首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
云南富乐厂铅锌矿床是滇东北矿集区东南部的典型矿床之一。在矿区进行大比例尺构造填图的基础上,运用构造成矿动力学的理论和方法,筛选典型断裂构造进行力学性质的鉴定,对不同期次、不同方向的断裂特征进行了系统阐述,初步划分了构造期次,总结了构造体系。认为该区断裂经历了晋宁期-澄江期近东西向的挤压作用,印支期-燕山早期北西-南东向挤压作用及后期燕山中晚期-喜马拉雅期的北东-南西向挤压作用的过程。晋宁-澄江期构造作用为该区成矿提供了有利的地质背景,印支期-燕山早期为该矿成矿主期,北东向压扭性断裂和北西向的扭张性断裂使得流体充填、富集成矿;后期近东西向的扭性断裂为破矿构造。通过矿区构造与成矿关系的研究,为隐伏矿预测与深部勘查提供了依据。  相似文献   

2.
云南郝家河铜矿床是楚雄盆地砂岩型矿床的典型代表。在矿区大比例尺构造地质填图的基础上,运用矿田地质力学的理论和方法,筛选典型断裂,进行断裂面力学性质的鉴定,划分构造期次,厘定构造体系,并对区内不同期次、不同方向断裂的地质特征及其与成矿的关系进行了详细的阐述。认为自燕山期以来该区经历了NE-SW向→近EW向→NW-SE向→近SN向4期构造主压应力的转换。燕山晚期NW向构造对早期成矿物质活化、迁移、重分配,造成铜的初始富集具有控制作用;燕山晚期—喜山早期近SN向断裂构造促使成矿物质富集,矿体形态多表现为层状、似层状;喜山早期NE向断裂构造促使含矿热液从地层中萃取大量含矿物质并发生再富集,形成富厚矿体;喜山中晚期近EW向断裂构造主要对已形成的矿体造成破坏。  相似文献   

3.
云南芦子园铅锌多金属矿床属于超大型矽卡岩型矿床。矿体产于上寒武统沙河厂组(∈_3s)大理岩与板岩层间破碎带中,构造控矿明显。矿区主要经历三期构造活动,早期为北东向压扭性断裂,是矿区的主要导矿和容矿构造,控制了矿体的空间展布;中期为北西向张扭性断裂,晚期为近东西向张性,中-晚期断裂为破矿构造,错断北东向断裂及矿体。  相似文献   

4.
根据泰宁何宝山金矿区的控矿构造特征的综合分析,认为何宝山金矿区断裂构造发育,主要有近南北向、北东向、北西向3组。北东向的断裂为导矿构造,南北向断裂为控矿构造。控矿断裂为2组近南北向的断裂裂隙群,具有明显的剪性特征,控制了金矿化蚀变带及金矿体的空间展布。近东西向断裂构造为成矿后期的,对南北向的控矿断裂构造具有破坏作用。金矿化蚀变体产于断裂破碎带内,明显受断裂控制。而金矿化程度与蚀变强弱、断裂的规模、破碎程度有直接相关。结合地质类比法,通过构造分析法及矿区地质条件、矿化特征综合分析,认为矿区F3断裂及弧形的拐弯处、F2-4断裂深部为矿体产出有利部位,矿区北部在断裂构造收敛部位、帚状构造砥柱边缘为寻找矿体有利地段。  相似文献   

5.
湖南宝山铜铅锌多金属矿床位于南岭东西向构造带与耒阳—临武南北向构造带的复合部位,是该区大型—超大型矿床的典型代表之一。矿床(体)与燕山早期花岗闪长斑岩体在空间上关系密切,均明显受构造控制。在大比例尺构造剖面精细解析基础上,分析构造类型及其主要特征,总结构造控岩控矿规律。研究认为:矽卡岩型铜钼矿体主要受北东—北东东向褶皱控制;热液脉型铅锌银矿体主要受褶皱翼部层间断裂及北东向压扭性断裂控制。构造应力场最大主应力方向经历了成矿前近南北向→成矿期近东西向→成矿后北东—南西向的转变。北东—北东东向压扭性断裂为导矿构造,北西西向张扭性断裂为控岩构造。构造不仅控制了成矿岩体的展布,而且控制了成矿类型的变化。在此基础上,建立了构造控岩控矿模式,指示已知矿体北西侧深部是有利的找矿地段。该研究为深部找矿预测提供重要依据,对坪宝矿田的找矿部署和深部勘查具有参考意义。   相似文献   

