辽东古元古代镁质非金属矿床成矿系统研究

辽东地区古元古代裂谷里尔峪组和大石桥组中分别分布有富镁质的碳酸盐岩建造, 其中产有硼矿、菱镁矿、滑石、岫岩玉等大型-特大型矿床.这些镁质非金属矿床的形成先与古元古代的蒸发岩系有关, 然后经历了吕梁期区域变质和热液交代变质改造, 以及印支、燕山期构造-岩浆作用改造等成矿系统作用过程.其中, 镁质碳酸盐岩建造、成矿构造、成矿流体对镁质非金属矿床的形成起着重要的控制作用.这些矿床也是古元古代矿源场、流体场、热场(能量场)、应力场等在一定的时空条件下耦合和后期构造-岩浆作用叠加改造的综合产物.      

Emanation-Sedimentary Metallogenic Series and Models of the Proterozoic Rift in the Kangdian Axis

The Kangdian axis basement can be divided into two tectonic layers. The lower tectonic layer is the crystalline basement which is made up of the Archaean Dibadu Formation and early Proterozoic Dahongshan Group. The former is a kata-metamorphic basic volcano-sedimentary formation of the old geosyncline (old continental nucleus), and the latter is a medium-grade metamorphosed alkali-rich basic volcanic (emanation)-sedimentary formation of the Yuanjiang-Dahongshan marginal rift. They are in disconformable contact. The upper tectonic layer is the folded basement, and made up of the middle-late Proterozoic Kunyang Group. It is the result of Dongchuan-Yuanjiang intercontinental rifting with discordant contract with the underlying and overlying strata. Along with the evolution of Proterozoic from early to late, four types of emanation-sedimentary deposits in the Kangdian axis rift were formed in turn: (1) emanation-sedimentary iron-copper-gold deposits related to basic volcanic rocks in the Yuanmou-Dahongshan     

Sedimentology of Proterozoic cratonic sheet sandstones of the eastern Canadian Shield: Sims Formation,Labrador, Canada

The upper lower Proterozoic to middle Proterozoic Sims Formation rests unconformably on lower Proterozoic strata of the Knob Lake Group of the Labrador Trough sequence. The 700 m-thick Sims Formation consists of basal fluvial arkoses and conglomerates (about 100 m) and an upper sheet-like sand body (about 600 m thick) composed of quartz arenites and minor quartz-clast conglomerates. This upper unit is interpreted as beach, shoreface, tidal and shallow-shelf deposits. The lowest 70 m of the quartz arenite unit appear to be of fluvial origin, but probably were formed by reworking of quartzose sands produced in coastal environments during a period of elevated sea level.The lower Sims Formation probably represents molasse shed from either the Hudson or Labrador orogens. Rivers flowed northwest away from these upland areas. The upper part of the Sims Formation records deposition during a period of slow, steady sea-level rise in an ocean that deepened to the west.The Sims Formation outliers are remarkably similar to outliers of the Sakami Formation of northern Quebec, a unit that has a poorly-constrained early to middle Proterozoic age. If these units are correlative, a hypothesis supported mainly by identical facies and facies sequences, then the transgressive quartz arenites would originally have covered an area of at least 200 000 km².     

Rhenium (Re)–Osmium (Os) geochronology of the Proterozoic Sirban Limestone Formation,NW Himalaya

The Proterozoic Sirban Limestone Formation (SLFm) exposed in a number of inliers in Jammu (India), NW Himalaya is a potential target for hydrocarbon and ore mineral exploration. The structural complexity not only makes correlation of the SLFm with coeval hydrocarbon producing Proterozoic formations in the neighbouring Salt Range in Pakistan and elsewhere in the world extremely difficult, but also limits the understanding of the genesis of sedimentary hosted mineral deposits. The base of the SLFm inliers is not exposed anywhere in the region and the age of this sequence has been suggested to range from Palaeoproterozoic to Neoproterozoic.     

