Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > Massachusetts
|Geologic age||Lower Devonian or younger|
|Original map label||Dfgd|
|Comments||Part of Merrimack Belt (Silurian, Devonian and Pennsylvanian Rocks) Secondary unit description per MA007 as reported in USGS Geologic Names lexicon (re.f MA024): Fitchburg Complex mapped as three small stocks intruding Worcester Formation east of Wekepeke fault and west of Clinton. Also intrudes Paxton and Littleton Formations. U-Pb zircon age of 390 +/-15 Ma and Rb-Sr whole-rock age of 402 +/-11 Ma were both reported by Zartman and Naylor (1984) (Wones and Goldsmith, 1991).|
|Primary rock type||granitic gneiss|
|Secondary rock type||mica schist|
|Other rock types||phyllite|
Metamorphic > Gneissstrongly foliated biotite granodiorite to tonalite gneiss
Metamorphic > Metasedimentary > Metaclastic > Phylliteintrudes and contains inclusions of Dl (Littleton Formation)
Metamorphic > Schistintrudes and contains inclusions of Dl (Littleton Formation)
Unpublished Digital Geologic Map of Massachusetts received from Rudi Hon at Boston College in 1998.
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.
|Geographic coverage||Middlesex - Worcester|
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