6.
新疆金山金矿床构造控矿规律及找矿评价标志研究   总被引:2,自引:1,他引:1       下载免费PDF全文
金山金矿床是中国西天山地区一个大型浅成低温热液型金矿,矿体产出主要受各种断裂构造控制。在多年勘探工作的基础上,通过野外填图和大量的勘探线剖面分析,笔者总结出断裂构造活动经历了成矿前、热液成矿期和成矿后3期。断裂控矿基本规律是:北西向断裂总体控制矿床的分布位置,南北向断裂晚期活动造成叠加富集成矿,北东向断裂早期伴随中酸性岩脉活动,成矿后活动造成矿体断开和升降,东西向-北西西断裂早期伴随火山喷发活动,成矿后活动切断南北向矿体。同时还总结了矿区的找矿评价标志。  相似文献   

7.
鄂东南徐家山金矿田成因研究   总被引:4,自引:0,他引:4  
鄂东南徐家山金矿田产于志留系(含碳)碎屑岩地层中。矿田内断裂构造发育,可分为近东西向、北东向、北西向和近南北向4组。近东西向断裂是区域构造的基础,是主要的导矿构造;北东向和北西向断裂控制了晚期岩脉及金矿体的分布,也是主要的储矿构造。主成矿期的流体为低—中等盐度、低密度流体,属酸性、弱还原环境,成矿压力为44.270一47.948MPa,属地壳浅层次成矿。矿区内与成矿有关的石英包裹体中的水均属大气降水(地下水),岩浆活动提供了部分矿质和热源。矿田内的金矿床为中低温热液型金矿床。  相似文献   

8.
阿延寿 《青海地质》1997,6(1):28-33
滩间山矿田产出部位及矿体延展严格受断裂构造制约。矿田地区发育北西向压扭性断裂,北东向张扭性断裂和近东西向扭性断裂,北西向,并东向断裂均为控矿断裂,但北东向断裂的控矿作用更为明显。  相似文献   

9.
江西永平铜矿田构造发育过程的初步探讨   总被引:1,自引:0,他引:1  
刘迅  黄震 《矿产与地质》1991,5(6):416-422
江西永平铜矿田构造发育过程,主要是在印支期近东西向挤压作用下形成近南北轴向的候家—嵩山倒转背斜及一系列压担性断裂.在褶皱过程中,翼部产生层间差异性滑动,形成层间破碎带和构造裂隙.在燕山早期第一阶段近南北向挤压作用下使轴向断裂张开,成为构造减压带而成矿.  相似文献   

10.
虎家尖银金矿床为赣东北地区典型的受一组NE向韧脆性断裂破碎带控制的中低温热液型银金矿床。矿床赋存于中元古界双桥山群浅变质岩中,矿脉均产于断裂带内,具舒缓波状、膨大缩小、分支复合、尖灭再现等特征。研究表明,控矿断裂具有长期性、多期次和继承性活动的特点,经历了早期压扭性塑性变形、中期张扭性脆性变形和晚期压扭脆性变形3个演化阶段。通过地质调查、数据处理和成矿构造分析,认为成矿期石英多金属硫化物阶段的构造应力场:σ1为190°∠2°,σ2为90°∠78°,σ3为280°∠12°,差应力约为71.3~99.3 MPa;银多金属硫化物阶段构造应力场方向与石英多金属硫化物阶段基本相同;石英碳酸盐阶段构造主应力方向表现为NW-SE向挤压。文章总结了断裂对矿体空间定位、似等距性分布、矿体侧伏等方面控矿规律,断裂面凹凸转换部位为成矿有利地段,矿体在水平方向和垂向上似等距性分布明显,并且整体大致呈45°向北东深部侧伏。结果表明,在矿区50线深部及北东部深部找矿潜力巨大,矿区外围北东向韧性剪切带有后期脆性变形叠加的断裂破碎带为找矿有利地段。这对赣东北地区同类型矿床的深部及外围找矿具有一定的指导和借鉴意义。  相似文献   

