TY - Generic T1 - Fracture characterization maps; a new type of geologic map for hydrogeologic applications T2 - Abstracts with Programs - Geological Society of America Y1 - 2005 A1 - Stephen B Mabee A1 - Joseph P Kopera KW - #StaffPubs KW - applications KW - aquifers KW - BEDROCK KW - characterization KW - classification KW - crystalline rocks KW - exploration KW - fractures KW - ground water KW - hydrodynamics KW - Hydrogeology 21 KW - mapping KW - movement KW - overburden KW - permeability KW - potentiometric surface KW - spatial distribution KW - surficial aquifers KW - thickness KW - water wells KW - water yield AB - Integration of a wide array of structural data with well-field hydrologic testing is increasingly recognized as a critical step in understanding groundwater flow behavior and recharge in crystalline bedrock aquifers (Lyford et al., 2003, Walsh and Lyford, 2002). As part of its rejuvenated mapping program, The Massachusetts Office of the State Geologist has been producing fracture characterization maps as a value-added accompaniment to traditional 1:24:000-scale bedrock mapping. Fracture characterization maps reclassify bedrock into domains of varying hydrologic significance, by combining rock properties (foliation steepness and development, partings, sheeting development, etc...) and type of overburden (permeable vs. non-permeable). The goal of these maps is to better understand preferential flow directions in the bedrock and the potential hydraulic connections between surficial and bedrock aquifers. Each fracture characterization map contains several summary panels, including standard geologic map bases overlain by typical rose diagrams and stereonets displaying fracture domains and trajectories, sheeting distribution, foliation trajectories, bedrock elevations, generalized piezometric surface configuration, and overburden type and thickness with separations into permeability class. A GIS well database is also included, showing well distribution, yield, bedrock elevation, and "hot-linked" well log images. All maps and raw data are made available to the public in paper, digital (PDF) or GIS format. We believe this approach will provide hydrologists and consultants with basic framework data that will expedite and improve the planning of subsurface investigations, construction activities, and groundwater exploration. JF - Abstracts with Programs - Geological Society of America PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 37 SN - 00167592 UR - https://gsa.confex.com/gsa/2005AM/finalprogram/abstract_94576.htm IS - 77 N1 - Accession Number: 2006-039166; Conference Name: Geological Society of America, 2005 annual meeting; Salt Lake City, UT, United States; Conference Date: 20051016; Language: English; Coden: GAAPBC; Collation: 1; Collation: 145; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 200612; Monograph Title: Geological Society of America, 2005 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic JO - Abstracts with Programs - Geological Society of America ER - TY - Generic T1 - Fracture characterization of crystalline bedrock for groundwater investigations; an example from the Marlborough Quadrangle, Massachusetts T2 - Abstracts with Programs - Geological Society of America Y1 - 2004 A1 - Scott A Salamoff A1 - Stephen B Mabee A1 - Joseph P Kopera A1 - Donald U Wise KW - #StaffPubs KW - aquifers KW - Assabet River Fault KW - BEDROCK KW - characterization KW - controls KW - crystalline rocks KW - fractured materials KW - fractures KW - geographic information systems KW - ground water KW - Hydrogeology 21 KW - hydrology KW - information systems KW - joints KW - Marlborough Quadrangle KW - massachusetts KW - Middlesex County Massachusetts KW - permeability KW - preferential flow KW - recharge KW - style KW - testing KW - theoretical models KW - United States AB - Integration of a wide array of structural data with well-field hydrologic testing is increasingly recognized as a critical step in understanding groundwater flow behavior and recharge in crystalline bedrock aquifers (Lyford et al., 2003, Walsh and Lyford, 2002). The Marlborough Quadrangle, about 40 km west of Boston, was selected as a test case of how a state geological survey can most effectively and efficiently collect and present such data in order to better constrain conceptual models of groundwater flow in general and to be of maximum use for hydrologists and consultants working on specific local problems. In this study, 3200 structural measurements were taken by a two-person team over a nine-week period at 68 stations distributed throughout the quadrangle and keyed into a GIS database. Specialized data sheets allowed efficient recording and digitization of orientations, lengths, spacing and mineralization, and separation of various classes of joints and veins. Fault data also included motion direction and sense. Summary maps in GIS format include standard geologic map bases overlain by typical rose diagrams and stereograms and maps such as fracture domains and trajectories, sheeting distribution, foliation trajectories, bedrock elevations, generalized piezometric surface configuration, and overburden type and thickness with separations into permeability class. Geology of the quadrangle can be separated into three zones: (a) north of the Assabet River Fault (ARF), (b) the area between the ARF and 1.5 km-wide Bloody Bluff Fault Zone (BBFZ), and (c) south of the BBFZ. Generalized foliations in the zones are: (a) 215, 50N, (b) 240, 65N, and (c) 270, 45N. Two pervasive, steeply-dipping (>60 degrees ) fracture sets occur throughout the quadrangle: an older 150 degrees set that includes sulfide-bearing veins and fracture surfaces along the ARF and a 015 degrees set of largely unmineralized common joints, macrojoints (>3 m length) and joint zones (av. 1.2 m width). Sheeting and unloading joints are generally coincident with shallow dipping foliation in (c) but cross-cut foliation in (a) and (b). We believe this approach will provide hydrologists and consultants with basic framework data that will expedite and improve the planning of subsurface investigations, construction activities and groundwater exploration. JF - Abstracts with Programs - Geological Society of America PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 36 SN - 00167592 UR - https://gsa.confex.com/gsa/2004NE/finalprogram/abstract_70321.htm IS - 22 N1 - Accession Number: 2005-077195; Conference Name: Geological Society of America, Northeastern Section, 38th annual meeting; Geological Society of America, Southeastern Section, 53rd annual meeting; Washington, DC, United States; Conference Date: 20040325; Language: English; Coordinates: N421800N421800W0713000W0713000; Coden: GAAPBC; Collation: 1; Collation: 113; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 200524; Monograph Title: Geological Society of America, Northeastern Section, 38th annual meeting; Geological Society of America, Southeastern Section, 53rd annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic JO - Abstracts with Programs - Geological Society of America ER -