吉林延边安图县海沟地区海沟岩群的建立及其意义

吉林延边安图县海沟地区的海沟岩群系1/5万区域地质调查新建的特殊岩石地层单位(Speciallithostrati-graphicunits),由3个岩组构成:团结岩组为碎屑岩夹大理岩;东方红岩组为一套中酸性火山熔岩及其火山碎屑岩夹凝灰质砂岩;四岔子岩组为一套含铁岩系,主要由黑云变粒岩、斜长角闪岩夹磁铁石英岩组成。三者的接触关系均为断层接触,而且四周为元古代、早古生代的花岗岩所侵吞,属华北板块北缘东段残留的的构造岩片堆积产物,其时代为中元古代。这个岩组的建立,对探讨华北板块北缘东段中元古代地层划分和对比、陆缘裂谷的形成演化与成矿作用的关系以及新元古代Rodinia超大陆的形成等均具有重要的意义。     

豫西南地区铅锌银沉积建造地球化学特征

通过对豫西南地区中元古界官道口群、上元古界栾川群与铅锌银有关的沉积建造中元素含量分布、表生富集特征及综合地球化学异常特征的研究, 认为官道口群、栾川群是铅锌银矿的矿源层, 并指出龙家园组、南泥湖组、煤窑沟组是寻找与官道口群碳酸盐岩和栾川群碎屑岩-碳酸盐岩沉积建造有关的层控铅锌银矿床的有利层位。     

Polygenetic Mineralization of the Early ProterozoicTongkuangyu Metaporphyry Copper Deposit inthe Zhongtiao Mountains, Shanxi Province

The Tongkuangyu metaporphyry copper deposit formed in the Early Proterozoic is tectonically located in the northern part of the Zhongtiao X -type palaeorift depression, on the southern margin of the North China platform. The genesis of the deposit has long been a hot subject of research of geologists working on mineral deposits. By means of the protolith reconstruction and fluid inclusion and isotope studies of host rocks of the deposits, the authors hold that this deposit is the product of combined exogenic, endogenic and metamorphic processes. Its formation mainly involved the following four stages: (1) the stage of formation of Mg- and Fe-rich tuffaceous variegated cupriferous sand-shale and K-rich biomodal volcanic rocks; (2) the early stage of formation of the metaporphyry copper deposit; (3) the stage of formation of the metaporphyry copper deposit; and (4) the stage of reworking of the metaporphyry copper deposit.     

国外超大型浅变质细碎屑岩型金矿床的地质特征

国外浅变质碎屑岩型金矿床的含矿岩系以含碳和黄铁矿,夹火山物质和热水沉积物,金含量高为特征.在含矿岩系的沉积、成岩过程中,局部可以形成贫金的含矿层,少数情况下以至于形成金矿体.含矿岩系的变质作用可能形成金矿化,或为后来的成矿作用造成有利的物理和化学环境.岩浆作用为成矿作用提供了部分成矿物质,或为改造成矿作用提供热源和动力.金矿床受构造控制,位于地热正异常区,金矿床的形成与热水沉积成矿作用、变质成矿作用、岩浆期后热液成矿作用和大气降水改造成矿作用等有关.超大型浅变质碎屑岩金矿床的形成过程持续时间长,具有多期多阶段的特点.改造成矿作用在超大型浅变质细碎屑岩型金矿床形成中起重要作用,中生代形成的超大型金矿床中,构造岩浆活化作用叠加十分重要.     

PRINCIPAL GEOLOGIC AND METALLOGENIC FEATURES OF THE MOUNTAINOUS TAYMYR

Within the mountainous Taymry the oldest formations are highly metamorphosed sedimentary and extrusive rocks of Proterozoic age, overlain by less altered rocks of the Sinian complex. These in turn are overlain with angular unconformity by Lower Cambrian deposits, whose age has been determined on the basis of fossils. Paleozoic rocks are widespread, and all systems of the era are represented. Proterozoic rocks occur on the northern coast of the peninsula. The younger Sinian and Paleozoic formations are south and southeast of these. Mesozoic rocks constitute small areas in depressions. Quaternary sediments, consolidated by permafrost, are widely distributed throughout the area. Magmatic activity is well developed. The lower Proterozoic magmatic cycles began with intrusion and extrusion of basic rocks, and ended with granitoid injections accompanied by formation of pegmatitic zones. In the upper Proterozoic, magmatic activity is again characterized in early stages by extrusion and intrusion of basic rocks, and later by the formation of granitic intrusions and their facies, as well as by extrusion of felsite porphyry towards the end of the era. Intrusions of granitoids appeared in the middle Paleozoic. The upper Paleozoic was marked by the formation of traprock and sulfide mineralization. In the early Mesozoic, the occurrence of small subalkaline intrusions resulted in the formation of ores of various types.     

