Silurian - Ordovician Mars Hill Conglomerate (MESOmh;0)

State	Maine
Name	Silurian - Ordovician Mars Hill Conglomerate
Geologic age	Silurian - Ordovician
Original map label	SOmh
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
Primary rock type	conglomerate
Secondary rock type
Other rock types
Lithologic constituents	Major Sedimentary > Clastic > ConglomerateW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith I - Conglomerate
Map references	Digital bedrock data downloaded from Maine Office of GIS in September 2005 from http://apollo.ogis.state.me.us/catalog/catalog.asp?state=2&extent=cover#bedrock Bedrock units table (publication date 11/15/2002) downloaded from same site. Permission to redistribute these data granted by Dr. Robert Marvinney, State Geologist of Maine, in September 2006. [http://apollo.ogis.state.me.us/catalog/catalog.asp?state=2&extent=cover#bedrock]
Unit references	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. Neuman, R. B., pers. communication, 1983. Genes, A.N., Newman, W.A. and Brewer, T.B., 1981, Late Wisconsinan glaciation models of northern Maine and adjacent Canada: Quaternary Research, v. 16, no. 1, p. 48-65. USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/]
Geographic coverage	Aroostook