A study of the deep mineralization evaluation based on field measured spectra in Wushan-copper deposit area

Abstract

With the development of Hyperspectra and the method of rock-mineral information extraction, several cores were analyzed based on analytical spectral devices (ASD) and rock-mineral information extraction in Wushan-cooper deposit area. Aiming at the low accuracy of mineral identification with hyperspectral data, the present study established regional spectra library on the basis of the study area geological background, section noise filtering and fast Fourier transform processing methods. Using the rapid quantificational identification model, the rock-mineral alternation information was extracted to build core profile and 3D model to discuss the deep mineralization evaluation. Combing with the regional metallogenic background, the alteration information indicated that the ore mineral was related with multiple alteration assemblages and there may be rock mass in deep space. The Cu element contents and ore mineral were closely related with the skarnization, silicification and chloritization. It also suggested that the deposit was skarn type in less than 1000 m depth, which was affected by the sandstone. Meanwhile, in more than 1000 m depth, the deposit was controlled by composite minerallzation types, which was associated with the previous geology and mineral deposits studies. In summary，this study supported a two stage mineralization model for the Wushan-copper deposit area，namely，the first stage of synsedimentary hydrothermal exhalative stage and the second stage of magmatichydrothermal ore-forming stage.