矿床分带研究综述   总被引：1，自引：0，他引：1  

张德会 《地质科技情报》1993,12(1):59-63

本文概括阐述了矿床分带研究的意义,评述了分带研究的现状,并对矿床分带研究的前景进行了展望。  相似文献   

韧性剪切带型金矿成矿特征研究现状   总被引：2，自引：0，他引：2  

银剑钊 《地质科技情报》1993,12(2):71-76

综述了近几年韧性剪切带型金矿研究成果,包括韧性剪切带与金矿化在时间、空间和成因的关系及剪切带的历史演化性质对成矿类型与地球化学特点的控制。在此基础上,预测了近期可能的几个发展方向。  相似文献   

铜镍硫化物矿床成矿理论的新进展   总被引：5，自引：0，他引：5  

刘凤山 《地质科技情报》1993,12(2):77-81

岩浆深部液态重力分异成矿作用、岩浆同化混染成矿作用、矿浆成矿作用、岩浆分离结晶作用和热液作用对铜镍硫化物成矿有重要影响。岩浆深部液态重力分异成矿作用是原始含矿岩浆产生多样性岩浆和铜镍等成矿元素原始富集的重要原因,矿浆成矿作用则与岩浆深部液态重力分异成矿作用密切相关,是含矿岩浆成矿过程中的特殊地质事件。  相似文献   

论甘孜丘洛成矿带微细浸染型金矿的成矿条件   总被引：2，自引：0，他引：2  

王小春 《矿物岩石》1993,13(1):68-75

甘孜丘洛成矿带微细浸染型金矿的成矿热液来自大气降水。矿化作用发生于燕山期的下渗雨水加热环流体系中。包裹体研究和热力学计算表明,成矿温度为93—306℃,成矿深度小于1km。矿化热液呈弱碱性,还原性较强,含盐度中等,贫氯富硫。Au以Au(HS)_2~-形式进行迁移,并在扩容减压带中沉淀富集。温度、压力降低和总硫活度减小是矿质沉淀的重要因素。  相似文献   

化探样品中微量铅、锡、铬、钼和钴的发射光谱法同时测定     

张明恭  陈梅一  苏勇 《矿物岩石》1993,(1)

本文以CdCl_2·2.5H_2O为反应剂,采用“下垫上滴”缓冲刺的装样形式,通过大量镉盐的蒸发控制电极温度,使被测元素预先分馏,有效地改善了它们的蒸发行为,同时,减小了基体效应、光谱背景。本法其有良好的精密度和准确度,各元素的检出限(×10~(-5))分别为:Pb(1),Sn(0.37),Cr(1.8),Ni(3.51,Mo(0.1)和Co(0.38),其相对标准偏差(RSD)为±3.7—9.5%  相似文献   

滇中地区晚三叠世的重力流沉积及其地质意义   总被引：4，自引：0，他引：4  

吴根耀  矢野孝雄 《大地构造与成矿学》1993,17(4):305-313

上三叠统云南驿组一段下部是钙质浊积岩,上部为陆源碎屑浊积岩及少量火山碎屑浊积岩;二段的角砾状灰岩有坍塌和重力滑动两种成因,夹钙质浊积岩。罗家大山组一段由火山碎屑质的碎屑流、浊流和颗粒流沉积组成,夹基性熔岩。它们是滇中裂谷的记录,物源区在西边,构成中国西南部三叠纪古特提斯的一部分。  相似文献   

Experimental Study on the Leaching of Gold from Greenstone1     

Liu Yushan  Zhang Guilan  Tian Jun 《《地质学报》英文版》1993,6(2):211-221

Abstract Experiments were conducted on the leaching of gold from greenstone by chloride solution under the temperature of 200-550°C and the pressure of 60 MPa. During part of the experiments, the oxygen fugacity was controlled. The results show that the leaching rate of gold is related to temperature, composition of the solution, pH and oxygen fugacity. In the experiment with oxidative acidic solution, the leaching rate was up to 50% or more. It is known that the leaching of gold is restricted by the reaction in which the gold is dissolved from the rock to form gold chloride complex. Therefore, the authors hold that the acidic chloride solution derived from granite magma has caused the remobilization-migration of gold from greenstone and its enrichment into ore.  相似文献   

A geochemical model for evaluating theories on the genesis of Florida''s sedimentary phosphate deposits     

Martha W. Gilliland 《Mathematical Geology》1976,8(3):219-242

Present ionic concentrations of Ca ⁺⁺,HCO ₃ ^- ,and HPO ₄ ⁼ in surface and groundwater runoff in Florida indicate that phosphorus is being concentrated in rock through dissolution and reprecipitation, with calcium phosphate increasing at the expense of calcium carbonate. Analog computer simulation of a systems model of this process suggests that significant enrichment can occur in 20 million years. The degree of enrichment depends on the supply of new phosphorus to Florida through rain and oceanic exchange processes. If the calcium phosphate content of original rock is 0.5 to 1.0 percent (0.52 to 1.05 percent P ₂ O ₅),a formation with 10 to 20 percent calcium phosphate (CaPO ₄ or 10.5 to 21.0 percent P ₂ O ₅)as in the Hawthorn Formation (Miocene)may result. Nutrient upwelling along the continental slope coupled with transport to the estuaries by lateral eddy diffusion can supply an additional 400 mg P|m ² |yr which, if deposited, would result in a sediment with a 4.3 percent CaPO ₄ (4.5 percent P ₂ O ₅)content. If this is enriched later by resolution, 40 percent CaPO ₄ (42 percent P ₂ O ₅)results. Through geologic time, the ocean may be considered as a source of phosphorus to the land through rain or estuarine sediment.  相似文献   

Influence of porefluid salinity on instability of sensitive marine clays: A new approach to an old problem     

M. A. Carson 《地球表面变化过程与地形》1981,6(6):499-515

The geographic association between earthflow occurrence, sensitivity of the sediment and salinity of the interstitial fluid has been examined in an area of exposed marine (Champlain Sea) deposits in the Lachute region northwest of Montreal, Quebec. Mapping of earth resistivity, as a means of calculating porefluid salinity, revealed that areas of large earthflows (>20 ha) coincided with sediment of very low porefluid salinity. Earthflow scars were absent from intervening areas of higher salinity (>5 gl^?1). Mapping of the thickness of the clay deposit by seismic refraction showed, furthermore, that low porefluid salinity occurred only in areas of relatively thin (<25 m) deposits resting upon more permeable drift or rock. Finally, laboratory tests confirmed that high sensitivity was restricted to areas of low porefluid salinity. The study thus provides a geomorphological verification of the importance of ‘salt depletion’ as a prerequisite for earthflow occurrence, and, by implication, presents mapping of porefluid salinity as a method of delineating zones which should be safe from landslide retrogression in this type of sediment.  相似文献   

Neoformation of montmorillonite by post-depositional subsurface weathering in a slope deposit in central France     

J. Sevink  J. M. Verstraten 《地球表面变化过程与地形》1978,3(1):23-29

Observations on an Early Quaternary slope deposit in the Massif Central indicated that the texture and mineralogy of this deposit have been seriously altered by post-depositional subsurface weathering. Analyses of clay fractions and water samples show that the montmorillonite present is a stable mineral in this environment and is, and has been, newly formed. As shown by water analyses from nearby sites, the chemical environment is strongly dependent on local factors. Consequently it can be seen that great care should be taken firstly in correlating different slope deposits on the basis of texture and clay mineralogy and secondly in using these parameters as (paleo) climatic indicators.  相似文献