%0 Map %D 0 %T Bedrock geologic map of the Ayer 7.5’ quadrangle, Worcester and Middlesex Counties, Massachusetts %A Kopera J.P. %K Ayer %K ayer granite %K Ayer Granodiorite %K Ayer Quadrangle %K Berwick %K Campbell Hill Fault %K chelmsford granite %K Clinton Newbury Fault %K Devens %K Harvard Conglomerate %K merrimack %K Oakdale formation %K pin hill %K Shepley's Hill %K Shirley Fault %K tadmuck brook schist %K Worcester Formation %X

Editing and review are still underway.  This map should be available in winter 2015/2016

%B Open File Report %7 15-01 %I Massachusetts Geological Survey %G eng %2

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%0 Map %D 0 %T Bedrock geologic map of the Ayer 7.5’ quadrangle, Worcester and Middlesex Counties, Massachusetts (2015) %A Joseph P Kopera %K Ayer %K ayer granite %K Ayer Granodiorite %K Ayer Quadrangle %K Berwick %K Campbell Hill Fault %K chelmsford granite %K Clinton Newbury Fault %K Devens %K Harvard Conglomerate %K merrimack %K Oakdale formation %K pin hill %K Shepley's Hill %K Shirley Fault %K tadmuck brook schist %K Worcester Formation %X

Editing and review are still underway.  This map should be available in winter 2015/2016

%B Open File Report %7 15-01 %I Massachusetts Geological Survey %G eng %2

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%0 Map %D 2012 %T Digital conversion of Peck, J.H., 1975, Preliminary bedrock geologic map of the Clinton quadrangle, Worcester County, Mass., U.S. Geological Survey Open File Report 75-658 %A Peck, J.A. %E Joseph P Kopera %K #BedrockMap %K #MGSPub %K andalusite %K ayer granite %K Berlin %K Bolton %K Boylston %K Clinton %K Clinton-Newbury Fault %K Devens %K Harvard %K Lancaster %K Leominster %K nashoba %K Oakdale Quartzite %K Peck %K phyllite %K quartzite %K Reuben's Hill Formation %K Sterling %K tadmuck brook schist %K Tower Hill quartzite %K Wekepeke Fault %K Worcester Formation %X This map is an interim product and will be superseded by an updated bedrock map of the quadrangle in 2016. This map is a digital version of USGS OFR 75-658: http://pubs.er.usgs.gov/publication/ofr75658 There are some cartographic errors in creating a digital version: A Jurassic diabase dike along the western edge of the quadrangle is not shown in the digital version. These errors are being corrected. %B Digital Conversion %7 DC12-01 %I Massachusetts Geological Survey %G eng %2 1:24000 %0 Map %D 2008 %T Preliminary Bedrock Geologic Map of the area surrounding Shepley's Hill, Towns of Ayer and Devens, Massachusetts %A Joseph P Kopera %K #BedrockMaps %K #MGSPub %K army %K arsenic %K Ayer %K ayer granite %K chelmsford granite %K Clinton Newbury Fault Zone %K Devens %K landfill %B Open-File Report %7 OFR08-05 %I Massachusetts Geological Survey %G eng %2

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%0 Map %D 2006 %T Preliminary bedrock geologic map of the Ayer quadrangle, Massachusetts %A Joseph P Kopera %K #BedrockMaps %K #MGSPub %K arsenic %K Ayer %K ayer granite %K Berwick formation %K Boxborough %K chelmsford granite %K Clinton-Newbury Fault %K Devens %K Fort Devens %K Groton %K Harvard %K Jahns %K LITTLETON %K Merrimack Terrane %K mylonite %K nashoba %K Nashua Trough %K Oakdale formation %K Shepley's Hill Landfill %K Shirley %K tadmuck brook schist %K Worcester Formation %X

This preliminary version of the Bedrock Map of the Ayer Quadrangle (Kopera, 2006) has been removed pending the release of an updated version in the near future. The above version should be considered outdated. If you would like a copy of this map, please contact Joseph Kopera at jkopera[at]geo[dot]geo[dot] umass[dot]edu

%B Open-File Report %7 OFR-06-02 %I Massachusetts Geological Survey %G eng %U http://www.geo.umass.edu/stategeologist/ %2

