Interstate 84 (I-84; I-86; State Route 15; Wilbur Cross Highway), Union, Tolland Co., Connecticut, USA
|Latitude & Longitude (WGS84):||41° 58' 33'' North , 72° 10' 57'' West|
|Latitude & Longitude (decimal):||41.97583,-72.18250|
|Köppen climate type:||Dfb : Warm-summer humid continental climate|
Started in 1940 and originally called the Wilbur Cross Highway (Route 15), then after 1970 Interstate I-86, and finally Interstate I-84, road construction uncovered minerals described from unspecified locations by Bartsch (1940) (coordinates are arbitrarily set for the intersection of I-84 and state Route 190):
"A considerable amount of blasting of outcropping ledges has been completed with still more to be done. Much interesting material is thus being exposed. Most of the rock consists of schists containing a large amount of poorly formed pinkish garnet and an equally large amount of pyrite. This latter mineral causes a rapid disintegration of the material on exposure. A large amount of limonite is being formed which can be seen filling seams up to 1/2 inch in thickness.
"There are, however, some interesting minerals to be found here. Oligoclase in rather large plates, translucent and in some cases nearly transparent, of a greenish color, is to be found in excellent specimens. One cavity with prehnite and calcite xls was secured. A vein of limestone produced an interesting find—coarse granular calcite containing crystals of pyroxene which are partially absorbed giving them a rounded appearance. A quick glance gave the impression of franklinite grains in calcite from Franklin, N. J. Several specimens of sphene were also found in the vein, as well as some amethyst."
7 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Ordovician - Cambrian|
443.8 - 541 Ma
|Gneiss (metavolcanic) member [of Brimfield Schist]|
Age: Paleozoic (443.8 - 541 Ma)
Stratigraphic Name: Brimfield Schist
Description: Medium-gray, medium-grained, layered gneiss and schist, composed of oligoclase, quartz, and biotite; some gneiss and most schist layers contain garnet and sillimanite; some gneiss layers contain garnet, hornblende or pyroxene or grade into amphibolite or calc-silicate rock. Probably includes metavolcanic rocks.
Comments: Part of Eastern Uplands; Iapetus (Oceanic) Terrane - Merrimack Synclinorium; Brimfield Schist and equivalent formations (includes Tatnic Hill Formation) (Upper? and Middle Ordovician). The age of the Brimfield Group in this area is Cambrian(?) based on the intrusion of 440 my Hedgehog Hill gneiss in the top of the Hamilton Reservoir Formation in the upper part of the Brimfield, although the top of the Brimfield may be Ordovician or older Paleozoic (Pease, 1989) per CT013.
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.