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1.
新疆卡拉麦里成矿带赋矿岩层—矿化蚀变遥感特征   总被引:11,自引:2,他引:11       下载免费PDF全文
基于TM图像固有的结构特征和光谱特征,采用不同波段假彩色组合、波段比值、主成分分析、色度变换等多功能能组合方法,对卡拉麦里成矿带特定地理地质背景下有关构造特征、赋矿地层、含矿岩体、矿化蚀变等示矿要素进行增强处理,取得了很好的应用效果,为大区域快速进行遥感地质填图,有效建立找矿识别标志作出了有意义的尝试。  相似文献   

2.
不同岩石矿物和矿化蚀变具有不同的光谱特征, 这是利用遥感技术进行岩石矿物和蚀变信息识别的基础。本研究在谢米斯台地区进行岩矿样品采集, 利用ASD野外光谱辐射仪采集光谱反射率数据, 通过去噪处理、标准化处理、微分处理和去包络线处理, 开展了典型岩矿样品、风化面与新鲜面样品和不同矿化蚀变的光谱特征提取和光谱分析。研究发现, 岩矿在380~1 100 nm波段的光谱特征, 主要是金属离子产生;在1 100~2 500 nm波段的光谱特征, 主要是阴离子基团中的羟基、碳酸根和水分子产生;矿化蚀变光谱具有可诊断性特征谱带, 是其矿物组成中的各种蚀变矿物特征信息的反映;受到矿物含量改变和外界环境因素的影响, 光谱的整体形态或局部特征都发生变化。岩矿光谱特征的提取和分析, 将提高和改善高光谱技术对不同区域同种类型的矿床勘查。  相似文献   

3.
浙江武义萤石矿田控矿构造地球化学特征   总被引:2,自引:0,他引:2  
以浙江武义萤石矿田为例,对此类浅成低温热液矿床的控矿构造地球化学特征,进行了初步研究和探讨,进一步揭示了萤石矿矿物组分的分配,迁移,分散,富集特征与控矿构造之间的内在联系。  相似文献   

4.
本介绍了太行山阜平地区8种变质岩石的稀土特征,表明含矿岩石与不含矿岩石的ΣREE、ΣLREE、ΣHREE及δEu等稀土特征不同。利用这些参数在变质岩区寻找有关的矿产具有一定的指导意义。  相似文献   

5.
黄伟兴 《广东地质》2004,19(1):30-36
叙述了粤东地区各期火山活动的地质特征,指出火山岩富含成矿元素,可给银多金属矿床带来成矿物质。依据矿床的成因-工业类型分类原则,将该区火山-次火山岩型银多金属矿床划分为两大类6亚类。并对各类矿床的赋矿围岩、控矿构造、与成矿有关的火山岩、矿体形态产状、近矿围岩蚀变、矿石矿物组合等主要地质特征进行描述。阐述了控制矿田、矿床(体)的构造条件、以及火山作用的控矿地质条件。  相似文献   

6.
通过对TM卫星数字图象的处理与解译,结合成矿地质特征的研究,对区内的金矿控矿条件提出一和些新认识。东峰顶地区不仅是EW,NE,NW及NNE向断裂的交汇处,而且还是断裂与环形构造的复合部位,为成矿的有利地带。NW与NNE向断裂为主要的控矿构造,两者各呈平行距状排列,组成“斜方格状结构”结构,每一结点可能具有对应成矿之特征。  相似文献   

7.
罗鹏  曹新志 《地质与资源》2009,18(4):304-308,244
浅部矿和深部矿的产出深度不同,由此派生出了一系列产出特征上的差异.针对浅部矿和深部矿的不同特点,所采用的勘查技术方法也必然存在差别.对浅部矿与深部矿在产出特征和勘查技术方法上的一些异同进行了重点论述,并强调相对成熟的浅部矿勘查理论和技术对深部矿勘查的指导及借鉴意义.  相似文献   

8.
运用剪切带控矿理论,通过对剪切带内变形岩石的应变测量和不同惊讶的成矿构造研究,阐明了辽宁东胜地区金、银、多金属剪切带矿床的控矿构造特征,探讨了此类矿床控矿构造与矿化的关系。  相似文献   

9.
鲁东地区较广泛地发育着元古宙中深变质岩系及非金属矿含矿变质建造,其中蕴藏的石墨,滑石、菱镁矿等非金属矿产在省内外占有重要地位。鲁东是山东省元古宙非金属矿重要成矿区。鲁东地区不同的非金属矿,明显受控于不同类型的含矿建造;而不同类型的非金属矿含矿建造的形成又明显受控于不同的大地构造环境。  相似文献   

10.
何凤萍  王正海  耿欣  等 《江苏地质》2013,37(2):183-187
针对庞西垌地区植被高覆盖特征,主要选用ETM+数据,结合DEM数据,采用正向主成分分析、波段比值、多波段信息合成等处理方法,提取与成矿控矿相关的线状、环状构造信息,结合该区相关地质资料,实现研究区构造综合解译.  相似文献   

