三种锰硅酸盐矿物的鉴别及其研究意义

蜡硅锰矿，粒硅锰矿，鉴别，研究意义     

A Study on the Geological—Geochemical Dynamics of Hydrothermal Ore Deposition as Exemplified by the Muping—Rushan Gold Deposit Belt,Eastern Shandong,China

This paper presents a method of establishing a hydrothermal ore-forming reaction system.On the basis of the study of four typical hydrothermal deposits,the following conclusions concerning geochemical dynamic controlling during hydrothermal mineralization have been sions concerning geochemical dynaamic controlling during hydrothermal mineralization have been drawn:(1)The regional tectonic activities control the concentration and dispersion of elements in the ore-forming process in terms of their effects on the thermodynamic nature and conditions of the ore-forming reaction system.(2)During hydrothermal mineralization the activites of ore-bearing faults can be divideb into two stages:the brittle splitting stage and the brittle-tough tensing stage,which would create characteristically different geodynamic conditions for the geochemical thermodynamic ore-forming system.(3)The hydrothermal ore-forming reaaction system is an open dynamic system.At the brittle splitting stage the system was so strongly supersaturated and unequilibrated as to speed up and enhance the crystallization and differentiation of ore-forming fluids.And at the brittle-tough tensing stage,the ore-forming system was in a weak supersaturated state;with decreasing temperature and pressure the crystallization of oreforming material would show down,and it can be regarded as an equilibrated state.(4)In the lates stages of hydrothermal evolution,gold would be concentrated in the residual ore-forming solution.The pulsating fracture activite in this stage led to the crush of pyrite ore and it was then filled with gold-enriched solution,forming high-grage“fissure”gold ore.This ore-forming process could be called the coupling mechanism of ore formation.     

低温条件下有机酸对铁、铜的淋滤实验研究

水／岩作用实验研究表明，在低温条件下柠檬酸、草酸和酒石酸对岩石中的铁、铜都有很高的淋滤率。这表明，在表生地质作用过程中有机酸对成矿元素有很强的活化能力。实验研究同时发现，有机酸对成矿元素的活化能力受其分解温度的限制，由于大部分有机酸的分解温度都在２５０℃以下，因而有机酸对成矿元素的活化仅限于低温条件。本次研究还显示，判断一种岩石能否成为矿源层，不能简单的以其中成矿元素的含量高低作为标准，其中更关键的因素是元素在岩石中的存在形式，如果成矿元素在岩石中难以活化的形式存在，那么含量再高也无法提供成矿物质     

地震CT及其地质解释

在金川公司龙首矿东采区1 280中段井下500m深的巷道中应用地震CT技术进行寻找深部隐伏矿体的实验。波速图像表明,研究区内中西部有一高速异常区,推断为花岗岩体和含矿的超基性侵入岩体。区内还有一个横贯测区中央近东西走向的低速断裂带。这些推断结果为后期的钻探和巷道开掘所证明。     

北秦岭南缘弧前盆地沉积作用及盆地发展

秦岭被商丹缝合带分为北秦岭和南秦岭两个部分,在北秦岭南缘残留着与俯冲作用相关的岛弧火山岩以及弧前沉积体。对沿海丹带两个地区(黑河地区和黑山地区)弧前沉积体岩相组合和相序的研究显示,它们主要由深水浊积岩系。火山碎屑岩,扇三角洲沉积以及局限性台地碳酸盐岩和陆棚碎屑岩组成。总的沉积序列显示向上变浅趋势,但在弧前内侧边缘则表现为向上变深趋势。两个不同地区岩相和相序的差异明显受物源、海平面变化以及特别是构造作用的挫制。深水浊积岩系所反映的线状物源供给形式、扇三角洲体系的发育和其内部不同沉积段反复重叠的特征指示一种活动构造环境。弧前区构造发展一方面与其前部加积或下部垫底作用有关,另一方面则在很大程度上受由斜向俯冲而导致的伸展作用的影响。     

丰城洛市地区推,滑覆构造特征及其成因探讨

介绍了洛市地区推、滑覆构造特征、运动学标志及其形成时期、成因模式。     

蚀变带元素地球化学成矿预测法──以金龙山微细浸染型金矿为例

金矿化作用伴围岩蚀变，且多受断裂控制，反映在地球化学上出现某些元素的异常。在已发现一害矿化体并掌握一般控制矿特征的地区，利用已有工程在蚀变带内连续捡块采样，分析有关批示元素，总结有关的地球化学指标，建立地球化学预测模式，对已知矿体及外围异常进行了地球化学评价。     

原生金矿成矿年龄测定研究

金成矿年龄和矿源同位素组成的准确测定，对金矿地质研究和找矿具有重要意义。本文根据３年多野外和室内工作的总结，获得了多个典型矿床的年龄和同位素测定结果：华北古陆北缘北侧槽区乌花敖包金矿测定为１３０—１２０Ｍａ的晚期造山作用成矿；南侧台区赛乌素金矿为２１１±１５Ｍａ的再循环古陆改造成矿；中段台区后沟一黄土梁金矿为２４３±７Ｍａ的古陆再造成矿；胶东焦家－乳山金矿为１２２．７±３．４Ｍａ和１２８±２３Ｍａ的燕山期成矿；华夏古陆八宝山金银矿为１４０±５Ｍａ的火山热液成矿。     

Early Estimation of Strong Aftershock Duration Time

In order to solve the problem of early estimation of moderately strong aftershock duration time in an earthquake sequence,this study has been conducted.First,the definition of the strong aftershock has been given.It is pointed out that there is a difference in the strong aftershock duration time between the main shock type sequence and the strong earthquake swarm sequence.After dividing the three cases,i.e.,a strong aftershock duration time larger than 1 day,smaller than 1 day,and no strong aftershock occurred in a main shock type sequence by using the pattern recognition method,we gave the rough correlation relation between strong aftershock duration time and first large shock magnitude for two types of sequences.Finally,the judgment index and method of estimating strong aftershock duration times for different sequence types have been given.     

Coal-generated oil in Tuha Basin

The Turpan-Harmi (abbreviated to Tuha below) Basin is a typical basin of coal-generated oil accumulation in China. The Middle-Lower Jurassic coal measures are considered the main source beds. Hence, both desmocollinite and suberinite are considered the contributors for coal-generated oil. Principal geochemical features of the crude oil in the Tuha Basin are rich in alkanes (70%—80%), high pristane/phytane ratio (6—8), abundant heavy carbon isotope (δ¹³C PDB= -26%–-23%) and absolute GP sterane predominance. The hydrocarbon generation process from the coal series is characterized by multistages, early generation and early expulsion.