PANAJI
The Union Mines Ministry will undertake specialised thematic mapping-cum-exploration of Goa schist belt -- a geological feature within the broader Shimoga-Goa supracrustal belt -- to assess the potential of different crucial mineral resources including gold, copper and other rare earth elements (REEs).
The study that will commence in the financial year 2025-26, will also map younger ultramafic and granitic rocks around Ponda, Sanvordem and Quepem taluka.
According to the Ministry, despite the extensive research of the area, several geological problems remain unresolved, particularly concerning the lithostratigraphy, structural geology, and mineralization potential of the region and hence the proposed study will address these gaps through detailed mapping, petrographic analysis, and geochemical characterization.
“The proposed study area within the Goa schist belt is a region of significant geological interest, hosting a variety of rock types, including schistose rocks, ultramafic complexes, and younger granites,” the Ministry said in their proposal.
“The full extent of mineralization potential in the region, particularly for REEs, base metals, and platinum group elements (PGEs), remains to be explored. The laterite overlying ultramafic rocks also needs to be assessed for its potential to host nickel, copper, and chromium mineralization,” the Ministry added.
The Goa schist belt, part of the larger Dharwar Craton, represents a complex geological terrain characterized by a variety of lithological units. The schistose rocks of this belt have been classified into several formations, including the Barcem, Sanvordem, Bicholim, and Vageri formations, which rest on an Archaean gneissic basement. The region also hosts ultramafic rocks, particularly those associated with the Usgaon/Motimakki complex, as well as younger granites and basic intrusive.
The geological history of this area has been the subject of several studies, with early surveys conducted by the Portuguese and later, more systematic work by the Geological Survey of India (GSI)
“The potential for mineralization in the Goa schist belt has been a focus of several studies, particularly those conducted by the GSI. The area has been reported to host a variety of mineral deposits, including sulfides, chromite, nickel, and rare earth elements (REEs). The presence of platinum group elements (PGEs) such as ruthenium, rhodium, and palladium has also been noted, further highlighting the mineralization potential of the region,” the Ministry said.
Early investigations by GSI in the 1980s and thereafter indicated the presence of base metal mineralization, with significant findings of copper, chromium, and nickel. The surveys conducted during the same period also indicated the presence of sulfide mineralization.
The recent work by Santra and Norboo (2022-23) reported multiple signatures of mineralization, including disseminated sulfides in volcanics, ultramafic-hosted chromite, and pegmatite-hosted REE mineralization.
“In addition to base metals, the area also shows potential for precious metal mineralization, with gold values of up to 92 ppb reported from quartzites and dunites,” it said.
