大兴安岭地区富克山斑岩铜钼矿床地质特征与SWIR勘查应用

Geological Characteristics and Application of Short Wavelength Infra-Red Technology(SWIR)in the Fukeshan Porphyry Copper Deposit in the Great X ing'an Range Area

富克山铜钼矿是黑龙江省近年来的重大找矿成果之一.详细的野外观察和室内研究发现该矿床具有典型斑岩矿化特征.该矿床致矿斑岩为闪长玢岩,该岩性的侵位导致其自身及围岩中的钾化、黄铁绢英岩化和晚期绿泥石-黄铁矿三期蚀变.矿化主要赋存在与黄铁绢英岩化相关的伟晶岩和花岗闪长岩中.蚀变矿化与致矿闪长玢岩枝的空间分布特征指示矿区南西向深部可能存在大规模致矿岩体.白云母族矿物Pos2200和绿泥石的Pos2250峰位值研究发现,二者受原岩成分影响较大,不宜作为下一步找矿的勘查指标.白云母族IC值(伊利石结晶度)和绿泥石中MnO则主要受到温度的控制,是寻找热液矿化中心的有力工具.该项研究表明,蚀变矿化特征与SWIR分析结合将对矿床勘查起到较为重要的指示作用.

The Fukeshan copper depositis one of the major prospecting breakthroughs recently made in Heilongjiang Province.After detailed field work and microscopic observation,we found that this deposit has typical porphyry style characteristics.Out study shows that the diorite porphyry is the mineralization-causative porphyry.The emplacement of the diorite porphyry caused the potassic alteration,phyllicalteration and latest age chlorite-pyrite alteration in and around this porphyry.Mineralization in the Fukeshan deposit is mainly associated with phyllic alteration.Mineralization is mostly confined within diorite porphyry and granodiorite.Distribution of alteration and the causative diorite porphyry indicate that there may be a large-scale causative porphyry at depth in the southwest of the deposit.Detailed SWIR study indicates that the Pos2200 of muscovite and Pos2250 of chlorite are controlled by the composition of the original altered minerals,thus not suitable to be used as a vector for exploration.The IC values of muscovite group and MnO concentration in chlorite are controlled by temperature and can be used to be a vector to find the hydrothermal center at Fukeshan.This research highlights that the combination of alteration mapping and SWIR analysis can be of great help in mineral exploration.