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1.
金矿床主要矿物标型特征研究综述   总被引:7,自引:1,他引:7  
卿敏  韩先菊 《黄金地质》2003,9(4):39-45
总结了金矿床中金矿物、黄铁矿、方铅矿、闪锌矿及黄铜矿等金属矿物和石英、碳酸盐矿物、云母类矿物及金红石等非金属矿物的产状,晶体形态、比重、硬度、颜色、反射率、导电性、热发光性等物理性质,谱学特征以及化学成分特征。从中提取出不同类型金矿床成因信息,含矿与非矿矿物特征以及判定金矿化程度、矿床规模和矿体剥蚀程度的指标。  相似文献   

2.
中朝板块旋回层序、事件和形成演化的探索   总被引:11,自引:4,他引:11  
孟祥化  葛铭 《地学前缘》2002,9(3):125-140
通过 10余年来对中朝板块旋回层序、事件及构造演化的调查研究和综合分析 ,笔者编制了中朝板块旋回层序、事件和形成演化综合图 ,深刻地认识到地质科学是复杂性的科学体系。复杂系统研究要求重组现有的科学划分 ,实现跨越岩石矿物学、古生物学、层序地层学、地质地球化学、磁性地层学、古地理学、古构造学、天文学、海洋学及矿床学等不同学科的协同 ,从而促进学科的交叉和融合 ,以求学科体系理论和方法论的深刻变革 ,以推动地质科学的发展。这就是笔者提出以宇地系统观来综合研究地球、层序、事件和演化的基本思路。依据宇地系统作用原理 ,研究了中朝板块从元古宙至中新生代的旋回层序、事件和演化历史。从 180 0Ma至第四纪共划分出 2 0个超旋回或巨旋回周期和百余个奥尔特周期 ;还研究了海泛事件、隆升间断事件、跷跷板运动事件、臼齿碳酸盐事件、热事件、反极性事件、岩溶事件、火山喷发事件、风暴事件、物源区类型及古构造演化等一系列重大事件。应用宇地系统周期等时原理对中朝板块拗拉谷、鲕滩台地建造、前陆盆地演化和陆相裂谷盆地 ,按长偏心率周期进行了古地理演化的精细研究 ,再现了中朝板块构造、古地理和地层格架的演变 ,并对具全球性意义的大气圈、水圈、生物圈、沉积圈及成矿作用等重大地球  相似文献   

3.
贵州省大方县小屯乡法启村一组崩塌地质灾害为一高位崩塌地质灾害隐患,崩塌方式以零星崩落为主,威胁下部83户510名居民及法启火车站安全。本文以贵州省大方县小屯乡法启村一组崩塌地质灾害隐患为例,根据勘查及调查测绘,模拟剖面的选取,坡面的参数确定,运用Rockfall软件数值模拟,模拟出崩塌落石运动过程中的特征参数,掌握了崩塌落石的运动特征,为该地质灾害防治提供了重要的参数依据。研究结果表明,Rockfall数值模拟在零星高位崩塌地质灾害勘查中可分析出崩塌落石的主要堆积停留区、最远崩落距离和各点位的落石动能、最大弹跳高度等详细数据,避免了公式计算的单一性,体现了模拟的随机性,与崩塌地质灾害的实际运动特征更接近,可更有效的指导崩地质灾害的防治,具有重要实践意义。  相似文献   

4.
通过调查研究四川地区80个红层软岩边坡的几何形状、结构面产状、边坡岩体强度等特征,探讨了块度、回弹值、回弹比、JRC、坡高与坡度的关系.提出了回弹比,分析其与坡度、稳定性间的相关关系,指出回弹比是对边坡稳定性影响的一个重要因素.确定了各因素对坡度的影响的重要性依次是块度、回弹值、回弹比、JRC和坡高.  相似文献   

5.
The formation and distribution of fractures are controlled by paleotectonic stress field,and their preservative status and effects on development are dominated by the modern stress field. Since Triassic,it has experienced four tectonic movements and developed four sets of tectonic fractures in the extra low-permeability sandstone reservoir at the south of western Sichuan depression. The strikes of fractures are in the S-N,NE-SW,E-W,and NW-SE directions respectively. At the end of Triassic,under the horizontal compression tectonic stress field,for which the maximum principal stress direction was NW-SE,the fractures were well developed near the S-N faults and at the end of NE-SW faults,because of their stress concentration. At the end of Cretaceous,in the horizontal compression stress fields of the NE-SW direction,the stress was obviously lower near the NE-SW faults,thus,fractures mainly developed near the S-N faults. At the end of Neogene-Early Pleistocene,under the horizontal compression tectonic stress fields of E-W direction,stress concentrated near the NE-SW faults and fractures developed at these places,especially at the end of the NE-SE faults,the cross positions of NE-SW,and S-N faults. Therefore,fractures developed mostly near S-N faults and NE-SW faults. At the cross positions of the above two sets of faults,the degree of development of the fractures was the highest. Under the modern stress field of the NW-SE direction,the NW-SE fractures were mainly the seepage ones with tensional state,the best connectivity,the widest aperture,the highest permeability,and the minimum opening pressure.  相似文献   

