@conference {369, title = {Latest Paleozoic through Mesozoic faults in north-central Massachusetts and their correlations with New Hampshire}, booktitle = {Geological Society of America - Northeastern section}, year = {2016}, publisher = {Geological Society of America}, organization = {Geological Society of America}, address = {Albany, NY}, abstract = {

Several faults in south-central New Hampshire can be extended into Massachusetts (MA) as a result of detailed mapping in both states since publication of the MA state bedrock geologic map in 1983. Many of these faults delineate and/or cut Devonian metamorphic isograds in the Silurian Merrimack Belt in northern MA, and juxtapose chlorite-grade rocks in the Nashua sub-belt (NSB) between lithologically similar middle- to upper amphibolite-facies rocks on either side.

Recent mapping in the NSB, combined with previous studies, suggest it may represent a graben initially formed during latest Paleozoic transtension contemporaneous with formation of the Narragansett Basin in southeastern MA and RI. Mylonites along the Silver Hill-Wekepeke Fault (Robinson, 1981), bounding the western edge of the NSB, show east-side-down normal motion and west-side down normal motion along the Clinton-Newbury Fault Zone (CNFZ; Goldstein, 1994) which bounds the NSB{\textquoteright}s southeastern margin. A possible extension of the Flint Hill fault system (NH) forms the eastern edge of the NSB offsetting the CNFZ with normal west-side down motion near Ayer, MA. Late brittle normal faults in the NSB are abundant.\ Late, low-To, west-side-down shear zones in the Nashoba Terrane and similar rocks to the south may also be related to down-dropping of the NSB.

AFT ages were collected across north-central MA to constrain its late uplift history. A ~127 Ma AFT age in the NSB is discontinuous with AFT ages in the belts adjoining it, with ~182-144 Ma ages west across the Wekepeke fault and ~160-167 Ma east across the CNFZ. To the west, the brittle southern extension of the Pinnacle Fault in NH (Stodge Meadow Pond fault of Peterson, 1984) follows the western edge of the Fitchburg plutons in MA while a well-exposed west-side down brittle normal fault system, possibly the southward extension of the Campbell Hill Fault (NH), is developed along their eastern edge. AFT ages of ~144-136 Ma immediately west of the Pinnacle Fault in MA are discontinuous with ~117-115 Ma ages immediately to the east within the Fitchburg plutons. A single ~106 Ma age in the plutons west of the Campbell Hill Fault in MA is discontinuous with ~128-123 Ma ages to the east of it. The discontinuities amongst AFT ages across these faults suggest that they may have been active through the Cretaceous.

}, keywords = {$\#$Bibliography, $\#$StaffPubs, AFT, apatite, apatite fission track, brittle, Campbel Hill, Clinton Newbury, Cretaceous, extension, fault, fault zone, fault zones, faults, fission track, Fitchburg, Fitchburg Plutons, Flint Hill, I-290, Johnny Appleseed, Jurassic, merrimack, mesozoic, Nashua Trough, Normal Faults, Oakdale formation, Permian, Pinnacle, Rt 2, Sterling, Stodge Meadow Pond, Triassic, Wachusett, Wekepeke, Worcester Formation}, doi = {10.1130/abs/2016NE-272576}, url = {https://gsa.confex.com/gsa/2016NE/webprogram/Paper272576.html}, author = {Kopera J.P. and Roden-Tice, M.K. and Robert P Wintsch} } @proceedings {273, title = {Comparison of lineaments with bedrock structures along a cross-strike transect, eastern Massachusetts}, volume = {30}, year = {1998}, note = {Accession Number: 1999-032582; Conference Name: Geological Society of America, 1998 annual meeting; Toronto, ON, Canada; Conference Date: 19981026; Language: English; Coden: GAAPBC; Collation: 1; Collation: 278; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 199912; Monograph Title: Geological Society of America, 1998 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {1998/01/01/}, pages = {278 - 278}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, abstract = {Lineament data derived from three platforms, 1:58,000 color infrared photography (N = 770), 1:80,000 black and white photographs (N = 1106), and 1:250,000 SLAR imagery (N = 521), were used to determine the degree of coincidence between mapped faults and lineaments along a cross strike transect in eastern Massachusetts. The study area extends 27 km in an east-west direction and 8 km north-south and is located along the trace of a tunnel currently being constructed approximately 90 m below grade. Structural data are presently being collected from surface