西秦岭谢坑矽卡岩型铜金矿床地质特征与矿区岩浆岩年代学研究

谢坑铜金矿床位于西秦岭造山带西段,区域内主要出露下二叠统大关山群和下三叠统隆务河群,构造和岩浆活动发育.岩石学研究表明,谢坑铜金矿区内出露侵入岩主要为辉长闪长岩和辉长岩,它们是岗察岩体的重要组成部分.在辉长闪长岩与二叠纪灰岩接触带部位发育铜金和铁矿化并形成相关工业矿体.矿石类型主要有块状、脉状和浸染状三类.磁铁矿、磁黄铁矿表现为块状,黄铜矿为脉状和浸染状;脉状和浸染状黄铜矿穿插于块状磁铁矿矿石现象十分普遍,含金碳酸盐石英脉主要沿着矿石裂隙发育.围岩蚀变呈现清晰的蚀变分带现象,自岩体向外依次表现为钾化、青磐岩化和矽卡岩化.其中矽卡岩化主要发育于辉长闪长岩与灰岩接触带部位,与成矿关系密切,磁铁矿矿化主要发育于晚期矽卡岩阶段,磁黄铁矿、黄铁矿、黄铜矿等金属硫化物以及毒砂等矿物主要形成于早期硫化物阶段,金矿化主要发育于石英硫化物阶段.LA-ICP-MS锆石U-Pb测年结果表明,辉长闪长岩和角闪安山岩分别形成于243.8±1.0Ma和242.1±1.2Ma.该成岩、成矿时代与区城构造岩浆、成矿事件相一致.这些结果表明,谢坑铜金矿床为与西秦岭中三叠世孤岩浆作用密切相关的矽卡岩型矿床.     

南秦岭黄龙金矿磁黄铁矿标型矿物学特征及含金性研究

南秦岭南部构造带具备较好的金矿成矿条件与成矿背景,是该区域规模较大金矿带.金沟矿段是黄龙金矿床最主要的组成部分,该矿段矿石中磁黄铁矿和黄铁矿发育,其中磁黄铁矿矿石是矿床中含量最高的硫化物矿石.磁黄铁矿存在两种产出状态,分别为早期形成的呈浸染状、团块状分布的磁黄铁矿与晚期形成的脉状磁黄铁矿.成分分析结果表明以单斜磁黄铁矿为主.该矿床属中-低温矿床.微量元素结果显示富Co贫Ni,与金矿化关系密切.在含金性方面,脉状产出的磁黄铁矿优于团块状分布的磁黄铁矿,且脉体越细含金性越好,因此细脉状磁黄铁矿可作为该区重要的找矿标志.     

辽宁东平金矿床地质特征及找矿方向

南秦岭南部构造带具备较好的金矿成矿条件与成矿背景，是该区域规模较大金矿带.金沟矿段是黄龙金矿床最主要的组成部分，该矿段矿石中磁黄铁矿和黄铁矿发育，其中磁黄铁矿矿石是矿床中含量最高的硫化物矿石.磁黄铁矿存在两种产出状态，分别为早期形成的呈浸染状、团块状分布的磁黄铁矿与晚期形成的脉状磁黄铁矿.成分分析结果表明以单斜磁黄铁矿为主.该矿床属中-低温矿床.微量元素结果显示富Co贫Ni，与金矿化关系密切.在含金性方面，脉状产出的磁黄铁矿优于团块状分布的磁黄铁矿，且脉体越细含金性越好，因此细脉状磁黄铁矿可作为该区重要的找矿标志.     

