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71.
REE Biological Metallogeny —A Preliminary Study   总被引:3,自引:2,他引:3  
Five species of bacteria have been found in granite-weathering profiles of Ore District 701.They tend to decrease in varieties and quantities from the upper part down-ward, and no bacterium has been brought up below the depth of 10 m.The simulating experiments done by using humic acid of small molecular weight ,and decanedioic acid extracted from the samples and the bacteria mentioned above have shown that:(1)The dissolving rates of REEs from humic acid original rock or decanedioic acid original rock are lower than those from humic acid bacteria original rock or decanedioic acid bacteria original rock.The presence of bacteria may accelerate the formation of REE-organic complexes and make the complexes increase in quantity.Aminoacids in the bacteria are involved in coordination balance.The concentrations of the complexes tend to increase as a result of the formation of the complexes,i.e., the dissolution, complexation, migration and accumulation of REEs from the original rocks will be accelerated.(2)The metabolism of microorganisms has contributed a lot to keeping a pH environment in the weathering crust.  相似文献   
72.
青海锂矿成矿特征及找矿潜力   总被引:2,自引:0,他引:2  
潘彤  李善平  王涛  韩光  贾建团 《地质学报》2022,96(5):1827-1854
锂资源是高新产业发展的保障性资源和战略性资源之一。青海省锂矿资源丰富,锂矿床类型以盐湖卤水型储量巨大,硬岩型次之,硬岩型锂矿以伟晶岩型为主。盐湖锂矿集中分布于柴达木盆地,硬岩型主要在柴达木盆地北缘、三江北西青海段;成矿时代主要是新生代、中生代两个时期。本文通过对分布于柴达木盆地盐湖型锂矿床察尔汗盐湖、东台台吉乃尔盐湖、南翼山富钾锂卤水矿;分布于柴达木盆地北缘硬岩型的茶卡北山锂铍、三江北西青海段草陇锂铍矿五个典型矿床的赋矿特征、成矿作用及机理的探讨,建立了青海省锂矿成矿系列,在分析了区域的不同类型锂矿找矿远景基础上,认为盐湖卤水型和花岗伟晶岩型锂矿应该作为重点预测类型,并对成矿潜力进行了分析,为今后的锂矿找矿工作提供了理论依据。  相似文献   
73.
全球锑矿床成矿学基本特征及超大型锑矿床成矿背景初探   总被引:9,自引:0,他引:9  
本文对全球锑成矿的基本特征进行了初步研究并编制了全球锑成矿图。研究表明全球锑成矿的一般规律具以下特点:锑成矿与大陆型壳体的构造发展阶段及演化程度具显著相关性,全球锑矿床可划分为地槽型(或古地槽型)和地洼型两种基本大地构造类型;锑成矿在时、空分布上具有不均一性,成矿主要集中于大陆壳体较晚地质历史(中、新生代)的地槽区和地洼区;锑成矿是地洼区特征性成矿之一,往往在分异,演化程度较高的地洼区内形成锑成矿高峰;沿与深部上地幔关系密切的浅部碎裂岩断层带以中─低温热液交代或充填的方式富集是地洼型锑成矿的基本型式。最后文中对超大型锑成矿富集特殊性与非超大型锑工业富集的一般性进行了对比研究。  相似文献   
74.
地体构造对研究地台和地盾区域成矿规律的重要性   总被引:3,自引:0,他引:3  
30年前板块构造理论的建立引起所有相关的地球科学的革命,其中包括区域成矿学。然而随着地球科学理论的发展,板块构造理论对于解释地壳,特别是早前寒武的地盾、地台和克拉通区的复杂构造现象显得不完备,因此,近20年来地体构造理论的发展补充了板块构造理论的不足。近年来,各国地质学家相继发现世界上各地盾、地台和克拉通区,如华北地台、乌克兰地盾、阿尔丹地盾、加拿大地盾、非洲地台、澳大利亚耶尔冈克拉通等是由多个地体所组成。每一个地体是一个独立的和基本的地质构造单元,彼此间由地缝合线或深断裂隔开。由于每个地体的地质特征、构造环境和成矿作用各不相同,因而地体构造成为区域成矿学的一个重要组成部分。  相似文献   
75.
成矿动力学刍议   总被引:6,自引:2,他引:6  
李德威 《地球科学》1993,18(4):407-413
  相似文献   
76.