11.
平面应变状态下岩石剪切带网络数值模拟研究   总被引:9,自引:3,他引:6  
研究了围压、端面约束、试件高度及界面特性对剪切带网络形成的影响。首先对影响剪切带网络形成的因素(包括试件高度、围压及温度、试件端部轴向应变大小的计算方法的差异)进行了分析。之后采用FLAC 3D对平面剪切带网络进行了数值模拟,其中摩擦角及内聚力为应变软化。探讨了倾向于出现剪切带网络的若干条件。若端面缚束较强且存在一定的侧压力,试件中部出现多重剪切带。若端面缚束较弱,试件端部易于形成剪切带网络,且随试件高度的增加剪切带条数增加。界面法向和切向刚度越大,剪切带穿越断层并按其固有方向延伸能力越强,剪切带网络格局越明显。获得的数值结果可在实验中找到佐证,并且可以用来解释地震中的一些剪切应变局部化现象。  相似文献   

12.
基于应变梯度理论的韧性剪切带理论研究   总被引:10,自引:0,他引:10  
地质领域中存在的大量事实都可以归为应变局部化范畴,韧性剪切带是剪切应变局部化带。本文首次应用应变梯度塑性理论对韧性剪切带进行了理论分析。获得了韧性剪切带内部局部剪应变(率)分布规律,剪切带错动总位移及剪切带法向位移的理论表达式,以及韧性剪切带内部体积应变(率)和孔隙率分布规律。剪应变局部化导致了体积应变和孔隙率局部化。随着应变软化的加剧,剪应变、体积应变和孔隙率局部化加剧;随着应力率绝对值的增加,剪应变率、体积应变率集中程度增强。   相似文献   

13.
This study demonstrates the use of ASTER data for the mapping of gypsum deposits and associated geological formations that occurred in the Thumrait region of southern Oman. The measurement of spectra over samples of gypsum in the 1,300–2,500 nm wavelength using a PIMA spectrometer showed the presence of distinct absorptions at 1400–1600, 1750, 1940, 2,100, and 2,400 nm characteristics to O? H stretching, H2O combinations, and S? O bending overtones and stretching, respectively. Studying the unique spectral absorption characters of gypsum samples, we developed a false color composite (FCC) and an image by decorrelation stretch using the spectral bands 7, 3, and 2 of ASTER. The results FCC showed the regions of gypsum occurrences, and the decorrelated image discriminated the gypsum occurrences from other geological formations of the area. The study of surface mineralogy of the region using the VNIR‐SWIR bands by the spectral angle mapper method showed the presence of sulfate, carbonate, and clay minerals of the geological formations in the study area. We compared the results of ASTER with the results obtained using spectral bands 12, 8, and 4 of Sentinel‐2A processed by the same methods. The study showed that the spectral bands of ASTER can be used for mapping the gypsum and associated geological formations.  相似文献   

14.
剪切带损伤研究对于理解材料破坏机制和建立剪切带本构模型具有重要意义。为了研究单轴压缩黏性土样的剪切带损伤演化规律,根据纵向应变较高时清晰剪切带位置布置切向测线,对数字图像相关方法获得的结果进行双三次样条插值,从而获得光滑性较好的各种应变场。将土样整体的损伤变量-纵向应变曲线与各条剪切带的损伤演化曲线进行了对比。研究发现:(1)总体上,土样整体的损伤变量演化曲线呈线性,而各条剪切带的损伤变量演化曲线均上凹,这表明随着纵向应变的增加,各条剪切带的损伤发展越来越快;(2)各条剪切带的损伤变量演化曲线的轮廓线呈马尾形,这说明随着剪切带的逐渐发育,各条剪切带的相互影响和作用规律变强;(3)对于含水率较低的土样,平行或共线剪切带的损伤变量变化基本同步,特别是在剪切带充分发育之后,但两条剪切带的距离应较小;在一定时期,共轭或交叉剪切带中剪切带的损伤占优,这与剪切带的相互竞争有关,但若两条剪切带达到独立发展的程度,则二者的损伤变量变化可以同步;对于含水率较高的土样,各条平行或共轭剪切带的损伤变量变化基本同步,剪切带的相互作用不明显。  相似文献   

