深部矿产资源立体地球化学勘查方法技术体系     

史长义  王惠艳 《地质学报》2022,96(11):3705-3721

深部矿产资源的勘查是战略性矿产资源勘查的一个重要方面。找矿实践证明，化探方法技术在矿产勘查乃至深部找矿中发挥了重要的、不可或缺的作用。找矿工作的不断深入和找矿难度的不断加大，促使化探方法技术不断的发展和完善，在传统方法技术的基础上，研发出了许多新的方法技术。本文从方法论和系统论的角度出发，对现有的找寻深部隐伏矿盲矿的有效化探方法技术进行了系统的归纳和总结，提出了立体地球化学勘查方法技术体系的概念，将立体地球化学勘查方法技术划分为地面地球化学测量方法技术和地下地球化学测量方法技术，建立了深部矿产资源立体地球化学勘查方法技术体系。不同的方法技术有不同的优势和不同的适用条件，实际工作中应当根据不同的勘查阶段，不同的勘查目的和不同的地质地球化学条件选择不同的立体方法技术组合才能发挥出最大效益，取得最大效果。  相似文献   

中国南方离子吸附型稀土矿床成矿类型及其母岩控矿因素探讨     

付伟  赵芹  罗鹏  李佩强  陆济璞  周辉  易泽邦  许成 《地质学报》2022,96(11):3901-3923

传统认为中国南方的离子吸附型稀土矿床可划分为以“足洞式”为代表的重稀土型和以“河岭式”(或“花山式”)为代表的轻稀土型两种矿化类型。然而，近年来发现的许多矿床(如清溪、寨背和馒头山等)的赋矿风化壳中出现了轻稀土矿与重稀土矿并存现象，表现出特殊的“上轻下重”双层矿体结构。这指示了除重稀土型和轻稀土型之外，还存在着轻重稀土共生型的过渡类型。本研究通过对三种不同成矿类型的若干典型矿床系统对比，指出成矿类型的多样性与母岩性质密切相关，尤其是母岩的稀土元素地球化学和稀土载体矿物属性是制约成矿类型变化的关键因素。统计数据表明，从重稀土型→轻重稀土共生型→轻稀土型，成矿母岩的全岩稀土总量变化不大(ΣREY: 200×10-6~450×10-6→200×10-6~500×10-6→200×10-6~800×10-6)，但轻重稀土配分值出现较显著的区间性差异(ΣLREE/ΣHREY: 02~1→1~5→2~10)。与之同时，母岩中能为离子相稀土提供物源且具有重稀土配分属性的稀土副矿物类型和数量明显减少，这与全岩稀土元素地球化学特征中重稀土分量占比的降低趋势也互相匹配。该结果指示，以往认为重稀土配分母岩形成重稀土矿床、轻稀土配分母岩形成轻稀土矿床的传统观点需要外延，即一部分具有低度轻稀土配分属性(1＜ΣLREE/ΣHREY＜5)且含有丰富易风化稀土副矿物的母岩还可能形成轻重稀土共生型矿床，该认识可为今后离子吸附型稀土矿床勘查工作提供新的找矿依据。  相似文献   

北京云蒙山地区花岗岩穹隆及伸展构造的探讨   总被引：9，自引：0，他引：9  

张建新  曾令森 《地质论评》1997,43(3):232-240

北京云蒙山花岗岩为一中生代侵入的花岗岩穹隆,花岗岩穹隆的叶理普遍发育,叶理轨迹基本平行于穹隆的外部边界,并显示出从核部到边部逐渐增强,东南侧明显强于西北侧的特点。变形构造研究显示,花岗岩穹隆的边部及围岩中普遍存在不同层次及不同运动方向的伸展构造。东南侧以具河防口－水峪伸展型韧性剪切带为特征,剪切运动标志显示为从ＮＷ－ＳＥ的正剪切运动,有限应变分析估算其剪切位移量在１０ｋｍ以上,剪切带上部被河防口正  相似文献   

High-resolution sequence stratigraphy of the Lower Triassic ‘Buntsandstein’ in the Netherlands and northwestern Germany     