Abstract. Determinations of SO3 and Cl contents of igneous accessory apatite were carried out on Late Cenozoic intermediate to silicic intrusive and volcanic rocks in the Japanese island arcs of the western Pacific rim including the southwestern Kuril arc (eastern Hokkaido), Northeast Japan arc (southwestern Hokkaido through northeastern Honshu to central Honshu), Izu‐Bonin arc, Kyushu‐Palau ridge, Southwest Japan arc (northern Kyushu) and northern Ryukyu arc (southern Kyushu). These were compared to those from the Western Luzon arc, Philippines, to better understand the metallogenesis of porphyry Cu deposits in the western Pacific island arcs. In addition, SO3 and Cl contents of accessory apatite in the Cretaceous magnetite‐series granitic rocks in the Kitakami belt (northeastern Honshu) and the Miocene ilmenite‐series granitic rocks in the Outer Zone of Southwest Japan (southern Kyushu) were also examined. Microphenocrystic apatites in shallow intrusions associated with porphyry Cu deposits in the Western Luzon arc contain >0.1 wt% S as SO3. Such high SO3 contents of microphenocrystic apatite are a common characteristic of hydrous mag‐matism in the Western Luzon arc, from 15 Ma old tonalitic plutonic rocks of the Luzon Central Cordillera to present‐day volcanism at Mount Pinatubo. The accessory apatite in intrusive rocks associated with porphyry Cu deposits, especially those at the Santo Tomas II deposit, show significantly high Cl contents (>2 wt%). The SO3 contents of microphenocrystic apatite in most of the hydrous silicic rocks along the volcanic front, in andesites related to native sulfur deposits, and in Miocene and younger shallow granitic intrusions in northeastern Honshu, are generally <0.1 wt%. On the other hand, the SO3 contents of apatite in such rocks from eastern Hokkaido, southwestern Hokkaido, Izu, northern Kyushu and southern Kyushu are similar to those from the Western Luzon arc. The SO3 contents of accessory apatite in the Cretaceous magnetite‐series granitic rocks in the Kitakami belt are variable, whereas those of the Miocene ilmenite‐series granitic rocks in southern Kyushu are extremely low. The Cl contents of accessory apatite in some rocks of the Northeast Japan arc, Izu‐Bonin arc and Southwest Japan arc are significantly high. In terms of the Cl and SO3 contents of microphenocrystic apatite, Cenozoic Japanese arc magmatism show similarities with arc magmatism associated elsewhere with porphyry Cu mineralization, except for the most of northeastern Honshu of the Northeast Japan arc. Apatite commonly occurs as inclusions in other phenocrystic phases. Thus the variation in SO3 contents of apatite is a feature of early stage magmatic differentiation. The SO3 contents of microphenocrystic apatite are considered to reflect the redox state of the magma source region or fluids encountered during magma generation.  相似文献   
77.
山东省金矿床成矿系列及成矿规律   总被引:10,自引:0,他引:10  
以矿床成矿系列理论为指导,选择山东矿业大省中具有重要经济地位的金矿床作为主要研究对象,分析矿产资源潜力和危机形势,通过区域成矿背景的研究,了解地层、构造、岩浆岩对成矿的“捐赠作用”,指出了地层含矿、构造控矿、岩浆致矿的作用,并紧紧地将地壳运动演化与矿产形成联系起来。分析了矿床成因,详细划分了矿床类型。总结了山东金矿床成矿规律,建立了成矿系列。  相似文献   
78.
The Inner Arc of the Central Andes, broadly corresponding to the Eastern Cordillera, is the location of a rich Tertiary and Triassic Sn–W–(Ag-base metal) metallogenic province, commonly referred to as the Bolivian tin belt. We propose that the Tertiary metallogeny, which generated most of the tin ores, was a direct consequence of discrete “collisions” between the South American plate and the Nazca slab and sub-slab mantle, during the ongoing Andean orogeny. Evidence supporting this proposal include: (1) the coincidence of the tin province and the Inner Arc in a marked “hump” in the Andean orogen, which may represent tectonic indentation; (2) the symmetry of the tin province with respect to the Bolivian orocline, the axis of which corresponds to the direction of highest compression; (3) the relative symmetry of the magmatism and tin mineralization with respect to this axis; (4) the concurrent timing of mineralization and compressional pulses; (5) the similar host rock geochemistry and ore lead isotope data, testifying to a common crustal reservoir; and (6) the striking similarity of the igneous suites, associated with the ore deposits to those from “typical” collisional orogens. A number of studies have called upon a persistent tin anomaly to explain the metallogeny of the region. We propose, instead, that the latter is better explained by periodic compressional interaction between the Farallon/Nazca oceanic plate and the South American continent. This led to the generation of peraluminous magmas, which during fractional crystallization exsolved the fluids responsible for the voluminous Sn–W mineralization.  相似文献   
79.
田薇 《矿产与地质》2006,20(3):237-242
伊犁晚古生代裂谷陆相火山岩型铜银矿产于碱性火山岩中,在区域上表现出层控特点,即沿着上、下二叠统过渡界面分布,且多产于火山旋回顶部层位,明显受火山穹隆、火山洼地和火山机构及其派生构造的控制。具有准斑岩型、火山沉积型、火山热液型配套的矿床类型。多以火山构造为成矿基础而构成铜银成矿集中区。其中,托斯巴火山穹隆区、阿克吐别克火山向斜区和特提达坂火山穹隆区的多矿点火山构造类型区具有最佳的找矿前景。  相似文献   
80.
大陆成矿作用是当代区域成矿学研究的重大前沿,增进对大陆碰撞造山带成矿作用的理解和认识是孕育和建立大陆成矿理论框架的核心和关键。长期以来,由于对系统完整地记录大陆碰撞过程的典型造山带的成矿作用缺乏深入系统的研究,对碰撞造山过程及壳/幔相互作用与成矿作用的耦合关系和成因联系缺乏深刻的理解,导致了对碰撞成矿阶段以及各阶段动力学过程认识不清,引发了较多争议。青藏高原造山带,成矿规模大、形成时代新、矿床类型多、保存条件好,为系统地研究大陆成矿作用、解决上述存在的问题提供了天然实验室。“印度-亚洲主碰撞带成矿作用”973项目组通过对青藏高原碰撞造山带成矿作用历时3年的系统研究,建立了青藏高原重要成矿事件的时空坐标,初步建立了成矿作用的地球动力学模型或构造控制模型,提出了一套完整的大陆碰撞带成矿理论新框架,包括三大成矿作用和12种矿床类型:同碰撞造山成矿作用(65-41 Ma,4种矿床类型),晚碰撞转换成矿作用 (40-26Ma,4种矿床类型),后碰撞伸展成矿作用(25-0 Ma,4种矿床类型)。其主控因素分别为:碰撞造山背景、壳源岩浆活动和大规模剪切变形;陆内转换背景、幔源岩浆活动和大规模走滑-推覆-剪切作用;后碰撞伸展环境、壳/幔岩浆作用和热液对流系统。  相似文献   
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