11.
填海工程使滨海地区的地下水物理化学条件改变,导致该区域地下水中重金属浓度升高。本文以深港西部通道填海区为例,采用实验室模拟填海条件的办法,初步探讨了影响填海区地下水重金属迁移的关键因素。模拟实验结果表明,填海区地下水中钨元素含量升高与地下水淡化、淤泥氧化过程以及填料风化有关;铜元素含量升高则与淤泥氧化过程以及填料风化有关;钒元素含量升高与地下水淡化和淤泥氧化过程有关,而其他元素含量升高则主要与填料风化释放有关。  相似文献   

12.
Summary The Middle Proterozoic Faraday Metagabbro in the Bancroft area of eastern Ontario has been subjected to syn-orogenic textural and mineralogical modifications resulting in the formation of scapolite-bearing metagabbro and gabbroic blastomylonite assemblages. The elemental flux during cryptic and overt scapolitization has been calculated usingGresens general metasomatic equation which applies corrections for density and volume changes during alteration. Metasomatic variation diagrams using analyses from two primary gabbros and six altered rocks indicate that Na, K, Cl, Li, Rb, and Ba are the principal introduced elements and that Cu and S were removed. These changes are very similar to those involved in the formation of metasomatic nepheline-bearing rocks elsewhere in the district and, furthermore, nephelinization and scapolitization were broadly coincident in time and space. It is concluded that the nephelin- and scapolite-bearing rocks and their cryptic facies are different manifestations of the same metasomatic agent and that the source of the fluids was a possible horizon of evaporitic sediments within the country rocks in which the gabbro was emplaced.
Metasomatose im Faraday-Metagabbro, Bancroft, Ontario, Kanada
Zusammenfassung Der Mittel-proterozoische Faraday-Gabbro in der Umgebung von Bancroft (Ost-Ontario) erfuhr synorogene Veränderungen in Textur und Mineralogie, die zur Bildung skapolit-haltiger Metagabbros und gabbroider Blastomylonite führten. Die während kryptischer und offener Skapolitisierung stattfindende Elementtransport wurde mit Hilfe der vonGresens entwickelten generellen metasomatischen Gleichung errechnet; Korrekturen für Varänderungen in spezifischer Dichte und Volumen wurden angebracht. Metasomatische Variationsdiagramme basierend auf Analysen an zwei primären Gabbros und sechs modifizierten Gesteinen zeigen, daß Na, K, Cl, Li, Rb und Ba die hauptsächlich zugeführten Elemente darstellen, und daß Cu-und S-Konzentrationen abgebaut wurden. Diese Veränderungen sind vergleichbar mit solchen, wie sie bei der Bildung metasomatischer, Nephelin-haltiger Gesteine erkannt wurden. Außerdem fallen Nephelinisierung und Skapolitisierung zeitlich und räumlich in etwa zusammen. Daraus kann geschlossen werden, daß Nephelin- und Skapolit-haltige Gesteine und deren kryptische Phasen durch den gleichen metasomatischen Prozeß entstanden sind, und daß die Herkunft der umwandelnden Lösungen möglicherweise in evaporitischen Sedimenten zu suchen ist, in die der Gabbro intrudierte.


With 3 Figures  相似文献   

13.
新疆维吾尔自治区阿图什市木吉地区邻近帕米尔,是印度板块与欧亚板块碰撞挤压应力最集中的地区,地层变质和变形强烈,研究基础薄弱。木吉群由变质砂岩、板岩、千枚岩、石英岩、钙质石英岩、变粒岩、二云石英片岩、大理岩等组成,一直未发现任何化石。最近,笔者在木吉乡的喀拉足克沟和阿拉木陶沟的粉砂岩、钙质粉砂岩中发现了一些植物管胞片和孢粉化石:Gran-ulatisporites sp.,Cycloranisporites sp.,Verrucosisporites sp.,Pityosporites sp.,Punetatosporites sp.,Leiotriletes sp.,Apicu-latisporites sp.,Platysaccus sp.,Cycodopites sp.等。从地层接触关系和孢粉化石的整体面貌看,木吉地区含上述孢粉化石的木吉群的时代可能为泥盆纪—石炭纪。  相似文献   

