how much of sri lanka surface is earth mantle

Sri Lanka’s surface is not earth mantle. Almost all of it is crust : a source on Sri Lanka geology says more than 90% of the island’s surface lies on Precambrian strata, and research on its crust finds Moho depths of about 30–40 km, which means the mantle is far below the surface.

What that means

• The mantle is the layer beneath Earth’s crust, not something exposed at the surface.

• Sri Lanka sits on relatively old continental crust, so the mantle is not at the surface over any meaningful area.

• In practical terms, the percentage of Sri Lanka’s surface that is mantle is about 0%.

Quick scoop

So the short answer is: none of Sri Lanka’s surface is Earth’s mantle ; the island is covered by crust instead.