新疆特克斯基性岩体地质特征及找矿方向研究     

高纪璞  李先梓  杨合群  罗玉鹏  姚文光 《西北地质科学》1991,(33)

特克斯基性岩体是伊犁地块中部基性岩带中一个规模较大的似层状侵入体,其年龄为277-298 Ma,系华力西运动晚期产物。它侵入于早中石炭统的火山-沉积建造岩系,其形态和产状受先期火山机构的破火口控制。岩体中主要岩石类型为辉绿辉长岩和橄榄辉绿辉长岩。岩石的m/f值为1.67-3.52,(La/Yb)N值为1.72-2.39。岩石中造岩矿物主要为斜长石(An_(55.17-82.32))、单斜辉石(En_(35.81-47.07) Fs_(8.89-17.62) Wo_(41.15-49.88))和橄榄石(Fo_(56.10-78.28))。研究结果表明,该岩体的岩浆经历了深部分异、多次侵入和就地分异这样一个复杂的演化过程,母岩浆属钙碱性玄武岩系列,成岩温度为1230-640℃,成岩压力约0.2GPa。矿物和岩石化学特征反映的该侵入体的成矿专属性属Fe-Ti-V与Cu-Ni-Pt两系列间的过渡类型。目前所见到的矿化现象主要为一些铁铜硫化物的局部富集;铜含量最高可达2.63％;铂、钯、金、银与铜密切相关。文中根据地质和物化探成果对岩体找矿前景作了初步评价,并提出了今后工作建议。  相似文献   

攀枝花层状基性侵入体氧同位素初步研究          下载免费PDF全文

牟保磊 《岩石矿物学杂志》1991,(1)

攀枝花层状辉长岩侵入体,自下而上可分为四个岩带。各种样品的δ18O值: 8个全岩样品中的6个为 6.27— 6.91‰;23个钛磁铁矿中的19个为 1.28— 2.39‰;21个斜长石中的12个为 6.18— 7.60‰。氧同位素特征表明,岩体源自上地幔。Ⅰ岩带氧同位素平衡温度较低455℃—730℃,可能是成岩后叠加地质作用影响的结果;Ⅱ岩带856—1045℃;Ⅲ岩带652—740℃;Ⅳ岩带62 1.—871℃。  相似文献   

赤柏松矿田含镍基性岩侵入体的成因矿物学研究     

傅德彬 《矿物学报》1991,11(3):243-250

本文从成因矿物学角度对所述岩体中主要造岩矿物橄榄石、辉石与斜长石的颜色、形态、晶胞参数、化学成分、微量元素、稀土及氧、硫、锶稳定同位素等方面进行了研究,从而揭示了岩体的成岩成矿物质来源、形成温度、压力,fo_2,Eh、pH值等物理-化学条件与成岩成矿作用特征。同时,概括出岩体的成矿特点与找矿准则。  相似文献   

关于我国国家重力控制网重新平差的探讨   总被引：2，自引：0，他引：2  

丘其宪 《地球物理学报》1993,36(4):544-546

本文简要地介绍了我国1985重力基本网和一等网的有关情况,探讨了国家重力控制网重新平差的必要性和设想.  相似文献   

丰城县洛市—铁路头地区晚元古代早期火山活动及沉积建造特征   总被引：4，自引：0，他引：4  

赵永祥  饶明辉 《华东地质学院学报》1993,16(4):364-376

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Geochemistry and geotectonic setting of Late Proterozoic Katangan basic rocks from Kibambale in central Shaba (Zaire)     

A. B. Kampunzu  M. Kanika  D. Kapenda  K. Tshimanga 《International Journal of Earth Sciences》1993,82(4):619-630

The Late Proterozoic Katangan basic rocks (dolerites and basalts) outcropping at Kibambale in central Shaba (Zaire) are classified as extension-related tholeiites. The concentrations of immobile major and trace elements resemble those encountered in Phanerozoic enriched oceanic ridge basalts (E-MORB) emplaced in incipient oceanic rifts such as Red Sea and Tadjura Gulf troughs. This conclusion is also sustained by: elemental ratios which are MORB-like; multielement chondrite- and MORB-normalized patterns; sedimentological data, especially the shallow water conditions which prevailed during the deposition of lower Kundelungu tillite in which these basic rocks are interstratified; and the geological and structural framework, notably the emplacement of these igneous rocks in a basin not distant from the Kibaran continental land mass.In this area the geological units containing the igneous rocks are not affected by significant tangential tectonism and so the present structural relationships are relatively undisturbed compared with those which prevailed during the emplacement of the igneous rocks.  相似文献   

