共查询到20条相似文献，搜索用时 62 毫秒
1.
普朗斑岩型铜矿是格咱地区印支期斑岩型铜矿的典型代表,产于义敦构造-岩浆带南端的复式岩体。复式岩体为浅成-超浅成的中酸性斑(玢)岩体,可划分为3个侵入阶段,最早为石英闪长玢岩,中期为石英二长斑岩,晚期为花岗闪长斑岩。岩石地球化学特征表明,岩石富集Ba、La、Rb、Sr、K和亲铜元素Cu、Pb,亲铁元素Mo、Ni,亏损Nb、Zr、Hf、Ti。斑(玢)岩与岛弧花岗岩的岩石系列相同,属钙碱性岩系,成因类型一致,属I型花岗岩。普朗斑岩型铜矿床主要产于印支期的中酸性斑(玢)岩体,成矿作用受岩浆岩、侵位地层、热液运移、热液蚀变作用和构造空间的控制,其印支期构造-岩浆-热液之间的耦合,共同形成了斑岩成矿系统。 相似文献
2.
普朗斑岩铜矿床是云南中甸地区最大的斑岩型铜矿床,其成矿作用与普朗复式岩体存在密切的成因联系。对普朗复式岩体成矿的第1期石英闪长玢岩和第2期石英二长斑岩,以及不成矿的第3期闪长玢岩开展了锆石原位微量元素和磷灰石原位主量元素成分的研究。结果表明,锆石Ce/Ce~*值、Ce~(4+)/Ce~(3+)比值和Ce/Nd比值指示,不成矿的第3期闪长玢岩与成矿的第1期石英闪长玢岩的岩浆相对氧化状态大致相当,且明显高于成矿的第2期石英二长斑岩。磷灰石Cl、OH和SO3成分指示,普朗复式岩体3期斑岩具有相似的岩浆含水量,但成矿的第1期石英闪长玢岩和第2期石英二长斑岩较不成矿的第3期闪长玢岩具有更高的岩浆挥发分Cl含量和硫逸度。岩浆的高氧逸度和硫逸度、富水和富挥发分Cl均是形成斑岩铜矿床的关键因素,普朗不成矿的第3期闪长玢岩与成矿的第1期石英闪长玢岩和第2期石英二长斑岩均具有富水和高氧逸度特征,但第3期闪长玢岩较成矿的第1期石英闪长玢岩和第2期石英二长斑岩具有明显更低的岩浆挥发分Cl含量和硫逸度,这很可能是导致第1期石英闪长玢岩和第2期石英二长斑岩成矿,而第3期闪长玢岩不成矿的重要原因之一。 相似文献
3.
4.
为查明普朗超大型斑岩铜矿床外围岩体的岩石类型及其地球化学特征,对其外围东部斑岩体的岩石学、岩石地球化学及成岩年代进行了研究。结果表明,外围东部斑岩类型为石英闪长玢岩,缺少二长斑岩;岩石属钙碱性系列;富集轻稀土及Cs、Rb、K等大离子亲石元素,相对亏损Y、Hf、Zr等高场强元素。石英闪长玢岩的侵位年龄为(221.3±0.3)Ma,与I号复式岩体中的闪长玢岩年龄一致。通过与首采区I号复式岩体进行对比,认为外围东部石英闪长玢岩体相当于首采区闪长玢岩体的边缘部位,二者属于同一个侵入体,但在岩石学及岩石化学特征上有一定区别。由于普朗矿区外围东部缺乏主成矿阶段的二长斑岩体,因此不利于斑岩型矿体的形成。 相似文献
5.
普朗斑岩铜矿地处甘孜-理塘结合带西侧德格-中甸陆块东缘,印支期义敦-中甸岛弧带南段。矿区地层为上三叠统图姆沟组,主要出露普朗印支期复式中酸性斑(玢)岩体,构造裂隙发育,岩石蚀变强烈,具典型的“斑岩型”蚀变分带:由中心向外依次为强硅化带→硅化钾化带→绢英岩化带→青磐岩化带。岩浆岩、岩浆侵位的地层、热液蚀变作用、热液运移和矿质沉淀的构造空间控制了本矿床的产出。其成矿作用发生于普朗复式斑岩体内,矿化与蚀变相伴进行,在岩体中心形成由细脉浸染状矿石组成的筒状矿体,岩体边部产出脉状矿体。成矿元素以铜为主,伴有金、银、钼、钯、硫等多种有用组分。矿床规模达到超大型。 相似文献
6.
