Primary Lithology (at bedrock surface): sedimentary clast breccia with shaly matrix; clasts and blocks of Cretaceous shale and varied Paleozoic lithologies in silty-sandy clay matrix (see above; thickness 0-200 ft; 60 m). Secondary Lithologies: crystalline rock megabreccia (locally forms bedrock surface), fractured and brecciated Proterozoic basement lithologies, dominantly gneiss but including granite and other igneous-metamorphic rocks (maximum thickness unknown). Suevite and impact-melt breccias (locally forms bedrock surface), clasts of Proterozoic crystalline basement rocks, melt-rock, and minor Proterozoic “red clastics” in a matrix of melt-rich material (devitrified) and/or sandy-silty debris (thicknesses to 380 ft; 115 m). Keweenawan shale-clast breccia (locally forms bedrock surface), dominated by gray to black shale clasts (small to large) derived the lower “red clastics” sequence, common melt clasts, minor basement and Phanerozoic clasts, in a silty-sandy shaly matrix or melt-rich matrix (thicknesses to 250 ft, 75 m).