Tibbit Hill Formation (VTCAZth;0)

Tibbit Hill Formation

Largely metabasalt and minor metasedimentary rocks consisting of massive, fine-grained, dark-green metabasalt flows, pillow basalt, vesicular basalt composed of albite, epidote, chlorite (±actinolite); and interbedded phyllitic grits, feldspathic quartzite, chloritic metawacke, and basaltic tuffaceous metasedimentary rocks, all similar to rocks of the Pinnacle Formation. Volcanics are alkalic to transitional metabasalts. Cover rocks of the Lincoln Mountain massif and northwestern flank of the Green Mountain massif.

State	Vermont
Name	Tibbit Hill Formation
Geologic age	Cambrian and Neoproterozoic
Lithologic constituents	Major Metamorphic > Metaigneous > Metavolcanic > MetabasaltLargely metabasalt and minor metasedimentary rocks consisting of massive, fine-grained, dark-green metabasalt flows, pillow basalt, vesicular basalt composed of albite, epidote, chlorite (±actinolite). Volcanics are alkalic to transitional metabasalts. Minor Metamorphic > MetasedimentaryMinor metasedimentary rocks consisting of massive, fine-grained, dark-green metabasalt flows, pillow basalt, vesicular basalt composed of albite, epidote, chlorite (±actinolite); basaltic tuffaceous metasedimentary rocks Metamorphic > Metasedimentary > Metaclastic > Metasandstone > MetagraywackeInterbedded chloritic metawacke. Metamorphic > Metasedimentary > Metaclastic > QuartziteInterbedded feldspathic quartzite.
References	Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, 3 sheets, scale 1:100,000. https://pubs.er.usgs.gov/publication/sim3184
NGMDB product	NGMDB product page for 96860
Counties	Franklin

Tibbit Hill Formation

Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, 3 sheets, scale 1:100,000.