地苏嘎印支期斑岩体位于中甸岛弧东斑岩带的北端,岩性为石英闪长玢岩,与普朗超大型斑岩铜矿的成矿岩体同属于甘孜—理塘洋壳俯冲作用晚期岩浆活动的产物。全岩地球化学特征显示,地苏嘎石英闪长玢岩具有中等的SiO2含量,较高的Al2O3及全碱(K2O+Na2O)含量。全岩亏损高场强元素,富集大离子亲石元素,稀土元素配分曲线呈典型的右倾状,显示出轻稀土富集、重稀土相对亏损的特点。主量元素和微量元素成矿指示方面的研究结果表明:与普朗38个与成矿有关的石英闪长玢岩的全岩数据相比,地苏嘎石英闪长玢岩具有相对较低的SiO2和Y含量、较高的∑REE和(La/Yb)N比值,但二者的Al2O3/(CaO+Na2O+K2O)比值及MnO含量差别不大。在成矿与非成矿斑岩的SiO2- Al2O3/(CaO+Na2O+K2O)和Y-MnO图解中,地苏嘎石英闪长玢岩与普朗石英闪长玢岩数据投图结果类似。此外,地苏嘎斑岩体在物探异常、化探异常及遥感影像特征上具有明显的矿化标志,同时岩体的剥蚀深度小于侵位深度,有利于矿床的保存。以上研究结果表明地苏嘎斑岩体具有成为斑岩型铜矿床的潜力。 相似文献
7.
赋矿的普朗含矿复式斑岩体,具典型斑状特征及铜、钼、铁成矿专属性,由边缘到中心具石英闪长玢岩→石英二长斑岩演化关系,硅化钾化、绢英岩化蚀变与铜矿关系密切,尤以石英二长斑岩蚀变和矿化作用最强烈。硫同位素表明岩体属幔-壳源硫特征,铅同位素显示岩体铅集中分布于造山带演化线附近及下地壳、造山带、岛弧重叠区的特征。 相似文献
8.
冈底斯成矿带是在青藏高原上发育的巨型铜矿带,存在中侏罗世俯冲型、始新世同碰撞型和中新世后碰撞型三期斑岩成矿作用。其中,中新世出现了斑岩成矿大爆发,形成铜资源量超千万吨的中国第一大铜矿——驱龙铜矿在内的一系列大型-超大型斑岩铜矿床。通过大量详实的野外调查与综合研究,认为冈底斯含矿岩体并非传统的单一斑岩体,而是形成时间相近、多期次侵入的复式小斑(杂)岩体,其成矿及改造贯穿于复式小杂岩体的每次侵入过程。矿区大规模蚀变与矿化并非围绕某单一小斑岩体分布,而成矿物质及成矿流体也不是直接来源于浅侵位的小斑岩体,而是来源于地壳下部10km左右二次岩浆房的多次泵出,是深部同一岩浆房的岩浆不断演化的结果。多期次的岩浆侵入源源不断地供给成矿物质、成矿流体及成矿热动力,是形成大型-超大型斑岩铜矿床的极重要找矿标志。笔者提出"在相同环境下小(斑)杂岩体侵入的期次越多、岩性及成矿元素越复杂越有利于成大矿"这一理论新模型,丰富与完善了经典的斑岩铜矿成矿理论,对推动在冈底斯斑岩铜矿带进一步进行地质勘查评价工作部署及找矿突破具有重要的指导与借鉴意义。 相似文献
9.
中甸雪鸡坪斑岩铜矿地质及找矿远景 总被引：3，自引：0，他引：3
雪鸡坪斑岩铜矿含矿母岩为印支期浅成相同熔型石英二长闪长玢岩、石英闪长玢岩、石英二长斑岩组成的复式岩株。发育面型蚀变带,经历气成一高温热液、中低温热液及低温热液三次矿液叠加成矿。在钾化带及石英一绢云母化带发育浸染状及网脉状铜矿化。认为普朗及其南部、地苏嘎是区内形成大型斑岩铜矿最有希望地区。 相似文献
10.
近期钻孔资料揭示,西藏尼木县厅宫铜矿区主要为二长花岗(斑)岩、花岗闪长斑岩、钾长花岗(斑)岩和石英闪长玢岩构成的复式斑岩体,白容铜矿区的容矿岩石为花岗闪长斑岩、闪长玢岩,以及正长斑岩、安山玢岩脉;铜(钼)矿化呈面型分布,含矿斑岩体几乎全岩矿化,与围岩接触带附近矿化强度增强;矿化垂向厚度达数百米,强弱不均,自上而下可分为氧化带、过渡带、原生带;硅化、绢云母化、高岭土化、黄铁矿化等蚀变广泛而强烈. 相似文献
11.
以29口钻孔的重矿物百分含量数据来分析样本,通过Q型聚类分析、因子分析方法恢复不同物源体系的发育范围及其母岩类型,并以不同物源体系的边界范围为限定条件,结合ZTR指数及其等值线图,对珠江口盆地惠州凹陷M层物源特征进行了系统的研究。研究结果表明：研究区发育3大物源沉积区,分别为东北-北部物源沉积区、西北物源沉积区和东南物源沉积区,且各区重矿物组合特征明显,主次物源分明,整体表现为母岩类型复杂的特征。东北-北部沉积物主要母岩为酸性岩浆岩,次要母岩为变质岩和沉积岩,西北沉积物主要母岩为中性及基性岩浆岩,次要母岩为酸性岩浆岩和变质岩,东南沉积物主要母岩为中性及基性岩浆岩,次要母岩为变质岩。东北-北部物源区和西北物源区为远源沉积的产物,而东南物源区为近源沉积的产物。东北-北部物源区沉积物来自北方和东北方向,而西北物源区和东南物源区沉积物分别来自西北方向和东南方向。 相似文献
12.
