Devonian Trout Valley Formation (MEDtv;0)

State	Maine
Name	Devonian Trout Valley Formation
Geologic age	Devonian
Original map label	Dtv
Comments	Probably named for Trout Brook valley. Crops out over an area about 1.5 by 8 mi. Consists of predominantly clastic rocks, mainly a heterogeneous assemblage of light-bluish-gray to black shale, siltstone, sandstone, and conglomerate; includes small amount of black sideritic ironstone and sandstone. Maximum exposed thickness of 1000 ft. To the north and west, abuts high-angle normal fault and is on downthrown side of fault. To the south and east, unconformably overlies series of felsite lavas, tuffs, and welded tuff called Traveller rhyolite by Toppan (1932). Plant fossils described. (ME019) Unit description from USGS GEOLEX website (ME078). U- unmetamorphosed W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith H - Lithic sandstone and conglomerate
Primary rock type	sandstone
Secondary rock type	conglomerate
Other rock types	clastic
Lithologic constituents	Major Sedimentary > Clastic > Mixed-clasticU- unmetamorphosed W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith H - Lithic sandstone and conglomerate Sedimentary > Clastic > ConglomerateU- unmetamorphosed W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith H - Lithic sandstone and conglomerate Sedimentary > Clastic > SandstoneU- unmetamorphosed W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith H - Lithic sandstone and 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. Dorf, Erling and Rankin, D.W., 1962, Early Devonian plants from the Traveler Mountain area, Maine: Journal of Paleontology, v. 36, no. 5, p. 999-1004. Andrews, H.N., and Kasper, A.E., 1970, Plant fossils of the Trout Valley Formation: Maine Geol. Surv., Bull. 23, p. 3-16. Andrews, H.N., Kasper, A.E., Forbes, W.H., Gensel, P.G., and Chaloner, W.G., 1977, Early Devonian flora of the Trout Valley Formation of northern Maine: Rev. Paleobot. Palynol., v. 23, p. 255-285. USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/]
Geographic coverage	Piscataquis