14.
Study of the cross-stratification and other sedimentary structures in the Lower Greensand of the Weald, England, and Bas-Boulonnais, France, indicates that the sediments were deposited by the lateral migration of sand waves in a neritic sea. Comparison of the Lower Greensand sea with the modern North Sea was attempted. If those sediments were deposited as a result of tidal current similar to the present-day North Sea then the Lower Greensand shoreline could be deduced as running northwest-southeast, indication that the western part of the London Platform was submerged.  相似文献   

15.
西藏阿里札达盆地上新统中犀类化石的发现及意义   总被引:9,自引:10,他引:9  
首次在西藏阿里札达盆地上新世河湖相沉积地层中发现了犀类化石,对其基本特征进行了描述,初步鉴定为犀类额鼻角犀亚科第三庶骨化石,在同一层位中还采集了大量孢粉、微体古生物和植物化石。结合区域地质特征和产出犀类化石地层的沉积学特征等的分析,认为札达盆地上新世时代表着温暖湿润向寒冷潮湿-温和干旱的气候变化过程。这一发现有助于进一步认识青藏高原新近纪上新世的生物演化、气候变化和构造活动,为研究青藏高原新近纪以来的生物进化、湖泊与河流演化、气候变化.古地理与古环境变迁,以及新生代地层的划分对比等提供了新资料。  相似文献   

16.
The paper reports newly obtained data on the geochronology of the Dovyren intrusive complex and associated metarhyolites of the Inyaptuk Formation in the Synnyr Range. The data were obtained by local LA-ICPMS analysis of zircons in samples. The U-Pb age of olivine-free gabbronorite from near the roof of the Yoko-Dovyren Massif is 730 ± 6 Ma (MSWD = 1.7, n = 33, three samples) is close to the estimated age of 731 ± 4 Ma (MSWD = 1.3, n = 56, five samples) of a 200-m-thick sill beneath the pluton. These data overlap the age of recrystallized hornfels found within the massif (“charnockitoid”, 723 ± 7 Ma, MSWD = 0.12, n = 10) and a dike of sulfidated gabbronorite below the bottom of the massif (725 ± 8 Ma, MSWD = 2.0, n = 15). The estimates are also consistent with the age of albite hornfels (721 ± 6 Ma, MSWD = 0.78, n = 12), which was produced in a low-temperature contact metamorphic facies of the host rocks. The average age of the Dovyren Complex is 728.4 ± 3.4 Ma (MSWD = 1.8, n = 99) based on data on the sill, near-roof gabbronorite, and “charnockitoid”) and is roughly 55 Ma older than the estimate of 673 ± 22 Ma (Sm-Nd; [13]). The U-Pb system of zircon in two quartz metaporphyre samples from the bottom portion of the Inyaptuk volcanic formation in the northeastern part of the Yoko-Dovyren Massif turns out to be disturbed. The scatter of the data points can be explained by the effect of two discrete events. The age of the first zircon population is then 729 ± 14 Ma (MSWD = 0.74, n = 8), and that of the second population is 667 ± 14 Ma (MSWD = 1.9, n = 13). The older value pertains to intrusive rocks of Dovyren, and the age of the “rejuvenated” zircon grains corresponds to the hydrothermal-metasomatic processes, which affected the whole volcano-plutonic sequence and involved the serpentinization of the hyperbasites. This is validated by the results of Rb-Sr isotopic studies with the partial acid leaching of two serpentinized peridotite samples from the Verblyud Sill. These studies date the overprinted processes at 659 ± 5 Ma (MSWD = 1.3, n = 3).  相似文献   

17.
西藏措勤县雄玛地区林子宗群帕那组火山岩大地构造位置位于冈底斯—念青唐古拉山板片,地层分区上属于冈底斯地层区、隆格尔—南木林地层分区。岩性主要为一套以浅灰色、灰绿色流纹质凝灰岩为主,夹浅黄绿色、灰绿色流纹岩及英安岩、火山角砾岩、杂砂岩及砾岩的岩石组合。之下与永珠组和拉嘎组呈喷发不整合接触。岩石地球化学特征表明该火山岩系属过铝质的高钾钙碱性—亚碱性系列,稀土元素地球化学中轻稀土元素明显富集,微量元素中大离子亲石元素(Rb、K、Th、U、LREE)富集,高场强元素(Nb、P、Ti)亏损。以上特征说明雄玛地区林子宗群帕那组火山岩岩浆源于陆壳重熔,属与俯冲造山有关的陆相火山岩,同时又兼具陆—陆碰撞的特点。推测帕那组火山岩形成于新特提斯洋壳俯冲基本结束,印度板块与欧亚板块碰撞开始的构造背景下,年龄大概在38Ma左右,为始新世晚期。  相似文献   