exposures along the tunnel trace and from within the 5 m diameter tunnel bore. These structural data will be compared with lineament data in the future. Reported here are the results of a comparison between the locations of lineaments and the position of major faults mapped on the Bedrock Geologic Map of Massachusetts (1:250,000). Lineaments were first mapped on acetate overlays in two independent trials and compared to determine which lineaments could be reproduced at the same geographic location. Reproducibility results indicate that 21 to 33\% of the lineaments can be reproduced at the same spatial position and are comparable to results obtained from other studies. The length of reproducible lineaments proximal to and approximately parallel with mapped faults was compared with the total length of faults (137 km) within the study area. Results show that a small percentage of the faults are coincident with reproducible lineaments. Three percent of the lengths are mapped by reproducible lineaments observed on the SLAR imagery, 7\% by the 1:80,000 scale photographs, and 5\% by the 1:58,000 color infrared photography. This indicates that 97\%, 93\%, and 95\% of the reproducible lineaments, respectively, are related to other geologic features in the bedrock or nothing at all.}, keywords = {$\#$StaffPubs, aerial photography, BEDROCK, eastern Massachusetts, faults, geophysical surveys, imagery, lineaments, massachusetts, remote sensing, SLAR, Structural geology 16, surveys, tectonics, United States}, isbn = {00167592}, author = {Curry, Patrick J. and Williams, Katherine W. and Stephen B Mabee and Hardcastle, Kenneth C.} } @proceedings {289, title = {Factors influencing groundwater inflows in a newly constructed cross-strike tunnel, eastern Massachusetts; 5, Geochemical interpretation of groundwater inflows}, volume = {31}, year = {1999}, note = {Accession Number: 2001-037342; Conference Name: Geological Society of America, 1999 annual meeting; Denver, CO, United States; Conference Date: 19991025; Language: English; Coden: GAAPBC; Collation: 1; Collation: 348; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 200111; Monograph Title: Geological Society of America, 1999 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {1999/01/01/}, pages = {348 - 348}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, abstract = {Samples of ground and surface waters in and above the tunnel (Curry et al., this volume) were collected to characterize the chemistry of groundwater discharging from fractures and faults. Forty-two water samples were collected: 32 along a transect of the tunnel and 10 from surface waters above the trace of the tunnel. All samples were analyzed for major anions and cations, and delta (super 18) O. Analysis of the anion/cation data indicated that these waters are dominated by sulfate+chloride and calcium+magnesium. However, five sub-classifications can be discerned based on the relative concentrations of ions in the samples. The five sub-classifications are Cl > HCO (sub 3) > SO (sub 4) > NO (sub 3) :Ca > Na+K > Mg (15 samples), Cl > HCO (sub 3) > SO (sub 4) > NO (sub 3) :Na+K > Ca > Mg (7 samples), Cl > HCO (sub 3) > SO (sub 4) > NO (sub 3) :Ca > Mg > Na+K (6 samples), Cl > SO (sub 4) > HCO (sub 3) > NO (sub 3) :Na+K > Ca > Mg (3 samples), and HCO (sub 3) > Cl > SO (sub 4) > NO (sub 3) :Ca > Na+K > Mg (2 samples). Results from statistical analyses indicate that alkalinity, calcium, sodium and potassium do vary as a function of bedrock type and that these differences are significant at the 95\% confidence level.In addition, preliminary oxygen isotope data indicate that two large, discrete water producing fault zones located in the eastern part of the tunnel are isotopically enriched (average delta (super 18) O = -7.75) relative to other water producing features in the tunnel (average delta (super 18) O = -8.96). The delta (super 18) O values obtained from all surface water bodies located above the tunnel average -7.56 whereas those values in surface ponds immediately above the fault zones average -6.71. Nitrate levels also show elevated levels in two water producing fault zones (>10 mg/L for some samples) and may result from accidental contamination during sampling, the use of explosives at discrete locations in the tunnel, or from leaking septic systems. The results of the oxygen isotope and nitrate analyses also suggest that some of the fault zones in the tunnel may have a rapid and direct hydraulic connection to the surface.