河南银洞沟造山型银矿床碳硫铅同位素地球化学

河南内乡县银洞沟大型脉状银多金属矿床产于北秦岭造山带朱夏断裂北侧的二郎坪地体内,含矿围岩是二郎坪群火山岩-碎屑岩建造,矿体定位于断裂构造带内,产状受断裂构造控制,矿石组构、矿物组合、围岩蚀变类型和分带等地质特征均与典型造山型金矿一致,应属造山型银矿.矿床硫化物δ~(34)S介于+4.7～+8.1‰,高于有机物和岩浆岩.流体包裹体中CO_2的δ~(13)C介于-0.2～+0.9‰,与海相碳酸盐一致,高于其它所有地质体.矿石硫化(206)Pb/~(204)Pb=18.2026～18.4462,~(207)Pb/~(204)Pb=15.5835～15.7739,~(208)Pb/~(204)Pb=38.5478～39.0890,显示铀铅富集,钍铅微弱亏损.这些同位素地球化学特征均指示夹杂沉积硫酸盐的碳酸盐-碎屑岩沉积建造是最为理想的物源,对比研究东秦岭北坡相关地质单元,认为成矿物质和流体主要来自二郎坪群和秦岭群,尤其是雁岭沟组含碳酸盐岩地层对于成矿流体和物质的贡献不可替代.中生代华北与华南板块碰撞造山过程中,秦岭群沿朱夏断裂向北陆内俯冲到二郎坪地体之下,并通过俯冲变质脱水而为银洞沟矿床的形成提供了大量成矿物质和流体.朱夏断裂北侧依次出现银洞沟银矿、许瑶沟金矿、松垛隐伏花岗岩基、栾川斑岩钼矿带,构造-成岩-成矿空间格局与CMF模式(碰撞造山成岩成矿和流体作用模式)完全一致,证明了CMF模式的科学性和普适性和同位素示踪成矿物质和流体来源的有效性.银洞沟矿床的发现和研究结果证实了前人预测的朱夏断裂北侧"桑坪-米坪-许瑶沟铜金铅锌银等多金属矿化带"的客观存在,该带应作为银金多金属矿床勘查的重点区带.     

河南省内乡县银洞沟银矿床流体成分研究

河南省内乡县银洞沟银矿床是产于东秦岭北部二郎坪地体中的断控脉状矿床,主要赋矿围岩为二郎坪群小寨组绢云石英片岩。流体包裹体的气相、液相和稀土元素研究表明,成矿流体的 CO_2含量为12.829%～22.172mol%,属于 CO_2-NaCl-H_2O 体系,与世界造山型流体成矿系统一致。成矿流体系统在早阶段主要为来自赋矿地层改造-变质脱水作用的深源变质水,经中阶段沸腾,向晚阶段大气降水热液演化。在早阶段,Ag 等成矿元素通过与 Cl~-等离子络合而被萃取、富集到成矿流体中,并被搬运;流体沸腾导致大量金属成矿物质在中阶段快速沉淀。而不同深度、不同阶段的流体包裹体中 Mg~(2 )、Ca~(2 )、REE 等含量差异可由围岩的热液蚀变所致。     

河南银洞沟银多金属矿床地球化学特征与成矿机理初探

银洞沟银多金属矿是一个典型的碰撞造山带型脉状矿床,产出于北秦岭褶皱带二郎坪地体早古生界二郎坪群(Pz1 er)内,是在二郎坪地体内所取得的重大找矿突破,具大型乃至超大型规模.金属矿物以独立矿物(银金、辉银矿)、硫化物形式赋存,银、铅、锌共生关系密切.通过对矿床地质、铅同位素、碳氢氧同位素、稀土元素和流体包裹体地球化学特...     

