Potentials of Airborne Hyperspectral AVIRIS-NG Data in the Exploration of Base Metal Deposit—A Study in the Parts of Bhilwara, Rajasthan

Arindam Guha,Joyasree Sinha,Ratnakar Bhaisal,Nisha Rani,Uday Kumar Ghosh,K Vinod Kumar,Amin Beiranvand Pour,Pamaraju V N Rao,Nikhil Kumar Baranval,Snehamoy Chatterjee

doi:10.3390/rs13112101

Abstract

In this study, we have processed the spectral bands of airborne hyperspectral data of Advanced Visible Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) data for delineating the surface signatures associated with the base metal mineralization in the Pur-Banera area in the Bhilwara district, Rajasthan, India.The primaryhost rocks of the Cu, Pb, Zn mineralization in the area are Banded Magnetite Quartzite (BMQ), unclassified calcareous silicates, and quartzite. We used ratio images derived from the scale and root mean squares (RMS) error imagesusing the multi-range spectral feature fitting (MRSFF) methodto delineate host rocks from the AVIRIS-NG image. The False Color Composites (FCCs) of different relative band depth images, derived from AVIRIS-NG spectral bands, were also used for delineating few minerals. These minerals areeither associated with the surface alteration resulting from the ore-bearing fluid migration orassociated with the redox-controlled supergene enrichments of the ore deposit.The results show that the AVIRIS-NG image products derived in this study can delineate surface signatures of mineralization in 1:10000 to 1:15000 scales to narrow down the targets for detailed exploration.This study alsoidentified the possible structural control over the knownsurface distribution of alteration and lithocap minerals of base metal mineralizationusing the ground-based residual magnetic anomaly map. This observationstrengthens the importance of the identified surface proxiesas an indicator of mineralization. X-ray fluorescence analysis of samples collectedfromselected locations within the study area confirms the Cu-Pb-Zn enrichment. The sulfide minerals were also identified in the microphotographs of polished sections of rock samples collected from the places where surface proxies of mineralization were observed in the field. This study justified the investigation to utilize surface signatures of mineralization identified using AVIRIS-NG dataand validated using field observations, geophysical, geochemical, and petrographical data.

Highlights

Spectral analysis was used as the basisfor deriving the AVIRIS-NG-based image products (Figure 3)
We found that calcareous silicates, amphibolite, and sericitized quartzite have their diagnostic absorption features in the short-wave infrared (SWIR) domain, whereas
Some of the surface imprints identified in the areas such as Gurla, Mangalpura, and Lanpriya are associated with localized enrichment of metal, and these areas could be important for identifying pocket loads of base metal

Summary

Introduction

Radiometer (ASTER) for mineral mapping due to superior spectral, spatial, and radiometric resolution of airborne hyperspectral data like AVIRIS-NG data [7]. In this respect, comparative analysisof AVIRIS-NG and ASTER data confirmed the potential of airborne AVIRIS-NG data over ASTER data for delineating surface exposures of kimberlite and chromite, as these rocks generally have few isolated and small-sized surface exposures [1]. A recent study showed comparative utilization of airborne hyperspectral data, anddifferent spaceborne multispectral data, including Landsat, ASTER, and Sentinel, for mineral mapping [10]. The integrations of multi-sensors data for mineral mapping were reported in the literature [11,12]

Methods

Results

Discussion

Conclusion