Nathan Hall Quarry (Clark Hill Quarry), East Hampton (Chatham), Middlesex Co., Connecticut, USA
|Latitude & Longitude (WGS84):||41° 35' 38'' North , 72° 32' 24'' West|
|Latitude & Longitude (decimal):||41.59389,-72.54000|
|Köppen climate type:||Dfa : Hot-summer humid continental climate|
The Nathan Hall Quarry (one of the quarries on Clark Hill) is located in the Meshomasic State Forest off of Woodchopper's Road. It is a small quarry in a zoned granite pegmatite and based on the few references, it appears to have operated completely before 1922. There is nothing specific in the mineralogical literature, but presumably it was quarried for feldspar and/or mica. The F. W. Beers County Atlas of Middlesex, Connecticut, published in 1874, shows a large rectangle of land north of Clark Hill Road owned by "N. Hall". The Hall Cemetery is on Clark Hill Road near the entrance to Woodchopper's Road. It is often incorrectly called the Nathan Hale Quarry (such as Schooner, circa 1980s) and is sometimes confused with the State Forest Quarry #1 just to the north.
Collecting is allowed only via permit issued by the Connecticut DEEP to educational organizations (schools, mineral clubs, etc.). See link below.
Besides the rock-forming albite, microcline and quartz, sharp muscovite crystals are very common and the large, dark almandine-spessartine garnets, although fairly rare, are noteworthy. XRF analyses of several garnets from Nathan Hall show them all to be almandine, but with a significant spessartine component. As a result, a black, probable manganese oxide, stain typical covers and surrounds these crystals. Annite (fka biotite) is also common, mostly in bladed crystals up to several feet long. Beryl is uncommon, but crystals can be large, gemmy, and terminated and vary in color from yellow through green to aqua. Zircon, uranium minerals (beautiful meta-autunite and metatorbernite halos around uranophane-altered uraninite), and fluorapatite are sprinkled throughout. There is schorl, plus interesting tapered pseudomorphs of muscovite after schorl. Schorl also occurs in the adjacent Littleton schist. Massive quartz, which encloses the sharp micas and matrix microclines, is very abundant at Hall, but good crystals are usually pocket micros. Although tiny columbites are common, large ones are very rare but well-formed. One find of monazite-(Ce) was confirmed by XRD and three tapiolite-(Fe) crystals were confirmed by Raman spectroscopy.
One mystery about this locality is the reported abundance of rose quartz by Foye (1922). Very little if any true rose quartz has been found here despite myriad field trips since the early 1990s (it is present at the nearby State Forest Quarry #1, which did not open until the early 1940s). One possible resolution is that the rose quartz is really from the small quarry in Cobalt along Great Hill Pond Brook that Hiller's 1971 collecting guide book calls the "Nathan Hale Quarry". The names Nathan Hale (the famous official State Hero) and Nathan Hall are commonly confused and Nathan Hall had several quarries, with the one in Cobalt thus possibly one if his also. This small quarry was described by Rice and Foye in their 1927 guide to Middletown area geology, though not given a name, nor did they mention rose quartz. However, Foye worked at Wesleyan University in Middletown and on display there at the Joe Webb Peoples Museum is a large specimen of rose quartz with the locality given as "Cobalt". It seems likely he may have confused the origin of the rose quartz (though the location of the Nathan Hall Quarry is correct in Foye (1922)), especially if Nathan Hall operated both quarries. Unfortunately, the quarry on Great Hill Pond Brook has been inaccessible for several decades.
26 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
358.9 - 419.2 Ma
Age: Devonian (358.9 - 419.2 Ma)
Stratigraphic Name: Littleton Formation
Description: Gray to silvery, generally non-rusty, medium-grained, massive to well-layered alternating schist and micaceous quartzite, composed of quartz, muscovite, biotite, garnet, and oligoclase, also staurolite, graphite, and ilmenite, and in certain areas kyanite or sillimanite in schist.
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. 
|Devonian - Silurian|
358.9 - 443.8 Ma
|Paleozoic sedimentary and volcanic rocks|
Age: Paleozoic (358.9 - 443.8 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.