中国自然灾害的区域组合规律   总被引：28，自引：2，他引：28  

李炳元  李钜章 《地理学报》1996,51(1):1-11

中国自然灾害多种多样，按直接致灾因子划分为２０个基本自然灾害类型，其中旱灾、洪灾、涝灾、地震灾、滑坡和泥石流灾为主要基本自然灾害类型。宏观地貌格局及其引起的自然环境的分异对大多数自然灾害类型的区域分异有决定性影响。自然灾害的区域组合规律反映在自然灾害地域差异上。本文根据地学区划的一般原则，以及孕灾大环境与自然灾害类型宏观区域组合，将中国划分为东部委风平原山地重度灾害大区、西北干旱高中山盆地中度灾害  相似文献   

Magnetic anomalies of two-dimensional bodies and algorithms for magnetic inversion of dykes and basement topographies     

I. V. Radhakrishna Murthy 《Journal of Earth System Science》1990,99(4):549-579

Generalized equations for the anomalies in any component of the earth’s magnetic field due to two-dimensional bodies of arbitrary magnetization are derived in terms of a new parameter, called the direction of measurement. Schemes for inverting the magnetic anomalies of arbitrarily magnetized dykes and basement topographies are then developed and the relevant computer software is presented. In both the schemes, the initial values of the parameters are calculated by the computer, so that the input merely consists of the anomalies and their distances. The differences in the observed and calculated anomalies are solved iteratively for the errors in initial values of the parameters.  相似文献   

Prograde and retrograde metamorphism of hematitebearing basic schists in the Sanbagawa belt in central Shikoku   总被引：2，自引：0，他引：2  

M. OTSUKI  S. BANNO 《Journal of Metamorphic Geology》1990,8(4):425-439

The mineral assemblages of hematite-bearing basic schists in intermediate high-pressure metamorphism are temperature dependent. For assemblages with excess hematite, albite, muscovite and quartz, the paragenetic relations can be dealt with in terms of a four-component system, without omitting or grouping major components.
In the Sanbagawa belt in central Shikoku, the dominant amphibole in the hematite-bearing basic schists changes from winchite, via crossite and barroisite to hornblende. The stability of amphibole is described chemographically within a pseudoternary system with another excess phase, epidote. Many amphiboles are chemically heterogeneous owing to retrograde reactions which produced low- T/P amphibole around the prograde amphibole. The examination of amphibole zoning makes it possible to draw a retrograde P-T trajectory which passes on the lower pressure side of the prograde one.  相似文献   

Vortex Rossby Waves in Asymmetric Basic Flow of Typhoons     

Tianju WANG  Zhong ZHONG  Ju WANG 《大气科学进展》2018,35(5):531-539

Wave ray theory is employed to study features of propagation pathways(rays) of vortex Rossby waves in typhoons with asymmetric basic flow, where the tangential asymmetric basic flow is constructed by superimposing the wavenumber-1 perturbation flow on the symmetric basic flow, and the radial basic flow is derived from the non-divergence equation. Results show that, in a certain distance, the influences of the asymmetry in the basic flow on group velocities and slopes of rays of vortex Rossby waves are mainly concentrated near the radius of maximum wind(RMW), whereas it decreases outside the RMW. The distributions of radial and tangential group velocities of the vortex Rossby waves in the asymmetric basic flow are closely related to the azimuth location of the maximum speed of the asymmetric basic flow, and the importance of radial and tangential basic flow on the group velocities would change with radius. In addition, the stronger asymmetry in the basic flow always corresponds to faster outward energy propagation of vortex Rossby waves. In short, the group velocities, and thereby the wave energy propagation and vortex Rossby wave ray slope in typhoons, would be changed by the asymmetry of the basic flow.  相似文献