Howe Quarry (Howe #1 Quarry; Huspband Quarry), South Glastonbury, Glastonbury, Hartford Co., Connecticut, USA
|Latitude & Longitude (WGS84):||41° 38' 22'' North , 72° 36' 1'' West|
|Latitude & Longitude (decimal):||41.63944,-72.60028|
|Köppen climate type:||Dfa : Hot-summer humid continental climate|
George Andrews opened the Howe No. 1 quarry in a granite pegmatite about 1870. Several years later the northern half of the pegmatite was sold to Joshua and William P. Huspband and the southern half was leased for 20 years to Charles Hall. In 1905 Louis W. Howe of South Glastonbury acquired both parts of the property and produced 65,000-70,000 tons of feldspar between 1905 and 1928, when it became inactive. The opencut trending N. 5° E ended up being about 100 feet wide, almost 800 feet long, and 100 feet deep at the south end. For a time it was the largest pegmatite quarry in Connecticut. The feldspar was sold for use in porcelain and for Bon Ami scouring compound. In the early 1990s Vespa Stone Products attempted to use some of the dump material for crushed stone, but too much mica made this unacceptable for construction.
The typical granite pegmatite consists of at least three units: a thin wall zone of plagioclase-microcline perthite-quartz pegmatite that contains about 0.08 percent of beryl in crystals as much as a fifth of an inch in cross section, a core of microcline perthite-plagioclase-quartz pegmatite containing less than 1 percent of muscovite, The core of microcline perthite-plagioclase-quartz rock appears to have formed most of the pegmatite and to have been coarsely crystallized and therefore amenable to hand cobbing. The white microcline is intergrown with small amounts of albite. It seldom occurs in pure masses more than 3 feet across, the bulk of the material shipped being an irregular or graphic intergrowth of quartz and feldspar.
The largest mica “books” were not more than 5 inches across and showed wedge structure, crumpling, or ruling. None of the mica is of commercial quality.
Biotite is present only here and there. It occurs in small crystals in the finer-grained portions of the pegmatite.
In a few places there is a small quantity of red, well crystallized garnets up to an inch in diameter.
Black tourmaline is present, but none of the crystals observed were more than one-half inch in diameter. Occasionally it is present in granular masses of minute crystals that form veins, one-sixteenth to one-fourth of an inch wide, traversing the pegmatite.
Small fracture filling units about a foot in maximum thickness contained as much as 1 percent of beryl. Although the beryl content was extremely small, crystals more than 6 inches in diameter have been described.
Rare minerals are generally lacking from this pegmatite, but some molybdenite, columbite, uraninite and secondary uranium minerals have been found.
22 valid minerals. 1 erroneous literature entry.
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
|Late Ordovician - Middle Ordovician|
443.8 - 470 Ma
|Collins Hill Formation|
Age: Ordovician (443.8 - 470 Ma)
Stratigraphic Name: Collins Hill Formation
Description: ( = Partridge Formation of New Hampshire) - Gray, rusty-weathering, medium- to coarse-grained, poorly layered schist, composed of quartz, oligoclase, muscovite, biotite, and garnet, and commonly staurolite, kyanite, or sillimanite, generally graphitic, interlayered with fine-grained two-mica gneiss, especially to the west, and with calc-silicate and amphibolite layers, also rare quartz-spessartine (coticule) layers.
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.