114铀矿床地质特征及成矿作用

114矿床位于南岭伟向构造带大东山-贵东亚带,粤北山字型西翼,系产于碳酸盐岩断裂带中的中低温热液充填交代单铀矿床。铀矿体主要产于石炭纪和二叠纪地层中,受新华夏系北西向张性构造复合早期构造带控制。     

Ore Mineralization in Pleistocene Sediments of Long Strait (East Siberian Sea)

Doklady Earth Sciences - A mineralogical–geochemical study of Late Pleistocene bottom sediments of the LV 77-10 core collected in the central part of Long Strait was carried out. Two horizons...     

湘西层控白钨矿床地质特征及其成矿作用

湖南西部层控白钨矿床,主要分布于江南地轴西缘雪峰弧形构造带的东段和中段,贼存于元古界板溪群浅变质的硅铝质碎屑岩内。矿床的空间分布总是与特定的地层层位联系在一起,其下常有不整合面或假整合面存在,地层控矿的专属性是这类矿床的重要地质特征。区内东西向、北东向构造的转折或复合部位,以及主干断裂旁侧的羽状断裂带,是矿床的主要控矿构造:而矿化强度则受到岩石物理性质和化学成分的制约。矿体具有多层性,多数为盲矿体。成矿作用是在区域地层具有较高的初始钨丰度基础上发生的。区域变质作用或花岗岩浆侵入是成矿物质活化转移的主要热源。成矿流体为低盐度、中低温度,以变质水为主并有大气循环水加入的混合热液。硫同位素组成具变质硫特点。属于变质热液成因的层控白钨矿床。     

相山铀矿田邹家山矿床成矿流体特征

通过流体包裹体的岩相学研究、显微测温和激光拉曼探针测试,探讨了邹家山铀矿床成矿流体特征、演化及矿质沉淀方式。研究结果表明,该矿床的成矿流体为中低温热液,碳氢化合物对铀的富集具有不可忽视的作用,流体持续的沸腾作用是矿质沉淀的主要因素。     

Structural evolution of Mesozoic complexes in Western Chukotka

Detailed structural investigations were carried out in the Pevek area in order to verify the tectonic evolution of the Mesozoic thrust and fold belt in Chukotka. South-vergent F₁ folds in Triassic rocks were proved to be the earliest structures formed during the first deformation stage DI. These structures were deformed by north-vergent folds F₂ that were formed during the second deformation stage DII. North-vergent folds are the main structures of the Jurassic–Lower Cretaceous complex. The fold structures of the first two stages are deformed by shear folds F₃ finishing the stage DII. All these structures are deformed by submeridionally trending normal faults referred to the deformation stage DIII.     

Features of Ore Formation of Gold Deposits of the Glukharinskii Ore Cluster (Cis-Kolyma Terrain)

Doklady Earth Sciences - This paper reports on new data on δ34S and δ18O isotopy for trace and rare-earth elements of the Au deposits of the Glukharinskii ore cluster. The geochemical...     

Zircon from Intraplate Gabbroic Rocks of Western Chukotka (Anyui Plutonic Complex) and Interpretation of Its Age

Doklady Earth Sciences - The timing of intraplate magmatism in Western Chukotka manifested in the formation of gabbroic rocks of the Anyui plutonic complex of the Anyui–Chukotka fold belt is...     

鲁西归来庄金矿田成矿系列及成矿作用研究

归来庄金矿田内金矿化类型较多,主要由隐爆角砾岩型、镁质碳酸盐岩微细浸染型、含铁矽卡岩上叠加型、斑岩型和破碎带蚀变岩型等多种类型的矿床(点)组成。在成因上均与铜石富钾碱性潜火山杂岩关系密切,岩浆活动为成矿提供了热液和热源。杂岩体构成的潜火山穹隆及伴生的环状放射状构造,控制着矿体的分布。新太古代泰山岩群为主要矿源层;寒武纪朱砂洞组上灰岩段之碳酸盐岩是磨坊沟金矿的有利含矿层位;寒武系上部—奥陶系下部的白云质灰岩、白云岩等是归来庄金矿的有利围岩。矿田内与中生代燕山早期中偏碱性潜火山杂岩有关的金（铜、铁)成矿亚系列多种类型金矿化相伴产出,受潜火山穹隆的控制,它们生成于不同深度不同地质构造部位,赋存于不同的地质体中,是在铜石潜火山中低温热液成矿系统中生成的金矿类型组合。每一矿床都是统一的成矿模式中的一个个体,它们构成了一个较完整的成矿亚系列。     

