Terrane Unit : MO Name : Monashee Description : Craton-related metasedimentary rocks overlying basement paragneiss and orthogneiss of Early Proterozoic age. Geological record differs from that of Ancestral North America. Assemblages : lPm Monashee Complex Plutonic Rocks : EPnMO Monashee, LPyC Mt. Copeland Age Range: Lower Proterozoic - Upper Proterozoic Maximum Age: 2500.0 Ma Minimum Age: 770.0 Ma