%0 Conference Proceedings %B Abstracts with Programs - Geological Society of America %D 2009 %T Embracing the digital revolution; issues of concern to geological surveys %A Joseph P Kopera %K #StaffPubs %K cartography %K digital cartography %K digitization %K geographic information systems %K Geologic maps 14 %K information systems %K mapping %K techniques %X Advancements in GIS and digital mapping techniques have improved the efficient production and visualization of geologic data. The Office of the Massachusetts State Geologist (OMSG) utilizes these tools extensively to produce geologic maps and fulfill its mission of making geologic data freely accessible to the public. Such tools have increased efficiency at the OMSG in fieldwork preparation and map production, in addition to creating new types of geologic maps. This same technology also creates new problems that need to be addressed: 1.) Accessing digital data inherently requires more specialized knowledge than reading a paper document. Most citizens do not have access to commercial GIS software, know how to use it, or know where to get digital data. 2.) The longevity of digital data at present is problematic. Various proprietary data formats and unstable digital media quickly become antiquated and unusable. 3.) Digital geospatial datasets tend to lack uniform and adequate metadata on their quality, origin, purpose, context, and appropriateness of use. In the rush to embrace digital technology it is useful to keep in mind that such tools should simplify our work as geologists and increase the utility and availability of the data we produce. Issues of accessibility can be addressed by education and the adoption of non-proprietary open-source software, data formats and standards. Problems with the viability of data may eventually be solved by advances in technology. In the meantime, stable paper or mylar maps should be not be abandoned. The creation and maintenance of high-quality metadata and well-organized, thorough, centralized databases is critical in keeping the flood of new digital data navigable. In the end, we must be able to easily modify any new technology we adopt to address the problems it presents, or we risk compromising our discipline to fit the limitations of that technology. %B Abstracts with Programs - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 41 %P 99 - 99 %8 2009/02/01/ %@ 00167592 %G eng %U https://gsa.confex.com/gsa/2009NE/finalprogram/abstract_155603.htm %N 33 %! Abstracts with Programs - Geological Society of America %0 Conference Proceedings %B Abstracts with Programs - Geological Society of America %D 2010 %T Evidence for arsenic-mineralization in granitic basement rocks, Ayer Granodiorite, northeastern Massachusetts %A Koteas, G. Christopher %A Keskula, Anna J. %A Stein, Carol L. %A McTigue, David F. %A Joseph P Kopera %A Brandon, William C. %K #StaffPubs %K acadian %K arsenic %K arsenides %K arsenopyrite %K Ayer Granodiorite %K Berwick formation %K fractured materials %K geochemistry %K granodiorites %K Igneous and metamorphic petrology 05A %K igneous rocks %K lower Paleozoic %K massachusetts %K Merrimack Synclinorium %K metals %K metamorphic rocks %K metamorphism %K metasedimentary rocks %K metasomatism %K Middlesex County Massachusetts %K migration of elements %K mineralization %K Mineralogy of non-silicates 01C %K northeastern Massachusetts %K orogeny %K Paleozoic %K plutonic rocks %K pollutants %K pollution %K pyrite %K sulfides %K United States %X Core samples of the Ayer Granodiorite along the eastern margin of the Merrimack Belt in northeastern Massachusetts host a series of sulfide and oxide phases that resulted from interaction with sulfide-bearing meta-sedimentary host rocks. Euhedral arsenopyrite grains are found with ilmenite, apatite, and REE phosphates in zones that generally mimic the intersection between a gneissic fabric and a relict magmatic foliation. Arsenopyrite crystals are typically elongate with this lineation. Euhedral to subhedral pyrite crystals have also been observed, but are localized to areas without As-bearing phases. Micro-fractures that parallel either a steep NW-striking joint set or gently-dipping sheeting joints are commonly filled with interwoven calcite cements and As-bearing Fe-oxides. Surface coatings of major fracture sets are also characterized by Fe-As-rich rinds that host micron-scale sub-angular particles of quartz, feldspars, and phyllosilicates. Where micro-fractures are most concentrated, sulfide-bearing minerals are less common; however, subhedral to anhedral arsenopyrite grains do occur along some open micro-fractures. These crystals preserve lobate grain boundaries and are associated with As-bearing Fe-oxide-rich coatings along adjacent fractures. The presence of 1) pyrite, 2) arsenopyrite associated with phosphates, and 3) As-bearing fracture coatings suggests multiple stages of mineralization. We propose that intrusion-related fluid-rock interaction associated with heating of nearby sulfide-bearing schists of the Berwick Formation during Acadian orogenesis may have provided the necessary constituents for growth of sulfide phases in the Ayer. It appears that Late Devonian greenschist facies metamorphism and metasomatism led to mineralization that generated arsenopyrite and accompanying phosphates; however, the role of the cross-cutting Clinton Newbury Fault Zone as a conduit for hydrothermal fluids may also be important. Lower temperature As-bearing Fe-oxide and calcite coatings on open fractures surfaces may be associated with a change from lithostatic- to hydrostatic-pressures during post-glacial regional uplift. This mineralization appears to be synchronous with intense microfracturing that post-dates all other mineralization. %B Abstracts with Programs - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 42 %P 160 - 160 %8 2010/03/01/ %@ 00167592 %G eng %U https://gsa.confex.com/gsa/2010NE/finalprogram/abstract_169998.htm %N 11 %! Abstracts with Programs - Geological Society of America