甘肃省肃北县黑刺沟金矿床地质特征及成因初探

黑刺沟金矿床位于甘肃省肃北县,所属构造体系为南祁连加里东褶皱带,出露地层主要有奥陶系、志留系、石炭系、三叠系、侏罗系等,褶皱和断裂构造发育,岩浆活动频繁,主要侵入体是加里东晚期第二次的石英闪长岩株。黑刺沟金矿是一个多层分布的层控型金矿,矿化体形态为层状、似层状,受滨海、浅海沉积相控制。从矿床的地质特征来看,与岩浆热液作用有关。本矿床的成因属古砾岩迭加岩浆热液型:古砾岩+上升洋流→矿源层+岩浆热液+不整合构造→金矿床。通过航磁异常的分析,深部可能存在一巨大近东西向的磁铁矿系列花岗岩基,研究矿床特征,对指导该区找矿具有重要的意义。     

试论蛇绿碳酸岩与金矿化关系——以东准卡拉麦里蛇绿带中金水泉金矿为例

世界上分布了众多的蛇绿岩带,如加拿大的Abitibi 蛇绿岩带、欧洲的阿尔卑斯蛇绿岩带等,还有古特提斯蛇绿岩带、古亚洲洋蛇绿岩带。这些蛇绿岩带中均有脉状、透镜状碳酸岩分布。这种碳酸岩与蛇纹岩具有明显的成因关系,人们将其称为蛇绿碳酸岩（Ophicarbonate）。国内外涉及这类特殊岩石类型的研究较少,特别是关于它与金成矿关系的论述几乎未见。东准噶尔卡拉麦里蛇绿岩混杂岩带中分布了众多的碳酸岩脉,它们似乎与本带中的金矿化有密切的空间分布关系和成因联系,本文通过各自的地质特征和成矿、成岩地球动力学背景来讨论二者的关系。     

低山头地区多金属矿床地质特征及其成因研究综述

本文以格尔木地区地山头多金属矿区为研究对象。由于其大地构造位于东昆仑陆块(Ⅱ级),Ⅲ级构造单元属东昆中多旋回岩浆弧带,对这一特殊的地区开展研究,对整个东昆仑地区找构造热液型多金属矿床具有很重大的指导意义。文中通过对热液型矿床的时间、空间分布及成因等分析研究,同时结合该矿区地质资料,初步断定该矿床为构造热液型矿床。     

湘东北幕阜山岩体西南铜铅锌矿成矿特征及找矿方向研究

湘东北幕阜山岩体南部分布有多个铜铅锌矿床,矿床受北东向区域构造控制,岩浆期后热液提供了主要的成矿物质来源;矿床成矿模式可概述为:燕山早期岩浆活动开始,区域北东向断裂开始发育并充填早期岩浆期后热液,形成无矿或矿化较弱的石英脉;燕山晚期,次级北西向断裂开始发育,以岩浆期后热液为主的含矿热液沿及北东向主断裂其次级构造充填,形成中低温热液充填型铜铅锌矿床。幕阜山地区铜铅锌矿找矿应注意在岩体南部舌状凸起地段沿秦家坊断裂及次级张扭性断裂的分枝复合、膨大、断裂面舒缓波状等部位寻找。     

陕西庙梁金矿床地质特征、矿床成因及找矿前景分析

庙梁金矿位于山柞旬泥盆系北部多金属矿集区的中心地带,地处华北板块与杨子板块拼接消亡带南缘的南秦岭造山带内,总体构造线呈北西西向,有北北东及近南北向构造叠加。矿体受构造控制时,矿液沿层间脆-韧性破碎带、层间裂隙带贯入、沉淀,形成构造石英脉蚀变岩型金矿;在隐爆角砾岩中受断裂破碎带和角砾岩间隙的共同控制,形成蚀变隐爆角砾岩型金矿。成矿热液属于低温变质热液+岩浆期后中温含矿热液侵入赋矿构造、在隐爆角砾岩中还萃取地层岩石中有益组分。因此矿床成因类型属沉积-浅成岩体侵位期后热液-迭加地下水循环改造的中低温热液型金矿床。早期花岗斑岩体的侵入,是形成矿区金矿床的重要条件。岩浆侵入活动产生了隐爆角砾岩,叠加改造了地层岩石的变形变质程度,形成相对高级别变质岩石和断裂破碎带,岩浆期后产生了丰富的含矿热液,为构造破碎带和角砾岩的蚀变岩和金矿床的形成奠定了成矿物质基础,且多期次岩浆侵入活动,成矿热液多次叠加,成为本区主要成矿组分金的富集成矿起到了关键作用,是矿区金矿床形成的重要成矿机制。本文在充分收集和研究区域矿产分布特征及矿化特征的基础上,结合区内金矿体矿物组成、化学成分特征以及控矿因素的研究,对庙梁金矿床的成因类型进行了初步的研究和探讨,并总结出此类矿床的找矿标志。并结合地质特征及与热液成因类型,认为本矿区具有良好的找矿前景。     

鲁西地区金矿类型与找矿方向

鲁西地区主要有两种金矿类型：火山热液型和绿岩带型。火山热液型金矿成矿物质来源丰富、成矿热动力强,形成了一系列大中型金矿床;绿岩带型金矿床,在成矿物质来源、成矿热动力及赋矿构造空间等方面存在先天不足,只能形成小型金矿或矿(化)点。鲁西地区主要的找矿方向为寻找与燕山期侵入杂岩体有关的火山热液型金矿床。     

