Reflectance Spectral Characteristics of Rocks and Minerals in Jiajika Lithium Deposits in West Sichuan

Abstract

BACKGROUND The Sichuan Jiajika ore field is one of the most concentrated areas of lithium resources in China and even in the world. At present, the understanding of the spectroscopy of the Jiajika lithium deposit is still very poor. OBJECTIVES To better understand the spectra of lithium ore deposits and provide the basis for hyperspectral study of lithium ore deposits by spectrum measurement of typical rocks. METHODS Spectra of typical rocks and minerals collected in Jiajika area were measured by Analytical Spectral Devices (ASD) FieldSpec-4 Spectroradiometer and a spectral library of this area was built. The spectral characteristics of rocks and minerals including biotite schist, grenatiteschist, grenatite cordieriteschist, hornstone, granite, pegmatite containing spodumene, pegmatite without spodumene, quartz vein, feldspar, spodumenemono, biotite, aquamarine were analyzed. RESULTS The results indicate that there are differences in spectral characteristics between rock masses and surrounding rocks. The reflectance of surrounding rocks is less than 0.2, and absorption characteristics are not obvious, whereas the reflectance of rock masses is less than 0.5, and there are three absorption features at 1413 nm, 1911 nm, 2197 nm. In addition, granite, pegmatite containing spodumene, and pegmatite without spodumene can be discriminated by their unique spectra on 1413 nm and 2197 nm. The unique spectral characteristics of spodumene and aquamarine can be applied for ore exploration. CONCLUSIONS The research on the surface spectroscopy of the Jiajika type lithium ore deposit carried out in this paper has important guiding significance for hyperspectral remote sensing mapping and geological prospecting.

Keywords

• jiajika
• typical rocks and minerals
• ground-object spectrometer
• spectrum measurement