攀西红格钒钛磁铁矿矿田富钴硫化物中钴的地球化学特征及其地质意义

攀西红格钒钛磁铁矿矿田白草矿区发育富钴硫化物矿物,关于其成因和形成环境方面的研究较为薄弱。本文采用矿物学、矿物化学、地球化学等方法对其进行系统研究。矿石中主要富钴硫化物为磁黄铁矿（Po）、黄铁矿（Py）、镍黄铁矿（Pn）、硫钴镍矿（Se）。磁黄铁矿Co、Ni平均质量分数分别为0.21%、0.42%,Co/Ni平均值为1.10;黄铁矿Co、Ni平均质量分数分别为0.18%、0.29%,Co/Ni平均值为0.77;镍黄铁矿Co、Ni平均质量分数分别为2.67%、34.30%,Ni/Fe平均值为1.08、S/Fe平均值为1.91、M/S^#平均值为1.13;硫钴镍矿Co、Ni平均质量分数分别为24.30%、22.90%,Co/Ni平均值为1.06。根据Po-Py矿物温度计,白草矿区富钴硫化物结晶温度在267~490℃之间,表明其形成于中高温的条件。通过与地幔包体镍黄铁矿S/Fe、M/S^#特征值的对比,结合磁黄铁矿具有陨硫铁（Tr）同质多象晶体的特征,认为白草矿区硫化物具有地幔源的特征,说明成矿物质来源于地幔。白草矿区钴地球化学特征研究表明,在硫化物熔体分离过程中,钴迁移至单硫化物固溶体形成Po-Py固溶体,再由Po-Py固溶体中迁移至Pn、Se,形成了Se、Pn、Po-Py、Ccp（黄铜矿）中Co质量分数依次递减的现象。     

金川铜镍硫化物矿床磁黄铁矿矿物学特征及成因意义

金川铜镍硫化物矿床矿石类型主要为浸染状矿石、海绵陨铁状矿石及块状矿石。采用矿相显微镜观察、磁性胶体浸润与电子探针分析等方法,对3种类型矿石中磁黄铁矿的结构状态、共生组合与成分特征作了研究,探讨了矿石成因及成矿过程。在浸染状矿石与海绵陨铁状矿石中,磁黄铁矿为单纯的六方(NC型)磁黄铁矿,或者六方与单斜(4C型)磁黄铁矿构成的不规则状交生体。这2类矿石中磁黄铁矿的成因很可能是岩(矿)浆中S含量低,且高温结晶后缓慢降温,后期又受到了富硫和/或高氧逸度流体的交代作用。在Ⅱ矿区块状矿石中,单斜与六方磁黄铁矿构成平行叶片状交生体,表明六方磁黄铁矿在高温下结晶后温度曾快速下降,这期间仅出溶了微量的黄铁矿,而当温度下降到254℃以下时,发生了六方磁黄铁矿中单斜磁黄铁矿出溶作用。磁黄铁矿的结晶类型、金属原子(Fe、Ni、Cu、Co)与硫原子比值M/S演化等佐证了块状矿石晚期贯入成因。依据Fe-S系统相图拟合曲线计算得到块状矿石中六方磁黄铁矿结晶温度为743~518℃,且在结晶过程中,硫逸度logf(S2)曾从0.427降至-3.767。     

新疆哈密磁海铁矿床中钴的地球化学及地质意义

新疆磁海铁矿是一个富硫、富钴的磁铁矿矿床。矿床中的钴,主要产于黄铁矿、磁黄铁矿等硫化物中,并有钴的独立矿物辉砷钴矿和斜方砷钴矿。磁铁矿矿石中含钴较高,个别富硫化物磁铁矿矿石中钴可达0.16%,达到综合利用价值。对磁海铁矿床中钴的产出特征、化学成分、赋存状态研究,结合铁和钴的元素地球化学性质,认为该矿床的成矿物质来源较深;铁和钴在岩浆-热液成矿过程中属于不同阶段的产物,钴趋于在热液晚期阶段富集。     

含铜黄铁矿型矿床研究中的几个问题

含铜黄铁矿型矿床包括块状硫化物型铜矿床及别子型矿床。一般认为其形成与海底火山喷气-沉积作用有关。但对这类矿床的认识却存在很多争议。 1.对含铜黄铁矿型矿床的新认识。过去很多人都把这类矿床与块状硫化物矿床联系在一起。近年来作者研究表明,很多这类矿床不仅有块状硫化物矿石,而且还含有浸染状、细脉状、网脉状以及条带状矿石。且这些矿石往往是属同一成因的,因此将这类矿床统统以块状硫化物矿床命名是不符合实际的。比如加拿大Gold-Stream地区与基性火山岩有关的铜锌矿床;其中包含两种矿石,一种是产于绿色和暗色钙质千枚岩中薄层浸染状硫化物矿石,另一种为产于绿岩带地层间隙中的块状硫化物矿石,其间含有磁黄铁矿和黄铜矿的薄层紧密混合     

