Determination of total, commonality, and uniqueness of interpreted structural elements from remotely sensed data in Alaska

Statistical analysis is conducted to determine the unique value of real- and synthetic-aperture side-looking airborne radar (SLAR) to detect interpreted structural elements. SLAR images were compared to standard and digitally enhanced Landsat multispectral scanner (MSS) images and to aerial photographs. After interpretation of the imagery, data were cumulated by total length in miles and by frequency of counts. Maximum uniqueness is obtained first from real-aperture SLAR, 58.3% of total, and, second, from digitally enhanced Landsat MSS images, 54.1% of total.Publication authorized by the Director, U.S. Geological Survey, on 20 September 1984.     

胶东邓格庄和金青顶金矿区煌斑岩特征及其与金矿成矿关系

胶东邓格庄和金青顶金矿区煌斑岩的岩石学、岩石化学和微量元素特征显示其为 碱性煌斑岩类的棕闪斜煌斑岩,起源于上地幔。煌斑岩脉空间上与金矿脉关系密切,形成时间 与金成矿作用接近,岩脉的Au、Ag和挥发分的含量较高。煌斑岩浆可能为金矿成矿提供了部 分成矿物质和挥发分。煌斑岩的特征及其与金成矿的关系说明了与金矿成矿有关的地质作用 不仅发生于地壳范围,而且涉及上地幔。     

遥感方法在辽宁抚顺-清原地区砂金预测中的应用

以辽宁抚顺-清原地区砂金预测工作为例,阐述遥感方法在砂金预测中的应用.运用地球资源卫星图像解译原生金矿富集成矿的有利条件（线性构造、环状影像体）,运用航片解译砂金富集成矿的有利地貌条件,最终预测砂金成矿远景区.     

遥感技术在黑龙江呼玛地区金矿找矿中的意义

提出了森林茂密,松散覆盖层较厚地区的遥感基础图象制作方法,利用热红外波段及生物地球化学遥感技术地植被覆盖区与金有关异常信息的提取;建立了植被覆盖区遥感构造解译标志,解译出４组线性构造,百余个环形构造和一个大型环块构造;将区域构造应力场的演化划分为３个阶段,ＮＥ－ＮＮＥ与ＮＷ,近ＥＷ向构造带相互交织成菱形格子状构造是本区构造的基本格架;大型环块构造及其周边环形构造和菱格状构造的各“角”区,往往是金矿     

Collapse hazard assessment in evaporitic materials from ground penetrating radar: a case study

Evaporitic materials have been studied by means of ground penetrating radar (GPR) in order to evaluate the collapse hazard. The obtained 200 MHz GPR profiles show a low signal-noise ratio over the first 3 m depth, where well-defined and continuous reflectors can be observed. Between 3 and 4.5 m depth, the signal to noise ratio decreases due to attenuation of the electromagnetic (EM) waves. As a result, reflectors located deeper than 3 m become more discontinuous and poorly defined. GPR profiles show trails of continuous and subhorizontal reflectors, with a slightly undulated and irregular geometry. Although some of these reflectors laterally vanish or seem to disappear, sudden interruptions or hyperbolic reflections that could be originated by the occurrence of cavities have not been detected. These reflectors have been interpreted as corresponding to several evaporitic layers (gypsum) that constitute the main lithology in the area. Clear interruptions of reflectors have only been observed in some GPR profiles, and they could be attributed to small (1–2 m long) subvertical faults, with only a few centimetres offset. These faults may be generated by the accommodation of the evaporitic layers to local collapses affecting deeper materials.     

Exploration of gold mineralization in a tropical region using Earth Observing-1 (EO1) and JERS-1 SAR data: a case study from Bau gold field,Sarawak, Malaysia

Bau gold mining district, located near Kuching, Sarawak, Malaysia, is a Carlin style gold deposits. Geological analyses coupled with remote sensing data were used to detect hydrothermal alteration rocks and structure elements associated with this type of gold mineralization. Image processing techniques, including principal components analysis, linear spectral unmixing, and Laplacian algorithms, were employed to carry out spectrolithological–structural mapping of mineralized zones, using Advanced Land Imager, Hyperion, and JERS-1 synthetic aperture radar scenes covering the study area and surrounding terrain. Hydrothermally alteration mineral zones were detected along the SSW to NNE structural trend of the Tai Parit fault that corresponds to the areas of occurrence of the gold mineralization in the Bau limestone. The results show that potentially interesting areas are observable by the methods used, despite limited bedrock exposure in this region and the constraints imposed by the tropical environment.     

鄂东南地区赋存于沉积岩中金矿床的勘查进展和研究现状

赋存于沉积岩中的金矿床包括了绝大部分卡林型、少数造山型和部分斑岩成矿系统外围浸染型金矿床.鄂东南地区是长江中下游七个重要矿集区之一,发育一系列与岩浆岩有关的矽卡岩型、斑岩型矿床,以往的勘探和研究也主要围绕着岩体及接触带附近的斑岩、矽卡岩型矿床展开.对于岩浆岩外围赋存于沉积岩中的金矿床虽然也有发现,但并未引起足够重视.近...     

资源危机金矿深部与外围找矿前景的若干判别标志

确定资源危机金矿深部及外围的找矿前景是一个非常重要的研究课题，本首先分析了岩金成矿和危机矿山的一些基本特点，然后结合多年的找矿实践，从金矿具有“特殊性”的认识出发，提出了判断危机矿山深部与外围成矿远景的6条标志，介绍了在中国东部4个典型金矿山深部脑外围的找矿预测成果，表明在成矿物质丰富的矿化集中区内开展成矿预测的成功率比较高。     

陕西岩金矿床控矿条件分析

区域地质、矿床（田）构造、地层岩性、岩浆岩和围岩蚀变等对金矿成矿均有不同程度的控制作用。陕西省岩金矿成矿物质主要来自地壳深部，构造是金矿成矿的主导控制因素。其它条件也能为金矿成矿提供部分物质、热源和水源以及影响金矿成矿的物理化学环境。同时，又通过自身的物理化学属性制约构造的发育和金矿成矿的方式、类型和矿化强度。