6.
汤原断陷构造复杂,后期改造强烈,原型盆地认识不清,导致原始沉积沉降中心不明确,制约了油气勘探的进展。本文从剥蚀量计算入手,分别采用镜质体反射率(Ro)法和地层趋势法,对宝泉岭组、达连河组及新安村组的地层剥蚀量进行计算,结合地震及构造特征,并利用地质建模技术恢复了不同时期的原型盆地形态,通过计算恢复认为:新安村组时期,原始厚度最厚发育在东部边界断裂下降盘,沉积沉降中心被断陷中部低凸起分为南北两个部分,此时期沉积沉降中心位于断陷东部边界断裂中段;达连河组时期,早期的两个沉积沉降中心逐渐合并为一个,断陷西部、南部出现规模较小的沉降带,最厚处依然位于东部断裂带下降盘,而沉积沉降中心迁移至东部边界断裂北段;宝泉岭组时期,早期的两个沉积沉降中心完全合并为一个,断陷西部的沉降带规模扩大,形成一东一西的两个主要沉积沉降中心,沉积沉降中心由一个变为两个。在此基础上,明确了原型盆地格局形态及不同时期沉积沉降中心分布及迁移过程。  相似文献   

7.
In the old mining area of Rodalquilar, mine wastes, soil and sediments were characterized and the results revealed high concentration of Au, Ag, As, Bi, Cu, Fe, Mn, Pb, Se, Sb and Zn in tailings and sediments. The contaminant of greatest environmental concern is As. The mean concentration in the tailings was 679.9, and 345 mg/kg in the sediments of Playazo creek. The groundwater samples from the alluvial aquifer showed high concentration of Al, As, Cd, Fe, Hg, Mn, Ni, Pb, Se, Sb and Zn and very high concentration of chloride and sulfate, which were above the concentration defined in the European standards for drinking water. The presence of As in groundwater may be caused by the oxidation of arsenian pyrite, the possible As desorption from goethite and ferrihydrite and the jarosite dissolution. Groundwater concentrations of Cd, Fe, Mn, and possibly Cu, were associated with low values of Eh, indicating the possible dissolution of oxy-hydroxides of Fe and Mn. The mobility of metals in the column experiments show the release of Al, Fe, Mn, Cr, Cu, Ni, V and Zn in significant concentrations but below the detected values in groundwater. However, As, Cd, Sb, Se Pb and Au, are generally mobilized in concentrations above the detected values in groundwater. The possible mass transfer processes that could explain the presence of the contaminants in the aquifer and the leachates was simulated with the PHREEQC numerical code and revealed the possible dissolution of the following mineral phases: jarosite, natrojarosite, arsenian pyrite, alunite, chlorite, kaolinite and calcite.  相似文献   

8.
北京市延庆区是首都生态涵养区,开展土壤重金属分布特征及来源解析研究对保障土地安全利用、防控生态环境风险具有重要意义。采集延庆区2 354件表层土样及44件深层土样,测试分析了重金属元素As、Cd、Cr、Hg、Ni、Pb、V、Zn及Sc等含量。采用空间分布分析、多元统计分析与受体模型相结合的方法,阐明了土壤重金属元素分布特征,解析了土壤重金属潜在来源,并计算了不同来源对土壤重金属的相对贡献率。结果表明,表层土壤中V、Cr、Ni、As元素主要来源于成土母质,Cd、Zn、Pb含量高值区集中分布于人口密集区域,人为活动对该3种元素影响较大,而Hg主要受大气干湿沉降的影响。深层土壤中Hg元素在居民区含量较高,而其余元素均未受到人为活动的影响。  相似文献   

