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1.
新疆青河卡拉先格尔铜矿带Ⅱ-Ⅲ矿区含矿斑岩锆石年龄及地质意义 总被引：5，自引：3，他引：2
新疆青河卡拉先格尔斑岩铜矿带位于阿尔泰山脉东南缘,NNW向可可托海-二台断裂与NW向额尔齐斯-玛因鄂博断裂交汇处偏东南位置。该矿带由卡拉先格尔Ⅰ、Ⅱ、Ⅲ号和玉勒肯矿区组成,其含矿斑岩主要为花岗闪长斑岩和石英闪长玢岩,围岩为中泥盆统北塔山组玄武岩,其中围岩局部地段也发生了矿化。矿石矿物主要由浸染状黄铜矿、辉钼矿和斑铜矿以及细脉状黄铜矿组成。本文对卡拉先格尔Ⅱ和Ⅲ铜矿区含矿斑岩中的锆石进行LA-ICP-MS U-Pb定年,结果表明含矿斑岩的锆石时代分别为390.2±4.9Ma和393.3±9.8Ma,反映了含矿斑岩侵入时代为中晚泥盆世。结合区域构造背景和火山岩-侵入岩地球化学等资料,综合分析表明该斑岩铜矿的成矿构造背景为中晚泥盆世岛弧环境。 相似文献
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卡拉先格尔斑岩铜矿带位于我国新疆北部,大地构造位于中亚成矿域的中段、西伯利亚克拉通南缘与华北-塔里木克拉通北缘增生造山带的接合部位,夹于北西向额尔齐斯-玛因鄂博断裂带和北北西向可可托海-二台断裂带的交汇处。研究发现卡拉先格尔斑岩铜矿带在成矿构造地质、矿石组构、元素组合和成矿期次等方面表现出多期改造与叠加成矿的特征。在前期区域成矿背景、典型矿床研究的基础上,本文总结了卡拉先格尔斑岩铜矿带的构造演化与成矿过程:在中-晚泥盆世,卡拉先格尔斑岩铜矿带处于与俯冲有关的岛弧构造背景,有两期中酸性斑岩侵入与Cu-Au-Mo矿化作用;早石炭世时,区域处于碰撞造山阶段,NW向韧性剪切变形造成原斑岩中的矿化发生迁移与再定位,片理构造发育处局部得到富集;晚石炭世到二叠纪是后碰撞伸展阶段,形成了卡拉先格尔斑岩铜矿带一系列张性构造和叠加的脉状矿化;进入中生代后,常见热液脉状铜矿化充填叠加到早期矿化之上,但同时本矿带遭受强烈的抬升与剥蚀作用。 相似文献
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西准达尔布特—包古图地区出露两类中酸性侵入岩,一类为海西晚期(<270Ma)花岗岩基,另一类为海西中晚期(330～320Ma)中酸性小斑岩体,包古图斑岩铜矿赋存于后者。岩石主量和微量元素分析表明,包古图含矿小斑岩基本满足埃达克岩的条件,即SiO2>56%,Al2O3>15%,MgO<3%,贫Y和Yb(Y<18×10-6,Yb<1.9×10-6),高Sr(>400×10-6),HREE明显亏损,其Nd和Sr同位素组成与洋中脊玄武岩(MORB)组成接近。但部分样品MgO含量较高(>3%),轻稀土元素丰度较低,偏离埃达克岩的组成范围。根据斑岩的地球化学组成并结合区域地质特征,笔者认为包古图含矿斑岩形成于与洋内俯冲有关的岛弧环境,但洋壳板片的初始熔体在上升过程中受到了地幔橄榄岩的不均匀混染。 相似文献
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新疆阿尔泰山南缘卡拉先格尔斑岩铜矿带成因再认识——来自哈腊苏铜矿硫-铅-氢-氧同位素和40/Ar-39Ar年龄的约束 总被引：16，自引：1，他引：16
通过对卡拉先格尔铜矿带中的哈腊苏斑岩铜矿床详细的野外地质调查和系统的同位素地球化学示踪和测年研究,探讨了阿尔泰南缘铜矿的成矿时代及矿床成因。研究表明,卡拉先格尔铜矿带的铜矿化主要呈不均匀团块、细脉或细脉浸染状产于受断裂控制的钾长石_石英脉、绿帘石脉以及石英_方解石脉中,线型分布明显,空间分布极不均匀,缺乏典型斑岩铜矿的面型蚀变矿化分带。含矿钾长石脉40Ar_39Ar年龄为(230±5)Ma,大大晚于容矿斑岩脉的形成时代〔锆石SHRIMPU_Pb年龄(380.8±5.7)Ma〕。硫_铅同位素指示成矿物质主要源于火山岩地层和花岗闪长斑岩脉。氢_氧同位素显示成矿流体为岩浆水和大气降水的混合物。据此认为,卡拉先格尔铜矿带主成矿时代为印支期,成矿作用与后造山阶段沿NNW向老山口断裂发育的偏碱性岩浆活动有关,但不排除存在同造山期的斑岩型矿化。 相似文献
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云南普朗印支期超大型斑岩铜矿床：岩石学及年代学特征 总被引：44，自引：14，他引：44