}, keywords = {$\#$StaffPubs, anions, BEDROCK, cations, classification, discharge, eastern Massachusetts, fault zones, faults, geochemistry, ground water, hydraulic conductivity, hydrochemistry, Hydrogeology 21, Isotope geochemistry 02D, isotope ratios, isotopes, massachusetts, movement, New England, nitrate ion, O-18/O-16, oxygen, samples, stable isotopes, surface water, tunnels, United States}, isbn = {00167592}, author = {Weaver, Rebecca A. and Stephen B Mabee and Williams, Katherine W. and Curry, Patrick J.} } @proceedings {296, title = {Fracture patterns across two terrane boundaries in eastern Massachusetts; implications for regional groundwater flow and recharge}, volume = {38}, year = {2006}, note = {Accession Number: 2010-054322; Conference Name: Geological Society of America, 2006 annual meeting; Philadelphia, PA, United States; Conference Date: 20061022; Language: English; Coden: GAAPBC; Collation: 1; Collation: 434; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201030; Monograph Title: Geological Society of America, 2006 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {2006/10/01/}, pages = {434 - 434}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, abstract = {The integration of structural data and field-based observations is becoming increasingly critical in understanding groundwater flow behavior and recharge potential. Over the past 3 years, the Office of the Massachusetts State Geologist (OMSG) has collected 8225 fracture measurements from 187 stations across 3 adjacent quadrangles as part of its bedrock geologic mapping program. These data provide a north-south transect across the Nashoba Terrane and its boundaries with the Merrimack Belt and Avalon Terranes in eastern Massachusetts. Areas with similar fracture patterns can be grouped into "hydrostructural domains" with distinct hydrogeologic properties. Within the above transect, hydrostructural domains were observed to closely correspond with bedrock lithology and ductile structure, and therefore, tectonic history. Such domains are commonly bounded by faults or intrusive contacts. Common features observed across all domains include a NE-striking regional foliation with corresponding NW-striking, steeply-dipping cross-joints. Strongly layered metasedimentary and metavolcanic rocks of the Merrimack Belt and the Marlborough Formation in the Nashoba Terrane tend to have the most pervasive and closely-spaced foliation-parallel fractures (FPF). Foliation intensity and FPF generally increases towards shear zones and regional fault systems, especially within granites and gneisses. The moderate to steeply dipping, well-developed FPF in these rocks provides a potentially excellent conduit for vertical recharge and a strong NE-trending regional anistropy that may control groundwater flow. Granitoidal rocks have very consistent NS-EW orthogonal networks of vertical fractures and subhorizontal sheeting joints, providing excellent potential for vertical recharge and near-surface lateral flow. Features such as small brittle faults, fracture zones, fold axes, and fracture sets distinct to each domain may dominate local groundwater flow and recharge. Abstract 116563 modified by 72.70.224.253 on 7-12-2006}, keywords = {$\#$StaffPubs, Avalon Zone, BEDROCK, eastern Massachusetts, faults, foliation, fractures, ground water, Hydrogeology 21, joints, massachusetts, Merrimack Belt, movement, observations, patterns, properties, recharge, shear zones, style, terranes, United States}, isbn = {00167592}, url = {https://gsa.confex.com/gsa/2006AM/finalprogram/abstract_116563.htm}, author = {Stephen B Mabee and Joseph P Kopera} } @proceedings {299, title = {Ground truth? Relationship between lineaments and bedrock fabric}, volume = {21}, year = {1989}, note = {Accession Number: 1991-043915; Conference Name: Geological Society of America, 1989 annual meeting; St. Louis, MO, United States; Conference Date: 19891106; Language: English; Coden: GAAPBC; Collation: 1; Collation: A68; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 1991; Monograph Title: Geological Society of America, 1989 annual meeting; Monograph Author(s): Dymek, Robert F. [chairperson]; Shelton, Kevin L. [chairperson]; Reviewed Item: Analytic}, month = {1989/01/01/}, pages = {A68 - A68}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, keywords = {$\#$StaffPubs, aerial photography, BEDROCK, fabric, faults, fractures, granites, ground truth, igneous rocks, joints, lineaments, Maine, orientation, pegmatite, plutonic rocks, quartz veins, SLAR, structural analysis, Structural geology, Structural geology 16, United