北祁连山石居里铜矿硅、铅、硫同位素组成特征   总被引：1，自引：0，他引：1  

宋忠宝  杨合群  邬介人 《西北地质》2003,36(2):83-86

石居里铜矿是北祁连山典型的塞浦路斯型铜矿。通过对矿石和围岩的硅、铅和硫同位素研究,作者认为,硅同位素组成δ^30Si(-0．9‰～-0．2‰)与火山岩的δ^30Si范围一致(落在火山岩范围内),由此可知是火山成因的产物。矿石中黄铁矿、黄铜矿的铅同位素组成同各矿区范围玄武岩的铅同位素组成相近,以此为线索结合Rona(1983)的试验规律,推断本区成矿金属主要来源于蚀变玄武岩。硫同位素δ^34S值变化于1．5‰～8．88‰。矿化剂硫来源于火山岩源与海水源的不同比例混合。  相似文献   

西南地区晚二叠世氧、碳稳定同位素的古地理意义   总被引：22，自引：4，他引：22  

邵龙义  窦建伟  张鹏飞 《地球化学》1996,25(6):575-581

对西南地区的１９个晚二叠世碳酸盐岩型煤系剖面进行了碳酸岩稳定同位素的测定，探讨了其“年代效应”的校正及古盐度与古温度计算问题。结果表明：在兴文、贵阳、金沙、南桐、重庆一线以西的地区，Ｚ值＜１２０，δ１３Ｃ值明显低于此线以东的地区，但与Ｓｃｈｏｐｆ给出的淡水石灰岩的δ１３Ｃ范围相比偏高，说明为海陆过渡相沉积；而此线以东的地区Ｚ值＞１２０，δ１８Ｏ、δ１３Ｃ均说明为海相沉积，与以前的沉积环境研究结论一致。用校正后的δ１８Ｏ计算出碳酸盐岩形成时的介质古温度为１４．８－５０．９℃，且大多在２３－３１℃，说明当时该区为温暖－炎热的气候，与古地磁资料显示的当时该区处于赤道附近的热带地区的结论基本一致。  相似文献   

长白山天池火山区深部流体成分及其稳定同位素组成   总被引：17，自引：1，他引：17       下载免费PDF全文

上官志冠  许相希 《地质科学》1996,31(1):54-64

天池火山区深部流体成分和稳定同位素组成特征指示,该区地下有相对独立的四个含水层。2.2km以上为冷水层,2.2-3.4km、3.5-3.9km、4km以下分别为上部、中部和深部热水层。现代水热活动均伴随强烈的深源气体释放,碳和氦同位素比值揭示,这些气体属幔源气体,其中仅混入少量大气,壳源物质混染不明显。大规模幔源气体释放主要集中在天池火山湖周围,这表明该区地壳浅部可能存在一定规模的热的幔源岩浆体。据碳同位素地质测温估算,该岩浆体的热变质带顶部距地面约5km.气体动态变化显示该岩浆体目前处在不稳定期,值得引起重视。  相似文献   

氢氧稳定同位素习性及其在四川盆地卤水成因研究中的应用   总被引：1，自引：0，他引：1  

林耀庭  熊淑君 《化工矿产地质》1996,18(4):300-306

四川盆地地下卤水分布广泛，类型繁多。通过氢、氧同位素地质学的方法研究盆地卤水成因，将其划分为淋滤型、海源沉积型、混合型、具岩浆水特征的海源沉积型等四种类型。在四川盆地使用氢、氧稳定同位素进行地下卤水分类，可获确定的成因涵义，且分类明确，标志明显，取得了较好的效果  相似文献   

Determining the direction of contact metamorphic fluid flow: an assessment of mineralogical and stable isotope criteria   总被引：1，自引：0，他引：1  

