比值分析及其在伴生元素评价中的应用

比值分析是利用伴生元素含量(x)与主元素含量(c)在矿石中的比值(α=x_0/c_0),在矿物中的比值(b=x_i/c_i)以及两者的比值(称比值系数k=b/α),对伴生元素赋存规律进行分析研究的方法。b值和矿石中仅有一种矿物含某种伴生元素的a值,可确切了解伴生元素自身变化、富集规律及其在载体矿物中分布的均匀程度;矿石中与各矿物相关联的k值具有如下关系:k_1+k_2+…=1,据此可确定伴生元素在各有关矿物中的分配情况和判断赋存有该种伴生元素的矿物是否全部查明。     

How many sutures in the southern Central Asian Orogenic Belt：Insights from East Xinjiang-West Gansu（NW China）？

How ophiolitic mèlanges can be defined as sutures is controversial with regard to accretionary orogenesis and continental growth.The Chinese Altay,East junggar,Tianshan,and Beishan belts of the southern Central Asian Orogenic Belt（CAOB） in Northwest China,offer a special natural laboratory to resolve this puzzle.In the Chinese Altay,the Erqis unit consists of ophiolitic melanges and coherent assemblages,forming a Paleozoic accretionary complex.At least two ophiolitic melanges（Armantai,and Kelameili） in East Junggar,characterized by imbricated ophiolitic melanges,Nb-enriched basalts,adakitic rocks and volcanic rocks,belong to a Devonian-Carboniferous intra-oceanic island arc with some Paleozoic ophiolites,superimposed by Permian arc volcanism.In the Tianshan,ophiolitic melanges like Kanggurtag,North Tianshan,and South Tianshan occur as part of some Paleozoic accretionary complexes related to amalgamation of arc terranes.In the Beishan there are also several ophiolitic melanges,including the Hongshishan,Xingxingxia-Shibangjing,Hongliuhe-Xichangjing,and Liuyuan ophiolitic units.Most ophiolitic melanges in the study area are characterized by ultramafic,mafic and other components,which are juxtaposed,or even emplaced as lenses and knockers in a matrix of some coherent units.The tectonic settings of various components are different,and some adjacent units in the same melange show contrasting different tectonic settings.The formation ages of these various components are in a wide spectrum,varying from Neoproterozoic to Permian.Therefore we cannot assume that these ophiolitic melanges always form in linear sutures as a result of the closure of specific oceans.Often the ophiolitic components formed either as the substrate of intra-oceanic arcs,or were accreted as lenses or knockers in subduction-accretion complexes.Using published age and paleogeographic constraints,we propose the presence of （1） a major early Paleozoic tectonic boundary that separates the Chinese Altay-East Junggar multiple subduction system     

广东泥盆—石炭系沉积盆地构造与层控矿床

广东及其邻域晚古生代沉积盆地的大地构造性质，属于海西－印支期拗拉槽。泥盆－石炭纪期间，先后经历了拗拉槽旋回的上拱开裂阶段，陆内裂谷阶段和挠曲下翘阶段。可划分出３个构造区，裂陷海槽区，走滑海盆地和盆级稳定区，前两者均发衣下部碎屑岩建造，中部深色碳酸盐岩建造，上部浅色碳酸盐岩建造三元组合，矿床主要产在沉积于陆内裂谷阶段的深色碳酸盐岩建造之内及其下与下部碎屑岩建造的过渡部位，矿种较多，矿物组合以硫化物的     

凡口铅-锌矿床的成因

凡口铅-锌矿床形成于泥盆系沉积-成岩期间的古隆起上,同时发育有同生断层,可能还有同期的火山次火山活动。矿床主要形成于地层的成岩阶段。成矿物质主要来自沉积建造,并在中晚期成岩溶液中呈有机络合物和氯络合物形式迁移,沿同生断层上升。当通过处于早期成岩阶段富含H_2S的水质地带时,不同水质发生混合,成矿物质通过交代尚处于疏松一半疏松状态的碳酸盐泥,沉淀下硫化物。随后经历与围岩相同的区域地质演化,定型为现今状态的矿床。     

广东泥盆系的含矿性

广东泥盆系是许多重要金属矿床的赋存层位。本文拟将目前与此有关的资料作一概略归纳,提出一些初步看法和问题,请批评指正。一、地层划分对比和矿产赋存概况广东泥盆系在粤北、粤中和粤西大部分地区由一套碎屑岩和碳酸盐岩组成,在50年代至70     

试谈相关分析在伴生有益元素评价工作中的若干应用问题

相关分析是数理統計方法的一种,不少书籍和文章已經做了介紹,它常被运用到伴生有益元素的評价工作中。但在这方面迄今所討論的范围多限于单相关分析的步驟和方法,較少提到单相关分析的局限性,也很少介紹偏相关分析的方法和必要性,而这些对于实际工作是很有意义的。本文根据在