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青海日龙沟锡多金属矿床地质特征及矿床成因探讨 总被引:2,自引:0,他引:2
日龙沟锡多金属矿床位于鄂拉山多金属成矿带中的塞什塘—铜峪沟—日龙沟多金属成矿亚带西端;矿区内的下二叠统地层为矿床的主要赋矿层位,矿体的产出明显受一定的地层层位控制,虽然不连续,但总体呈层状,页层间破碎带产出;矿化类型总体属蚀变岩型,矿床成因为沉积一变质改造型。 相似文献
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内蒙古驼峰山含铜硫化物矿床地质特征及成因初探 总被引:2,自引:0,他引:2
内蒙古中部黄岗梁-甘珠尔庙成矿带已发现多处颇具规模的含铜硫化物矿床,驼峰山矿床位于其中。据现有矿区地质结合区域相关地质资料认为,矿区地层为下二叠统海相火山-沉积岩,是一套优地槽型的沉积建造。含铜硫化物矿体即赋存于火山穹隆附近下二叠统大石寨组中酸性火山岩中,矿体呈层状、似层状、透镜状,与围岩基本整合。矿石主要成分为硫、铜、铁,主要共生组合矿物为黄铜矿、黄铁矿等。总之矿床应属与海相火山作用有关的硫化物矿床。在本区域找矿工作中应重视物探异常提供的信息。 相似文献
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大铜沟铜矿体赋存于石炭系上统土坡组底部,即石炭系下统臭牛沟组平行不整合面之上。矿体呈似层状。含矿岩性为灰白色石英岩状砂岩及灰绿色粉砂质板岩。矿化主要为细脉状、浸染状。矿石矿物为孔雀石、兰铜矿,偶见辉铜矿及黄铜矿。铜矿石中伴生金。控矿因素为层位、岩相、岩性及构造条件。成因类型为沉积-改造砂(页)岩型铜矿床。 相似文献
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龙尾沟铜(钨)矿床是祁连山地区新近发现的一处斑岩型矿床,其评价及研究对祁连山地区铜矿勘查具有重要的指导和借鉴作用。本文通过对含矿斑岩年代学及地球化学、矿体产出特征及矿石物质组成、围岩蚀变等进行了系统研究,结果表明,花岗闪长斑岩形成年龄为358.7Ma;矿体呈似层状、透镜状和脉状产出,主要产于高钾碱性系列斑岩体内,并受近南北向构造控制;矿石矿物主要为黄铜矿、黄铁矿、磁黄铁矿、白钨矿,呈细脉-浸染状、浸染状产出;矿化以富铜、钨、金贫钼为特征;与成矿关系密切的围岩蚀变主要为绢英岩化,次为钾硅酸盐化和硅化;矿床成矿时代为海西早期,形成于陆内造山伸展环境。从成矿背景分析认为祁连山地区陆内造山环境所形成的斑岩型铜矿具有良好的找矿前景。 相似文献
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通过对查干德日斯铜(金)矿区地质地球化学勘查工作,区内发现铜矿体1条、铜(金)矿化体1条、铜矿化蚀变带8条。铜(金)矿化体均赋存于NEE向、NNW向断裂破碎带内,且以NEE向为主;矿化与褐铁矿化石英脉密切共生,伴随明显的硅化、钾化热液蚀变。认为矿区Cu-Au-Ag原生晕组合异常明显,与断裂构造套合良好;铜(金)矿化受构造控矿特征明显,热液充填-交代作用强烈,初判为热液充填交代型矿床。矿区深部矿成矿地质条件优越,找矿前景良好。 相似文献
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尹福光 《沉积与特提斯地质》2003,23(4):79-83
康滇地区裂谷作用已得到证实,但形成这种地堑地垒的格局有多种解释,以传统的地质力学分析为主。笔者借以热力学的自由热对流原理来加以论述:攀西巨厚的火山岩体在下覆异常地幔热作用下,发生自由热对流,引起热量散失,使地壳沉降与隆起不均衡,生成地堑地垒的格局。自由对流单元的侧向迁移,使盆地形成非对称性。 相似文献
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A detailed investigation of the protoglobigerinids from the Kimmeridgian section of the Montagne de Crussol, SE France is presented. This monotonous succession of predominantly carbonate beds represents peri-platform hemipelagic deposits, well dated by ammonites. Three species were determined in thin sections and in isolated forms after extraction by acetolysis. Favusella? parva (Kuznetsova) is the most common species occurring in almost the entire succession from the Orthosphinctes to the Beckeri zones. Favusella hoterivica (Subbotina) has been retrieved less frequently from the Platynota to the Beckeri zones, and it is its oldest occurrence. The rare Globuligerina bathoniana (Pazdrowa) occurs only in the Late Kimmeridgian. Based on our study and the review of the literature a palaeogeographical map was plotted, showing that most of the protoglobigerinid occurrences are in deep water facies of the northern margin and central part of the Tethys. These records demonstrate the presence of Globuligerina bathoniana, G. oxfordiana (Grigelis), Favusella hoterivica, F.? parva and Compactogerina stellapolaris (Grigelis) in the Kimmeridgian. 相似文献