Geluk  M.C.  Röhling  H.-G. 《Geologie en Mijnbouw》1997,76(3):227-246

Detailed log correlations of the largely fluvio-lacustrine Lower Triassic Buntsandstein (Late Permian-Early Anisian), carried out on 80 wells in the Dutch onshore and offshore areas, can be linked to northwest-German high-resolution sequence stratigraphy. The correlations show that cyclic sedimentation occurred in large parts of the basin. Seven 1st-order sequences are recognised, namely the Main Claystone, Rogenstein, Volpriehausen, Detfurth, Hardegsen, Solling and Lower Röt Sequences. They are overlain by the lower part of the Upper Röt–Lower Muschelkalk Sequence. Distinct sequence boundaries have been identified at the bases of four sequences: Volpriehausen, Detfurth, Solling and Upper Röt. The higher-order sequences consist of fining-upwards cycles with a thickness of up to tens of metres. The sequences are laterally persistent and have a characteristic expression on gamma-ray and sonic logs. In the Lower Buntsandstein, they display a uniform character throughout most of the area, with only minor differences in thickness or lithology. NNE-oriented lows and swells were formed during deposition of the Volpriehausen, Detfurth and Hardegsen Sequences. Uplift prior to the deposition of the Solling Sequence caused deep erosion on the swells in the basin and minor erosion in the lows. The high-resolution sequences probably represent alternating, relatively wet and dry climatic periods, with a periodicity of about 100 000 years. An analysis of the sequences suggests that their reduced thickness on the swells is mainly the effect of erosion. This is supported by analyses of the accumulation patterns and rates.  相似文献   

Sector collapse,sedimentation and clast population evolution at an active island-arc volcano: Stromboli,Italy   总被引：1，自引：0，他引：1  

P. Kokelaar  C. Romagnoli 《Bulletin of Volcanology》1995,57(4):240-262

Sciara del Fuoco is the subaerial part of a partially filled sector-collapse scar that extends to 700 m below sea level on Stromboli volcano. The collapse occurred <5000 years ago, involved 1.81 km³ of rock and is the latest of a series of major collapses on the north-west flank of Stromboli. A north-east trending arc-axial fault system channels magmas into the volcano and has caused tilting and/or downthrow to the north-west. The slope of the partial cone constructed between the lateral walls of the collapse scar acts as a channelway to the sea for most eruptive products. From 700 m below sea level and extending to >2200 m and >10 km from the shore to the NNW, a fan-shaped mounded feature comprises debris avalanche deposits (>4 km³) from two or more sector collapses. Volcaniclastic density currents originating from Sciara del Fuoco follow the topographic margin of the debris avalanche deposits, although overbank currents and other unconfined currents widely cover the mounded feature with turbidites. Historical (recorded) eruptive activity in Sciara del Fuoco is considerably less than that which occurred earlier, and much of the partial fill may have formed from eruptions soon after the sector collapse. It is possible that a mass of eruptive products similar to that in the collapse scar is dispersed as volcanogenic sediment in deep water of the Tyrhennian basin. Evidence that the early post-collapse eruptive discharge was greater than the apparent recent flux (2kg/s) counters suggestions that a substantial part of Stromboli's growth has been endogenous. The partial fill of Sciaria del Fuoco is dominated by lava and spatter layers, rather than by the scoria and ash layers classically regarded as main constituents of Strombolian (cinder) cones. Much of the volcanic slope beneath the vents is steeper than the angle of repose of loose tephra, which is therefore rapidly transported to the sea. Delicate pyroclasts that record the magmatic explosivity are selectively destroyed and diluted during sedimentary transport, mainly in avalanches and by shoreline wave reworking, and thus the submarine deposits do not record well the extent and diversity of explosive activity and associated clast-forming processes. Considerable amounts of dense (non-vesicular) fine sand and silt grains are produced by breakage and rounding of fragments of lava and agglutinate. The submarine extension of the collapse scar, and the continuing topographic depression to >2200 m below sea level, are zones of considerable by-passing of fine sand and silt, which are transported in turbidity currents. Evidently, volcanogenic sediments dispersed around island volcanoes by density currents are unlikely to record well the true spectrum and relative importance of clast-forming processes that occurred during an eruption. Marine sedimentary evidence of magmatic explosivity is particularly susceptible to partial or complete obliteration, unless there is a high rate of discharge of pyroclastic material into the sea.  相似文献   

