高植被覆盖区铜钼矿遥感植被地球化学特征提取

发布时间：2017-12-28 12:14

本文关键词：高植被覆盖区铜钼矿遥感植被地球化学特征提取　出处：《中国地质大学》2016年博士论文　论文类型：学位论文

【摘要】：福建省漳州市平和县位于武夷山成矿带南部,区内构造以断裂为主,福安——南靖NE向深断裂、上杭——云霄NW向深断裂均通过本区,并发育了多条NE向、NW向构造带,同时,将乐——华安、泰宁——龙岩两条SN向大断裂带及厦门——南靖EW向大断裂带也直接影响着研究区以致形成了极为复杂的地质构造格架,同时地形地貌也受到构造活动的影响。已初步查明区内发现有铜、钼、铁、铅、锌、金等多金属及叶腊石、高岭土、泥煤等多种矿产。该区域成矿条件优越,找矿潜力大,植被发育旺盛、为亚热带季风性湿润气候,是一个植被覆盖的典型区域,局部第四系覆盖较厚,地形起伏较大,传统野外地质工作条件艰苦,非常适合运用快速有效且成本低廉的遥感方法在植被覆盖区进行地质找矿。本文结合了遥感、植物学、植物地球化学、岩石学等相关知识,较为系统地勘查了位于平和地区典型铜钼矿区(钟腾、泮池铜钼矿区)和铜、钼、铅、锌等多金属异常区及其外围地区的自然景观、植被群落特征、典型地物的光谱特征和卫星影像特征；通过多光谱影像识别提取了研究区内的线性构造,并据此利用分形理论分析了线性构造与矿床空间分布之间的关系；统计了铜钼矿区、化探异常区的岩石、上方土壤和植被中的主要成矿元素和伴生元素含量特征；在确定了铜钼矿区附近有效指示性植被和指示元素的同时,分析了矿区与矿区外围常见植物的光谱特征,找出了指示性优势植被中的光谱反射率异常；将成矿母质岩石、土壤、植被、植被光谱反射率曲线和航空高光谱影像中所呈现的继承性异常串联起来,建立关系模型,反演出高植被覆盖铜钼矿区的遥感植物地球化学指示性元素含量空间分布特征。在高植被覆盖区内金属矿床预测提供新的思路,具有良好的应用价值和推广意义。本文主要获得了以下几点成果和认识：1、研究区内的低温热液型矿床与多光谱遥感影像上解译提取的线性构造存在密切的相关性,基于盒子维数分形理论的统计方法进行线性构造的定量分析可以得知,区内线性构造具有统计自相似性,从统计出的线性构造分维等值线图结果来看,已发现的热液型矿点大多分布在分维值的高值区域附近,其中两个铜钼矿点的分维值分别是1.43(钟腾铜钼矿区)和1.52(泮池铜钼矿区),大小矾山(明矾矿区)的分维值均为1.37。低值区域或附近未发现矿点分布。同时,在遥感线性构造分维10次趋势图中可以清晰地看到,位于中部呈现的环形高值区域与ETM+影像中的钟腾环形构造位置相吻合,该环形构造是区域内最大的火山机构。综合上述定量分析结果可得知,低温热液型矿床或矿化点常处于断裂构造较发育且空间分布较复杂的区域,这些线性构造空间复杂度高的区域往往是导矿容矿的有利场所。2、从研究区典型常见植被波谱反射率曲线的特征分析结果可以发现,区内低温热液型铜钼矿区(矿点)或化探异常区域与矿区外围典型植被波谱分析结果在波形特征、红边特征、叶绿素即水吸收特征、植被指数特征等方面有较大差异,且表现较为统一。矿区植被叶片或冠层反射率值均低于矿区外围,红边位置发生了位移,存在“蓝移”或“红移”现象,叶绿素及水吸收特征存在差异,同时植被指数也存在明显的差异。因此,借助柚树、芒萁、乌毛蕨、茅草等区内常见典型植被波谱特征分析结果,可以明确矿区植被在生长过程中受到了下伏矿体中成矿金属元素迁移的影响,使得金属元素在叶体内富集,影响了植被的正常生长,从含水量、叶绿素含量和细胞结构等方面产生了变化,这些变化导致矿区与矿区外围植被的波形特征存在差异。从最终分析结果可知,柚树及芒萁的异常更为明显,乌毛蕨次之,茅草的效果不明显,因此,可将柚树和芒萁作为区内具有有效指示性的优势候选植被。3、研究区岩石、土壤以及植被中的元素含量测试分析结果得知,铜钼矿区或化探异常区域的主要成矿元素以及伴生元素的元素含量多数高于矿区外围或背景平均含量,说明矿区上方岩石、土壤和植被中的相关元素具有一定的物质继承性,呈现出明显的植物地球化学异常。4、不同植被或相同植被不同器官中元素的吸收聚集能力有所不同,研究区内大多数常见植被种属的叶部对元素聚集能力强于茎部,如柚树、叶部富集W、Mo、 Co、Bi和Cu元素,芒萁的叶部除了上述元素还包括Zn和Pb,茎部没有发现富集元素,但是柚树的茎部却富集Zn和Pb等。5、根据植被元素含量的衬度系数和屏障系数两个参数,并结合矿区常见植被波谱分析的结果,确定了研究区的有效指示性植被和指示元素。通过统计最终确定选择芒萁、柚树作为本次遥感植被地球化学统计的参考植被,即区域有效指示性植被,指示性元素有Pb、Mo、Co、Bi。6、以泮池铜钼矿区附近为例,将植被地球化学异常特征与野外光谱反射率异常特征和高光谱影像数据结合起来,建立植被光谱吸收深度与指示性元素含量的多元回归关系,构建回归方程,定量反演指示性元素在研究区泮池铜钼矿区附近的空间分布情况,结合多光谱影像对于区内热液型矿床的空间分布特征分析以及其他相关材料,证明基于遥感植被波谱异常提取植被覆盖区铜钼矿床矿化信息的方法能够较好地反映出区内的成矿元素及其伴生元素异常的空间分布特征,具有较好的找矿应用效果。
[Abstract]:Fujian city of Zhangzhou province Pinghe county is located in the southern Wuyishan metallogenic belt, regional faults, Fu'an - Nanjing, Shanghang - NE trending deep faults NW trending deep faults through the sky in this area, and developed several NE trending and NW trending tectonic belt, at the same time, Huaan, Taining, Longyan, two SN to the fault zone and Xiamen Nanjing fault zone EW to directly affect the study area so as to form a very complex geological structure, and topography is also affected by tectonic activity. Has been initially identified with copper, molybdenum, iron, lead, zinc, gold and other metals and pyrophyllite, kaolinite, peat and other minerals found in the area. The metallogenic conditions of the regional advantages, prospecting potential, vegetation development, strong subtropical humid monsoon climate, is a typical area of vegetation