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Bedrock geologic map of the Grafton quadrangle, Worcester County, Massachusetts

Scientific Investigations Map 3171

Prepared in cooperation with the Commonwealth of Massachusetts, Massachusetts Geological Survey, Brigham Young University
By:
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Abstract

The bedrock geology of the 7.5-minute Grafton, Massachusetts, quadrangle consists of deformed Neoproterozoic to early Paleozoic crystalline metamorphic and intrusive igneous rocks. Neoproterozoic intrusive, metasedimentary, and metavolcanic rocks crop out in the Avalon zone, and Cambrian to Silurian intrusive, metasedimentary, and metavolcanic rocks crop out in the Nashoba zone. Rocks of the Avalon and Nashoba zones, or terranes, are separated by the Bloody Bluff fault. The bedrock geology was mapped to study the tectonic history of the area and to provide a framework for ongoing hydrogeologic characterization of the fractured bedrock of Massachusetts. This report presents mapping by G.J. Walsh, geochronology by J.N. Aleinikoff, geochemistry by M.J. Dorais, and consists of a map, text pamphlet, and GIS database. The map and text pamphlet are available in paper format or as downloadable files (see frame at right). The GIS database is available for download. The database includes contacts of bedrock geologic units, faults, outcrops, structural geologic information, and photographs.

Study Area

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Bedrock geologic map of the Grafton quadrangle, Worcester County, Massachusetts
Series title:
Scientific Investigations Map
Series number:
3171
Year Published:
2011
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
U.S. Geological Survey
Description:
Map: 46.08 x 32.24 inches; Pamphlet: iv, 39 p.; Downloads Directory
Country:
United States
State:
Massachusetts
County:
Worcester County
City:
Grafton
Other Geospatial:
Grafton Quadrangle
Datum:
North American Datum 1927
Projection:
Polyconic projection
Scale:
24000