新疆米特河一带构造演化与成矿关系探讨

新疆米特河一带属东特提斯构造域的一部分,通过前人资料分析,该区内沉积建造及岩浆活动、变质作用均指示特提斯洋为一个多岛小洋盆。在早石炭世末及晚石炭世末特提斯洋经历了两次开合旋回,其不同时期演化阶段,可形成不同类型的矿床,其构造演化与成矿关系十分密切。笔者通过研究,总结出区内找矿方向主要有以下四类:海相火山岩型铜锌矿;岩浆熔离型基性-超基性岩型镍矿;高温热液型铜铅锌金矿;构造破碎岩型金矿。     

青海省双尖山地区镍多金属矿地质特征与找矿远景探讨

研究区大地构造位置位于秦祁昆造山系之东昆仑弧盆系北昆仑岩浆弧带。出露的地层较简单,由老到新主要为下元古界金水口岩群白沙河岩组、晚古生代泥盆纪牦牛山组。断裂构造发育,在构造接触带及其附近往往形成中低温热液的金、铜矿等多金属矿种,寻找岩浆熔离型铜镍矿具有较大的潜力。     

德钦赛坡铜铅多金属矿地质特征及找矿方向

赛坡铜铅多金属矿地处金沙江板块结合带洋内弧中,区内构造复杂,岩浆活动频繁,多期次的围岩蚀变,前后叠加改造,带来了丰富的热液和矿质,形成区内众多的铜多金属矿床、点,是三江成矿带重要的成矿区之一。赛坡铜铅多金属矿矿体产于印支—燕山期中酸性岩体内、外接触带、岩体内部破碎带或裂隙带及围岩中的矽卡岩带内,含矿地层为泥盆系中、上统里农组(D_(2+3)l),为一套火山碎屑—碳酸岩的沉积建造。初步认为矿床经历了火山沉积盆地热水沉积初始成矿,花岗闪长斑岩-矽卡岩主导成矿——后期构造热液叠加成矿的复杂而漫长的成矿过程。根据赛坡铜铅多金属矿地质特征及成矿规律,结合区内地球化学异常元素组合、地层、构造等特征,认为是区内形成热液(斑岩)—矽卡岩型铜矿最有希望地区。     

银山Au-Cu多金属矿床构造动力热液与火山岩浆热液双重耦合成矿作用

根据矿床特征及与邻区矿床的对比,论证了构造动力热液成矿作用在银山矿床形成过程中的意义;提出了矿区火山岩浆热液成矿作用的新认识,即火山-岩浆热液成矿与石英斑岩桨演化阶段关来更密切,矿化与深部大斑岩体有关,形成内带斑岩型Au、Cu矿化到外带脉型Au、Cu、Pb、Zn、Ag矿的成矿系列。根据两种成矿作用之间相互时空关系,认为银山矿床是构造动力热液与火山-岩浆热液双重机合成矿的产物。     

Physicians and the medical society--between the interests and values

Macrophages may be a potential regulator of ovarian functions. The goal of this study was to determine the changes in the macrophage frequency (number of cells per unit square of tissue) during follicular growth, ovulation, and postovulatory follicular regression in chickens. Cryostat sections of ovarian stroma containing primary follicles, small white follicles, and preovulatory and postovulatory follicles of laying hens were immunostained for macrophage using mouse anti-chicken macrophage monoclonal antibody. Macrophages were observed under a light microscope and counted by a computer assisted image analyzer. The frequency of macrophages in the theca layer was significantly greater in the small white follicles than in the primary follicles (P < 0.01) and also greater in the preovulatory follicles than in the small white follicles (P < 0.01). No significant differences were observed in the macrophage frequency between the third largest and largest preovulatory follicles. In the theca layer of postovulatory follicles, macrophage frequency was significantly greater than in that layer in the preovulatory follicles (P < 0.01); however, the frequency of macrophages decreased significantly in the Day 3 postovulatory follicles as compared with Day 1 postovulatory follicle (P < 0.05). These results suggest that macrophages may play an important role in the follicular development and regression of postovulatory follicles.     

Dermatology and the Internet--uses for the clinic and research

Improvement brought to iodinated molecules aims to obtain an optimal enhancement effect together with a lower toxicity. However, benign adverse events remain a common risk, and anaphylactoid reactions from the intravascular administration of iodinated contrast media may occur at random and are unpredictable. Although most contrast reactions are mild and self-limited, severe and even life-threatening reactions can occur at any time and for any kind of agent. Physicians must be aware of possible complications related to administration of this kind of agents and must be able to identify patients at risk, to care for prevention and prescribe an appropriate premedication regimen.     

Kinematics of the pelvic girdle and the thoracic and lumbar segments in the course of the lateral inclinations and rotations of the spine

Physiological displacements of the trunk are the addition of these of the pelvic girdle and thoracic and lumbar spine segments. For a long time (3), this conjunction had been noticed but without numbered precisions. The purpose of this communication is to appreciate quantitatively, from a series of 16 subjects, the respective share of each components during lateral bending movements in the frontal plan and movements of rotation in the transverse plan. It results from this work that the pelvic girdle presents as reduced amplitude (4 degrees) in lateral bending on the other hand, displacement predominate to the level of thoracic spine (50 degrees). In rotation pelvic displacements are very important (30 degrees), while the spine so thoracic that lumbar has a weak participation (inferior to 5 degrees). Moderated abduction of hips increases by significant manner the motility of the pelvic girdle.     

Design and analysis of the tunnel connecting the beamcorridor and the spectrum hall of the CSNS

There is a tunnel connecting the beamcorridor and the target station in the spectrum hall in the CSNS project. The length of the tunnel is about 20 m. The shielding design of the tunnel is very significant for the persons working in the spectrum hall beca     

谈投标报价策略和技巧

建筑企业参加投标竞争,目的在于得到对自己最有利的施工合同,从而获得尽可能多的盈利.为此,做出投标决策以后,必须仔细研究投标报价策略,并借助投标报价技巧,以达到既能中标又能赢利的目的.