cover, local Quaternary thick, undulating terrain, traditional field geological work conditions, very suitable for the use of fast effective and low cost method of remote sensing in vegetation covered area for geological prospecting. This paper combines remote sensing, botany, plant geochemistry, petrology and other related knowledge, systematic exploration in flat area and typical copper molybdenum mine (Zhong Teng, pan Chi copper molybdenum mine) and satellite image features and spectral characteristics of copper, molybdenum, lead and zinc polymetallic anomaly area and peripheral area of the natural landscape, the characteristics of the vegetation community, typical objects; by multi spectral image recognition and extraction of linear structure in the area, and then use fractal theory to analyze the relationship between the linear structure and spatial distribution of deposits; statistics of the copper molybdenum mine, the main ore-forming elements in the geochemical anomaly area above the rock, soil and vegetation and the element content in determining the characteristics of associated; copper molybdenum mine near the effective vegetation and indicative indicator elements at the same time, analyzed the spectral characteristics of mining area and mining area periphery common plants, found that Shows the advantage of the spectral reflectance of vegetation anomaly; inheritance of ore-forming material will rock, soil and vegetation, the vegetation spectral reflectance curve and aerial hyperspectral image anomaly in series, establish the relation model, inversion of high vegetation cover copper molybdenum mine remote sensing and geochemical features indicative of spatial distribution of element contents. It provides a new way of thinking for the prediction of metal deposits in the high vegetation cover area, which has good application value and popularization significance. This paper obtained the following results and understanding: linear structure interpretation from 1, within the area of epithermal deposit research and multi spectral remote sensing image has close correlation, quantitative linear structure analysis can be learned by statistical method of box dimension based on fractal theory, the linear structure in the area has statistical self the similarity of fractal dimension contour from linear structure statistical graph results, hydrothermal type occurrences have been found mostly in the high value area near the fractal dimension, the fractal dimension of two copper molybdenum ore values were 1.43 and 1.52 (Zhong Tengtong molybdenum mine) (Pan Chi copper molybdenum mine). The size of Fanshan (alum mine) the fractal dimension value is 1.37. The low value area or were found near the ore distribution. At the same time, we can see clearly in the 10 trend map of the fractal dimension of remote sensing linear structure. The ring high value area in the middle part coincides with the position of the clock ring structure in the ETM+ image. The ring structure is the largest volcanic organization in the area. Based on the above quantitative analysis, we can know that the low-temperature hydrothermal deposits or mineralization sites are often located in the areas where the fault structures are more developed and the spatial distribution is more complex. These regions with high linear structure and high spatial complexity are often the favorable places for ore hosting and ore hosting. 