西藏绒布地区遥感异常提取及成矿预测研究

发布时间：2019-02-17 07:53

【摘要】：对矿床的预测是国内外学者的争相研究热点,其中又以矿产资源勘察技术的研究为主要研究对象。矿床及其周围的地质信息(地质构造)、地球物理特征和地球化学信息以及遥感地质等信息构成认识成矿规律和资源潜力评价的基础。矿产资源的勘察是多种学科异常信息的提取与集成。在遥感找矿的研究重点则是遥感蚀变信息提取以及遥感构造的目视解译。本文依托西藏绒布地区1:5万区域地质调查项目,研究区位于西藏绒布地区,属特提斯喜马拉雅构造带,是西藏地区有利的成矿带之一。区内构造活动强烈,形成了良好成矿地质条件。研究区周边已查明有沙拉岗锑矿床、浪卡子金矿床、扎西康铅锌多金属矿床等多种类的铅、锌、铜、锑、铁等金属矿产和磷、灰岩等非金属矿产和地热等矿产资源。但由于交通、人文等多种原因导致研究区的矿床勘探程度较低,目前为止仅发现一处石灰石矿。本文以遥感地学分析为手段,对该地区的区域地质资料、遥感数据、地球化学数据分析,结合前人的现代成矿预测理论,对综合信息叠加分析,划分出成矿远景区。本论文主要完成了以下内容和成果:(1)以研究区为背景,认真了解对比多种遥感数据后选取了Lansat 8 OLI数据和ASTER遥感数据这两种数据为研究区的遥感数据源。对这两种遥感数据进行了预处理,包括辐射定标、FLASSH大气校正、数据融合、图像裁剪等。(2)根据OLI和ASTER数据的特性,对OLI遥感数据进行7、5、2波段组合成假彩色影像,以及对ASTER遥感数据6、3、1波段组合成研究区研究地图。根据OLI遥感影像波谱特性,所成影像较ASTER影像精细,在OLI 752波段合成假彩色影像基础上,辅以收集的该地区1:25万地质图对该研究区进行1:5万地质解译,勾画出地层界线。以及通过人工目视解译,结合区域线环构造特征进行了研究区线环解译工作,并通过对解译的线性构造结果的方位、密度和频度进行分析。(3)通过对遥感蚀变信息地质与波谱特征的研究,采用掩膜去干扰,主成分分析法和波段比值提取了研究区的不同级别的铁染、羟基、泥化以及青磐岩化蚀变信息,并对所提取的已分级蚀变异常信息做并集处理,得到全区综合蚀变异常分布图。对所提取的遥感蚀变异常信息进行了密度分析,得出蚀变异常分布规律。(4)结合研究区地质背景,即区内的岩浆岩、断层、褶皱等分布,综合遥感影像提取的线环构造信息、蚀变异常信息以及收集到的区内化学异常信息,基于ArcGIS平台,叠加分析后圈定了巴登成矿远景区、松岗成矿远景区、贡扎-玉让成矿远景区、道弄成矿远景区、雄勒成矿远景区、板得勒成矿远景区和则浦成矿远景区。该成矿远景区的圈定为未来该地区找矿奠定了一定的基础。
[Abstract]:The prediction of mineral deposits is a hot topic for scholars at home and abroad, among which the research on mineral resources exploration technology is the main research object. The geological information (geological structure) geophysical and geochemical information and remote sensing geology of the deposit and its surroundings form the basis of understanding the metallogenic law and the evaluation of resource potential. The exploration of mineral resources is the extraction and integration of abnormal information of many disciplines. The research focus of remote sensing prospecting is remote sensing alteration information extraction and visual interpretation of remote sensing structures. Based on the regional geological survey project of 10: 50 000 in the Xizang area, the study area is located in the Xizang area and belongs to the Tethys Himalayan tectonic belt, which is one of the favorable metallogenic belts in the Tibet region. The tectonic activity in the area is strong, forming good metallogenic geological conditions. It has been found that there are many kinds of lead, zinc, copper, antimony, iron and other non-metallic minerals, such as phosphorus, limestone and other non-metallic minerals and geothermal resources in the periphery of the study area, such as the Saragang antimony deposit, the Langkazi gold deposit, the Zaxikang lead-zinc polymetallic deposit and so on. However, due to traffic, humanities and other reasons, the exploration degree of ore deposits in the study area is low, so far only one limestone deposit has been found. By means of remote sensing geoscience analysis, this paper analyzes the regional geological data, remote sensing data and geochemical data of the area, and combines with the modern metallogenic prediction theory of predecessors, and analyses the comprehensive information superposition and analyzes the comprehensive information, and classifies the metallogenic areas into distant areas. The main contents and achievements of this thesis are as follows: (1) the Lansat 8 OLI data and ASTER remote sensing data are selected as the remote sensing data sources in the study area. The two kinds of remote sensing data are preprocessed, including radiometric calibration, FLASSH atmospheric correction, data fusion, image clipping and so on. (2) according to the characteristics of OLI and ASTER data, the OLI remote sensing data are combined into pseudocolor images in 7 / 5 / 2 bands. The ASTER remote sensing data of 6 ~ 3 ~ 1 band are combined to form a study map of the study area. According to the spectral characteristics of OLI remote sensing images, the resulting images are more precise than ASTER images. On the basis of synthetic pseudocolor images in the band of OLI 752, the study area is interpreted by the collected 1: 25 million geological map. Draw the boundaries of the strata. And by artificial visual interpretation, combining with the structural characteristics of the regional line ring, the interpretation of the area line ring is carried out, and the orientation of the result of the interpretation of the linear structure is obtained. The density and frequency were analyzed. (3) by studying the geological and spectral characteristics of remote sensing alteration information, using mask de-interference, principal component analysis (PCA) and band ratio were used to extract different levels of iron staining and hydroxyl groups in the study area. The mud and palliation alteration information are obtained, and the extracted graded alteration anomaly information is processed together to obtain the distribution map of the comprehensive alteration anomaly in the whole area. The density analysis of remote sensing alteration anomaly information is carried out, and the distribution law of alteration anomaly is obtained. (4) the distribution of magmatic rock, fault and fold is combined with the geological background of the study area. Based on ArcGIS platform, the line ring structure information, alteration anomaly information and chemical anomaly information collected from remote sensing image are synthesized, and the Badden metallogenic area and Songgang metallogenic area are delineated by superposition analysis. Gongza-Jade let metallogenic remote area, road-made ore-forming area, Xiongle ore-forming area, Bandele ore-forming area and Zipu ore-forming area. The delineation of the ore-forming area lays a certain foundation for the prospecting of this area in the future.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P627;P612

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