塔里木南缘达拉库岸铜镍矿矿物特征与成矿意义

达拉库岸岩体位于塔里木南缘活动带,喀拉米兰晚古生代沟弧系中段北侧。主要岩石类型有二辉橄榄岩、单辉橄榄岩、橄榄二辉岩、单辉辉石岩、含长辉石岩和辉长岩。矿石结构类型是星点状、斑杂状、浸染状和海绵陨铁结构;硫化物包括磁黄铁矿、黄铜矿、镍黄铁矿和黄铁矿,矿物组构特征显示出成矿过程的多阶段性,成矿时代可以划分为岩浆成矿、残余岩浆热液成矿以及表生氧化期。从岩体特征、矿石结构/构造、硫化物晶体化学特征和质量平衡等综合分析,岩体具有形成岩浆型铜镍硫化物矿床的良好条件,后期勘探应重视使用物探方法圈定岩体和矿体。     

新疆若羌县坡一岩浆硫化物矿床地质特征及成因初探

坡一岩浆硫化物矿床赋矿岩石主要为华力西中期第一侵入次第二阶段纯橄榄岩、辉石橄榄岩、橄榄辉石岩、辉石岩.镍矿体主要分布于超基性岩体中部、底部.矿石类型以星散浸染状为主,次为稀疏浸染状、少量稠密浸染状、海绵陨铁状,半块状-块状、脉状.金属硫化物主要为镍黄铁矿、磁黄铁矿及黄铜矿,次为黄铁矿、白铁矿.通过对坡一岩浆硫化物矿床岩相学、岩石化学、稀土微量元素特征、成矿作用总结分析,初步探讨矿床成因.     

西藏列廷冈铁多金属矿床磁铁矿元素地球化学特征及地质意义

西藏列廷冈矿床是林周盆地Fe-Mo-Cu-Pb-Zn矿集区内近年来新发现不久、规模较大的矽卡岩型铁多金属矿床。矿区磁铁矿发育,主要包括块状、浸染状和脉状3种类型。基于详细的野外地质调查和室内矿相学研究,将矿床成矿期划分为矽卡岩期和热液期2期,进而划分为5个成矿阶段:早期矽卡岩阶段、退化蚀变阶段、早期热液阶段、石英-硫化物阶段和碳酸盐阶段,其中,块状磁铁矿主要形成于退化蚀变阶段,浸染状和脉状磁铁矿主要形成于早期热液阶段。以磁铁矿为主要研究对象,采用电子探针(EPMA)和单矿物微量稀土元素ICP-MS分析实验,重点对磁铁矿元素地球化学特征、成因矿物学进行系统研究。研究结果表明,3种不同类型磁铁矿内均含Ti、Si、Ca等次要元素以及Na、K、Cr、Ni、Co、Pb、Ba、Sn、Sr、Sb、Cu等多种可检测到的微量元素,且矿物内主要发生了Al、Mg、Mn等元素的类质同像置换,综合TiO_2-Al_2O_3-MgO、TiO_2-Al_2O_3-(MgO+Mn O)和(Ca+Al+Mn)-(Ti+V)、Ni/(Cr+Mn)-(Ti+V)等多种磁铁矿成因判别图解投图结果及矿体野外宏观地质特征,表明矿区磁铁矿均为热液成因。块状磁铁矿具明显的Eu正异常,浸染状和脉状磁铁矿具Eu负异常,均无明显Ce异常特征,表明富Eu成矿流体在矽卡岩期的高温氧化环境下形成了矽卡岩型块状磁铁矿体,在热液期则逐渐转变为低温还原环境,形成浸染状和脉状磁铁矿及多种金属硫化物,且铁的物质来源主要与矿区花岗闪长岩和花岗斑岩紧密相关。     

Global repeating events in the history of the Earth and the motion of the Sun in the Galaxy

Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.     

