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The place where the rock 'laterite' was named — now a National Geological Monument.

Angadipuram is the type locality of laterite — the iron- and aluminium-rich, brick-red rock that hardens once it is dug out and exposed to air. The Scottish physician Francis Buchanan-Hamilton named it here in 1807, from the Latin later, “brick”; the term is now used the world over. The Geological Survey of India has declared the site a National Geological Monument.

Laterite forms by intense chemical weathering in hot, wet climates: rain strips silica and soluble bases out of the underlying rock and leaves a residue of iron and aluminium oxides behind. Across Kerala and the Western Ghats it is still cut in neat blocks straight from the ground as a traditional building stone.

Sources

• Geological Survey of India — National Geological Monuments

A short reference note: this summary draws on third-party sources such as the Geological Survey of India and Wikipedia. In time I plan to give every geological feature its own learning-oriented write-up — with custom diagrams, graphs, and study pointers — as I’ve already done for the 11 locations that have an Instagram reel.