|Name||Silurian - Ordovician unnamed volcanic rocks|
|Geologic age||Silurian - Ordovician|
Igneous > Volcanic > Mafic-volcanicGS - Greenschist facies; Protolith W - mafic to felsic volcanic rocks
Igneous > Volcanic > Felsic-volcanicGS - Greenschist facies; Protolith W - mafic to felsic volcanic rocks
|Comments||Named Mars Hill Till for Mars Hill, Aroostook Co., northern ME. Unit is described as an irregular hummocky sheet of outwash, kames, kettles, and smaller till hummocks and an extensive moraine complex, characterized by distinct ridges, that rises above the general level of the drift surface. Clasts in the drift include DeBoullie Granodiorite, Chapman Sandstone, Mapleton Sandstone, and Mars Hill Conglomerate. Till was deposited by the Laurentide ice sheet or by a separate ice cap in ME. Correlates with the Van Buren Till (new name), also deposited by the Laurentide ice sheet, and the Lennoxville till of southeastern Quebec. It is the youngest till in Aroostook Co. and lies at the surface. Thickness ranges from 0 to 30 m. Unit is late Wisconsinan (Pleistocene). (ME060) Unit description from USGS GEOLEX website (ME078). W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith I - Conglomerate.|
Osberg, P.H., Hussey, A.M., and Boone, G.M., 1985, Bedrock geologic map of Maine: Maine Geological Survey, Dept. of Conserv., scale 1:500,000.