States, veins}, isbn = {00167592}, author = {Stephen B Mabee and Hardcastle, Kenneth C. and Donald U Wise} } @proceedings {267, title = {A new way of looking at, and mapping, bedrock; the hydrostructural domain map of the Ayer Quadrangle, northeastern Massachusetts}, volume = {38}, year = {2006}, note = {Accession Number: 2008-100620; Conference Name: Geological Society of America, 2006 annual meeting; Philadelphia, PA, United States; Conference Date: 20061022; Language: English; Coden: GAAPBC; Collation: 1; Collation: 166; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 200816; Monograph Title: Geological Society of America, 2006 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {2006/10/01/}, pages = {166 - 166}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, abstract = {While traditional bedrock geologic maps contain valuable information, they commonly lack data on fractures and physical properties of the rock. The increased need for better understanding of groundwater behavior in bedrock aquifers has made this data critical. Hydrostructural domain maps reclassify bedrock based on fracture systems and physical properties that may have implications for groundwater flow and recharge. These maps are constructed from detailed field observations and measurements of 2000-3000 fractures from 60-70 stations across a 7.5{\textquoteright} quadrangle. Hydrostructural domains are displayed on the map as traditional lithologic units would be, with detailed descriptions and photos of the fracture characteristics and physical properties of each hydrostructural "unit". In the Ayer Quadrangle, such domains closely correspond with bedrock lithology and ductile structural history. Steeply dipping metasedimentary rocks of the Merrimack Belt have pervasive, closely spaced, throughgoing fractures developed parallel to foliation, and therefore provide an excellent potential for vertical recharge. Where these rocks are intensely cut by a strong subhorizontal cleavage, a parallel fracture set dominates providing an opportunity for lateral flow. Massive granites generally have a well developed, widely-spaced orthogonal network of fracture zones which may provide excellent local recharge. High-grade gneisses of the Nashoba Terrane have poorly developed fracture sets except near regional shear zones, where foliation parallel fractures and cross-joints may provide good vertical recharge and provide a strong northeast trending flow anisotropy. These maps are intended to provide a regional-scale information to assist in site-specific groundwater investigations. We believe that such maps are an example of how new types of geologic maps can, and must, be developed to address changing societal needs.}, keywords = {$\#$StaffPubs, aquifers, Ayer Quadrangle, BEDROCK, faults, foliation, fracture zones, fractures, ground water, Hydrogeology 21, joints, mapping, massachusetts, measurement, Merrimack Belt, movement, Nashoba terrane, northeastern Massachusetts, observations, orientation, physical properties, recharge, shear zones, Structural geology 16, style, United States}, isbn = {00167592}, url = {https://gsa.confex.com/gsa/2006AM/finalprogram/abstract_116561.htm}, author = {Joseph P Kopera and Stephen B Mabee} } @proceedings {316, title = {A structural framework for the Nashoba Terrane in eastern Massachusetts.}, volume = {45}, year = {2013}, pages = {107}, abstract = {The exhumation and tectonic significance of the migmatitic Cambro-Ordovician arc-complex of the Nashoba terrane, located between lower-grade rocks of the Avalon and Merrimack terranes in Massachusetts, has historically presented an enigma, in part, due to a lack of detailed analysis of internal structure. We propose a new terrane-scale structural model based on nearly a decade of detailed geologic mapping to provide a framework for future study. A subvertical NE-striking composite fabric (S (sub n/n-1) ) forms the dominant structural grain of the terrane. S (sub n) commonly deforms an older layer-parallel foliation (S (sub n-1) ) about meter- to kilometer-scale, upright to steeply inclined, NE- and SW-plunging, tight disharmonic folds (F (sub n) ). In the Nashoba Formation migmatites, S (sub n) commonly transposes a subhorizontal S (sub n-1) enveloping surface into spaced meter-scale subvertical shear bands that are absent in the dominantly metavolcanic Marlborough Formation. Fold axis-parallel mineral stretching and intersection lineations (L (sub n) ) are locally overprinted on S (sub n) by subhorizontal peak metamorphic to retrograde mineral