Mapping of heavy mineral placers through marine GIS expert system: a case study in Kalaignanapuram coastal stretch, southeast coast of Tamil Nadu, India

The aim of the present study is to develop a knowledge-driven expert system for mapping the potential heavy mineral placer deposits along the coast using integrated Geographical Information System (GIS) and fuzzy logic techniques. The study has been carried out in Kalaigananpuram coastal stretch, southeast coast of India, where high-quality heavy mineral placers are deposited naturally. A total of six transects was laid perpendicular to the coastline, in which 36 samples per transect of 2 m interval per month was taken for analysis. Standard techniques were adopted for evaluating the beach profile, grain size, and heavy mineral weight percent. Moreover, the statistical results of these parameters were considered for mapping the heavy mineral placer potential zone in the study area. A fuzzy-based expert system model was developed through ArcGIS model builder to map the mineral potential zone. In this study, three evidential layers were fuzzified using the linear membership function. These evidential layers were further ranked based on expert knowledge from placer minerals exploration researchers. The analyzed results reveal that heavy mineral placer deposits are observed in the berm and high-tide region of the study area. The annual average weight percent of heavy mineral placer deposits in the study area range from 40 % to 60 %. The extracted heavy mineral placer potential maps can be used for sustainable mining and surveying purposes.