Tatnic Hill Formation - Fly Pond Member

Calc-silicate gneiss and marble.
State Massachusetts
Name Tatnic Hill Formation - Fly Pond Member
Geologic age Ordovician or Proterozoic Z
Lithologic constituents
Major
Metamorphic > Gneiss > Calc-silicate-gneissCalc-silicate gneiss and marble.
Metamorphic > Metasedimentary > Metacarbonate > MarbleCalc-silicate gneiss and marble.
Comments Part of Nashoba Zone (Silurian and Older Rocks). The age of the Putnam Group, including its Tatnic Hill Formation, is considered to be Late Proterozoic(?) based on the 730 my age of the Fishbrook Gneiss in MA and the 440 my age of the Hedgehog Hill gneiss intruded into the upper part of the younger Brimfield Group (Pease, 1989) per MA009.
References
NGMDB product
Counties Worcester