Exfiltrative Mineralization in the Bukantau Ore District (Central Kyzyl Kum Region,Uzbekistan)

Manganese and gemstone (turquoise and cacholong) deposits of the central Kyzyl Kum region formed during the development of the sedimentary cover. Aggressive metal-bearing fluids were formed within the cover due to equilibration of sediments. Tectonic reactivation of the region resulted in the formation of erosion windows in the sedimentary cover and ascending gleyey (H₂S-free) solutions were discharged within the erosion windows. Various geochemical barriers in near-surface zones favored the concentration of Mn, gem-stone-forming elements, and associated components. Their virtually simultaneous deposition from the same ore-forming fluids at different geochemical barriers was responsible for the differentiation of mineralization in the cross section. Processes of recent activation migrated from the southeast to northwest with the successive formation and erosion of ephemeral manganese and gemstone deposits in the same direction. At present, only the youngest deposits located in the northern central Kyzyl Kum region are sufficiently well retained.     

Deformations and Structural Evolution of Mesozoic Complexes in Western Chukotka

Detailed structural investigations have been carried out in the Pevek district to specify tectonic evolution of the Chukotka mesozoids. The earliest south-verging folds F1 formed in Triassic rocks at the first deformation stage DI. These structures are overlapped by the northern-verging folds F₂ and overthrusts pertain to the second deformation stage DII. Folding structures F₁ and F₂ were deformed by shear folds F₃, completing stage DII. The DI and DII structures are complicated by roughly NS-trending normal faults marking deformation stage DIII. It has been established that DI is related to the onset of opening of the Amerasian Basin in the Early Jurassic, or, alternatively, to the later accretion of the Kulpolnei ensimatic arc toward the Chukotka microcontinent. DII marks the collision of Siberia and the Chukotka microcontinent in the Late Neocomian. Normal faulting under the roughly E–W-trending extension during DIII is likely related to rift opening of the Podvodnikov and Makarov–Toll basins in the deep Amerasian Basin. Formation of the Okhotsk–Chukotka volcanoplutonic belt completed the structural evolution of the studied region.     

Geochronology and Ore Mineralization of the Dzheltula Alkaline Massif (Aldan Shield,South Yakutia)

The Dzheltula alkaline massif is located in the Tyrkanda ore region of the Chara–Aldan metallogenic zone of the Aldan–Stanovy Shield (South Yakutia). The region contains separate placer gold objects, which are being explored at the present time, and ore-bearing Mesozoic alkaline intrusions, which are weakly studied due to their poor accessibility. The Dzheltula massif (DM) is the largest exposed multiple-ring intrusion within the Tyrkanda ore region; therefore, it is considered as a typical object for geological, petrological, geochronological, and metallogenic studies. The DM consists of five magmatic phases of syenite composition. ⁴⁰Ar–³⁹Ar dating has established that the crystallization age of the oldest phase, the leucocratic syenite porphyry (pulaskite), is 121.1 ± 1.3 Ma. The crystallization age of the cross-cutting phases represented by syenite–porphyry dikes (laurvikites and pulaskites) ranges from 120.1 ± 2 to 118.3 ± 2.1 Ma. The youngest phase of the massif, trachyte, crystallized at 115.5 ± 1.6 Ma. According to the mineralogical and geochemical studies, two types of ore mineralization, namely gold and uranium–thorium–rare-earth (U–Th–REE), are established within the DM. The gold mineralization was found in the quartz–chlorite–pyritized metasomatites. It is confined to the NNE- and NNW-trending fault zones and coincides with the strike of the syenite porphyry dike belt. Uranium–thorium–rare-earth mineralization has been established in the quartz–feldspathic metasomatites localized in the outer contact of the massif. The juxtaposition of mineralization of different types in some zones of the Dzheltula syenite massif significantly increases the ore potential of the studied object within the Tyrkanda ore region.     