截潜工程在计算山前侧向补给量中的应用

在计算山前侧向补给量的方法中,最常用的就是达西断面法,但达西断面法需要获取较多的参数,对于山前无钻孔或只有少量钻孔且水文地质研究程度较低的区域,很难采用达西断面法来计算得到山前侧向补给量。对于无法运用达西断面法但存在完整式截潜工程的山丘区,可以结合完整式截潜工程的截潜量利用水量均衡法计算山前侧向补给量。     

"青藏高原南部空白区基础地质调查与研究"计划项目新成果、新进展

通过2004年度各相关图幅的大力工作，在基础地质、矿产和资源等方面取得了大量实际材料，综合研究区域构造．地层格架、青藏高原地质图和青藏高原南部火山岩及其地球动力学意义等，取得重要进展和新认识，在矿产资源、旅游和人文景观等方面也取得重要阶段性成果。     

“青藏高原南部空白区基础地质调查与研究”计划项目新成果、新进展

通过2 0 0 4年度各相关图幅的大力工作,在基础地质、矿产和资源等方面取得了大量实际材料,综合研究区域构造地层格架、青藏高原地质图和青藏高原南部火山岩及其地球动力学意义等,取得重要进展和新认识,在矿产资源、旅游和人文景观等方面也取得重要阶段性成果。     

关中盆地大荔地区地下水氟水文地球化学规律

为了研究关中盆地大荔地区氟的水文地球化学规律,采集239个地下水样品及35个土壤样品,分析了水化学类型和水化学组分对氟的影响,结果表明在弱碱性环境下,重碳酸钠型是促进氟富集并增强围岩向地下水中转化的主要因素;硫酸钙镁型的地下水抑制氟富集。水化学组分中Na+、Cl-、HCO3-、pH与氟呈正相关,而Ca2+则抑制水溶液中氟含量增加;迁移系数与HCO3-、pH呈正相关关系,与其他主要离子呈负相关关系。利用Preeqic软件分析了饱和指数和Ca2+、F-的离子活度,得出萤石的平衡控制着氟和钙的水文地球化学行为,F-可能来源于萤石和方解石的分解。     

Determination of Emissions in the City by the Rate of Change in the Integral Content of Impurities in the Atmospheric Boundary Layer

Doklady Earth Sciences - A new approach to the problem of determining the density of emission fluxes of anthropogenic impurities from distributed urban sources by the rate of growth of the integral...     

Terrane tectonics in the formation of the groundwater runoff in the active water-exchange zone of mountainous river valleys in the cryolithozone

The significant role of the drainage area’s geological background in the formation of the groundwater runoff in the active water-exchange zone was revealed for the first time on the basis of long-term observations of streams of the Upper Kolyma River region during the autumn-winter low-water period, when the rivers are fed only by the groundwater recharge. The analysis of all the available data made it possible to define the characteristic periods in the autumn-winter low-water season. The waters of the seasonally thawed layer play the dominant role in the river’s recharge in September; the suprapermafrost water, in January; and the subgelisol water (nonfreezing water streams) during the 30-day-long period of the minimal flow. The quantitative parameters of the groundwater runoff corresponding to its module during this period reflect the water influx to the active water-exchange zone. It is established that the latter is minimal in the In’yali-Debin synclinorium, which consists of sedimentary rocks formed in deepwater trough environments. Their subsequent transformation proceeded under the action of subduction-accretionary and shear strains. The water availability in the active water-exchange in the Ayan-Yuryakh anticlinorium zone is substantially higher, although the Late Paleozoic and Early Mesozoic sedimentary formations of this area were also deposited in deepwater trough settings, but their subsequent evolution was related to the uplift of the anticlinorium. The maximal watering is observed in the active water-exchange zone of the Omulevka terrane, which is composed of Paleozoic terrigenous-carbonate and carbonate formations. The differences in the hydrogeological regimes of the terranes may be significant with respect to their geoecology.