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Fletcher Granite Quarry (H. E. Fletcher Quarry; Chelmsford Grey Quarry), Westford, Middlesex Co., Massachusetts, USA

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Latitude & Longitude (WGS84): 42° 37' 58'' North , 71° 25' 3'' West
Latitude & Longitude (decimal): 42.63278,-71.41750

An active granite quarry operated by Fletcher Granite Company. Opened in 1881. Located in the town of Westford near the Chelmsford line.

Mineral List

Regional Geology

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

Frasnian - Eifelian
372.2 - 393.3 Ma
Chelmsford Granite

Age: Devonian (372.2 - 393.3 Ma)

Stratigraphic Name: Chelmsford Granite

Description: Light-gray, even and medium-grained, muscovite-bearing granite; locally foliated; intrudes Sb.

Comments: Part of Merrimack Belt (Silurian, Devonian and Pennsylvanian Rocks). Secondary unit description per MA007 as reported in USGS Geologic Names lexicon (ref. MA024): Chelmsford Granite intrudes Berwick Formation, Ayer Granite, and Dracut Diorite northwest of Clinton-Newbury fault. Occurs as two elongate, northeast-striking bodies occupying an area of 60 sq km. Described as light colored and gneissic. Zartman and Naylor (1984) could not obtain a definitive age but believed Chelmsford was in same age range as Ayer because the age of the Chelmsford lay within margin of error for their age determinations. Devonian age shown on MA State geologic map is based on their Pb-Pb age of 389 +/-5 Ma (Wones and Goldsmith, 1991).

Lithology: Major:{granite}

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. [133]

Data and map coding provided by, used under Creative Commons Attribution 4.0 License

This page contains all mineral locality references listed on This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.


Dale, T. N. (1910). Supplementary Notes on the Commercial Granites of New England, in Contributions to Economic Geology, USGS Bulletin 470.

External Links - Fletcher Granite Company

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