| State | Maine |
|---|---|
| Name | Cambrian Hurricane Mountain Formation, amphibolite and greenschist |
| Geologic age | Cambrian |
| Lithologic constituents | Major
Metamorphic > Amphibolite (Zeolitic (prehnite-pumpellyite))W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith V - Basaltic volcanic rocks; Also GS - Greenschist facies
Igneous > Volcanic > Mafic-volcanic > BasaltW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Also GS - Greenschist facies; Protolith V - Basaltic volcanic rocks
|
| Comments | Secondary unit description from USGS Geologic Name lexicon (ref. ME078): Rye Formation consists of a series of variably mylonitized, polymetamorphosed calcareous and noncalcareous metasandstone and metasiltstone, migmatized and non-migmatized metapelite, rusty-weathering sulfidic graphitic phyllite, marble, and amphibolite. Age of the Rye is uncertain. Assigned an age of Precambrian Z(?) to Ordovician based on cross-cutting metadiorite that yielded an age of 477 Ma (Rb/Sr, Gaudette and others, 1984) and an approximate 460 40Ar/39Ar metamorphic age on hornblende from amphibolite not involved in later ductile faulting (West, 1993). GS - Greenschist facies; Protolith Q - Interbedded pelite and sandstone |
| 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.US Geological Survey, 2005, National Geologic Map Database, Geologic Names Lexicon "GEOLEX", http://ngmdb.usgs.gov/Geolex/. |
| NGMDB product | |
| Counties | Somerset |