中国某些板内构造与矿床的关系

简要介绍了几种代表性矿床与某些板内构造的关系,其中包括郯庐断裂及其有关矿床、拉分盆地宁芜铁矿、伸展构造与胶东金矿、陆内碰撞造山带与豫西金矿、昆阳裂谷与东川铜矿等,并初步探讨了这些板内构造与板块构造活动的关系及其深部机制。     

川滇黔菱形地块地球物理基本特征及其与内生成矿作用的关系

扬子准地台西南缘是我国重要的成矿区带。通过该区区域地球物理资料(包括重力测量、航空磁测、深反射地震和天然地震资料)的分析整理和编图，发现在扬子地台西南缘存在着一个菱形块体——川滇黔菱形地块，由四条(隐伏)深断裂带所围限。地球物理资料较为清楚地反映了菱形地块的构造格架。西侧重力异常梯度陡变，地壳厚度急剧变厚；内部存在由地幔隆起形成的重力高异常带，隆起带可能是菱形地块在元古宙时期裂解留下的遗迹；沿边界断裂地震活动剧烈而频繁。菱形块体的边界断裂及其内部的隆起带控制着本区的成矿作用，不同时期的矿产在菱形地块内有规律地分布。沿近南北向地幔隆起带分布有元古代沉积-喷流型Fe—Cu矿床，其两侧分布有与晚古生代峨眉山玄武岩有关的铜矿和密西西比型铅锌矿床；沿菱形块体边界分布有新生代与超壳深断裂有关的富碱斑岩型金(多金属)矿床，沿菱形地块内部的南北向深断裂(如小江深断裂)有剪切带型金矿床。不同类型的矿床有时相互叠加形成复合成因的矿床(如东川地区)。这表明，不同时期的构造背景控制着不同类型矿床，同时表明，扬子地台西南缘是一个不够稳定的地块(准地台或活化了的地台)，菱形地块陡变的地球物理特征明显不同于其东侧稳定块体(缓变)。     

滇中易门狮子山铜矿床构造控矿规律

易门狮子山铜矿床是元古宙昆阳裂谷中的典型"东川式"铜矿床,具有层构双控、构造改造明显、多种矿体类型共存的特点.应用矿田地质力学的理论和方法,系统鉴定了主要断裂结构面力学性质,认为矿床受一系列轴向北东向的紧闭倒转复合倾伏褶皱和北东向压扭性断裂的控制,进一步总结了构造控矿特征;经构造筛分,厘定了构造体系,提出北东向构造带是主要控矿体系,该体系的主演化期为晋宁期-澄江期,叠加了印支期的变形,晋宁期-澄江期的改造作用使围岩中铜质活化、转移、富集成矿;概括出"层楼式"、"背斜+断裂"、"多字型"构造控矿型式,为深部隐伏矿定位预测提供了依据.     

安徽宣城铜山构造控矿特点及成矿规律的探讨

笔者通过野外调查和室内分析研究,将宣城铜山矿区构造运动分为五个构造期,並根据构造应力场的变化规律和各种侵入岩受不同构造应力场控制的特征,判别出矿区岩浆演化明显地由超酸性到中基性、超基性的序列,同时论述了矿区构造控矿特征及成矿规列,预测了成矿远景区。 一、矿区区域构造概况 宣城铜山铁、铜多金属矿床位于长江中下游坳陷带南缘,梵峥山——幕阜山基底构造隆起带东段北侧的次级近东西向隆起带上。矿区南东为江南深断裂,北西为句容——青阳深断裂;临近矿区东侧为近南北向的麻姑山——大昆山大断裂,西侧有丹阳湖——水阳江大断裂(见图1)。矿区位于上述深大断裂之间的十里长山复背斜南东翼,故其构造发展和矿     

易门凤山铜矿床控矿型刺穿体和非控矿型刺穿体对比研究

1矿床地质特征凤山铜矿床位于昆阳裂谷中段近SN向的易门裂陷盆地西侧,绿汁江深断裂东侧。矿区主要出露中元古界昆阳群绿汁江组(Pt2lz),为一套厚大的碳酸盐岩建造。受多期构造地质作用影响,矿床严格受刺穿构造控制(如:21#矿体、10#矿体,59#矿体),59#矿体受南部刺穿体控制,F10断裂走向NW,倾向SW,倾角陡,控制了该刺穿体     

东川播卡金矿品位统计学特征及与矿化的关系

东川播卡金矿,位于金沙江与小江夹持的三角成矿带上,为昆阳群中迄今发现的唯一独立大型金矿。矿区出露中元古界昆阳群浅变质岩系。结合近年来勘探成果,收集矿石品位进行统计学研究,探讨品位与矿化关系。     

滇中易门县狮子山铜矿及近外围成矿因素及找矿方向

滇中易门县狮子山铜矿是产于扬子古陆边缘昆阳裂谷易门裂陷盆地内典型东川式层状矿床, 是在昆阳裂谷背景下经同生沉积和二次富集作用而成, 在鹅头厂组、落雪组、因民组等地层中均有不同矿体产出,矿床成因属热卤水沉积型东川式铜矿床。矿床的形成经历了同生阶段、成岩阶段和后生阶段。矿床在同生沉积阶段形成, 成岩阶段固结成岩, 后期的岩浆活动对矿床起到一定富集和改造作用。本文研究认为, 矿床受地层与岩性、岩相古地理、构造、岩浆岩等因素的控制, 通过对矿床成矿要素的分析和总结, 归纳了该区的找矿标志, 提出了矿区本部和近外围的找矿方向和靶区优选。     

新疆晚古生代裂谷中同生断裂的控矿问题

新疆晚古生代裂谷中同生断裂具有明显的控矿作用,体现出"三同一体"和多组断裂构造交会的区域构造特征.以构造的不同级别、期次,对矿带、矿田、矿床予以控制,在构造交会和构造复合地段使矿田或矿床就位.由于构造的近等距性发育,从而制约矿田或矿床的近等距分布,更由于裂谷同生断裂的多次开合和地质动力性质转换,形成了多层次、多形式、多矿种、多类型、且具有矿种分带性的综合矿产链.     

河南嵩县萑香洼金矿床断裂构造控矿特征

萑香洼金矿床产于华北陆块南缘中元古界熊耳群火山岩系中．矿床严格受断裂构造控制。本文根据区域和矿区断裂构造特征，分析了萑香洼金矿床不同构造层次对金矿的控矿作用，总结了断裂构造的控矿特征，认为区域性深大断裂(Fm、Fs、F1)为导矿构造，控制金矿带、矿床的分布；次级的NW向(F985等)和近E-W向(F14等)断裂构造为主要容矿构造，控制矿体的产出；NNE向(F201等)断裂为成矿后构造，起破矿作用。容矿断裂在主成矿期经历了“挤压-拉张”的脉动式活动．具“韧脆性”特征。     

河北省青龙县三家子金矿地质特征及成因探讨

三家子金矿位于冀东金成矿带东部,矿区内分布大量受断裂构造控制的含金石英脉,通过野外和室内研究,确定其成矿物质来源于燕山期岩浆期后热液。这些成矿热液在沿矿区内深大断裂F1向上运移过程中,部分成矿物质在F1断裂沿走向变化处发生沉淀,其它成矿物质在F1断裂派生的次级张裂隙中沉淀。该矿床属于受断裂控制的中低温、岩浆期后热液矿床。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)