Massachusetts pegmatite

Region East, Northeast
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Clark Ledge pegmatite (western of 2 polygons) and Long Hill pegmatite (eastern of 2 polygons) (Bradley and others, 2016). Rocky Hill (eastern) also noted by Billings and Wolfe (1944).
Identified resources Historical production of lithium (spodumene).
Production Spodumene production (to 50 feet depth) at Long Hill estimated to be 10,000 to 20,000 tons; average spodumene contained 10.4% Li (Billings and Wolfe, 1944).
Status Past mining.
Estimated resources Unknown.
Geologic maps Peper and Wilson (1978), scale 1:24,000; Hatch and Warren (1982), scale 1:24,000; Holmes (1968), scale 1:24,000; Hepburn (2016), scale 1:24,000.
Geophysical data Inadequate Rank 3 to 4 aeromagnetic coverage and Rank 4 aeroradiometric coverage.
Favorable rocks and structures Pegmatite associated with granite in graphitic schist.
Deposits Clark Ledge lithia mine (MRDS dep_id: 10067347), Long Hill, Taylor Ledge lithia mine (MRDS dep_id: 10067345).
Evidence from mineral occurrences MRDS; Bradley and others (2016).
Geochemical evidence Spodumene occurs in exceptional abundance; spodumene pegmatites also contain minor amounts of green to blue tourmaline, as well as amblygonite, pollucite, and purpurite (Billings and Wolfe, 1944).
Geophysical evidence Unknown.
Evidence from other sources Unknown.
Comments Two polygons are included for the two areas of pegmatite. See Pearre (1956), Billings (1941; 1944) and Billings and Wolfe (1944) and Bradley and others (2016). Bradley and others (2016) locate Clark Ledge at (42.4199, -72.8719) and Long Hill at (42.5064, -71.7822) (datum not given in publication).
Cover thickness and description Exposed at the surface.
Authors Gregory J. Walsh, Nora K. Foley, Stephen B. Mabee.
New data needs Detailed geologic mapping >1:24,000; geophysics.
Geologic mapping and modeling needs Existing 1:24,000 scale mapping may be adequate.
Geophysical survey and modeling needs High resolution aeromagnetic and aeroradiometric data can assist with framework geology such as structural features and contacts.
Digital elevation data needs Liar complete or planned/funded.