普朗斑岩铜矿位于云南西北晚三叠世义敦岛弧南段的滇西中甸弧内。义敦岛弧北部产有著名的呷村式黑矿型块状硫化物矿床,南部大量发育斑岩型铜矿床,普朗斑岩铜矿床即是其中的典型代表。普朗矿床由南、北两个复式岩体(矿段)组成,两个矿段均由一系列NW向构造控制的石英闪长玢岩、石英二长斑岩小岩株组成,是普朗铜矿区的主体,探明铜矿石量1．6亿吨,铜平均品位0．57%,铜金属量114万吨,伴生金金属量28．80吨,金品位0．18g/t;钼6399吨,品位0．004%。普朗斑岩铜矿床远景储量400万吨以上,为一个具有超大型规模远景储量的斑岩型铜矿床。普朗斑岩体容矿围岩SiO_2＞56%,MgO 1．34%～2．73%,Sr 661×10~(-6)～909×10~(-6),Y 10．78×10~(-6)～17．92×10~(-6),Yb 1．07×10~(-6)～1．87×10~(-6),LREE富集,δEu 0．83～0．93,Sr/Y比值22～64,K_2O/Na_2O比值0．52,具有与洋壳俯冲产生的埃达克岩(Ⅰ型埃达克岩)相似的地球化学特征。普朗斑岩铜矿形成于印支期,在我国斑岩铜矿床中具有其特殊性(不同于青藏高原喜马拉雅期斑岩铜矿带,如冈底斯斑岩铜矿带、玉龙斑岩带等;也不同于古亚洲成矿域的海西期斑岩铜矿带,如土屋-延东斑岩铜矿带,以及中国东部的燕山期斑岩铜矿带,如德兴斑岩铜矿),无论对中甸岛孤带的基础地质还是矿产资源评价预测的研究,该类矿床都具有重要的意义。普朗斑岩铜矿床含矿黑云石英二长斑岩的钾硅酸盐化(黑云母化和钾长石化)的成矿热液活动时间为235．4±2．4Ma～221．5±2．0Ma之间,石英-辉钼矿阶段的辉钼矿成矿(Re-Os)年龄大致为213±3．8 Ma;对矿区主矿体的热液黑云母单矿物的~(40)Ar/~(39)Ar测年,无论是含铜钼的矿化岩体,还是仅含铜的斑岩体,其成矿年龄(坪年龄)变化于为214．58±0．91Ma至216．0±1Ma之间,与辉钼矿Re-Os年龄非常接近,为晚三叠世诺利期。这表明普朗斑岩铜矿床的成矿作用在印支期完成。 相似文献
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新疆准噶尔北缘玉勒肯哈腊苏斑岩铜矿床年代学研究 总被引：7，自引：3，他引：4
玉勒肯哈腊苏铜矿是近几年准噶尔北缘卡拉先格尔斑岩铜矿带发现的又一个中型斑岩铜矿,其成岩成矿年代学的研究可以对矿床模型构建、区域成矿规律的总结提供制约。矿区侵入岩发育,矿化主要受闪长玢岩控制,少部分赋存在似斑状黑云母石英二长岩和北塔山组火山岩、火山碎屑岩中。本文利用锆石LA-ICP-MSU-Pb法和辉钼矿Re-Os法对矿区岩体和矿化进行了成岩成矿年代学研究。结合前人的研究,认为矿区存在5次主要岩浆侵入事件:382Ma石英闪长岩侵入,379Ma形成含矿闪长玢岩,375～374Ma形成似斑状黑云石英二长岩,348Ma形成黑云母石英斑岩脉,266Ma形成二长斑岩,前三次岩浆侵入活动对应构造环境为板块俯冲阶段,后二次岩浆侵入活动为后碰撞阶段。9件辉钼矿样品Re-Os同位素等时线年龄为373.9±2.2Ma,表明铜钼成矿时代为中泥盆世晚期,与闪长玢岩侵入有关。 相似文献
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希勒克特哈腊苏铜矿位于阿尔泰铜矿带南缘,即原卡拉先格尔斑岩铜矿带内。初步的研究和钻孔资料表明,铜矿体完全受斑岩体(石英闪长斑岩和花岗闪长斑岩)控制,矿石具细脉浸染状构造,金属矿物主要为黄铜矿和黄铁矿以及少量的磁铁矿、斑铜矿和镜铁矿。其中磁铁矿形成早于黄铜矿,指示了岩浆具有较高的氧化状态。矿化蚀变分带与斑岩铜矿基本相似,岩体内见钾长石化、黑云母化、硅化和黄铁矿化,接触带见石英绢云母化,围岩见青磐岩化。含矿斑岩的地球化学特征表明其属于埃达克岩(adakite):高SiO2(63%～66%)、高Al2O3(15%～17%)、富集Sr(378×10-6～447×10-6)、无负Eu异常、亏损Y(10×10-6～14×10-6)和Yb(1.3×10-6～1.5×10-6)以及低的Sr同位素初始值(0.70439)、高的(εNd)t(+6.9～+8.2)和低的δ18OV-SMOW(<10‰)。其Rb-Sr等时线年龄为(332.8±8.5)Ma,为早石炭世侵位的产物,其形成与蒙古洋板块向南俯冲造成的洋壳部分熔融有关,因此其成矿地质背景与世界巨型斑岩铜矿十分相似。另外,在希勒克特哈腊苏铜矿外围还有数个与其十分相似的铜矿点,因此该地区展示了良好的找矿前景,同时也是中国又一个潜在的斑岩铜矿带。 相似文献