I. CARTWRIGHT  I. S. BUICK 《Journal of Metamorphic Geology》1996,14(3):289-305

ABSTRACT One-dimensional fluid advection-dispersion models predict differences in the patterns of mineralogical and oxygen isotope resetting during up- and down-temperature metamorphic fluid flow that may, in theory, be used to determine the fluid flow direction with respect to the palaeotemperature gradient. Under equilibrium conditions, down-temperature fluid flow is predicted to produce sharp reaction fronts that separate rocks with isobarically divariant mineral assemblages. In contrast, up-temperature fluid flow may produce extensive zones of isobarically univariant mineral assemblages without sharp reaction fronts. However, during contact metamorphism, mineral reaction rates are probably relatively slow compared with fluid velocities and distended reaction fronts may also form during down-temperature fluid flow. In addition, uncertainties in the timing of fluid flow with respect to the thermal peak of metamorphism and the increase in the variance of mineral assemblages due to solid solutions introduce uncertainties in determining fluid flow directions. Equilibrium down-temperature flow of magmatic fluids in contact aureoles is also predicted to produce sharp δ¹⁸O fronts, whereas up-temperature flow of fluids derived by metamorphic devolatilization may produce gradational δ¹⁸O vs. distance profiles. However, if fluids are channelled, significant kinematic dispersion occurs, or isotopic equilibrium is not maintained, the patterns of isotopic resetting may be difficult to interpret. The one-dimensional models provide a framework in which to study fluid-rock interaction; however, when some of the complexities inherent in fluid flow systems are taken into account, they may not uniquely distinguish between up- and down-temperature fluid flow. It is probably not possible to determine the fluid flow direction using any single criterion and a range of data is required.  相似文献   

树轮稳定碳同位素研究的应用现状与发展趋势   总被引：2，自引：0，他引：2  

刘广深  米家榕 《世界地质》1996,15(4):42-48

获取历史时期环境气候变迁资料是研究环境气候变迁的基础，在各种获取资料的方法中，树轮同位素方法是较为新颖，准确，定量的一种高分辨率方法。本文较为系统，深入地评述了树轮稳定碳同位素方法的原理及其在环境气候变迁研究的应用现状，并简要归纳了研究工作中的发展趋势。  相似文献   

Weathered Mantle Hosted Gold Deposit atShewushan, Hubei, Central China   总被引：1，自引：0，他引：1  

Hong Hanlie Wang Qinyan The Center for Material Research  Testing  Wuhan University of Technology  Wuhan Bian Qiujuan Faculty of Earth Sciences  China University of Geosciences  Wuhan 《中国地质大学学报(英文版)》2001,12(1)

1The Shewushan gold dePOsit consists of a series of mineralized faults containing high gold grades (1. OX 10-6 to 19. 5 X10-s ) in a larger lower 'grade zone (0. 2 X 10-8 to 1. 0 X 10-6 )peripheral to these. The total reserve was approximately I X10,tons with an average grade around 2. 2 X 10-s. The discovery outcrop is of intense silicification and anomalous gold values(up tO 3. 4 X 10-e ). Hubei No. 4 Geological Party investigatedthe data from Hubei Regional Measuring Party and Hubei…  相似文献   

天山地区影响稳定积雪形成的初始气候条件研究──以天山积雪雪崩研究站为例     

徐俊荣  仇家琪 《干旱区地理》1996,(4)

本文利用天山积雪雪崩研究站的历史资料分析了影响稳定积雪形成的初始气候条件，对降雪量的月间分布、降雪及气温与地温对稳定积雪的影响进行了阐述。  相似文献   

Seismic moment assessment of earthquakes in stable continental regions—II. Historical seismicity     

Arch C. Johnston 《Geophysical Journal International》1996,125(3):639-678

  相似文献   

The deadliest stable continental region earthquake occurred near Bhuj on 26 January 2001     

B.K. Rastogi  H.K. Gupta  Prantik Mandal  H.V.S. Satyanarayana  M. Kousalya  R. Raghavan  Richa Jain  A.N.S. Sarma  N. Kumar  C. Satyamurty 《Journal of Seismology》2001,5(4):609-615

A large destructive earthquake occurred on 26 January 2001 in the region of Kutch, Gujarat, in Western India, with magnitude Mw 7.7. The earthquake caused very heavy damage and a large number of casualties with more than 20,000 deaths. A preliminary study of ground deformation, damage pattern and aftershock distribution is presented.  相似文献