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Montgomery County Detail 1
Click on a tile to display information about the associated rock types or formations.
Upper Pelitic Schist (Late Precambrian ?) Lower Pelitic Schist (Late Precambrian ?) Baltimore Gabbro Complex (Early Paleozoic- Late Precambrian ?) Urbana Formation (Late Precambrian ?) Ijamville Formation / Marburg Schist (Late Precambrian ?) New Oxford Formation (Triassic) Marburg Schist (Late Precambrian ?) Georgetown Mafic Complex (Early Paleozoic- Late Precambrian ?) Lowland Deposits (Quaternary) Upland Deposits -Western Shore (Quaternary)  
Boulder Gneiss (Late Precambrian ?) Metagraywacke (Late Precambrian ?) Ultramafic Rocks (Early Paleozoic- Late Precambrian ?) Sugarloaf Mountain Quartzite (Late Precambrian ?) Ijamville Formation (Late Precambrian ?) Diabase Sills and Dikes (Triassic) Ellicott City Granodiorite (Paleozoic) Guilford Quatrz Monzonite (Paleozoic) Potomac Group (Cretaceous) Kensington Quartz Diorite (Paleozoic)  
Montgomery Count Geology: Detail 1