Plainfield Formation

Pale-tan to gray, fine-grained quartzite, and pale- to medium-gray quartz-mica schist. Quartzite is massive to layered (bedded?). Includes Plainfield Formation and some rock mapped formerly as Blackstone Series.
State Rhode Island
Name Plainfield Formation
Geologic age Late Proterozoic? or older?
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > QuartzitePale-tan to gray, fine-grained quartzite; massive to layered (bedded?).
Metamorphic > Schist > Mica-schistpale- to medium-gray quartz-mica schist
Comments Part of Hope Valley Subterrane
References

Hermes, O.D. (comp.), Gromet, L.P. (comp.), Murray, D.P. (comp.), Hamidzada, N.A., Skehan, J.W., and Mosher, S., 1994, Bedrock geologic map of Rhode Island: Rhode Island Map Series No. 1, Kingston, Rhode Island, scale 1:100,000.

NGMDB product
Counties Providence - Washington