喷气热液活动有关。  相似文献   

The Coupled Re—Os and Pt—Os Systematics：A Theoretical Consideration     

熊永良  翟裕生 《中国地球化学学报》1995,14(1):52-59

The ^190Pt-^186Os system should be a unique tracer for mantle processes be-cause both Pt and Os are concentrated in the mantle.The ^190Pt-^186Os system will also be a good supplement to the ^187Re-^187Os system for dating and tracing mantle pro-cesses because the ^190Pt-^186Os system is not so easily contaminated by crustal materials as the ^187Re-^187Os system.In turn,the application of the ^187Re-^187Os system to Pt-enriched materials uncontaminated by crustal materials will indirectly refine the half life of ^190Pt.The ^190Pt is refined.In the coupled ^187Re-^187Os and ^190Pt-^186Os sys-tematics,an ^186Os*/^190Pt-^187Os*/^187Re Concordia diagram similar to the ^206Pb*/^238U-^208Pb*/^232Th Concordia can be constructed.In such a Concordia diagram,a date will be obtained so long as the ^190Pt-^186Os system remains closed even if the ^187Re-^187Os sys -tem is contaminated by crustal materials.In addition ,for the coupled ^190Pt-^186Os and ^187Re-^187Os systematics,the mantle processes and the interactions between the mantle and the crust will be described by two ratios:^186Os/^188Os and ^187Os/^188Os .The coupled ^187Re-^187Os and ^190Pt-^186Os systematics will be a powerful tool in the investigation of the geodynamic history of the Earth because the ^187Re-^187Os system is sensitive to the interactions between the mantle and the crust,while the ^190Pt-^186Os system is a good tracer for mantle processes.  相似文献   

Implications of εNd—La／Nb,Ba／Nb,Nb／Th Diagrams to Mantle Heterogeneity—Classification of Island—arc Basalts and Decomposition of EMII Component   总被引：1，自引：0，他引：1  

李曙光 《中国地球化学学报》1995,14(2):117-127

A group of εNd/Nb,Ba/Nb,Nb/Th diagrams are used to study mantle heterogeneity.Island-arc basalts(IAB) are distributed in a triangle of these diagrams. Three end-member components (the MORB-type depleted mantle, the fluid released from subducted oceanic crust and the sediments from the continental crust) of the source of IAB may be displayed in these diagrams. Two types of IAB are identified .They are of the two-component type (with little continental sediments), such as the basalts from Aletians and New Britain ,and the three-compeonent type, such as those from Sunda, Lesser Antilles and Andes. In addition ,the EMII type mantle-derived rocks may also be divided into two groups. One is exemplified by continental flood basalts and some peridotite xenoliths, similar to IAB, with high La/Nb and Ba/Nb and low Nb/Th ratios, The other includes the Samoa-type oceanic island basalts, with low La/Nb and Ba/Nb and high Nb/Th ratios. The corresponding two sub-components of EMII are EMIIM, which is related to the metasomatism of lithosphere mantle by fluids released from the subducted oceanic crust, and EMIISR, related to the intervention of recycling continental sediments into the convective mantle.  相似文献   

The Material Sourece of a New Type of Copper Deposits—Evidence from Stable Isotopes   总被引：1，自引：0，他引：1  

颜文  甫为民等 《中国地球化学学报》1995,14(2):168-178

The new type of copper deposits concerned with in this paper are vein copper deposits found in the Lanping-Simao Rift Basin, Yunnan,China. As is indicated by H,O,C,S,Pb and Sr isotopes, water and mineralizers in the ore-forming fluids were derived from heated meteoric water and mantle, respectively.The metallic elements(Cu,Ag,Pb,Zn,As,Sb,Fe,REE,etc.)are characterized by a mixed source from the crust and the mantle.  相似文献   

唐山豪门（集团）公司玉田啤酒厂饮用天然矿泉水     

李金  梁爽 《华北地质矿产杂志》1995,10(4):454-458

玉田啤酒厂饮用天然矿泉水井位于城关镇三里屯西２００ｍ，玉田酒厂院内，矿泉水赋存于第四系砂、砾卵石层中，属含锶、偏硅酸的重碳酸钙·镁型矿泉水，现已开发利用。  相似文献   

玉田东吉庄饮用天然矿泉水成因分析及水质评价     

陆贺田  张志强 《华北地质矿产杂志》1995,10(4):495-499

东吉庄矿泉水是１９８９年由地质矿产部环境管理司会同卫生部、轻工业部等有关单位的国家饮用天然矿泉水技术评审组鉴定通过，符合ＧＢ８５３７－８７的国家标准要求，属含锶重碳酸镁·钙·钠型低矿化度中性饮用天然矿泉水，已于同年建立了奥玉饮料厂，生产瓶装矿泉水及奥玉饮料。为了保护矿泉水资源免遭环境污染，对该矿泉水水源地进行了水源地保护规划。  相似文献   

华南金矿二元混合成矿模式   总被引：2，自引：1，他引：2  

王联魁  张绍立  黄智龙 《矿床地质》1995,14(1):1-11

根据华南六个有代表性金矿的成矿时代、断裂构造、围岩、侵入岩、中基性岩墙、成矿类型、成矿阶段，矿石组成、成矿温度、包裹体成分以及稳定同位素等多方面研究，发现华南大部分金矿具有共同特征；主要成矿时代为燕山期，远落后于围岩时代；是沿地壳级大断裂形成的后生矿床，六个金矿的铅同位素组成可分出高值区（组）和低值区（组），表明成矿物质有深浅两个不同来源；不同金矿氢、氧同位素指示成矿热液水为深源岩浆水与古大气降水  相似文献   

白云鄂博矿区磷灰石氧同位素研究     

方涛  裘愉卓  陈成业  陈洪新  王远军 《矿物学报》1995,(2)

通过新建立的BiPO4转化法，笔者分析了白云鄂博矿区部分磷灰石的氧同位素组成，其变化范围为6．3‰～9．4‰，并通过与各种产状磷灰石及不同时代磷酸盐沉积的氧同位素对比、磷灰石形成温度的计算，以及磷灰石Sr－Pb同位素数据的分析，推断矿区磷灰石的形成可能与热水沉积作用有关。  相似文献