State | Massachusetts |
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Name | Moretown Formation |
Geologic age | Middle Ordovician or older |
Lithologic constituents |
Major
Metamorphic > Schist > Mica-schistmedium- to coarse-grained, poorly bedded mica-rich schist showing dark-green chlorite clots
Minor
Metamorphic > Granoblastic > GranofelsSome pinstriped granofels
|
Comments | Part of Rowe-Hawley Zone (Ordovician and Older Rocks). Early Ordovician age from zircons (479+/-8 Ma) constrains the age of the previously undated Moretown Formation to Early Ordovician or older. Moretown had been interpreted as Middle Ordovician based on correlations with the Beauceville Formation of southern Quebec and the Missisquoi Formation of VT (Karabinos and Williamson, 1994) per MA005. |
References | Zen, E-An (ed.), Goldsmith, R. (comp.), Ratcliffe, N.M. (comp.), Robinson, P. (comp.), Stanley, R.S. (comp.), Hatch, N.L., Jr., Shride, A.F., Weed, E.G.A., and Wones, D.R., 1983, Bedrock Geologic Map of Massachusetts: U.S. Geological Survey, Reston, VA, scale 1: 250,000.https://pubs.er.usgs.gov/publication/70046713 Karabinos, Paul and Williamson, B.F., 1994, Constraints on the timing of Taconian and Acadian deformation in western Massachusetts: Northeastern Geology, v. 16, no. 1, p. 1-8. |
NGMDB product | |
Counties | Franklin |