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Selenium isotope fractionation during reduction by Fe(II)-Fe(III) hydroxide-sulfate (green rust) 总被引:1,自引:0,他引:1
Thomas M. Johnson 《Geochimica et cosmochimica acta》2003,67(3):413-419
We have determined the extent of Se isotope fractionation induced by reduction of selenate by sulfate interlayered green rust (GRSO4), a Fe(II)-Fe(III) hydroxide-sulfate. This compound is known to reduce selenate to Se(0), and it is the only naturally relevant abiotic selenate reduction pathway documented to date. Se reduction reactions, when they occur in nature, greatly reduce Se mobility and bioavailability. Se stable isotope analysis shows promise as an indicator of Se reduction, and Se isotope fractionation by various Se reactions must be known in order to refine this tool. We measured the increase in the 80Se/76Se ratio of dissolved selenate as lighter isotopes were preferentially consumed during reduction by GRSO4. Six different experiments that used GRSO4 made by two methods, with varying solution compositions and pH, yielded identical isotopic fractionations. Regression of all the data yielded an instantaneous isotope fractionation of 7.36 ± 0.24‰. Selenate reduction by GRSO4 induces much greater isotopic fractionation than does bacterial selenate reduction. If selenate reduction by GRSO4 occurs in nature, it may be identifiable on the basis of its relatively large isotopic fractionation. 相似文献
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通过对分离结晶作用和批式熔融作用Cly/Clx-Cly图解的数学分析,笔者认为,虽然ClLa/Clsm-ClLa图解在一定程度上能区分这两种不同岩浆作用过程,但是,Treuil等的解释是不完全的。直线的斜率和截距还极大地受参数Cox,Coy,Dx,Dy的影响。该图解并非总是有效。本文还给出了一般式Cly/Clx-Cly在其它方面的可能应用。 相似文献
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在山东蒙阴金伯利岩中,首次发现了沂蒙矿类质同象系列新的富Ti矿物(变)种。理想的晶体化学式可表达为:K(Ti5Fe3Cr2Mg2)12O19(简称K-Ti沂蒙矿)(Ba,K)(Ti5Fe4Mg2Cr)12O19(简称Ba-Ti沂蒙矿)从而与原来确定的沂蒙矿K(Cr5Ti3Fe2Mg2)12O19和钡钛铁铝矿(Ba,K)(Cr4Fe4Ti3Mg)12O19一起构成了金伯利岩中AM12O19磁铁铅矿型矿物的K-Cr、Ba-Cr、K-Ti、Ba-Ti四种端元类型的复杂类质同象系列。新发现的两个矿物(变)种均产出于具叶片状尖晶石出溶体的镁钛铁矿中。根据结构已知的沂蒙矿中原子的占位和配位多面体情况,分析了K-Ti,Ba-Ti沂蒙矿中各原子的占位和配位多面体,认为新发现的两个(变)种在成分上与沂蒙矿和钡钛铁铬矿有明显的区别。根据镁钛铁矿、尖晶石、沂蒙矿新(变)种、钙钛矿之间的相互关系,探讨了它们的形成环境,从而为这类矿物的地幔成因提供了直接证据。 相似文献