9.
本文对东准噶尔造山带三塘湖盆地西北缘奥依托浪格地区石炭纪巴塔玛依内山组进行了火山岩地质、岩相学、地球化学特征研究,并结合相关年代学成果,探讨了火山岩成因、形成环境与东准噶尔造山带构造演化。研究认为:该区石炭纪巴塔玛依内山组火山岩具明显的陆相火山岩、双峰式火山岩特征,岩石组合基性端元以玄武岩为主,酸性端元为珍珠岩、英安岩;主量元素特征显示基性端元为钙碱—碱性性质,酸性端元珍珠岩、英安岩分别属于碱性、拉斑性质;微量元素特征显示基性端元相对富集Ba、K、Sr等大离子亲石元素(LILE),亏损Th、Nb、Nd等高场强元素(HFSE),酸性端元强烈亏损Ba、Nb、Sr、Sm、Ti等元素,富集K元素;稀土元素显示两端元均为轻稀土元素(LREE)相对富集、重稀土元素(HREE)相对亏损特征;珍珠岩主、微量元素特征与整体具有明显差异。综合研究表明:该双峰式火山岩基性端元来源于地幔岩的部分熔融,酸性端元英安岩来源于基性端元的分离结晶作用,珍珠岩则来源于下地壳的部分熔融;地球动力学背景为俯冲洋壳的拆沉作用,造成软流圈热源上涌,引发地幔岩的部分熔融与岩石圈的伸展减薄,进而诱发下地壳镁铁质岩的减压熔融;构造环境为后碰撞伸展阶段晚期,并指示了板块链式缝合的特点。  相似文献   

10.
豫北平原是河南省重要的能源、冶金和纺织等工业基地,也是粮棉油料作物的主要产区。同时,又是水资源较匮乏的地区。但大量咸水(矿化度>1 0g L)资源得不到开发利用,且广泛分布的咸水已日益突出地成为环境水文地质问题。根据大量实地调查资料和地质成果,文章较详细地论述了豫北平原咸水含水层分布、富水性、补给、径流和排泄、水化学和同位素、利用现状及动态等水文地质特征。为缓解豫北平原水资源供需矛盾的压力,变害为利,根据咸水的分布状况、咸水农业利用和咸水养殖利用的适宜性、咸水改造方法和补源条件等,提出咸水开发利用与改良规划应"以用为主,以用促改"。结合各地实际情况,对不同矿化度的咸水应采取不同的开发利用方式、改良方案和措施。  相似文献   

11.
灰色系统理论在北京山区泥石流危险度评价预测中的应用   总被引:9,自引:1,他引:9  
泥石流灾害是北京地区严重的地质灾害之一。其危险度的评价与预测对防灾减灾意义重大。文章根据灰色系统理论的多因素关联度分析法,进行泥石流沟危险度评价。泥石流的形成暴发是多种因素相互作用的结果。多因素关联度分析就是要找出这些因素与泥石流的密切关系程度,根据各因素对泥石流作用的大小,做出综合评判。文章应用泥石流发生的重要参数——物质冲出量、流域面积、相对高差、沟谷切割深度、沟床纵坡、植被覆盖度、土层厚度、形成区山体平均坡度、降水量、崩滑塌密度进行关联度分析,将泥石流的各影响因素与泥石流规模、发展态势的紧密程度做定量分析,以此衡量各因素与泥石流之间的关联程度,寻找主、次因素。各因素按不同数量等级划分为危险、较危险及一般3个条件值,并给予3个级别划分值。再根据各因素所占权重获得各量级得分,通过泥石流各因子权重、因素量级划分及评分标准,对北京市816条沟谷进行了危险度评价。确定危险沟谷104条,较危险沟谷542条,一般危险沟谷170条。在此基础上,结合泥石流沟危害目标的性质、灾害损失及保护价值,进行泥石流危害程度评价,确定危害严重沟谷41条,较严重沟谷331条,轻微沟谷444条。预测结果与实际情况较吻合。  相似文献   

12.
在早期长城纪演化阶段,燕山中晚元古代裂谷盆地构造拉张活动明显,它控制了整体沉积相带的展布,并在强烈活动期引发了一系列事件沉积。长城纪时期的古构造活动主要以四种方式影响盆地的充填,其中同沉积断裂活动在长城纪盆地演化过程中具有突发性或脉动活动的特点,记录了古地震、碳酸盐滑塌沉积、碎屑浊流沉积,并诱发火山活动形成火山碎屑重力流等地质事件。盆地的古水流、地层格架及特征沉积相带等分析显示,盆地主体展布为NE向;燕山元古代裂谷向外海出口的位置应处于中朝准地台的北部;现今所赤城-北票EW向断裂在长城纪大部分时期对盆地的沉积充填没有明显影响。  相似文献   