2, from a typical research area, analysis the common features of vegetation spectral reflectance curve can be in low temperature hydrothermal type copper molybdenum deposit (ore) or geochemical anomaly area and the periphery area of typical vegetation spectral analysis results in the waveform, red edge characteristics, chlorophyll absorption characteristics, namely water have great differences in vegetation index the characteristics, and the performance of the more uniform. The reflectance of vegetation leaf or canopy is lower than that of mining area, and the red edge position has shifted. There is "blue shift" or "red shift" phenomenon. Chlorophyll and water absorption characteristics are different. Meanwhile, there are obvious differences in vegetation index. Therefore, with the help of grapefruit tree, Dicranopteris linearis, orientale, grass in the region of typical spectral characteristics of vegetation analysis, clear vegetation affected the ore-forming elements underlying ore migration in the growth process, the metal elements in the leaves in vivo enrichment, affect the normal growth of vegetation, from water chlorophyll content and cell structure have changed, these changes lead to the waveform characteristics of the mining area and mining area periphery vegetation differences. From the final analysis results, and grapefruit tree dicranopterisdichotoma anomaly is more obvious, Blechnum the thatched effect is not obvious, therefore, the grapefruit trees and vegetation in the region as a dominant candidate pedata with effective indication. The test results of 3 elements in the study area, rock, soil and vegetation in that most of the main ore-forming elements in copper molybdenum mine or regional geochemical anomalies and associated elements were higher than the average content of periphery area or background, indicating the relevant elements of rock, soil and vegetation in mining area above the material has certain inheritance. Showing the geochemical anomaly of plant obviously. 4 elements in different organs of different vegetation or the same vegetation absorption aggregation ability of different vegetation in the study area the most common species of leaf elements accumulation ability in the stems, such as grapefruit tree, leaf Mo, Co and enrichment of W, Bi and Cu elements, the leaves of dicranopterisdichotoma in addition to the above elements including Zn and Pb, the stems found no enrichment of elements, but the stems of pomelo trees but the enrichment of Zn and Pb. 5. Contrast coefficient based on the content of vegetation elements
【学位授予单位】：中国地质大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P627

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