摘要
高光谱遥感技术可以有效地用于分析热液流体活动规律,进而指导找矿预测。利用国际先进的CASI/SASI航空高光谱遥感技术、并结合ASD便携式地面高光谱技术手段,文章从航空、地面、深部钻孔岩芯等不同尺度对白杨河铀矿区及周围地表和深部的热液蚀变类型和热液活动规律等进行了立体识别与研究。研究表明,白杨河铀矿区及周围航空高光谱遥感识别的蚀变矿物在空间上可分为北部蚀变区、矿区蚀变区、南部蚀变区等3个蚀变带。北部蚀变区发育一套以叶腊石、明矾石、高铝绢云母为主的酸性热液蚀变组合;矿区蚀变区地表发育高铝绢云母、中铝绢云母、赤铁矿、硅化等热液蚀变,矿区深部钻孔岩芯主要发育高铝绢云母、中铝绢云母、低铝绢云母、高岭石、赤铁矿、褐铁矿、绿泥石等蚀变矿物及其混合蚀变,且绢云母蚀变矿物的Al-OH吸收峰波长位置存在“单向递减”和“先减后增”等2种明显变化规律;南部蚀变区发育低铝绢云母和中铝绢云母蚀变。分析表明,北部蚀变区是相对的区域热液流体活动中心,铀矿区蚀变区是流体活动中心旁侧的一个明显的热液流体活动区,南部蚀变区是更加远离流体活动中心的,温度进一步降低的流体活动区。矿区北缘接触带的热液蚀变温度要比南缘接触带蚀变温度高,北缘接触带热液流体蚀变温度具有由中西部向东部不断降低、由接触带向接触带外围不断降低的特点。总之,白杨河铀矿区深部热液流体活动至少存在“直流型”和“分流型”2种典型的形式,前者反映热液流体活动温度自深部→接触带→浅部不断降低的特点,后者反映热液流体活动温度自接触带分别向上和向下逐渐降低的特点。此外,文章还对热液流体活动与铀矿化关系,以及矿区外围铀矿找矿方向进行了分析。
The study of the spatial regularity of hydrothermal fluid activity for Baiyanghe uranium deposit and peripheral areas in Xuemisitan of Xinjiang is helpful to the prediction of deep uranium mineralization and the expansion of prospecting mind to exploration outside the deposit.Based on the international advanced CASI/SASI airborne hyperspectral remote sensing technology and ASD portable ground hyperspectral technique,the authors identified and studied the type of hydrothermal alteration and the law of hydrothermal activity for the surface of Baiyanghe uranium deposit and its peripheral areas and the deep area of the deposit from different scales with airborne,surface,and drilling means.In uranium mineralization area and its peripheral areas,the altered minerals identified by airborne hyperspectral remote sensing can be divided into three alteration zones:northern alteration zone,mineralization alteration zone and southern alteration zone.A set of acidic hydrothermal alteration mineral assemblages mainly composed of pyrophyllite,alunite,Al-high sericite were developed in the northern alteration zone.On the surface of the uranium mineralization area,the main hydrothermal alterations of Al-high sericite,Al-medium se-ricite,hematite,silicitization are developed.In the deep borehole cores,the main alteration minerals and their associations are Al-high sericite,Al-medium sericite,Al-low sericite,hematite,kaolinite,Limonite,chlorite and their mixtures.There exist two kinds of variation regularity for the Al-OH absorption wavelength location of sericite in the drill hole.One is called decrease in one direction from surface to deep,and the other is called decrease at first and increase after that from surface to the depth.In the south area of the uranium deposit,main alteration minerals are Al-low sericite and Al-medium sericite.Analysis shows that the northern alteration zone has developed a set of acid alterations formed by boiling of volcanic gas and liquid,which represents the comparatively regional activity center of volcanic hydrothermal fluid.The uranium mineralization alteration area belongs to the lateral area with obvious hydrothermal activity and the south area is the area far away from the center,which has obvious hydrothermal fluid activity and lower temperature.Analysis also shows that the hydrothermal alteration temperature in the northern fringe zone is higher than that in the southern fringe zone.In the north fringe zone,the hydrothermal alteration temperature is characterized by gradual decrease from middle-west to east and from the contact zone outwards.There exist at least two typical forms for the hydrothermal fluid activity in deep zone of Baiyanghe uranium mineralization area.The former shows that the temperature of the hydrothermal fluid activity gradually decreases from the depth through contact zone to shallow zone,and the latter shows that the temperature of the hydrothermal fluid activity respectively decreases from the contact zone through the deep zone to the shallow zone.In addition,the relationship between hydrothermal fluid activity and uranium mineralization and the uranium-beryllium prospecting direction outside of Baiyanghe deposit area are also discussed.
作者
叶发旺
张川
徐清俊
孟树
邱骏挺
王建刚
YE FaWang;ZHANG Chuan;XU QingJun;MENG Shu;QIU JunTing;WANG JianGang(National Key Lab of Remote Sensing Information and Imagery Analysis,Beijing Research Institute of Uranium Geology,Beijing 100029,China;China University of Geoscience,Beijing 100083,China)
出处
《矿床地质》
CAS
CSCD
北大核心
2019年第6期1347-1364,共18页
Mineral Deposits
基金
国家自然科学基金项目(编号:41772354)
中核集团龙腾二期项目(编号:遥LTY1604)资助
关键词
地质学
高光谱遥感
矿物识别
热液流体活动
热液流体活动中心
白杨河铀矿床
新疆
geology
hyperspectral remote sensing
minerals identification
hydrothermal fluid activity
center of hydrothermal fluid activity
Baiyanghe uranium deposit
Xinjiang