Sinharaja metamorphic basement geology: charnockite-khondalite contact zones?

The underlying geological foundation of the Sinharaja World Heritage Wilderness consists entirely of Precambrian metamorphic rocks belonging to the Highland Complex. Stream bed exposures across Kudawa and Pitadeniya reveal a continuous sequence of interlayered garnet-sillimanite-graphite gneisses (khondalites), charnockitic pyroxene granulites, and calc-silicate marble lenses. These units were compressed and folded into tight regional synforms and antisedimentary domes during the Pan-African Orogeny 550 million years ago, creating the steep topography that governs rainforest stream hydrology.