Moretown Formation (MAOml;0)

State	Massachusetts
Name	Moretown Formation
Geologic age	Middle Ordovician or older
Original map label	Oml
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.
Primary rock type	mica schist
Secondary rock type	granofels
Other rock types
Lithologic constituents	Major Metamorphic > Schistmedium- to coarse-grained, poorly bedded mica-rich schist showing dark-green chlorite clots Minor Metamorphic > Granoblastic > GranofelsSome pinstriped granofels
Map references	Unpublished Digital Geologic Map of Massachusetts received from Rudi Hon at Boston College in 1998.
Unit 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., Wones, D.R., 1983, Bedrock Geologic Map of Massachusetts: U.S. Geological Survey, Reston, VA, scale 1: 250,000. 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.
Geographic coverage	Franklin