湖北竹山县银洞沟矿床成矿流体特征及矿床成因

银洞沟大型银多金属矿床位于南秦岭造山带,矿体主要受东西向的银洞岩背斜控制,呈脉状产于武当山群变火山岩.热液成矿作用包含4个阶段:(Ⅰ)细粒石英-闪锌矿-方铅矿阶段;(Ⅱ)细粒石英-银金矿化阶段;(Ⅲ)粗粒石英阶段,含少量方铅矿-闪锌矿-黄铜矿;(Ⅳ)块状铁白云石-石英阶段.银洞沟矿床流体包裹体可分为3类:NaCl-H2O型(W型)、CO2-H2O-NaCl型(C型)和CO2-CH4型(PC型).Ⅰ阶段石英中的流体包裹体以W和C型为主,含少量PC型,相比Ⅰ阶段,Ⅱ阶段的C型包裹体更多,而Ⅲ阶段仅发育W型包裹体.显微测温表明,Ⅰ阶段流体包裹体均一温度为308 ～ 436℃,盐度为5.1％～10.2％ NaCleqv;Ⅱ阶段均一温度为220～375℃,盐度为2.0％～ 10.7％ NaCleqv;Ⅲ阶段均一温度为122 ～272℃,盐度为0.4％～7.2％ NaCleqv.根据C型包裹体估算前两个阶段压力分别为330 ～463MPa和180～363MPa,相应成矿深度分别为12.5～17.5km和6.8 ～13.8km.从Ⅰ到Ⅲ阶段,δ18OW、δD平均值分别由8.4‰和-72‰,变化至0.9‰和-67‰,指示初始成矿流体来自变质热液,晚阶段混入了大气降水.流体包裹体与氢氧同位素数据表明,银洞沟矿床成矿流体为中温、低盐度、富CO2的变质热液,属于造山型矿床,流体的混合可能是金属沉淀的主要机制.     

河南银洞沟银金钼矿床铼-锇同位素定年和加里东期造山-成矿事件

河南内乡银洞沟银金钼矿床是夏馆银多金属矿田新发现的造山型矿床,赋矿地层为新元古代-早古生代弧后盆地堆积的二郎坪群火山-沉积岩系,二郎坪群在志留纪或加里东运动中遭受区域变形和变质.矿床5件辉钼矿Re-Os同位素模式年龄介于423.4±4.4～432.2±3.4Ma,加权平均年龄为429.3±3.9Ma(MSWD=0.73),指示秦岭地区存在显著的加里东期造山-成矿事件.     

河南省内乡县银洞沟银金多金属矿成矿年龄: 热液锆石LA-MC-ICP-MS U-Pb测年

北秦岭构造带广泛发育与古生代洋壳俯冲和碰撞造山有关的岩浆活动以及与造山过程有关的变质作用,但古生代热液脉型矿床在北秦岭构造带少见报道。银洞沟银金多金属矿为北秦岭构造带东部的一处中型热液脉型矿床,本文通过对该矿床赋矿围岩和含矿石英脉中锆石开展LA- MC- ICP- MS U- Pb测年和锆石成因研究,确定了矿床的形成时代,并探讨了矿床的成矿动力学背景。结果表明赋矿围岩黑云母二长花岗岩的形成时代为431. 4±2. 1 Ma,含矿石英脉中锆石结晶年龄为419. 4±5. 9 Ma,石英脉中锆石的岩相学、锆石中矿物和流体包裹体及锆石微量元素研究表明419. 4 Ma代表矿床的形成时代。结合前人的研究结果,确定银洞沟银金多金属矿为形成于晚志留世的造山型矿床,成矿作用与碰撞期后～420 Ma的变质作用密切相关,成矿流体来源于地层的变质脱水,成矿物质主要来源于秦岭岩群和二郎坪群。     

河南内乡县银洞沟银矿地质和流体包裹体特征及成因类型

河南内乡县银洞沟银(多金属)矿床位于东秦岭北部的二郎坪地体,属于断控脉状矿床。矿石有石英脉型和蚀变岩型,围岩蚀变以硅化、绢云母化、碳酸盐化、绿泥石化为主,主要银矿物为银黝铜矿、辉银矿、自然银等。成矿过程可以划分为早、中、晚3个阶段,分别形成含黄铁矿和/或毒砂的石英脉、多金属硫化物网脉和石英-碳酸盐细脉。脉石矿物石英、碳酸盐等含大量流体包裹体,包括富/纯CO2、含CO2水溶液和水溶液3种组分类型的包裹体。矿床形成于中温(270℃～370℃)、低盐度(<11.4%)、低密度流体系统。成矿早阶段以深源富碳流体为主,中阶段流体发生沸腾,晚阶段为盐水溶液。从早到晚,包裹体捕获压力由280MPa～320MPa降为90MPa～92MPa,成矿深度略有变浅,流体系统静岩压力变为静水压力体系,趋于开放,指示区域应力场由挤压向伸展转变。银洞沟银矿的地质特征和成矿流体系统与造山型金矿一致,应属造山型银矿;结合区域构造背景,认为银洞沟银矿形成于陆陆碰撞体制,并可以借助CMF模式解释成因。     