13.
The aim of the present study is to provide additional information about the properties and depositional environment of the Kipra lignite seam, which was deposited during the regressive stage of development of the Maritza-West basin. Petrographical and mineralogical data, along with ash yields and sulphur contents of 24 samples from a seam profile, have been used to study the vertical variation of the depositional settings during peat accumulation and subsequent coalification.The Kipra lignite is characterized by high ash yields and sulphur contents. It formed in a rheotrophic, low-lying mire with alkaline pH value. Vegetation with low preservation potential dominated within the palaeomire. During peat formation, frequent changes of the water level controlled the depositional environment. During the deposition of units 1 and 2, high water energy caused the transportation of high amounts of inorganic material into the mire, resulting in the formation of weakly gelified mineral-rich lignite. The organic matter from units 3 and 4 is characterized by enhanced gelification, which probably reflects the decreasing energy of the system. Good positive correlation between sulphur contents and the GI values was established in units 4, indicating that the gelification of the tissues was probably mainly controlled by the bacterial activity. In contrast, the gelification of the samples from unit 3 of the Kipra seam was probably governed by the redox conditions. The organic matter deposited under relatively wet conditions, in which the thermal and oxidative destruction of the tissues, was limited.A variety of major, minor and accessory minerals are present in Maritza-West lignite. The mineral composition is dominated mainly by pyrite, gypsum and calcite, and to a lesser extent limonite, quartz, kaolinite, montmorillonite, illite, chlorite and plagioclase. Jarosite, hematite, halloysite, mica, K-feldspar, aragonite, siderite, and dolomite were also determined in very low concentrations. These minerals formed syngenetically and epigenetically. The syngenetic stage is characterized mainly by the formation of pyrite, carbonates, silicates and sulphates, whereas the Fe-oxyhydroxides, partially the carbonates and almost all silicates are of detrital origin. During the epigenetic stage, carbonates, sulphates, clay minerals, pyrite, and Fe-oxyhydroxides were formed. Alteration products like gypsum, jarosite, limonite, chlorite, kaolinite, illite, mica, and calcite were generated due to the transformation of detrital and authigenic minerals.  相似文献   

14.
Osheepcheon Creek running through the Dogyae area is being polluted by the influx of the abandoned coal mine drainage. Generally, the more polluted water has lower pH and Eh and higher conductivity values. The concentrations of Mg, Ca, Fe, SO4, and some trace elements, such as Cd, Co, Cr, Mo, Ni, Pb, Rb, Sr, U and Zn, are tens to hundreds of times more concentrated in the abandoned coal mine drainage than in the unpolluted streamwater. However, most immobile toxic pollutants from the mine drainage are quickly removed from the streamwater by the precipitation of amorphous Fe hydroxide and sorption on the precipitated Fe hydroxide. The fast removal of the pollutants from the streamwater maintains the water quality of the creek as acceptable at most places along the stream path, except where the abandoned coal mine drainage flows in. However, the creek has the potential of deteriorating quickly if the mine drainage is allowed to be continuously combined with the streams. A function of pH, Eh, and conductivity has been developed with discriminant function analysis for the purpose of easy, fast, and inexpensive measurement of the degrees of pollution of the streams. The estimated pollution of the streams with the discriminant function are consistent with what the chemical compositions of the water samples indicate. The pollution map of the study area was constructed from the calculated scores with the discriminant function. The pollution map suggests that the pollutants mainly come from the west side of Osheepcheon Creek. Thus, the abandoned coal mine drainage from the west side has to be appropriately treated as soon as possible to prevent Osheepcheon Creek from being further polluted. Considering the topography, climate, and the amount of the mine drainage, an active treatment method is recommended.  相似文献   

15.
水库汛限水位调整与运用   总被引:20,自引:0,他引:20       下载免费PDF全文
基于对水库汛限水位主要影响因素的系统分析,从洪水资源安全利用的角度出发,阐明了水库汛限水位调整综合分析论证所应遵循的原则,提出了风险设计分析论证的框架、定量分析方法和汛限水位合理调整的论证。最后以海河流域潘家口水库为分析实例,从设计洪水、预报预泄、洪水预报调度方式、上下游防洪设计标准、上游移民淹没及土地退赔线、水库长期运行的风险和效益等多个方面分析论证了水库汛限水位的合理调整方案。  相似文献   

