GEOLEX database Geologic Unit: Middlefield Usage: Middlefield Granite (MA*) Age: Ordovician, Late Devonian* Geologic Province: New England province* Areal Extent: MA* Type Locality: Small north-south trending mass in Middlefield Twp., western part of Hampshire Co., western MA (Emerson, 1917). Unit Name History: Named (Emerson, 1917). Age modified (Hatch and others, 1970). MA State Geol. Map usage (Zen and others, 1983). Age modified (Robinson and Luttrell, 1985). Isotopic dating; Age modified (Karabinos and Williamson, 1994). Note: If you need more information, please contact Nancy Stamm (nstamm@usgs.gov). Asterisks (*) indicate usage by the U.S. Geological Survey. Other usages by state geological surveys. "No current usage" implies that a name has been abandoned or that it has fallen into disuse. Former usage and, if known, replacement name given in parentheses (). Slashes (/) indicate unit name usage violates the 1983 North American Stratigraphic Code. This violation may be explained within brackets ([ ]). U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA URL http://ngmdb.usgs.gov/ngmdb/ngm_catalog.ora.html Database project personnel Last modified: 7-Jan-2007