Can Imaging Spectroscopy Divulge the Process Mechanism of Mineralization? Inferences from the Talc Mineralization, Jahazpur, India

Abstract

Talc deposits of Jahazpur, Rajasthan, hosted by dolomite, are one of the largest high-quality talc deposits in India. In the present study, we use AVIRIS-NG datasets to study the link between the spatial pattern of talc mineralization, associated alteration minerals, and iron-oxide enrichment. It is noted that the majority of talc-bearing areas are characterized by the presence of clay minerals, such as an intimate mixture of kaolinite and muscovite, illite, dickite (indicative of phyllic and argillic alteration), and also enhanced iron enrichment. The talc-bearing zones are located adjacent to quartz-rich lithologies, and they are aligned along the Jahazpur thrust. Based on mineralogical and geological evidence, hydrothermal alteration of dolomites by silica and iron-rich fluid is proposed as major factorcontrolling talc mineralization. This study has implications for the identification of prospective zones of talc mineralization using imaging spectroscopy.

Remote Detection of Geothermal Alteration Using Airborne Light Detection and Ranging Return Intensity

“…Hydrothermal alteration on the surface can be regionally detected and remotely mapped due to the mappable size of their surface expressions, even from space. Many applications of spaceborne datasets (e.g., Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER, spatial resolution 15 m), Hyperion (spatial resolution 30 m)) and airborne optical datasets (e.g., Airborne Visible/InfraRed Imaging Spectrometer (AVIRIS, spatial resolution 2.4 m) or AVIRIS-Next Generation (AVIRIS-NG, spatial resolution 8.1 m)) have been reported to map hydrothermal alteration effectively in large areas [3][4][5][6][7][8][9][10][11]. For smaller areas, employing unmanned aerial vehicles (UAVs) could be an alternative to carrying remote sensors for mapping hydrothermal alteration, producing data in a higher spatial resolution, e.g., optical images of 0.05 m resolution [12].…”

“…Although various factors could influence LRI values, they represent the target (i.e., ground or rock) reflectivity at the laser wavelength. It can, therefore, potentially be used for hydrothermal alteration mapping when other airborne multi-and hyperspectral imagery (e.g., AVIRIS and AVIRIS-NG [5][6][7][8]10,11]) fails to map such small targets.…”