16.
西昆仑地区早古生代原特提斯洋的后碰撞阶段划分存在分歧,通过对库地蛇绿岩南侧苏盖提力克花岗岩开展区域地质调查、岩石学、地球化学、锆石U-Pb年代学等方面研究,从而为原特提斯洋构造演化及闭合时限提供地质依据。研究表明,苏盖提力克花岗岩锆石U-Pb年龄(LA-ICP-MS)为(422.5±2.5)Ma,属于晚志留世岩浆活动产物。苏盖提力克花岗岩含有典型矿物白云母,A/CNK=1.07~1.11,刚玉分子含量为1.07%~1.56%,属于S型花岗岩。地球化学上,该岩体富硅、碱,贫钙、镁,富K、Rb、Nb、Th,贫Sr、Ti、P,Rb/Sr比值高;结合区域地质背景及地球化学特征综合分析表明,苏盖提力克花岗岩是原特提斯洋闭合后碰撞阶段的产物,因而晚志留世是原特提斯洋由消减闭合到陆陆碰撞—碰撞后伸展转换时期。   相似文献   

17.
塔里木盆地玉北地区奥陶系沉积相与沉积演化模式   总被引:1,自引:0,他引:1  
在塔里木盆地玉北地区奥陶系层序地层格架建立的基础上,通过对岩心、钻井、测井、地震及古生物等相关资料分析,以地震地层学和海相碳酸盐岩沉积模式为指导,对玉北地区奥陶系沉积相进行详细的研究,结果表明研究区奥陶系可划分为台地潮坪、局限台地、开阔台地、台地边缘、陆架内缘斜坡和陆棚等6种沉积相,并明确了研究区奥陶纪各期沉积相平面展布特征,总结了纵向上的沉积演化规律为:早奥陶世早期发育台地潮坪相;早奥陶世晚期随着海平面的持续缓慢上升,过渡为局限台地相;中奥陶世演化为开阔台地相;晚奥陶世早期演变为斜坡相,至晚奥陶世中晚期则发育陆棚相沉积体系。综合考虑古地理沉积环境、沉积相平面组合规律及控制因素,建立了玉北地区奥陶系沉积演化模式。  相似文献   

18.
贵州广顺二叠系化学地层的划分及沉积环境分析   总被引:2,自引:2,他引:2  
南君亚  周德全 《矿物学报》1996,16(2):223-230
本文以贵州省广顺二叠纪坝子头-茶叶剖面作了基准剖面,通过野外观察和室内岩相分析,根据岩石的成岩作用,颜色,微相特征及岩层的厚度和叠置关系,进行了层序的划分。在此基础上,以该剖面59个岩层的17个微量元素(As,B,Ba,Co,Cr,Cu,Ga,Mn,Mo,Ni,Pb,Sn,Sr,Ti,V,Zn和Zr)为变量,用因子分析和群分析进行了化学地层单元的划分,通过化学地层和层序地层划分结果的对比,结合化学  相似文献   

19.
本文在概述车大人沟河流域泥石流形成的地形地貌、物源和水源等条件的基础上,采用多元线性回归分析方法,选取了物源储量、支沟完整性系数、支沟边坡坡度、支沟沟床比降、冲沟密度、侵蚀模数、不良地质现象和植被覆盖率等八个指标作为自变量,建立与泥石流活跃度间相关关系的数学表达式,计算出车大人沟河40条泥石流支沟活跃度值,从而进行分区评价。将该区泥石流活跃度划分为高、中、低易发区和不发育区,其结果与实地灾情相符,可为车大人沟河流域泥石流防治规划提供科学依据。  相似文献   

20.
系统分析青藏高原新生代中新世50余个沉积盆地的类型、构造背景、岩石地层序列,对青藏高原中新世构造岩相古地理演化特征进行分析和探讨。中新世,青藏高原海相沉积已经全面退出,全部转为陆相沉积,约23Ma时高原及周边不整合面广布,标志高原整体隆升。塔里木、柴达木及西宁-兰州、羌塘、可可西里等地区主体表现为大面积的构造压陷湖盆沉积。约17.2Ma左右,阿尔金山显著隆升,使柴达木盆地西叉沟一带再无生物礁灰岩出现,且在盆地西部出现了短暂的沉积间断。这一时期,柴达木盆地西部开始进入湖退期,而东南部则快速湖进;同时,大约17.7Ma索尔库里山间盆地初始凹陷形成。另外,高原腹地五道梁-沱沱河盆地受南部唐古拉山的挤压抬升,在16Ma左右结束了五道梁组的沉积,在可可西里—唢呐湖一带则再次凹陷接受唢呐湖组沉积,形成高原腹地的大型压陷湖盆。13~10Ma期间,藏南南北向断陷盆地的形成,是高原隆升到足够高度开始垮塌的标志;约8Ma以来,高原东北部几乎所有湖盆均进入湖退期,普遍出现冲积扇、辫状河和水下扇砂砾岩堆积。  相似文献   

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