坡地农林复合系统的结构类型与效益分析─以长江三峡库区坡地农业为例   总被引：4，自引：0，他引：4  

申元村  彭业轩 《地理研究》1995,14(3):43-51

本义认为现代术语的农林复合系统来源于生产实践,体现了农业与林业的有机结合、品种生态和经济的有机结合、产品多样化以及管理科学化4个方面相统一的特点。文章在分析三峡库区农林复合系统的类型结构基础上,提出了农林复合系统可以进行层次结构划分的观点。最后,以典型案例研究方法入手,对1种农林结构类型进行效益分析,结果表明,采用植物篱农林复合坡地系统,是现阶段生产力水平下实现坡地生态经济协调发展的有效途径,值得广泛推广。  相似文献   

A multivariate statistical and geostatistical study on the geochemistry of allochtonous karst bauxite deposits in Hungary     

Bárdossy  George  Kovács  Ó. 《Natural Resources Research》1995,4(2):138-153

A geochemical evaluation of the Szc-Halimba-Kisld area, Hungary, covering an area of more than 200 km² is presented using different statistical and geostatistical methods. The study area is a representative example of allochtonous karst bauxite accumulation. The three groups of deposits studied here have been explored and mined since 1950. Several thousand boreholes have been drilled, and bauxite cores were analyzed for the five main chemical components. A total of 80,000 pleces of analytical data were processed, followed by a geological examination of borehole logs and of mining excavations.The quantitative geochemical evaluation of the data set led to both geochemical and practical results: The geochemical behavior of the allochtonous, clastic karst bauxite deposits differs essentially from that of the autochtonous and parautochtonous ones, as well as that of the lateritic bauxite deposits. The deposits of the study area can be split into several subsequent geochemical-sedimentological units, each representing an event of bauxite transport and accumulation. Clear regional patterns can be revealed in the composition of these units. The geostatistically measured chemical variability of the geochemical units is rather different, the lowest units showing the smallest variability. The interrelations of the main chemical components are weaker and more irregular in the studied deposits than in the autochtonous lateritic bauxite deposits. Additional local genetic features, such as transport routes, can be delineated by the methods applied. Within each deposit, local changes of chemical composition and of its variability can be determined more precisely. These results can be used in bauxite prospecting and exploration, because areas of high or low bauxite quality can be predicted.  相似文献   

冀西北长城纪宣龙式铁矿层中微体植物化石的发现及其意义   总被引：10，自引：0，他引：10  

杜汝霖  刘志礼 《地质论评》1992,38(2):184-189

本文研究的是笔者等在冀西北长城系串岭沟组宣龙式铁矿层中发现的微体植物化石,这些化石都保存在铁质叠层石(肾状赤铁矿)和铁质核形石(鲕状赤铁矿)的基本层中。微化石以丝状体为主,部分为球状体。归属于原核生物蓝藻门颤藻科的两个属和色球藻科的一个属。化石层同位素年龄约在1800—1757Ma。这些化石与北美冈弗林特组微化石比较,既有些相似,又有些区别。该化石的发现为研究铁矿的成因,指示沉积环境及层位对比都很有意义。  相似文献   

漳州热田的对流热流和传导热流的研究   总被引：5，自引：1，他引：4       下载免费PDF全文

熊亮萍  汪集YANG 《地球物理学报》1990,33(6):702-711

漳州地热系统属对流型地热系统.漳州热田是我国东南沿海地区目前所见热田中温度最高（121.5℃）的一个.地表热流值的研究表明,热田中心具有最大的实测热流值（359mw/m²）.本文根据热田内152个钻孔的测温资料和56块岩石样品的热导率数据,采用三种不同方法计算出漳州热田及其邻近地区的大地热流值,并讨论了热流值分布的特点.  相似文献   

Visualization experiments of iron precipitates: Application for in-situ arsenic remediation     

M.I.M. Darwish  V.M. van Beek  J. Bruining 《Journal of Geochemical Exploration》2006,88(1-3):19

Laboratory experiments were carried out to acquire more insight and understanding of the phenomena associated with the in-situ arsenic remediation. Visualization techniques are the most informative for the detection of Fe(II) while flowing in soils. Green Rust (GR) was considered as representative of in-situ iron precipitates. In a visualization flat cell, the change in color of GR to orange, due to oxidation, was monitored by a digital camera and the images were analyzed giving the spatial and temporal distribution of Fe(II). Moreover, both oxygen and pH changes in time were recorded in two sections along the flow direction in the cell. The measured and calculated concentration profiles were compared and the actual reaction rates were predicted. The reaction rate constants measured in this study, under flowing conditions, are in a good agreement with the values obtained from batch experiments reported in the literature.  相似文献