The Bahía Mansa Metamorphic Complex or BMMC (Spanish: Complejo metamórfico Bahía Mansa, CMBM), also known as the Western Series, is a group of metamorphic geologic formations of the Chilean Coast Range in southern Chile. It consists mainly of pelitic schists, metagreywackes and oceanic type mafic metavolcanics. The complex owes its name to Bahía Mansa.