Beach Placer Deposit Modelling using Geospatial Methods: A Case Study from Brahmagiri Mineral Sand Deposit, Puri District, Odisha

Abstract

An integrated approach has been attempted for 3D representation of various geo-exploration data pertaining to Brahmagiri Mineral Sand Deposit (BMSD). GIS platforms are utilized to represent the prime depositional environments of sediments under which Total Heavy Minerals (THM) concentrated. In recent times, deeper exploration by sonic drilling has been carried out in the main sand bar of the deposit and retrieved huge lithological data. Different 3D visualization of exploration data using various geological Softwares (ArcGIS, Rockworks and Datamine) carried out.

Understanding the morphology of the deposit is carried out using the topographic representation on GIS platform. Discontinuous linear dune ridges are present across the deposit. Sand column explored at an average depth of 40m represents the variety of depositional environment (lagoonal, barrier and beach) within basin. Lithological correlation for the entire (20km) stretch of BMSD carried out and major sand units have been summarized for the area. Heavy mineral (HM) concentrations in each sand column and their correlation using geospatial methods classify the trend and extent of mineralization into two potential zones (Zone 1 and Zone 2) depth wise. This study emphasizes the relationship between surface and subsurface manifestation of exploration data which reveals that BMSD could be part of Barrier bar system having different sub-depositional environments as back-barrier, barrier beach and inlet channel which are controlling the total heavy mineral concentration at various depths. Upper zone of ore body is confined to beach regime whereas lower zone is controlled by combination of beach, back-barrier and inlet channel sediments.