排序方式: 共有24条查询结果,搜索用时 31 毫秒
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赤峰大井子铜多金属矿位于大兴安岭南段锡、铜、铅、锌、银、钼多金属成矿带上,矿体受断裂构造控制。基于构造叠加晕的理论研究基础,本次研究对矿区内最大的1#脉进行了系统的原生晕研究。研究表明,矿体前缘晕指示元素为F、B、As、Sb、Hg,近矿晕指示元素为Cu、Ag、Sn,尾晕指示元素为W、Mn、Ni、Ti、V;原生晕轴向分带及特征参数显示有“反分带”现象,预示矿体深部有盲矿体的存在。通过建立矿区1#脉构造叠加晕模型及构造叠加晕垂直纵投影图提出下一步找矿靶区。 相似文献
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广西的中酸性火山岩风化壳离子吸附型稀土矿床主要分布在桂西南崇左至凭祥一带,是一种非常具有找矿前景的矿床类型。文章从成矿母岩地球化学特征、风化壳结构特征、矿床地质特征及稀土元素配分等方面,对广西崇左地区火山岩风化壳离子吸附型稀土矿床的成因进行探讨。本区广泛分布的早三叠世中酸性火山岩稀土元素丰度高,在亚热带季风气候条件以及地表水和地下水的综合作用下发生分解,使原岩中的稀土元素在风化壳中发生迁移,并在全风化层的中下部至半风化层的顶部富集成矿,矿石稀土元素配分类型呈轻稀土富集的右倾型分布且Eu呈明显负异常。 相似文献
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东坪金矿位于河北省崇礼区,大地构造处于华北地台北缘,燕辽沉降带与内蒙地轴结合处南侧,距尚义-崇礼-赤城深大断裂10km。区内出露地层主要为太古界桑干群变质岩系,岩性以片麻岩为主。区内断裂构造较发育,主要有EW向,NW向和NE向,其中以EW向的最为发育。
区内岩浆岩也比较发育,沿尚义-崇礼-赤城深大断裂分布,主要有小张家口超基性岩、水泉沟碱性杂岩和上水泉花岗岩。水泉沟碱性杂岩体呈EW向展布,向南北两侧倾斜,主要岩性为碱性长石正长岩、辉石角闪碱性长石正长岩、辉石角闪正长岩和角闪碱性长石正长岩等。 相似文献
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石炭系上统黄龙组为浙江省重要的非金属矿床含矿层位。建德钦堂大理岩矿床由黄龙组石灰岩受热接触变质作用形成,规模达大型。大理岩矿体位于黄龙组中部,呈单斜产出,受碎斑熔岩破坏,矿体内部结构较复杂。矿石质量较稳定,CaO平均含量为54.8%,白度平均为90.6%,盐酸不溶物含量较低。原岩成分是影响大理岩矿石质量的决定因素,原岩方解石含量高、成分均一有利于形成优质大理岩矿石;碎斑熔岩侵出过程中形成的冷凝壳起到保温作用,不断上涌的岩浆为方解石重结晶提供了持续热源,二者是形成矿床的必要条件。 相似文献
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通过对桂东南六陈中酸性侵入岩进行LA-ICP-MS锆石U-Pb定年、岩石学和地球化学研究,表明六陈中酸性侵入岩主要为二长花岗岩-钾长花岗岩组合,少量花岗闪长岩,岩石普遍含角闪石;岩石属富碱、高硅、高钾,属高钾钙碱性系列;稀土总量较高(∑REE 237.65×10~(-6)~316.06×10~(-6)),具中等铕亏损的轻稀土富集型的稀土配分曲线特征;对岩体进行了高精度的LA-ICP-MS锆石U-Pb定年,加权平均值为(245.1±1.2)Ma。该岩体总体显示为富碱性A2亚型花岗岩,形成于华南后碰撞伸展构造背景。 相似文献
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Gut microorganisms play an important role in the digestion of their host animals. The purpose of this research was to isolate and assess the enzyme-producing microbes from the Apostichopus japonicus gut. Thirty-nine strains that can produce at least one of the three digestive enzymes (protease, amylase, and cellulase) were qualitatively screened based on their extracellular enzyme-producing abilities. The enzyme-producing strains clustered into eight groups at the genetic similarity level of 100% by analyzing the restriction patterns of 16S rDNA amplified with Mbo I. Phylogenetic analysis revealed that 37 strains belonged to the genus Bacillus and two were members of the genus Virgibacillus. Enzyme-producing capability results indicate that the main enzyme-producing microflora in the A. japonicus gut was Bacillus, which can produce protease, amylase, and cellulase. Virgibacillus, however, can only produce protease. The high enzyme-producing capability of the isolates suggests that the gut microbiota play an important role in the sea cucumber digestive process. 相似文献
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北京山区沟域经济发展的空间结构 总被引:1,自引:0,他引:1
Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The special spatial coupling relations in the distribution of different mountainous elements in valleys are new subjects for the mountain development studies, and such studies are meaningful both for researches and practices. Based on the long term researches on mountainous area development and following a brief exploration into the connotations and the spatial organizing process of valley economy, the authors analyzed the present situations of the development of valley economy in Beijing’s mountainous areas, studied the characteristics and the impacts of the spatial structural changes of the valley economy in Beijing’s mountainous areas, and finally proposed a rational arrangement of the spatial structure of the valley economy in Beijing’s mountainous areas. It is considered in this study that valley economy plays an important role in the development and functional transformation in Beijing’s mountainous areas in the new epoch. Firstly, valley economy is not outlined by the administrative boundaries, and it connects most of the villages in the mountainous areas roughly along the major transportation lines. Therefore, valley economy can exert positive influence on the development in the mountainous areas, at least in the aspects such as the rearrangement of industrial structure in the mountainous areas and the coordinated development of rural and urban areas. In addition, it is found that the valley economy in Beijing’s mountainous areas is evolved in a spatial organizing stage of secondary concentration, which is characterized by resource-saving, ecological protection and industrial optimization. Therefore, the development of valley economy will be helpful to the coordination between ecological protection and economic development in the mountainous areas, and will promote the integrated development of the mountainous areas. The developing mode of the valley economy in Beijing’s mountainous areas will provide the basis for the decision-making in the transformation of the functional roles of Beijing’s mountainous areas, and on the other hand, will present experiences for the studies in the mountainous areas outside of Beijing. 相似文献