Arute Field, New Britain, Hartford County, Connecticut, USAi

Regional Level Types
Arute Field	Construction Site
New Britain	City
Hartford County	County
Connecticut	State
USA	Country

Basalt bordering the vein is silicified and bleached to a light gray color. This type of alteration is typical of the N45°W [actually N45°E according to Hubert et al (1992)] faults in the New Britain area irrespective of the presence of the carbonate-quartz-barite veins.

Vein filling was accomplished initially by the deposition of quartz, calcite, and ferroan dolomite in open spaces along the active fault zone. Movement continued throughout this phase frequently brecciating previously deposited vein material. After faulting ceased barite which occurs in plumose crystal groups up to 20 cm long, filled the open space in the center of the vein and cemented the carbonate-quartz breccias. The ferroan dolomite of the carbonate zone is oxidized to a dark red-brown color at the boundary of the barite zone. Cavities between barite crystals are filled by small amounts of drusy quartz, ferroan dolomite, and aragonite.

Sphalerite, chalcopyrite, galena, and minor amounts of barite, chalcocite, covellite, and tennantite fill open spaces and replace carbonates within the quartz-carbonate zones. Sphalerite was the first sulfide deposited. Galena and chalcopyrite followed later.

Vitreous black carbonaceous spheres, 1 to 5 mm in diameter, occur throughout the vein but are most abundant along the boundary of the quartz-carbonate and barite zones. Presumably these spheres were droplets of oil suspended in the hydrothermal fluids which became accidentally trapped during the deposition of the vein minerals.