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金与铅锌矿化的时空关系及应用 总被引:16,自引:3,他引:16
近10年来,在秦岭铅锌矿带和青城子铅锌矿田等地相继发现了一批大、中型金矿床。铅锌矿和金矿床共同产出在同一构造背景下,金矿床通常位于铅锌矿之上,金矿的成矿时代明显晚于铅锌矿。初步的地质-地球化学研究表明:铅锌矿床形成于具高水岩比、高卤化物和高盐度特征的海底沉积喷流系统;此时,大多数的金迁移至低温热液柱中并在沉积物中初始富集。在后期(岩浆-)变质-构造作用过程中,金被转移至中高温、低水岩比和低卤化物活度的变质流体中,在有利的构造部位发生沉淀,在同一构造单元内成矿流体的成分和循环方式的差异引起金与铅锌矿床共存和分离。金与铅锌矿床的这一时空分布关系可被视为重要的勘查标志。根据金与铅锌矿化的时空关系,笔者提出应加强对我国元古宇宙裂谷、晚古生代拗陷内重要铅锌矿田的金、铅锌矿的勘查工作。 相似文献
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本文从历史的角度探讨地质科学与勘查找矿的关系。十九世纪中叶以前,地质学家并不找矿视为其工作范畴内的事情。然而,随着地质科学理论体系的成熟和发展,其知识和思想方法已广泛应用于勘查找矿,并且随着找矿难度的加大,勘查找矿越来越离不开地质科学理论的指导。勘查找矿的新发现、新成果也在不断地促进成矿理论的更新。同时也要避免迷信、盲从新理论和贬低地质理论在勘查找矿中的作用的两种错误倾向。 相似文献
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鄂尔多斯盆地镇泾区块长8致密砂岩储层普遍发育钙质夹层,本文利用露头、岩芯、薄片及测井等资料,对钙质夹层的岩性特征、电性特征、分布规律以及与天然裂缝分布的关系进行了研究。研究表明,钙质夹层具有明显的低伽马、低声波时差、高密度、高感应的特点,电成像测井表现为明显的亮色条带。钙质夹层主要分布在部分水下分流河道砂体的中部或下部及河口坝砂体的中部或上部,同时也发育在一些分选较好、颗粒支撑的薄层细砂岩中以及砂泥岩的接触地带。钙质夹层内主要发育高角度构造裂缝,不发育近水平成岩裂缝;与非钙质胶结致密砂岩储层相比,钙质夹层脆性较大,天然裂缝更为发育,且大部分裂缝被方解石充填,为无效裂缝;钙质夹层层厚及岩性界面控制着裂缝纵向延伸高度。论文成果对进一步研究致密储层天然裂缝的分布模式,弄清裂缝对注水开发的影响具有重要意义。 相似文献
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Variation Characteristics of Ambient NMHCs at Shangdianzi and Lin'an Regional GAW Sites 总被引:2,自引:1,他引:2 下载免费PDF全文
In order to study the variation characteristics of concentration of the atmospheric non-methane hydrocarbons (NMHCs) in background area of China, the atmospheric concentrations of NMHCs were measured at Lin'an (LA) regional GAW (Global Atmosphere Watch) Station (30°25'N, 119°44'E; 132.0 m ASL) and Shangdianzi (SDZ) regional GAW Station (40°19'N, 117°07'E; 286.5 m ASL) with the sorbent sorp-tion/thermal desorption/gas chromatographic method. Totally 145 samples were collected during the period of October 2003 and July 2004. Among the 52 NMHC species of C2-C10 detected there were 26 alkanes, 17 alkenes, and 9 aromatics. The average concentrations of total NMHCs (TNMHCs) at LA and SDZ were (238.5±126.0)×KT9C and (278.7±185.5)x10-9C, respectively. The results showed the ambient concentrations of TNMHCs at LA regional GAW Station increased notably over the last decade. The compositions of NMHCs at SDZ and LA were relatively similar. The proportions of alkanes, alkenes, and aromatics for SDZ and LA were hi ranges of (27.3±4.0)%, (10.3±3.5)%, and (62.5±4.8)%, respectively, with features of vehicle exhaust emissions. The concentrations of NMHCs at the two sites showed obvious diurnal and seasonal variations. The TNMHC concentrations in October-November were high at the two sites, and relatively low in April and July. The diurnal variation patterns at the sites were different. The high TNMHC concentrations at SDZ normally appeared in evening and night, but appeared in morning at LA. The TNMHCs concentrations at the two sites were significantly influenced by the meteorological condition. The high TNMHC concentration associated with the local wind from the urban areas or traffic in upper reaches. 相似文献
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同心式射流泵在深层井点降水中的应用 总被引:1,自引:1,他引:1
本文比较了几种深层干扰降水的特点,就国内深层降水设备存在的问题,有针对地研制了同心式射流泵井点降水系统,该系统利用喷射泵真空和排出口压力提升地下水,其降水深度大,集水效果好,出水量稳定,速度较快,设备结构简单可靠,解决了深大基坑砂、粘土地层中干扰降水的问题。 相似文献
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