湖北银洞沟银金矿床正花状构造样式及控矿作用

湖北银洞沟银金矿床位于南秦岭造山带的武当巨型推覆体中的银洞沟逆冲推覆岩席中，该矿区中发育3条主要的韧脆性剪切带，银洞沟韧脆性剪切带，姚家湾剪切带和西沟剪切带，由北向南呈近等距分布，在剖面上呈正花状构造样式，控制着银洞沟银金矿床，陕西白河银矿，西沟隐伏银金矿和姚家湾铅锌银金矿等。     

熊耳地体南侧中晚元古代地层碳氧同位素组成：CMF模式的证据

前人运用 CMF 模式(碰撞造山成岩成矿与流体作用模式)推断熊耳地体金银矿床的成矿流体主要来自其南侧中晚元古代地层(官道口群和栾川群)的陆内俯冲变质脱水作用,并推测该套地层富放射成因铅和锶,δ~(13)C 和δ~(18)O 值较高。为检验该推论和 CMF 模式正确与否,作者对该套地层开展了研究,本文报道了碳氧同位素研究结果。13件岩石样品δ~(18)O 值变化于9.1‰～16.7‰,平均13.3‰;4件δ~(13)C_(CaCO_3)值为-2.8‰～0.8‰,平均-0.9‰,计算表明,该套地层在320～373℃(熊耳地体多数矿床早阶段成矿温度范围)变质脱水所形成流体的δ~(18)O值为2.6‰～14.6‰,与推测结果一致,覆盖了熊耳地体已有早阶段成矿流体的δ~(18)O值(5.1‰～12.6‰),计算的中晚元古代地层变质流体的δ~(13)C_(CO_2)随介于-0.7‰～4‰,也与熊耳地体成矿流体的δ~(13)C_(CO_2)值(-2.1‰～4‰,成矿早阶段一般δ~(13)C_(CO_2)>0)一致。如此以来,我们的研究结果证明了前人的推论和 CMF 模式的科学性与实用性,CMF 模式可以用于指导熊耳地体或类似构造环境的矿床勘查和地质研究。     

河南内乡北部铅锌银矿床成矿物质来源的S、Pb同位素制约

河南省内乡县北部大型铅锌银矿床产于北秦岭造山带朱夏断裂北侧的二郎坪地体内,形成于晚元古代—早古生代弧后盆地环境的(变质)火山-沉积建造。矿区已发现铅锌银矿(化)脉近百条,矿脉多呈板状、脉状充填于近垂直造山带的断裂构造中,其中以较大规模的Y1、Y3、Y6、Y10和Z2号脉为代表。在矿床地质研究的基础上,选取Y1、Y3、Y6和Z2号矿脉中闪锌矿矿石和Y10号矿脉中方铅矿矿石进行了S同位素组成分析,δ34SV-CDT范围为1.89‰～7.34‰,指示硫主要来源于赋矿的古生界海相地层中硫酸盐的热化学还原;矿石中方铅矿的Pb同位素组成206Pb/204Pb范围为18.229 4～18.384 5,207Pb/204Pb范围为15.608 9～15.643 4,208Pb/204Pb范围为38.516 0～38.715 2,矿石铅μ值范围为9.50～9.55,ω值范围为37.45～38.35,指示成矿金属物质来源于赋矿的古生界变质火山-沉积地层。研究表明内乡北部铅锌银矿区的成矿物质可能来自秦岭群和二郎坪地层。     

摩擦桩基桩土间极限摩阻力取值问题探讨

通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。     

从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返

位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。     

The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads

In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.     

某高速公路下伏煤矿采空区稳定性分析

在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。      

混凝剂处理钻井废泥浆液的研究

通过烧杯搅拌实验对混凝剂处理钻井废泥浆液进行研究,从混凝剂适应p H值范围、混凝效果、沉降速度三方面研究比较,找出一种较为理想的混凝剂,并分析了影响混凝剂性能的主要因素,确定了混凝剂的最佳投放剂量。      

黄河源区水环境变化及黄河出现冬季断流的原因

自1954年有水文观测资料以来，黄河曾在青海省玛多县黄河沿水文站发生过3次断流。本文在分析黄河源区水环境特征及其影响因素的基础上指出，鄂陵湖、扎陵湖的环湖融区调节能力低，当遇到连续干旱、冬季其调节水量不足以维系黄河径流时便会发生断流，这是断流的主因。湖水位降低、开采沙金、过度放牧等自然和人为因素也会对黄河发生断流产生影响。鄂陵湖口附近黄河上修建的水电站开始蓄水，提高了两湖及环湖融区的调节能力，今后黄河冬季出现断流的可能性将大为降低。     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.     

