风化壳淋积型镍矿矿化特征矿物波谱响应及精细化遥感找矿模型研究

The weathering crust illuviation type deposit is the main occurrence of the nickel mineral resource, which is widely used as the most important strategic resource for the society and economic development. It is the focus not only in the the nickle mineral resource exploration in the future but also in the present overseas exploration led by our country. Because the spectral response mechanism of the mineralization characteristic minerals of the weathering crust type illuviation nickle deposit which can indicate the mineralization enrichment degree is not clear, and the effective method was not obtained yet, the available remote sensing technology can not have a useful role in the weathering crust illuviation type nickle mineral overseas exploration. Therefore, with the ASTER and Worldview-3 remote sensing data, taking the North Kenawe weathering crust illuviation type nickel mining area in Indonesia as the study area, collecting a lot of exploration data, using large sample field spectrum investigation data and the content testing data of the characteristic minerals, the mathematical fitting relationship between the Spectral Absorption Index of the field spectrum and the mineral contents will be analyzed in this study, and the remote sensing spectral response mechanism of the characteristic minerals closely related with the weathering crust illuviation type nickle deposit will be studied in detail. With the contrastive analysis of the results of the remote sensing enhancement processing methods, the weak remote sensing abnormity information extraction method of the weathering crust illuviation type nickle mineralization characteristic minerals will be explored also. With the Geographic Weighted Regression Model introduced in the fitting the relationship between the grade and the mineralization factors of the weathering crust illuviation type nickel deposit, the detailed quantitative weathering crust illuviation type nickel mineral prospecting model will be set up as well. By this way, the remote sensing mechanism of the weathering crust illuviation type nickle mineralization characteristics will be well recognized. The research results will provide the scientific basis to the nickle mineral overseas exploration development either.

风化壳淋积型镍矿是紧缺战略性矿产资源镍矿的主要赋存形式，也是未来全球镍资源利用和我国境外勘查的重点。但由于指示矿化富集的特征矿物遥感波谱响应机理及精细化遥感找矿方法等前沿科学问题未能解决，严重制约了风化壳淋积型镍矿勘查遥感技术应用。鉴于此，本项目拟采用ASTER及WorldView-3遥感数据，选取印度尼西亚北科纳威风化壳淋积型镍矿区为研究区，系统收集矿区已有丰富勘查成果，通过大量特征矿物波谱测试及特征矿物含量测定，开展实测波谱吸收指数与特征矿物含量的拟合关系分析，揭示风化壳淋积型镍矿矿化特征矿物遥感波谱响应机理；实验对比多种增强处理方法，探索风化壳淋积型镍矿矿化特征矿物遥感弱异常增强提取方法；引入地理加权回归模型，开展风化壳淋积型镍矿品位与矿化特征因子数学拟合关系分析，构建精细化遥感找矿模型，客观揭示风化壳淋积型镍矿矿化特征遥感响应机理，并为推进我国镍矿资源境外勘查进展提供科学依据。

本项目选取具有复杂地质背景的印度尼西亚北科纳威风化壳淋积型红土镍矿区，采用购置的WorldView-3、Aster、Landsat8影像数据，首先开展了线性构造、环形构造、地形阴影、植被等复杂地质背景条件解译工作，分析总结了北科纳威镍矿区复杂地质背景条件空间分布状况，研究区红土风化壳由上至下为：红土带（残余红土带）—腐岩带（风化蚀变橄榄岩带）—基岩带（原始橄榄岩带）的三个垂直分带特征，且区内主要矿化蚀变为褐铁矿、蒙脱石、高岭石、绿泥石、蛇纹石；基于WorldView-3遥感数据和USGS标准矿物波谱库，对风化壳淋积型镍矿矿化特征矿物展开了波谱响应机理研究，总结了褐铁矿、蒙脱石、高岭石、绿泥石、蛇纹石5种蚀变矿物的WorldView-3诊断性波谱；创新性引入分形多重分形理论，构建了基于“PCA+S-A”法复杂地质背景下风化壳淋积型镍矿矿化蚀特征矿物弱异常遥感信息增强提取模型，采用WorldView-3数据提取了褐铁矿、蒙脱石、高岭石、绿泥石、蛇纹石的空间分布信息，丰富了风化壳淋积型镍矿矿化遥感特征理论认识；创新性采用纳入了空间位置信息的地理加权回归方法对镍品位展开反演研究，结果表明地理加权回归结果明显优于多元线性回归和BP神经网络，R２达到0.9以上；构建了风化壳淋积型镍矿精细化遥感找矿模型:超基性岩风化的褐红色含镍铁质黏土区、断裂构造500m缓冲区、高程>400m、坡度<12°、坡向>100°、植被覆盖度<0.49、蒙脱石遥感异常。研究成果较好地深化了北科纳威风化壳淋积型镍矿矿化蚀变异常遥感响应机理，并为研究区及类似境外地区进一步找矿突破提供重要依据。.项目资助发表SCI论文12篇,中文核心期刊论文2篇，正在投稿SCI论文2篇。参加国内外学术交流3次。培养硕士研究生3人，均已取得硕士学位，其中3人博士在读；项目投入经费66万元，支出204726元，各项支出基本与预算相符，剩余经费455274元，计划用于本项目研究后续支出。