建水黑甲铁锰矿矿床成因探讨

建水县黑甲铁锰矿赋存于第四系残坡积层中,层状、似层状分布于平缓山坡及平坦低凹处,为一套含较多铁锰质结核、残块的第四系堆积矿.     

贵州省从江翁浪金矿床金的赋存状态和金矿物特征

从江翁浪金矿是黔东南地区蚀变岩型金矿的典型代表.前人对翁浪金矿的研究仅限于宏观的构造及围岩蚀变等方面,同时对该金矿床容矿岩石及矿石物质组分作过初步研究探讨.在前人工作的基础上,采用矿相鉴定、化学分析、单矿物试金分析、电子探针及X射线衍射等多种物理化学分析手段,对翁浪金矿床中金矿物类型、形态、成色、嵌布特征以及金的赋存状态、载金矿物等做了细致的微观分析研究.     

Metals contamination along the watershed and estuarine areas of southern Bohai Sea,China

Distributions and magnitude of metals in water, sediment and soil collected from the watershed and estuarine areas of southern Bohai Sea, were investigated. The largest dissolved concentrations of As, Cu and Zn in water were 347.70, 2755.00, 2076.00 μg/L, respectively, much higher than corresponding drinking water guidelines. The greatest concentrations of Cu, Zn, Cr, Ni, Pb, As and Cd in sediments were 1462.2, 1602.17, 196.43, 67.15, 63.54, 73.86 and 1.41 mg/kg, dw, respectively. The mean concentrations of Cu, Ni, Cd, Zn, Cr, Pb and As in soils were 24.67, 24.73, 0.14, 64.75, 56.52, 25.12 and 9.34 mg/kg, dw, respectively. Land use was confirmed to be an important factor of influence on soil metal concentrations. Metal contents along the watershed of Jie River were significantly greater than in other locations. The detection of metals in relatively high concentrations from different environmental matrices in this region indicates the necessity of further studies.     

http://www.sciencedirect.com/science/article/pii/S1674987111000806

Zoned tourmaline（schorl-dravite） in the matrix of hydrothermal explosive breccia and ore veins in gold deposits,Chita region.Eastern Transbaikalia.Russia,are associated with Na- and K-rich porphyry-type subvolcanic intrusives.δ¹⁸O values of tourmaline from three gold deposits（Darasun. Talatui,Teremkinskoye） are +8.3‰,+7.6‰,and +6.0‰and calculatedδ¹⁸O values of fluids responsible for the tourmalinization are +7.3‰,+7.7‰,and +4.2‰,respectively.These data imply an igneous fluid source,except at the Teremkin deposit where mixing with meteoric water is indicated.Wide ranges of Fe³⁺/Fe_tot,and the presence of vacancies characterize the Darasun deposit tourmaline indicating wide ranges of f（O₂） and pH of mineralizing fluids.Initial stage tourmalines from the gold deposits of the Darasun ore district are dravite or high mg schorl.Second stage tourmaline is characterized by oscillatory zoning but with Fe generally increasing towards crystal rims indicating decreasing temperature.Third stage tourmaline formed unzoned crystals with x_Mg（mole fraction of Mg） close to that of the hrst stage tourmaline,due to a close association with pyrite and arsenopyrite.From Fe³⁺/Fe_tot values,chemical composition and crystallization temperatures.logf（O₂） of mineralizing fluids ranged from ca.—25 to—20. much higher than for the gold-bearing beresite—listvenite association,indicating that tourmalinization was not related to gold mineralization.     

四川省九龙县黑牛洞铜锌矿的矿床地质特征、成因及其成矿时代

通过野外填图、坑探和钻探以及室内测试、研究认为:黑牛洞铜锌矿床原来可能是一个形成于中元古代大陆被动边缘裂谷的大型甚至特大型海相火山块状硫化物矿床;含矿围岩是糜棱岩、千糜岩、糜棱片岩、变晶糜棱岩、变粒岩、浅粒岩和构造蚀变岩,剪切型矿化和蚀变带包裹了矿体,原岩是石英砂岩、泥质石英粉砂岩、泥质岩和硅质岩夹基性火山岩、少量中—酸性、酸性火山岩,经过变质达到高绿片岩相—低角闪岩相.以块状、角砾状和准块状矿石为主的矿床是富铜矿,矿石的铜平均品位为1.68％,锌品位平均为1.53％;矿化与褪色带、硅化关系密切.矿化类型以广泛发育韧性剪切带型浸染状矿化岩或矿石(分别简称剪切型矿化岩或矿石)为特色,具有与糜棱岩、千糜岩相同的变形特征,可见两期以上的金属矿物透镜体、变形条带和不协调微褶皱.矿床具有原地韧性变形改造、变质再生矿床的特点;矿石、矿体的围岩和氢、氧、硫、铅、硅同位素特征显示,块状、准块状和角砾状矿石的矿质基本来源于剪切型矿化岩或矿石,是变质生成矿床,也是原矿石的再生矿床,而剪切型矿化岩或矿石可能是中元古代海底火山-裂谷作用形成的火山块状硫化物矿床经过多期韧性变形、变质改造形成的,是溶解为主的化学再活化的残余.构造改造、再生矿床的成矿时代为134.26±0.5Ma.,形成于燕山晚期.     

云南泸水自把铅矿矿床地质及成因

矿床受地层及断层双重控制,走向长大于3千米,共圈出V1、V2、V3三条矿体。含矿岩石以透辉石矽卡岩为主,矿石工业类型为硫化铅矿石和氧化铅矿石。矿床成因类型为与花岗岩有关的含矿热液沿破碎带充填-交代形成的矽卡岩型铅矿床。     

云南景东里竹山铁矿成矿规律

里竹山铁矿赋存在马邓岩群外麦地岩组中,成矿与区内基性火山岩(玄武岩)相关,矿石与围岩均具有相似特征。后期热变质作用、叠加改造作用并未完全改变其原岩结构构造特征,属于构造和海底基性火山喷发有关的沉积变质型磁铁矿床。     

冀北丰宁县茶棚银矿床成矿模式

茶棚银矿属与隐伏岩体/次火山岩有关的浅成低温热液矿床。侏罗系盖层继承下伏基底变质岩系中成矿元素的高背景;隐伏岩体/次火山岩提供热源和部分物源;近SN向断裂为元素富集提供成矿空间。研究成果可以指导同类浅剥蚀区隐伏矿体的找矿工作。     

泰国近岸古环境Toarcian-Aalenian期风暴沉积初探

Jurassic deposits of the Malayan Peninsula (Thailand) are stratigraphically limited to Toarcian and Aalenian only (Meesook & Sha, 2010, and literature cited therein). These are represented by wide spectrum of both clastic and carbonate rocks with full develop-ment of transitional ones. In the middle part of penin-sula (vicinity of Krabi) distribution of Jurassic facies suggest occurrence of full marine palaeoenvironments in NE part of it with gentle transition by lagoonal (brackish?) and tidal environments up to terrestrial ones in the SW part of peninsula. Sections studied, close to Thung Song city, are represented by 20 m thick sequence of thin-bedded limestones and marls of the Khlong Min Formation, most probably lagoonal palaeoenvironments (transitional = restricted ma-rine-brackish), indicated by specific benthic fauna dominated by different kind of ethological group of bivalves – infaunal, epifaunal and encrusted (epibion-tic) species like Protocardia, Praemytilus, Modiolus, Myrene, and Actinostreon. Very characteristic is a lack of full marine, stenohaline, other invertebrates – brachiopods, crinoids, echinoids etc.