State Routes 8 and 222 interchange, Thomaston, Litchfield County, Connecticut, USAi

Regional Level Types
State Routes 8 and 222 interchange	Road Cutting
Thomaston	- not defined -
Litchfield County	County
Connecticut	State
USA	Country

Construction of state Route 8 through town in the late 1950s uncovered two areas of mineralization preserved in collections, but poorly described. One is the Reynolds Bridge area at the south end of Thomaston near the border with Watertown. Minerals found there are covered by this page: https://www.mindat.org/loc-213284.html

Of particular note here is a calc-silicate assemblage rich in axinite-(Fe), a very rare mineral in Connecticut. Schooner (1961) reports that this was found "in the area around Thomaston Dam" but clearly not at the railroad cut just west of the dam. Yale Peabody Museum has two specimens of it that are cataloged as coming from an unspecified Route 8 road cut. Another specimen (https://www.mindat.org/photo-997893.html) is labeled as coming from a road cut north of Thomaston. I assume it is the large cut where Routes 8 and 222 intersect, which is where one would exit the highway to drive to the dam. There are some other cuts along the highway further north.

Some of the minerals noted in these specimens overlap with those listed in King (1986) as "from a single boulder found near Route 8". These minerals were collected by William Brunet and include diopside, amphibole, fluorapatite, pyrrhotite, quartz, plagioclase and titanite. Also from the area are "excellent examples of both zoisite (XRD) and clinozoisite (XRD) associated with quartz and plagioclase." The XRD was reportedly done by Dr. Richard Mitchell.

Other Regions, Features and Areas containing this locality

References