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National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Chelmsford Granite*
  • Modifications:
    • Age modified
    • Areal extent
    • Overview
  • AAPG geologic province:
    • New England province
Publication:

Robinson, G.R., Jr., 1978, Bedrock geologic map of the Pepperell, Shirley, Townshend quadrangles, and part of the Ayer quadrangle, Massachusetts and New Hampshire: U.S. Geological Survey Miscellaneous Field Studies Map, MF-957, 1 sheet, scale 1:24,000


Summary:

Chelmsford Granite extended from northern MA to southern NH. Follows usage of Lyons and Faul (1977). Age is refined to Early Devonian. Consists of white to light-gray, mildly to well-foliated, fine- to coarse-grained, locally pegmatitic or micropegmatitic oligoclase-quartz-microcline-(biotite)-(muscovite) granite.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Chelmsford Granite*
  • Modifications:
    • Overview
    • Geochronologic dating
  • AAPG geologic province:
    • New England province
Publication:

Goldsmith, Richard, Grew, E.S., Hepburn, J.C., and Robinson, G.R., 1982, Formation names in the Worcester area, Massachusetts, IN Stratigraphic notes, 1980-1982: U.S. Geological Survey Bulletin, 1529-H, p. H43-H56.


Summary:

Gore (1976) included the Chelmsford Granite in his "Ayer crystalline complex", suggesting that the Chelmsford and Ayer are related. Age is Early Devonian, based on radiometric dating of about 383 m.y. (R.E. Zartman, and R.S. Naylor, written commun., 1978). It cuts the Devens-Long Pond facies of Ayer Granite and may be genetically related to Clinton facies of the Ayer; however, Chelmsford should be a separate unit because of its age designation and composition. Usage should follow that of Robinson (1978).

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Chelmsford Granite*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • New England province

Map showing publication footprint
  • Usage in publication:
    • Chelmsford Granite*
  • Modifications:
    • Overview
    • Geochronologic dating
  • AAPG geologic province:
    • New England province
Publication:

Wones, D.R., and Goldsmith, Richard, 1991, Intrusive rocks of eastern Massachusetts, Chapter I, IN Hatch, N.L., Jr., ed., The bedrock geology of Massachusetts: U.S. Geological Survey Professional Paper, 1366-E-J, p. I1-I61.


Summary:

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. [Papers presented as chapters in U.S. Geological Survey Professional Paper 1366 are intended as explanations and (or) revisions to MA State bedrock geologic map of Zen and others (1983) at scale of 1:250,000.]

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Chelmsford Granite*
  • Modifications:
    • Overview
    • Revised
  • AAPG geologic province:
    • New England province
Publication:

Lyons, J.B., Bothner, W.A., Moench, R.H., and Thompson, J.B., Jr., 1997, Bedrock geologic map of New Hampshire: U.S. Geological Survey [State Geologic Map], 2 sheets, scale 1:250,000 and 1:500,000, Prepared in cooperation with DOE and State of New Hampshire


Summary:

Used as Chelmsford Granite and included within New Hampshire Plutonic Suite on 1:500,000-scale derivative map showing plutons. Not separately mapped on 1:250,000-scale geologic map. [No age given.]

Source: GNU records (USGS DDS-6; Reston GNULEX).


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Asterisk (*) indicates published by U.S. Geological Survey authors.

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