泰国—老挝呵叻高原钾盐矿床研究现状及展望

泰国—老挝境内的呵叻高原马哈萨拉堪组钾盐矿床是世界上最大的钾盐矿床之一。综合研究表明,马哈萨拉堪组赋钾蒸发岩形成于晚白垩世,其成盐物质来自海水。该含盐建造很可能形成于陆相环境中,为"海源陆相"沉积。在蒸发岩沉积过程中及沉积后,一直伴随着水—岩(盐)作用的发生,钾盐沉积之后往往受到该作用的改造。溢晶石的出现是该地区"异常"蒸发岩的表现特征之一,它的形成很可能与海水的变质作用有关,但其形成机制尚未得到合理解释。兰坪—思茅盆地勐野井组与呵叻高原马哈萨拉堪组联系密切且具有共同之处,但二者在时代、成盐期次对比等问题上存在较大争议。最后,针对今后该地区钾盐研究提出了一些新的研究思路与方法。     

澳大利亚西部哈默斯利铁成矿省BIF富铁矿的成矿特征与控矿因素

澳大利亚西部哈默斯利铁成矿省含有世界级高品位的赤铁矿体。主要铁矿床包括芒特维尔贝克、汤姆普莱斯山、帕拉伯杜等,它们均产于元古宙早期布罗克曼BIF型含铁建造中。高品住铁矿体的空间分布明显受到元古宙区域隆起和拉张环境下形成的古老正断层系统的控制。该成矿省高品位铁矿层的形成可分为3个阶段：第1阶段为深层阶段,该阶段硅从含铁建造中淋滤出来,留下薄层状富含铁氧化物、碳酸盐岩、硅酸镁和磷灰石的残余物;第2阶段为深部大气水氧化阶段,该阶段含铁建造的磁铁矿-菱镁矿组合被氧化为赤铁矿-铁白云石,并以发育假象赤铁矿为特征;第3阶段为浅层风化作用。通过对成矿特征和成矿模式的总结,认为成矿时代、断层、褶皱等构造特征及流体和表生风化作用是富铁矿床形成的主要控矿因素。     

扬子地台西缘铅锌矿床分布规律及矿源层探讨

为探索川滇黔相邻区铅锌矿床之成因规律,提升成矿理论认识及预测找矿效果,通过对区内铅锌矿床分布规律研究得出如下认识:1)发现矿床(点)之集群分布趋势,据此将成矿区域划分为3个矿集区;2)统计发现,震旦系和石炭系具有较高的成矿机率(51.57%),灯影组和摆佐组汇聚了区域80.98%的金属量;3)构造单元分级控制了成矿单元展布,而矿集区与二级构造单元之间具有不完全的对等性,矿集区Ⅰ、Ⅱ由康滇地轴和龙门山拗陷及二者向上扬子区域跨越地带联合控制;4)根据菱(赤)铁矿与铅锌矿空间耦合,以及菱(赤)铁矿伴生铅锌元素、铅锌矿物含量均较高等现象,论证了在盆地演化早期,古陆边缘拗陷带(或海盆)内之次级单元代表了浅海环境之低能较深水凹(断)陷或海湾环境,沉积了古生界志留系兰多维列统特列奇阶至下石炭统德坞阶和中元古界下昆阳群(会理群)两套含铁建造,形成了区域Pb、Zn成矿金属元素的初始富集,并于成岩-后生期经热液流体循环改造而成矿,含铁建造提供了成矿的主要矿质来源;5)本区成矿物质硫源-膏盐层主要赋存于灯影组和摆佐组下伏地层以及寒武系多个层位;6)矿源层、硫源共同决定了矿集区以及层控的形成机制,并成为控制其分布的决定性因素。     

印度南部元古代Cudappah盆地白云岩中的菱镁矿成矿作用及其构造-气候指示意义

Cudappah盆地是位于印度南部的一个元古代盆地，盆地中含有许多矿床，包括菱镁矿和滑石矿。该盆地发育于Chat活动带东部边缘，并发育沙质、粘土质和碳酸盐岩的多期重复沉积旋回。盆地可划分为四个次级盆地，即Papaghni、Nallamalai、Srisailam和Kurnool次级盆地。晶质菱镁矿床赋存于Papashni次级盆地的Vempalli组地层中。每个次级盆地很可能都沿着一系列裂谷中的断块发育，并且这些裂谷形成于中元古代的热事件。每个沉积旋回中发育有相似的沉积岩套表明，在盆地演化过程中具有相同的构造和气候环境。根据盆地中矿床(重晶石矿、菱镁矿和滑石矿)的产出，我们对每个次级盆地均提出了一个多期重复沉积旋回的演化模式，该旋回包括了从角砾岩到白云岩的变化。     