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%0 Map %D 2014 %T Preliminary Bedrock Geologic Map of the Hudson 7.5' Quadrangle Worcester and Middlesex Counties, Massachusetts %A Joseph P Kopera %A W.R. Hansen %K #BedrockMaps %K #MGSPub %K acton granite %K ayer granite %K Berlin %K Bolton %K Boxborough %K Clinton-Newbury Fault %K gneiss %K Harvard %K Harvard Conglomerate %K Hudson %K magnetite %K Malborough %K marble %K migmatite %K nashoba %K Stow %K tadmuck brook schist %K Vaughn Hills %X The Hudson quadrangle straddles the Clinton-Newbury Fault Zone (CNFZ), which separates low metamorphic grade Silurian turbiditic metasediments and Devonian plutons of the Nashua sub-belt (Robinson and Goldsmith, 1991) of the Merrimack Terrane to the northwest from the high-grade, migmatitic Cambro- Ordovician arc-complex of the Nashoba Terrane (Walsh et al., 2011; Loan 2011). This general area comprises the suture between the Gander and Avalon composite terranes of the Northern Appalachians (cf. Hibbard et al., 2006). Metasedimentary rocks of the Merrimack Terrane are generally poorly exposed, with intrusives (Day, Dayp, SDgdt) and the Clinton-Newbury Fault zone and associated rocks (Ot) forming a prominent northeast trending ridge (Oak Hill in the town of Harvard) marking the eastern bordering slope of the Worcester Plateau (Emerson, 1917, p. 16). Elevation and local topographic relief gradually decreases and glacial cover increases to the east-southeast across the strike of the Nashoba Formation, which, locally, forms low-relief NE-trending strike-parallel ridges. These are cut by dramatic cross-strike cliffs and glacial spillway gorges developed along cross-strike joints and brittle faults, most notably on the western slopes of Rattlesnake Hill, southern slope of Powder House Hill and in Camp Resolute in Bolton in the west-central portion of the quadrangle, and the southern slope of the hill along the west side of Codman Hill Road in Harvard in the north-central portion of the quadrangle. The migmatitic ortho- and paragneisses, schists and associated metavolcanic rocks of the Nashoba Formation (_Sn) form a northeast striking belt underlying the southern two-thirds of the quadrangle. These are intruded by a variety of presumed Ordovician to Silurian intermediate intrusives (OSd, OSaqd) and Devonian or younger tonalites to granites (Dan, Danp, Dac). %B Open File Report %7 14-01 %I Massachusetts Geological Survey %8 09/2014 %G eng %1 Note: This map supersedes "Preliminary bedrock geologic map of the Hudson quadrangle, Massachusetts", MGS map published in 2005 Report accompanies map-- be sure to download both! %0 Map %D 2005 %T Preliminary bedrock geologic map of the Hudson quadrangle, Massachusetts %A Joseph P Kopera %A Hansen, W.R. %K #BedrockMaps %K #MGSPub %K acton granite %K ayer granite %K Berlin %K Bolton %K Boxborough %K Clinton-Newbury Fault %K gneiss %K Harvard %K Harvard Conglomerate %K Hudson %K magnetite %K Malborough %K marble %K migmatite %K nashoba %K Stow %K tadmuck brook schist %K Vaughn Hills %X This map has been superseded by MGS OFR 14-01: Preliminary Bedrock Geologic Map of the Hudson 7.5' Quadrangle Worcester and Middlesex Counties, Massachusetts This map is an interim update to W.R. Hansen's 1956 Bedrock Geology of the Hudson and Maynard 7.5' quadrangles (USGS Bulletin 1038). This draft version of the Bedrock Map of the Hudson Quadrangle (Kopera, 2005) has been removed pending the future release of an updated version. The above version should be considered outdated. If you would like a copy of this map, please contact Joseph Kopera at jkopera[at]geo[dot]geo[dot]umass[dot]edu

%B Open-File Report %I Massachusetts Geological Survey %G eng %2

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%0 Map %D 2009 %T Preliminary bedrock geologic Map of the Webster quadrangle, Massachusetts %A Patrick J Barosh %K #BedrockMaps %K #MGSPub %K ayer granite %K Charlton %K Dudley %K Eastford granite %K Nashua Trough %K Oakdale Quartzite %K Oxford %K Paxton Formation %K Paxton Group %K Plainville %K Plainville Formation %K Southbridge %K Webster %K Worcester Formation %B Open-File Report %7 OFR-09-02 %I Massachusetts Geological Survey %G eng %2

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%0 Map %D 2009 %T Preliminary bedrock geologic map of the Westford quadrangle, Massachusetts %A Joseph P Kopera %A D.C. Alvord %A Richard H Jahns %A M.E. Willard %A W.S. White %K #BedrockMaps %K #MGSPub %K Acton %K amphibolite %K ayer granite %K Berwick formation %K Boxborough %K calc-silicates %K Carlisle %K Chelmsford %K chelmsford granite %K Clinton-Newbury Fault %K Concord %K diorite %K gneiss %K Groton %K LITTLETON %K magnetite %K marble %K migmatite %K Nashoba Formation %K phyllonite %K tadmuck brook schist %K Tyngsborough %K Westford %X Bedrock Geologic Map contains brittle fracture data Mapping still in progress. For interim fracture database, please contact Joe Kopera %B Open-File Report %7 OFR-09-01 %I Massachusetts Geological Survey %G eng %2

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%0 Map %D 2006 %T Preliminary fracture characterization map of the Ayer quadrangle, Massachusetts %A Joseph P Kopera %A Stephen B Mabee %A Powers, D.C. %K #FractureMaps %K #MGSPub %K Ayer %K ayer granite %K Boxborough %K chelmsford granite %K Devens %K fault %K Fort Devens %K fracture %K fracture trace %K Groton %K Harvard %K hydrostructural domain %K joint %K lineament %K LITTLETON %K Shirley %K water resources %X This preliminary version of the Fracture Characterization Map of the Ayer Quadrangle (Kopera, 2006) has been removed pending the release of an updated version of the underlying bedrock geologic map in the near future. The above version should be considered outdated. If you would like a copy of the outdated map, please contact Joseph Kopera at jkopera[at]geo[dot]geo[dot]umass[dot]edu %B Open-File Report %7 OFR-06-03 %I Massachusetts Geological Survey %G eng %2

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