18.
Over the past decade researchers working on the rocks of the Beaufort Group in the main Karoo Basin of South Africa have vastly increased our understanding of this important Permo-Triassic sequence. Many new fossil forms have been discovered, allowing for breakthroughs into the biodiversity, biogeography and biostratigraphy of the group. Taxonomic and phylogenetic advances are many and varied, and cover most of the vertebrate taxa, but with emphasis placed on the temnospondyl amphibians, archosauriforms and non-mammalian synapsids, in particular the anomodontia. Biostratigraphic breakthroughs have centered on the Middle Permian Eodicynodon and Tapinocephalus assemblage zones, the Late Permian Dicynodon Assemblage Zone, and the Triassic Lystrosaurus and Cynognathus assemblage zones. Correlation of these biozones with better dated sequences in Europe, Russia and China has allowed for many chronostratigraphic refinements, which are in turn vital for sequence stratigraphical analysis of the basin fill. Based on fossil data, both the lower (Ecca–Beaufort) and upper (Beaufort–Molteno) contacts of the group have been proved to be highly diachronous. The refined chronostratigraphic framework has also allowed for a better analysis of the basin evolution through time, particularly in terms of the correlation of external stimuli that affect basin sedimentation patterns.  相似文献   

19.
藏北羌塘丁固—加措地区康托组的时代   总被引:2,自引:0,他引:2  
自西藏区域地质调查大队创建康托组以来,康托组岩石地层单位广泛应用于羌塘地区,普遍认为其时代为新近纪.笔者于丁固-加措地区的康托组地层中采获古近纪轮藻化石Obtusocharat sp.,O.lanpingenis,Gyrogona qinajiangica和部分孢粉化石,并在康托组底部安山岩中获K-Ar年龄65.1~66.5Ma.上述轮藻组合与同位素年龄指示的地层时代为古新世-始新世,据此将测区康托组的时代确定为古近纪.由于测区康托组之上被唢纳湖组或鱼鳞山组角度不整合覆盖,因此康托组时代的确定不仅进一步完善了测区新生代地层系统,还指示测区在康托组与唢纳湖组或鱼鳞山组之间发生了一次强烈的构造运动.  相似文献   

20.
The Kaalamo massif is located in the Northern Ladoga region, Karelia, on the extension of the Kotalahti Belt of Ni-bearing ultramafic intrusions in Finland. The massif, 1.89 Ga in age, is differentiated from pyroxenite to diorite. Nickel–copper sulfide mineralization with platinoids is related to the pyroxenite phase. The ore consists of two mineral types: (i) pentlandite–chalcopyrite–pyrrhotite and (ii) chalcopyrite, both enriched in PGE. Pd and Pt bismuthotellurides, as well as Pd and Pt tellurobismuthides, are represented by the following mineral species: kotulskite, sobolevskite, merenskyite, michenerite, moncheite, keithconnite, telluropalladinite; Pt and Pd sulfides comprise vysotskite, cooperite, braggite, palladium pentlandite, and some other rare phases. High-palladium minerals are contained in pentlandite–chalcopyrite–pyrrhotite ore. Native gold intergrown with kotulskite commonly contains microinclusions (1–3 μm) of Pd stannides: paolovite and atokite. Ore with 20–60% copper sulfides (0.2–6.0% Cu) contains 5.1–6.6 gpt PGE and up to 0.13–2.3 gpt Au. Pd minerals, arsenides and sulfoarsenides of Pt, Rh, Ir, Os, and Ru are identified as well. These are sperrylite, ruthenium platarsite, hollingworthite, and irarsite; silvery gold and paolovite have also been noted. All these minerals have been revealed in the massif for the first time. The paper also presents data on the compositions of 25 PGE minerals (PGM) from Kaalamo ores.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号