The stages and duration of formation of gold mineralization at copper-skarn deposits (Altai–Sayan folded area)

Gold mineralization at copper-skarn deposits (Tardanskoe, Murzinskoe, Sinyukhinskoe, Choiskoe) in the Altai–Sayan folded area is related to different hydrothermal-metasomatic formations. It was produced at 400–150 ºC in several stages spanning 5–6 Myr, which determined the diversity of its mineral assemblages. Gold mineralization associated with magnetite bodies is spatially correlated with magnesian and calcareous skarns, whereas gold mineralization in crushing zones and along fault sutures in moderate- and low-temperature hydrothermal-metasomatic rocks (propylites, beresites, serpentinites, and argillizites) is of postskarn formation. Different stages were manifested with different intensities at gold deposits. For example, the Sinyukhinskoe deposit abounds in early high-temperature mineral assemblages; the Choiskoe deposit, in low-temperature ones; and the Tardanskoe and Murzinskoe deposits are rich in both early and late gold minerals. Formation of commercial gold mineralization at different copper-skarn deposits is due to the combination of gold mineralization produced at different stages as a result of formation of intricate igneous complexes (Tannu-Ola, Ust’-Belaya, and Yugala) composed of differentiated rocks from gabbros to granites.     

辽东地区硼矿床区域成矿系统分析

辽东硼矿体受层位控制,呈层状、似层状产出,其形成既与原始火山一沉积作用有关,又遭受多期次变质变形及热液的叠加改造,以及印支、燕山期构造一岩浆作用改造等作用过程,矿床为“火山（热水）沉积一变质热液叠加改造”的多期多成因层控矿床。认为多期多阶段变质热液形成与矿集区具有不同成矿有利性质的岩石之间发生的交代作用所引起的各种成矿...     

http://dx.doi.org/10.1016/j.gsf.2015.11.003

Banded iron formations(BIFs) are major rock units having hematite layers intermittent with silica rich layers and formed by sedimentary processes during late Archean to mid Proterozoic time. In terrestrial environment, hematite deposits are mainly found associated with banded iron formations. The BIFs in Lake Superior(Canada) and Carajas(Brazil) have been studied by planetary scientists to trace the evolution of hematite deposits on Mars. Hematite deposits are extensively identified in Meridiani region on Mars. Many hypotheses have been proposed to decipher the mechanism for the formation of these deposits. On the basis of geomorphological and mineralogical studies, aqueous environment of deposition is found to be the most supportive mechanism for its secondary iron rich deposits. In the present study, we examined the spectral characteristics of banded iron formations of Joda and Daitari located in Singhbhum craton in eastern India to check its potentiality as an analog to the aqueous/marine environment on Mars. The prominent banding feature of banded iron formations is in the range of few millimeters to few centimeters in thickness. Fe rich bands are darker(gray) in color compared to the light reddish jaspilitic chert bands. Thin quartz veins(4 mm) are occasionally observed in the handspecimens of banded iron formations. Spectral investigations have been conducted in VIS/NIR region of electromagnetic spectrum in the laboratory conditions. Optimum absorption bands identified include 0.65, 0.86, 1.4 and 1.9 mm, in which 0.56 and 0.86 mm absorption bands are due to ferric iron and 1.4 and1.9 mm bands are due to OH/H_2O. To validate the mineralogical results obtained from VIS/NIR spectral radiometry, laser Raman and Fourier transform infrared spectroscopic techniques were utilized and the results were found to be similar. Goethite-hematite association in banded iron formation in Singhbhum craton suggests dehydration activity, which has altered the primary iron oxide phases into the secondary iron oxide phases. The optimum bands identified for the minerals using various spectroscopic techniques can be used as reference for similar mineral deposits on any remote area on Earth or on other hydrated planetary surfaces like Mars.     

The Pre-Sinian Basement and Mineralization on the Western Margin of the Yangtze Paraplatform