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国内外学者对发育于弧环境和碰撞造山环境的斑岩铜矿成岩机制已取得了深刻的理解,但对产出在克拉通内部的斑岩铜矿成岩机制在认识上还有所欠缺。本文报道了侵位于144Ma木吉村斑岩铜矿内的含矿闪长玢岩的岩石地球化学资料,以揭示木吉村斑岩铜矿的含矿斑岩成因。岩石地球化学资料显示:含矿闪长玢岩具有较低的(^(87)Sr/^(86)Sr)i值(0.70599~70690)和εNd(t)值(-19.4~-14.9),富集轻稀土元素(LREEs)和大离子亲石元素(LILEs),相对亏损元素Y和Yb。木吉村含矿斑岩与王安镇杂岩体镁铁质岩(辉石岩、角闪石岩、辉长岩、辉长闪长岩、安山岩)具有相似的微量元素配分模式、Sr-Nd同位素组成及亲EMⅠ地幔特征,这些岩浆岩呈现持续性的成份演化趋势,反映出它们的同源性。木吉村含矿斑岩及相关的镁铁质岩石具有相对较低的(^(87)Sr/^(86)Sr)i值(0.70564~706897)和εNd(t)值(-19.4~-13.8),显著区别于中上地壳同位素区域。含矿斑岩起源于伸展背景下富集地幔部分熔融形成的玄武质岩浆,其上升过程中遭受了一定程度的下地壳混染。玄武质岩浆在深部岩浆房发生堆晶作用形成具典型堆晶结构的角闪石岩等基性岩,随后在浅部岩浆房经历两阶段辉长岩-辉长闪长岩、安山岩-闪长玢岩系列分离结晶作用形成含矿斑岩。此过程可能是形成华北克拉通木吉村斑岩铜矿含矿斑岩的机制和动力诱因。 相似文献
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东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。 相似文献
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The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
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. 相似文献
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郯庐断裂南段研究进展与断裂性质讨论 总被引：13，自引：3，他引：13
据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。 相似文献
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Guboglo M. N. 《GeoJournal》1980,4(1):53-58
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. 相似文献
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某高速公路下伏煤矿采空区稳定性分析 总被引：10，自引：0，他引：10
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。 相似文献
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Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 《《幕》》2008,31(3):315-318
The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs. 相似文献
18.
Dean S. Oliver 《Mathematical Geology》1998,30(7):911-933
In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix. 相似文献
19.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″. 相似文献
20.
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 相似文献