The Timor–Tanimbar region constitutes part of the non-volcanic outer Banda Arc of Eastern Indonesia. Here, the world's youngest ‘A’-type high-pressure metamorphic belt crops out with different stages of evolution. Whereas an advanced domal uplift stage is seen in Timor island, the high-pressure (HP) metamorphic belt is still in the first stage of tectonic extrusion on the eastern small islands of Kisar, Leti, Moa, Sermata and Laibobar. The metamorphic rocks on Leti are among the best exposed in the islands. They are tectonically juxtaposed against overlying ultramafic rocks and underlying unmetamorphosed continental shelf sediments, bound by normal and reverse faults, respectively. The Leti metapelites display four progressive metamorphic zones: chlorite–biotite, garnet, chloritoid–staurolite and kyanite zones, with increasing grade. Zonation in Leti metabasite unit is comparable, and progressively changes …