15.
张江勇  余克服 《地质论评》2008,54(3):362-372
珊瑚骨骼生长有年、月、日周期,能够当作古生物钟来记录地质历史。块状珊瑚骨骼密度条带年周期的发现对后来的珊瑚古气候研究产生了深远的影响,随后又发现世界各热带海域的珊瑚存在多种多样的骨骼密度变化模式,起先常从珊瑚的生长环境中寻找骨骼密度变化的控制因素,但是没有成功,从80年代后期,部分学者试图从珊瑚骨骼构架本身出发、综合考虑环境因素和骨骼密度条带之间的关系来探求骨骼密度变化的机理,并提出了一个可以解释大多数块状珊瑚骨骼密度条带变化模式的骨骼生长模型。块状珊瑚软体层厚度是一个十分重要但至今仍没引起足够重视的珊瑚生长参数,它相对于骨骼线性生长率的变化影响着骨骼密度变化模式。骨骼钙化作用和虫黄藻光合作用的相互关系还存有争议,珊瑚骨骼钙化机理仍在探索中。  相似文献   

16.
17.
《Tectonophysics》1999,301(1-2):21-34
In order to clarify deformation mechanisms and behaviours of quartz in a low-temperature regime in the earth's crust, microstructural analyses, particularly on kink bands have been carried out for quartz veins moderately deformed under subgreenschist conditions. Both the dominance of subbasal deformation lamellae and geometry of kink bands suggest that basal (0001) slip was the sole active slip system in the deformed quartz. On a morphological basis, kink bands in the quartz were classified into two types: type I is characterized by conjugate and narrow bands with angular hinge zones, and type II by a wide monoclinal band. Dynamic analyses using deformation lamellae and kink bands have revealed that type I kink bands were formed in grains with basal plane (sub-)parallel to the compression axis, whereas type II kink bands were formed in grains with basal planes inclined to it. Using a numerical model of kinking of elastic multilayers modified after Honea and Johnson (Tectonophysics 30, 197–239, 1976), changes of the level of yielding stress for kinking and the width of kink bands as a function of the angle θ between the slip plane and the compression axis have been examined. The theory predicts that type I kink bands were formed at a higher stress level than type II kink bands, and hence occurrence of type I kink bands suggests that a significant strain hardening occurred in the deformed quartz veins. The theory also well explains the fact that the width of type I kink bands (θ=0 to 10°) is narrower by an order of magnitude than type II kink bands (θ=10 to 80°).  相似文献   

18.
玉舍河自北北西向南南东穿过玉舍煤矿,垂直地层走向横切含煤地层,影响了河床下及周围煤层的开采。通过现场踏勘、水文地质条件分析、覆岩岩性分析及导水裂缝带高度预计等,对不同开采上限条件下开采后玉舍河及其周围地下水流场的变化情况进行了数值模拟,并计算了不同条件下的矿井涌水量,结合矿井充水因素分析,最终确定,玉舍河两岸100 m范围外、玉舍河下及其两岸100 m范围内当煤层与河流垂直距离>260 m时,可以安全开采;玉舍河下及其两岸100 m范围内,当煤层与河流垂直距离<260 m时,不可以开采。   相似文献   

19.
Deformation bands in porous sandstones have been extensively studied for four decades, whereas comparatively less is known about deformation bands in porous carbonate rocks, particularly in extensional settings. Here, we investigate porous grainstones of the Globigerina Limestone Formation in Malta, which contain several types of deformation bands in the hangingwall of the Maghlaq Fault: (i) bed-parallel pure compaction bands (PCB); (ii) pressure solution-dominated compactive shear bands (SCSB) and iii) cataclasis-dominated compactive shear bands (CCSB). Geometric and kinematic analyses show that the bands formed sequentially in the hangingwall of the evolving Maghlaq growth fault. PCBs formed first due to fault-controlled subsidence and vertical loading; a (semi-)tectonic control on PCB formation is thus documented for the first time in an extensional setting. Pressure solution (dominating SCSBs) and cataclasis (dominating CCSBs) appear to have operated separately, and not in concert. Our findings therefore suggest that, in some carbonate rocks, cataclasis within deformation bands may develop irrespective of whether pressure solution processes are involved. We suggest this may be related to stress state, and that whereas pressure solution is a significant facilitator of grain size reduction in contractional settings, grain size reduction within deformation bands in extensional settings is less dependent on pressure solution processes.  相似文献   

20.
Deformation bands are described in detail for the first time in carbonate rock from the subsurface and in chalk from the North Sea. The samples are from 2200 to 2300 m below sea level, in upper Maastrichtian to Danian chalk in the Oseberg Field. The deformation bands were investigated using thin-section analysis, SEM and computed tomography (CT). There is a reduction in porosity from 30 to 40% in the matrix to ca. 10% or less inside the deformation bands. They have apparent thicknesses ranging from less than 0.05–0.5 mm and have previously often been referred to as hairline fractures. Their narrowness is probably the reason why these features have not previously been recognised as deformation bands. The deformation bands in chalk are very thin compared to deformation bands in sandstone and carbonate grainstones which have mm to cm widths. This is suggested to be due to the fine grain size of the chalk matrix (2–10 μm), and it appears to be a positive correlation between grain-size and width of deformation bands. The deformation bands are suggested to have been formed as compactional shear bands during mechanical compaction, and also related to faulting.  相似文献   

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