The pre-Sinian basement on the southwestern margin of the Yangtze paraplatform consists of threemetamorphic rock series of different ages. Being products of different tectonic events and environments, theydiffer markedly in original rock sequences, metamorphism. tectonic style and characteristics of granitoids andmineral deposits. The Late Archean Kangdian cration mainly comprises the Kangding and Julin Groups with ametamorphic age of nearly 2500 Ma. They are supracrustal rocks dominated by mafic volcanics enclosed introndhjemitic rocks The craton is believed to represent a granite-greenstone terrane of Late Archaean age.There occur mineral deposits such as graphite and kyanite deposits of metamorphic origin, muscovite depositsin pegmatites and gold quartz veins in gneissic granites, banded hornblende-magnetite mineralization and cop-per and zinc mineralizations related to felsic volcanics. Large V-Ti-bearing magnetite deposits were also formedin the mafic. ultramafic stratiform intrusions emplaced on the margins of the craton during the MiddleProterozoic. Copper and nickel deposits are found in several ultramafic intrusions. Extending in a north-southdirection, the Proterozoic mobile belt consists mainly of the Early Proterozoic Hekou Group and MiddleProterozoic Huili and Kunyang Groups. and they are thought to be accumulations in a Proterozoic rift troughor aulacogen. During the Early Proterozoic, the rift trough was characterized by intense volcanism and pres-ence of iron ore deposits of volcano-magmatic type, iron-copper deposits of exhalative-sedimentary type. TheMid-Late Proterozoic of the rift trough mainly witnessed the formation of sedimentary stratiform copper de-posits and submarine sedimentary iron deposits. In the wake of the emplacement of the Jinningian andChengjiangian granites in the Late Proterozoic, skarn-type tin and tin-iron ore deposits were formed.     

中国北方早、中前寒武纪磷矿

中国北方早、中前寒武系磷矿有四个层位六种类型。太古代磷矿主要产于中朝地块内的华北陆核、辽吉南部—朝鲜北部陆核及山东陆核等陆核区。早元古代早期,在太古代陆核边缘或中间地块沉积了优地槽型磷矿。早元古代晚期有大陆边缘和拗拉槽白云质碳酸盐建造的磷矿床与克拉通内盆地陆屑和复理石建造的磷矿床,其中大陆边缘型最重要,构成了长约4000多公里的巨大“S”形成矿带。早元古代末期,五台运动之后,有同造山期的山间盆地磷矿床形成。     

安徽省池州地区区域成矿模式

安徽省池州地区矿床类型主要有矽卡岩型、斑岩型、热液型、风化淋滤型、沉积叠改型等。矽卡岩型是本区主要的矿床类型,根据其成矿特点可进一步分为：层控式、复合式、接触式。,矿床（体）主要赋存在S—O间剥离面奥陶系汤头组、泥盆系顶部层位、泥盆～石炭系界面、石炭系黄龙一船山组、二叠一三叠系碳酸盐地层。燕山早期中酸性岩浆岩、层间滑脱构造、有利成矿的碳酸盐地层、不同方向不同性质的构造结合部位是本区重要的成矿条件。本文在总结前人成果资料的基础上,建立了本区区域成矿模式,将矿床成矿系列主要划分为三个：①与燕山早期钙碱性幔壳同熔型第一次侵入体有关的以W、Mo为主的成矿系列;②与燕山早期钙碱性慢壳同熔型闪长岩类岩体有关的Cu、Fe、S、Pb、Zn、W、Mo、（Au、Ag）成矿系列;③与燕山晚期陆壳改造型富硅富碱花岗岩有关的Ag、Cu、Fe、Pb、Zn多金属成矿系列。     

Manganese deposits: Communication 1. Genetic models of manganese ore formation

Major regularities in the formation of manganese rocks and ores have been established on the basis of available published and original data. The proposed genetic classification of main manganese deposits (with model examples) is as follows: sedimentary-diagenetic (Nikopol, Bol’she-Tokmak; Ukraine), (volcanogenic) hydrothermal-sedimentary (deposits of the Atasui area, Kazakhstan; Magnitogorsk Trough, South Urals), epigenetic (catagenetic) (deposits of the Kalahari manganese ore field, South Africa; Usinsk deposit, Kuznetsk Alatau), and supergene (residual, infiltrational, cavern filling, and pisolitic deposits in India, Brazil, South Africa, and Australia). The results suggest the following conclusions: (1) all primary manganese rocks and ores at the known deposits are hydrothermal- and diagenetic-sedimentary formations of marine environments; (2) manganese concentrations achieve the size of deposits at postsedimentary stages of the initial manganiferous sediment and manganese rock transformation (diagenesis, catagenesis, and retrograde diagenesis); (3) indispensable participation of the isotopically light carbon dioxide related to the destruction of organic matter (OM) is a characteristic feature of manganese carbonate formation during diagenesis; and (4) the role of organic carbon in manganese ore formation becomes notable since early stages of Mn accumulation in the Precambrian sedimentary basins (terminal Archean-initial Early Proterozoic).