Western Ghats Laterite: an Architecturally and Culturally Iconic Stone from India with Special Reference to Goa

Laterite is a common rock found along the Western Ghats of Peninsular India. Laterites have developed mainly over Deccan Trap basalts in Maharashtra, gneisses and metasediments in Goa and parts of Karnataka, whereas it has developed on granulite-khondalite rocks in the southern state of Kerala. The laterite has been extensively quarried and utilised for years all along this unique geological and biodiversity hotspot in India. It was discovered to be a natural rock that, despite having significant porosity, which is unusual for a construction stone, became hard when exposed to air and was thus widely used as a building material. In the Western Ghats region of India, laterite has been extensively used in the construction of monolithic structures, temples, forts, convents, cathedrals and local residences. The umpteen uses of laterite can be witnessed in the states of Maharashtra, Goa, Karnataka, and Kerala. Lateritic rocks in Maharashtra and Goa are known for petroglyphs, cave shelters and cave temples. Some of these caves were shelters of early humans during Palaeolithic, Mesolithic and Neolithic-Chalcolithic periods. The oldest structures composed of laterite in Kerala are the megalithic monuments, which are regarded variations of urn burials because most of them had urns buried beneath them. Structures built during the Portuguese reign in Goa, spanning almost 450 years, bear testimony to a confluence of varied Indian, European and Islamic architectural styles which are unique to Goa. Some of the sites in Goa have been designated as UNESCO World Heritage Sites. Laterite is commonly used in the form of dressed blocks and rubble stone for construction purposes. The widespread use of laterite in the Western Ghats region of India reveals a lot about the cultures and customs that were in place during the past. We propose Western Ghats laterite from India for IUGS Heritage Stone designation in light of its widespread usage in the stone-architectural heritage sites and its contribution in promoting the cultural beliefs of the people of this region at various points in history.