lineations (L (sub n/n+1) ). Ambiguous D (sub n) kinematics in the NE transition SW along strike to top-to-NW normal fold vergence and drag along steep north-dipping S (sub n) axial planes and S (sub n) - S (sub n+1) shear bands. Later strain (S (sub n+1) - S (sub n+2) ) appears to be progressively partitioned at lower grade to pre-existing S (sub n) shear bands and discrete internal and terrane bounding fault zones which display early high-grade top-to-SE dextral or sinistral motion (S (sub n-1) - S (sub n) ) broadly overprinted by lower-grade top-NW movement (S (sub n+1) ). We propose a tentative tectonic history incorporating sparse existing geochronologic and petrologic studies: Top SW D (sub n-1) motion coeval with approximately 425 Ma sill-grade metamorphism and possible accretion. D (sub n) initiating syn approximately 395 Ma peak metamorphism with migmatite generation along S (sub n) and progressive bulk fabric development largely complete by the intrusion of the relatively undeformed approximately 349 Ma Indian Head Hill granite. Exhumation can be accommodated by well-documented syn-to-post D (sub n) regional sinistral motion combined with progressively lower grade top-NW extension along discrete structures continuing through deposition and deformation of presumed Carboniferous basin sediments along the terrane boundary.}, keywords = {$\#$StaffPubs, Cambrian, eastern Massachusetts, exhumation, fabric, fault zones, faults, foliation, massachusetts, metamorphism, Nashoba terrane, Ordovician, Paleozoic, Structural geology, tectonics, United States}, issn = {00167592}, url = {https://gsa.confex.com/gsa/2013NE/webprogram/Paper215867.html}, author = {Joseph P Kopera and Matthew A Massey} } @Map {371, title = {Bedrock geologic map of the Newton 7.5{\textquoteright} quadrangle, Middlesex, Norfolk and Suffolk counties, Massachusetts}, month = {05/2017}, publisher = {Massachusetts Geological Survey}, edition = {GM-17-01}, abstract = {

The Newton quadrangle, located west of Boston, Massachusetts, is mainly underlain by clastic sedimentary and minor igneous rocks occupying the topographic Boston Basin (Crosby, 1880; Emerson, 1917; LaForge, 1932; Billings, 1976 and references therein). Fault blocks dominated by older plutonic and volcanic rocks truncate the Basin sequence on the west and south. Although fossiliferous Cambrian strata overlying plutonic basement had been reported some 30 miles away in North Attleboro, MA (Billings, 1929), the first quadrangle map including the Newton area (1:62,500 Plate I of LaForge, 1932) portrayed the plutonic units as {\textquotedblleft}Early Paleozoic{\textquotedblright} and assigned all the others to the Devonian or Carboniferous periods. By the time the Newton quadrangle appeared at 1:24,000 scale (Kaye, 1980), emerging U-Pb zircon geochronology had revealed Neoproterozoic (Ediacaran in timescale of Gradstein et al., 2012) crystallization ages both for the Mattapan Volcanic Complex and the Dedham Granite on the south side of the map area (Kaye and Zartman, 1980; written communication of Zartman and Naylor, 1980 not published until 1984). The Boston Basin sequence in this map was inferred to be Neoproterozoic in the absence of a break with overlying Cambrian strata (Kaye and Zartman, 1980), an interpretation confirmed shortly thereafter by the discovery of Ediacaran microfossils in the top portion of the sedimentary section ({\textquotedblleft}Vendian{\textquotedblright} in Lenk et al., 1982). In the map presented here, U-Pb zircon dates obtained by the author over twenty years with colleagues at MIT{\textquoteright}s Radiogenic Isotope Lab constrain all map units except mafic dikes. During this interval, U-Pb analyses have become more precise and accurate, leading also to significant refinements to the dates used by Kaye in 1980, as discussed further in the section on Stratigraphy.\ 

}, keywords = {$\#$BedrockMaps, $\#$MGSPub, argillite, Boston, Boston Basin, Cambridge, faults, Lynn, Mattapan, Middlesex Fells, Newton, Roxbury, volcanics}, author = {Thompson, Margaret D.} } @Map {228, title = {[Draft] Preliminary bedrock geologic map of the Oxford quadrangle, Worcester County, Massachusetts, Providence County, Rhode Island and Windam County, Connecticut}, year = {2005}, publisher = {Massachusetts Geological Survey}, keywords = {$\#$BedrockMaps, $\#$MGSPub, Bloody Bluff, Douglas, faults, gneiss, granite, Lake Char, Marlborough Formation, Nashoba Formation, Nashua Trough, Northbridge granite gneiss, Oxford, Sutton, Webster}, author = {Patrick J Barosh} }