U. S. Route 7 Expressway (Danbury line to Iron Works District), Brookfield, Fairfield Co., Connecticut, USA

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The expressway section of U. S. Route 7 extending from Interstate 84 in Danbury to exit 12 at U. S. Route 202 in Brookfield was constructed between 1974 and 1976. The section from the Danbury/Brookfield line (from just north of the Agstone Co. marble quarry) to exit 12 at U. S. Route 202 (apparently the "Iron Works district" in Brookfield) traverses mostly sediments along the Still River and not much apparent bedrock. One roadcut is visible on the right of the northbound lanes, about 1 mile south of exit 12. However, Januzzi (1976) and (1994) reports a long list of minerals, many repeated in Weber and Sullivan (1995).

In Januzzi (1994) he shows photos of several minerals from the Iron Works district, apparently from exit 12, then the northern terminus of this stretch of expressway (which has since been extended further north), where bedrock evidently was encountered. Clarke (1958) shows outcrops in the area of exit 12, mapped as dolomitic marble of the Inwood (now called Stockbridge) marble, mixed with "younger granite" (now mapped as granite Proterozoic granitic gneiss).

Although the identical list of minerals in Januzzi (1976) and (1994) says all the minerals are from the U. S. Route 7 expressway construction, details accompanying photos in Januzzi (1994) indicate some came from pegmatites in the "Iron Works District", some locations "undisclosed". Because no one else has documented the specific localities and minerals, that information has largely been lost. That is unfortunate because, as Januzzi (1994) states:



The coordinates are for the approximate mid-point of this stretch of highway.

Mineral List

Actinolite Albite var: Andesine 'Allanite' Almandine Anatase Anglesite Aragonite Arsenopyrite Augite Bertrandite Beryl 'Biotite' Calcite Cerussite Chalcopyrite 'Chlorite Group'

Chondrodite Chrysoberyl Chrysotile Clinozoisite Dickinsonite-(KMnNa) Diopside Dolomite Elbaite Epidote Fluorapatite Forsterite Galena Greenockite Hematite ? Hemimorphite ? 'Hornblende' Hydrozincite ?

Ilmenite 'K Feldspar var: Adularia' ? Kyanite 'Limonite' Magnetite Microcline Molybdenite Muscovite var: Sericite Opal var: Opal-AN Orthoclase Palygorskite Phlogopite Pyrite Pyromorphite Pyrrhotite Quartz

Rutile 'Scapolite' Schorl 'Serpentine Group' Sillimanite Sphalerite Spodumene Staurolite Talc Titanite 'Tourmaline' Tremolite Triphylite Vivianite Wollastonite Zircon Zoisite

68 entries listed. 56 valid minerals.

References