Artemia in the Salt Lakes of Russia:the Productivity of Populations,the Reserves of the Cysts and the Fisheries

正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the     

天山南坡科其喀尔冰川表碛区小气候特征研究

利用天山南坡科其喀尔冰川3号观测站2009年全年的气象观测资料,分析研究了科其喀尔冰川表碛区的小气候特征. 结果表明：总辐射和净辐射夏秋季较高、冬春季较低;反射辐射和地表反照率反之. 与其他地区不同,该区主要受积雪物理性质和下垫面状况的影响,冬春季地表反照率日变化表现为由大到小的变化过程,夏秋季表现为倒U型. 温度年变化表现为夏秋季高、冬春季低,最高月均值出现在8月,为9.4℃,最低月均值出现在1月,为-9.6℃. 受山谷风和冰川风的影响,全年的风向以西北风和西北偏西风为主,风向的日变化以11：00为界发生转向. 受降水和冰川消融等的影响,比湿夏秋季月均值较大,冬春季月均值较小.     

Climate: Is the past the key to the future?

 The climate of the Holocene is not well suited to be the baseline for the climate of the planet. It is an interglacial, a state typical of only 10% of the past few million years. It is a time of relative sea-level stability after a rapid 130-m rise from the lowstand during the last glacial maximum. Physical geologic processes are operating at unusual rates and much of the geochemical system is not in a steady state. During most of the Phanerozoic there have been no continental ice sheets on the earth, and the planet’s meridional temperature gradient has been much less than it is presently. Major factors influencing climate are insolation, greenhouse gases, paleogeography, and vegetation; the first two are discussed in this paper. Changes in the earth’s orbital parameters affect the amount of radiation received from the sun at different latitudes over the course of the year. During the last climate cycle, the waxing and waning of the northern hemisphere continental ice sheets closely followed the changes in summer insolation at the latitude of the northern hemisphere polar circle. The overall intensity of insolation in the northern hemisphere is governed by the precession of the earth’s axis of rotation, and the precession and ellipticity of the earth’s orbit. At the polar circle a meridional minimum of summer insolation becomes alternately more and less pronounced as the obliquity of the earth’s axis of rotation changes. Feedback processes amplify the insolation signal. Greenhouse gases (H₂O, CO₂, CH₄, CFCs) modulate the insolation-driven climate. The atmospheric content of CO₂ during the last glacial maximum was approximately 30% less than during the present interglacial. A variety of possible causes for this change have been postulated. The present burning of fossil fuels, deforestation, and cement manufacture since the beginning of the industrial revolution have added CO₂ to the atmosphere when its content due to glacial-interglacial variation was already at a maximum. Anthropogenic activity has increased the CO₂ content of the atmosphere to 130% of its previous Holocene level, probably higher than at any time during the past few million years. During the Late Cretaceous the atmospheric CO₂ content was probably about four times that of the present, the level to which it may rise at the end of the next century. The results of a Campanian (80 Ma) climate simulation suggest that the positive feedback between CO₂ and another important greenhouse gas, H₂O, raised the earth’s temperature to a level where latent heat transport became much more significant than it is presently, and operated efficiently at all latitudes. Atmospheric high- and low-pressure systems were as much the result of variations in the vapor content of the air as of temperature differences. In our present state of knowledge, future climate change is unpredictable because by adding CO₂ to the atmosphere we are forcing the climate toward a “greenhouse” mode when it is accustomed to moving between the glacial–interglacial “icehouse” states that reflect the waxing and waning of ice sheets. At the same time we are replacing freely transpiring C3 plants with water-conserving C4 plants, producing a global vegetation complex that has no past analog. The past climates of the earth cannot be used as a direct guide to what may occur in the future. To understand what may happen in the future we must learn about the first principles of physics and chemistry related to the earth’s system. The fundamental mechanisms of the climate system are best explored in simulations of the earth’s ancient extreme climates. Received: 7 November 1996/Accepted: 23 January 1997