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 - TY - JOUR T1 - Comparison of three fracture sampling methods for layered rocks JF - International Journal of Rock Mechanics and Mining Sciences [1997] Y1 - 2010 A1 - Alex K Manda A1 - Stephen B Mabee KW - #StaffPubs KW - Big Quarry KW - carbonates KW - case studies KW - data acquisition KW - data processing KW - dolomite KW - Door Peninsula KW - fractures KW - geographic information systems KW - ground water KW - information systems KW - joints KW - layered materials KW - mapping KW - methods KW - movement KW - multiple scanline method KW - northeastern Wisconsin KW - numerical models KW - permeability KW - sampling KW - selection method KW - simulation KW - single scanline method KW - statistical analysis KW - Structural geology 16 KW - style KW - three-dimensional models KW - United States KW - Wisconsin AB - Three methods of fracture data collection are tested against each other in layered dolomitic rocks to evaluate the effectiveness of each method in sampling fracture properties. The methods tested are the single scanline method (SSM), selection method (SM), and multiple scanline method (MSM). Finite element techniques were first used to build a base model with the exact locations, sizes and orientations of each fracture observed in the natural fracture network. Then, a second set of models were stochastically generated using statistics from each sampling technique. For each network, the overall fracture intensity was used to assess the effectiveness of each sampling technique in capturing the real fracture properties. Fracture network permeability was also calculated for each of two directions to evaluate the transmissive properties of the networks. Although all three methods produced good matches of relative intensity and permeability between natural and synthetic fractures, the results reveal that a well-placed scanline performed the best at recreating natural fractures. However, the results from one variation of the SSM were only slightly better than the results from both versions of the SM. In general, the SSM provides the best results but possibly at heavy costs in time and labor, whereas the SM gives comparable results with less expenditure of energy and time. Thus, the SM is an adequate technique and recommended for use at large outcrops or where time, access or budget constraints are a concern. PB - Elsevier : Oxford-New York, International CY - International VL - 47 SN - 13651609 UR - http://www.sciencedirect.com/science/article/pii/S1365160909001804 IS - 22 N1 - Accession Number: 2010-041538; Language: English; Coordinates: N441500N452000W0865600W0880000; Coden: IJRMA2; Collation: 9; Publication Types: Serial; Updated Code: 201023; Illustration(s): illus. incl. 4 tables; Number of References: 25; Reviewed Item: Analytic JO - International Journal of Rock Mechanics and Mining Sciences [1997] ER - TY - JOUR T1 - A field study (Massachusetts, USA) of the factors controlling the depth of groundwater flow systems in crystalline fractured-rock terrain JF - Hydrogeology Journal Y1 - 2010 A1 - David F Boutt A1 - Diggins, Patrick A1 - Stephen B Mabee KW - #StaffPubs KW - aquifers KW - boreholes KW - crystalline rocks KW - eastern Massachusetts KW - fractured materials KW - fractures KW - ground water KW - hydraulic conductivity KW - Hydrogeology 21 KW - massachusetts KW - Nashoba terrane KW - permeability KW - porosity KW - preferential flow KW - shallow-water environment KW - substrates KW - United States AB - Groundwater movement and availability in crystalline and metamorphosed rocks is dominated by the secondary porosity generated through fracturing. The distributions of fractures and fracture zones determine permeable pathways and the productivity of these rocks. Controls on how these distributions vary with depth in the shallow subsurface (<300 m) and their resulting influence on groundwater flow is not well understood. The results of a subsurface study in the Nashoba and Avalon terranes of eastern Massachusetts (USA), which is a region experiencing expanded use of the fractured bedrock as a potable-supply aquifer, are presented. The study logged the distribution of fractures in 17 boreholes, identified flowing fractures, and hydraulically characterized the rock mass intersecting the boreholes. Of all fractures encountered, 2.5% are hydraulically active. Boreholes show decreasing fracture frequency up to 300 m depth, with hydraulically active fractures showing a similar trend; this restricts topographically driven flow. Borehole temperature profiles corroborate this, with minimal hydrologically altered flow observed in the profiles below 100 m. Results from this study suggest that active flow systems in these geologic settings are shallow and that fracture permeability outside of the influence of large-scale structures will follow a decreasing trend with depth. Copyright 2010 Springer-Verlag PB - Springer : Berlin - Heidelberg, Germany CY - Federal Republic of Germany VL - 18 SN - 1431217414350157 UR - http://link.springer.com/article/10.1007%2Fs10040-010-0640-y IS - 88 N1 - Accession Number: 2011-042136; Language: English; Coordinates: N420000N425000W0695500W0714500; Collation: 16; Publication Types: Serial; Updated Code: 201124; Illustration(s): illus. incl. 3 tables, geol. sketch map; Number of References: 58; Reviewed Item: Analytic JO - Hydrogeology Journal ER - TY - JOUR T1 - A method of estimating bulk potential permeability in fractured-rock aquifers using field-derived fracture data and type curves JF - Hydrogeology Journal Y1 - 2013 A1 - Alex K Manda A1 - Stephen B Mabee A1 - David F Boutt A1 - Cooke, Michele L. KW - #StaffPubs KW - aquifers KW - boundary conditions KW - eastern Massachusetts KW - fractured materials KW - fractures KW - ground water KW - Hydrogeology 21 KW - massachusetts KW - Nashoba terrane KW - naturally fractured reservoirs KW - numerical models KW - permeability KW - prediction KW - pump tests KW - simulation KW - two-dimensional models KW - United States AB - A method is devised for estimating the potential permeability of fracture networks from attributes of fractures observed in outcrop. The technique, which is intended as a complement to traditional approaches, is based on type curves that represent various combinations of fracture lengths, fracture orientations and proportions (i.e., intensities) of fractures that participate in flow. Numerical models are used to derive the type curves. To account for variations in fracture aperture, a permeability ratio (R) defined as the permeability of a fracture network in a domain divided by the permeability of a single fracture with identical fracture apertures, is used as a dependent variable to derive the type curves. The technique works by determining the point on the type curve that represents the fracture characteristics collected in the field. To test the performance of the technique, permeabilities that were derived from fractured-rock aquifers of eastern Massachusetts (USA) are compared to permeabilities predicted by the technique. Results indicate that permeabilities estimated from type curves are within an order of magnitude of permeabilities derived from field tests. First-order estimates of fracture-network permeability can, therefore, be easily and quickly acquired with this technique before more robust and expensive methods are utilized in the field. Copyright 2012 Springer-Verlag Berlin Heidelberg PB - Springer : Berlin - Heidelberg, Germany CY - Federal Republic of Germany VL - 21 SN - 1431217414350157 UR - http://link.springer.com/article/10.1007%2Fs10040-012-0919-2 IS - 22 N1 - Accession Number: 2013-055373; Language: English; Coordinates: N421500N424500W0704500W0714500; Collation: 13; Publication Types: Serial; Updated Code: 201334; Illustration(s): illus. incl. 4 tables, geol. sketch maps; Number of References: 41; Reviewed Item: Analytic JO - Hydrogeology Journal ER -