两种煤质分析指标的关联方程组研究 总被引：5，自引：0，他引：5
在综合分析大量文献资料的基础上，采用多元线性回归方法，利用MATLAB对大量煤质分析结果进行了回归分析，推导出了煤质元素分析与工业分析的关联方程组。新方法实现了由工业分析结果求元素分析成分的目的，具有重大的实用意义。 相似文献
13.
An algorithm andFortran-iv computer program,cabfac, forQ-mode factor analysis is described. The program will accept up to 1500 items and 50 variables on a moderate-size computer. 相似文献
14.
Ibsen Chivatá Cárdenas 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2019,13(1):53-65
In this paper, we report on the use of Bayesian networks, BNs, learnt from data generated by physical and numerical models, to overcome to a certain degree a number of complications in traditional slope stability analyses that jointly consider the mechanical and hydraulic properties of soils. Discrete Bayesian networks resulted to be useful and efficient to acquire knowledge from simulated data and to identify significant factors by the combined use of backward inference and global sensitivity analysis. Further, BNs enable decision thresholds to be estimated quickly. Along with this, backward inference and global sensitivity analysis are performed in BNs at low computation costs. Moreover, under conditions in which knowledge is scarce, we show how a practitioner can be better informed using the proposed approach. All these previously under-reported modelling features in the specialised literature encourage the further application of the proposed approach to enhance slope stability analysis. 相似文献
15.
A piston core from the southern Blake Basin penetrated nine distinct bioclastic carbonate turbidites separated by pelagic terrigenous clay units. X-ray diffraction analysis of the carbonate mineralogy of the graded, laminated, and homogenous units of the individual turbidite units indicated a general loss of unstable carbonates in the homogenous unit beyond that contained in the lower two units. Univariate and multivariate statistical tests were employed to determine the significance of the changes and to determine if different units of a turbidite sequence could be consistently grouped by statistical methods. Principal components, discriminant function, and cluster analysis were used in the multivariate tests. The graded and laminated units were closely related in mineralogy with little significant differences. The mineralogy of the homogenous units was significantly different than that of the other two units except in one example. Cluster analysis generated five groupings of the samples with the end members consisting of graded and laminated units at one end and homogenous units at the other. 相似文献
16.
以有限元结构矩阵分析为理论基础，结合应力应变测试和现场实际使用情况，利用计算机结构分析程序，对ＺＴ－Ａ系列三个不同高度钻塔的天梁、塔腿和绷绳做了结构应力分析，弄清了Ａ形塔在承受垂直荷载、水平荷载以及偏载条件下，组成钻塔的各构件的荷载及应力分布；对钻塔设计提出了改进意见；并从整体角度分析了绷绳的作用；对在不同荷载条件下有无绷绳时钻塔的结构应力从量上做了对比；最后提出了应当如何布置提升系统才会使钻塔处 相似文献
17.
正Shrimps of genus Artemia are the inhabitants of continental and marine waters with salinity of 70 to 350 g/l and above.Artemia is able to survive in the conditions in which other animals cannot exist.This is due to adaptations:effective osmoregulation system,the ability to synthesize of respiratory pigment(hemoglobin)and diapauses cysts(Litvinenko at.al.,2009).Cysts of this 相似文献
18.
Paul F. Czeglédy 《Mathematical Geology》1972,4(4):291-305
On the basis of samples taken from a known topographic surface, the parameters of two types of linear models are estimated. The first category is defined by polynomials or trigonometric functions, whose parameters are simultaneously computed from available data. In the second category a set of local centers is defined, and in the neighborhood of each center a fixed-degree polynomial is developed. An approximative resemblance index is calculated, and contour maps corresponding to various models are compared with the topographic map. It is found that with an increasing number of grid points, maps of local polynomials are converging both in continuity and in resemblance. For a sufficient number of grid points, this resemblance is always higher than those produced by models of the first category. 相似文献
19.
Finite element limit analysis with plane strain condition is employed to determine the upper and lower bound solutions of the undrained limiting pressure behind soil gaps and the lateral force acting on a pile per unit length in a contiguous pile wall. Computed bound solutions confirm serious limitations of existing studies in predicting these two solutions. Predicted failure mechanisms and the arching effect behind soil gaps are discussed. A closed-form equation of the limiting pressure factor is proposed for a convenient and accurate prediction of the lateral force acting on a pile in contiguous pile walls in practice. 相似文献
20.
Ulf Grenander 《Mathematical Geology》1975,7(3):267-278
A deformation mechanism is described and analyzed. It is intended for height patterns exposed to erosion and tectonic activity.
A simulation experiment is carried out for this model. Closedform expressions are derived for the covariance field, the properties
of spectral estimates, and for the optimal retrospective reconstruction of earlier, unknown height patterns. For obvious reasons
the author is in no position to make claims about the verisimilitude of the model. It is offered as an example of a potential
application to geology of the theory of patterns developed by the author and his coworkers in recent years. It is hoped that
those more qualified than the author in the subject matter area can extend and modify the analysis to make it closer to geological
reality.
supported by NSF grant GJ-3100X. 相似文献