A detailed petrogenetic study of two major intrusive complexes within the Bays-of-Maine igneous complex: the Pleasant bay layered gabbro and the Mt Desert Island igneous complex of gabbroic, dioritic and granitic rocks. In both areas layers of chilled to fine-grained gabbro and medium-grained diorite to granite occur intercalated with gabbroic cumulates. Although these unusual layers have in the past been interpreted as dikes or sills, field relations appear to be more consistent with their interpretation as conformable layers deposited on a magma chamber floor. Field, petrographic, and geochemical studies will be directed toward testing that thesis.