Gold Mineralization in the Eastern Tannu-Ola Ore District of the Altai-Sayan Folded Area (Russia)

Please refer to the attachment(s) for more details     

内蒙古朝克温多尔金(铜、钼)矿成矿地质特征

朝克温多尔金(铜、钼)矿是天津地质矿产研究所于2005年在内蒙古阿巴嘎旗西部进行化探异常三级查证时发现的一处多金属矿床.经过两年的地质普查工作,矿区内发现了多条金、铜、钼独立和共生矿(化)体,矿体主要产于二叠系的NW向断裂破碎带中,以盲矿体为主,显示出良好的找矿前景.笔者通过对矿体、矿化蚀变等成矿特征及地球化学特征的分析,初步认为成矿物质来源于深部岩浆,矿床为与岩浆热液有关的、受断裂控制的次火山-热液型金(铜、钼)矿床.     

Age of Detrital Zircons from Sandstones of the Mesozoic Flysch Formation in the South Anyui Suture Zone (Western Chukotka)

The South Anyui fold zone (western Chukotka) is considered a suture zone related to closure of the South Anyui oceanic basin and collision of Eurasia with the Chukotka–Arctic Alaska microcontinent in the Early Cretaceous. The existence of a compensatory sedimentation basin (foredeep) during folding in the terminal Jurassic–initial Cretaceous remains debatable. This work presents first data on age estimates of detrital zircons from Upper Mesozoic terrigenous sequences of the South Anyui suture zone obtained by the fission-track method. The distal flysch of presumably Late Jurassic age and the proximal flysch of probably Late Triassic age were sampled in the Uyamkanda River basin. The fission-track dating showed that sandstones from the flysch sections contain detrital zircons of two different-age populations. Young zircon populations from sandstones of distal turbidites in the upper course of the Uyamkanda River (two samples) are 149 ± 10.2 and 155.4 ± 9.0 Ma old (Late Jurassic), whereas those from coarse-grained proximal turbidites sampled in the lower course of the Uyamkanda River (one sample) is 131.1 ± 7.5 Ma old (Early Cretaceous). The data obtained indicate that the Late Mesozoic folding in the South Anyui suture zone was accompanied by the formation of a marginal sedimentary basin. Sediments accumulated in this basin compose tectonic nappes that constitute a fold–thrust structure with the northern vergence.     

Lower-Middle Triassic rocks in the Enmynveem River (western Chukotka)

The Lower-Middle Triassic section of the Enmynveem River dated on the basis of macrofauna includes three genetic types of sediments with different structural-textural features: (1) sediments of high-density autokinetic flows; (2) sediments of low-density turbidity flows; and (3) background sediments with thin interlayers of fine-grained turbidites. It has been established that sandy-silty sediments of all three genetic types formed on the continental slope in deep-water conditions, but their accumulation was related to the erosion of rocks in various provenances. Some sediments were formed as the result of the erosion of proximal volcanic complexes, whereas other sediments were related to the erosion of metamorphic rocks on the distal continental land.     

相山矿田铀多金属成矿条件分析

相山矿田是我国目前最大的火山岩型铀矿田.我们在铀矿勘探过程中,于相山矿田西部河元背、牛头山等矿区深部陆续发现多金属（Pb、Zn、Ag等）矿化现象,呈现出多金属矿的找矿前景.通过与银山、紫金山等多金属矿区对比分析,认为相山矿田具有良好的铀多金属成矿地质条件.文章对矿田的区域构造背景、深部地质环境、小岩体活动及控矿构造等成矿条件进行了分析,认为在相山矿田的中心部位或深部,可能存在大规模的铜铅锌银等多金属成矿作用.     

胶东半岛西北部金矿带成矿构造应力场及成矿微量元素分布特征研究

本文重点研究成矿构造应力场控制的成矿期构造活动，以讨论矿带范围内构造应力、应变能的分布规律，分析矿液运移、富集成矿的机制，并探讨构造应力与成矿元素分布之间的关系和构造作用中的地球化学过程。     

Specific Features of Geotectonic Development and Ore Potential in Southern Altai (Eastern Kazakhstan)

Geology of Ore Deposits - The article considers the peculiarities in the geotectonic development and ore potential of geological structures in Southern Altai, Eastern Kazakhstan. The territory...