@proceedings {292,
	title = {Foraminifera ecology on the continental shelf, Merrimack Embayment, Gulf of Maine, New England},
	volume = {42},
	year = {2010},
	note = {Accession Number: 2010-092674; Conference Name: Geological Society of America, Northeastern Section, 45th annual meeting Geological Society of America, Southeastern Section, 59th annual meeting; Baltimore, MD, United States; Conference Date: 20100314; Language: English; Coordinates: N423000N430000W0703000W0705000; Coden: GAAPBC; Collation: 1; Collation: 82; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201049; Monograph Title: Geological Society of America, Northeastern Section, 45th annual meeting; Geological Society of America, Southeastern Section, 59th annual meeting; joint meeting, abstracts volume; Monograph Author(s): Anonymous; Reviewed Item: Analytic},
	month = {2010/03/01/},
	pages = {82 - 82},
	publisher = {Geological Society of America (GSA) : Boulder, CO, United States},
	address = {United States},
	abstract = {During the late Pleistocene the Merrimack River paleodelta formed as post-glacial rebound produced a local low stand in sea level. Drowned as sea level rose, the paleodelta is now being reworked by a variety of processes. This study uses benthic foraminifera as a biotic and environmental proxy to study the sand and gravel resources of the paleodelta. Nineteen sediment samples were collected from the paleodelta along two east-west transects east of the Merrimack River. From these samples nearly 6000 benthic foraminifera, representing 62 species, were collected and identified. Although dissolution compromised the preservation of calcite tests within six samples, the resulting data is robust and allows for numerous conclusions to be drawn. Specifically, benthic foraminifera become more common distally and specific species inhabit specific areas of the paleodelta. Distribution patterns of some species have changed significantly since the late 1940s, with some species migrating landward, others, seaward. Distributions of some taxa differ significantly between the two transects, both in the present day and from the past. These differences may point to the influence of, and changes in, the Merrimack River outflow upon water column nutrient delivery, productivity and food availability over the past 60 years. Species diversity and evenness peak at the delta break, coincident with low species dominance at 50 meters water depth. Q-mode cluster analyses show three distinct assemblages, "shallow" (< or =30 meters water depth), "deep" (> or =40 meters), and "delta edge" (50 meters). There is no apparent correlation between foraminiferal distributions and deltaic bedforms, and in turn, sediment type. This implies that foraminiferal distributions are controlled by other environmental variables such as food. In summary, benthic foraminiferal assemblage analyses complement geophysical techniques. Benthic foraminifera can also help assess the marine impact of, e.g., mining sediment resources, watershed development, pollution, rising sea level, and increased fishing.},
	keywords = {$\#$StaffPubs, applications, Atlantic Ocean, benthic taxa, Cenozoic, cluster analysis, deltaic environment, Economic geology, geology of nonmetal deposits 28A, Foraminifera, gravel deposits, Gulf of Maine, Invertebrata, Maine, marine environment, marine sediments, massachusetts, Merrimack River valley, microfossils, mining, North Atlantic, paleoecology, paleogeography, Pleistocene, Protista, Quaternary, Quaternary geology 24, sand deposits, sea-level changes, sediments, shelf environment, species diversity, statistical analysis, United States, upper Pleistocene},
	isbn = {00167592},
	url = {https://gsa.confex.com/gsa/2010NE/finalprogram/abstract_170108.htm},
	author = {Steven A Nathan and Leckie, R. Mark and Stephen B Mabee}
}
@proceedings {302,
	title = {Implications of diurnal river fluctuations on mass transport in a valley-fill aquifer},
	volume = {38},
	year = {2006},
	note = {Accession Number: 2010-061334; Conference Name: Geological Society of America, 2006 annual meeting; Philadelphia, PA, United States; Conference Date: 20061022; Language: English; Coden: GAAPBC; Collation: 1; Collation: 468; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201034; Monograph Title: Geological Society of America, 2006 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic},
	month = {2006/10/01/},
	pages = {468 - 468},
	publisher = {Geological Society of America (GSA) : Boulder, CO, United States},
	address = {United States},
	abstract = {Aquifers located in isolated stratified drift deposits in the northeastern portion of the US are extremely fragile and important groundwater resources. These aquifers, when restricted to bedrock valleys, are often strongly coupled to significant surface water drainage systems. In northwestern Massachusetts, surface water associated with the Deerfield River watershed is highly regulated by dams to protect against flooding and to generate hydroelectric power. Regular releases of water from these dams cause diurnal fluctuations in river stage. In a previous study performed by the USGS, measurements from two clusters of wells show a significant response to river stage fluctuations in the aquifer. Fluctuations in river stage and resulting changes in head levels in the aquifer cause a switch from a losing to a gaining stream. The flow reversals have implications for mass transport and nutrient cycling within the hyporheic zone. In this paper we investigate the physical hydrologic controls on mass transport in the shallow aquifer. Using a coupled groundwater flow and transport code, we built a quasi three dimensional transient numerical model to approximate the head changes in the aquifer caused by the stage fluctuations in the river. Flow velocities and residence times were estimated in the aquifer for a variety of flow conditions. The mixing process driven by the aquifer head changes were quantified in the proximity of the hyporheic zone and shown to significantly influence both vertical and horizontal flow velocities in a region close to the stream-aquifer boundary. The diurnal river stage changes also appear to influence farfield hydrologic conditions and potentially hydrologically isolate the river and hyporheic zone. To further investigate these mixing processes we applied a mass transport code with conservative tracers to the aquifer. Fluctuation of the river stage combined with the heterogeneous nature of the aquifer creates a pumping mechanism that creates excess mixing within shallow portions of the aquifer. Aquifer dispersivity and molecular diffusion both contribute to the anomalous mixing modeled in the shallow aquifer. Mixing driven by stream stage changes has important implications for nutrient cycling as well as contaminant transport in the shallow aquifer.},
	keywords = {$\#$StaffPubs, aquifers, BEDROCK, clastic sediments, controls, diffusion, diurnal variations, drainage, drift, Eastern U.S., Environmental geology 22, floods, fluctuations, geochemical cycle, geologic hazards, ground water, measurement, mixing, models, Northeastern U.S., numerical models, nutrients, pollution, processes, pumping, quantitative analysis, residence time, sediments, shallow aquifers, surface water, three-dimensional models, tracers, transport, United States, valleys, water pollution, water resources, water wells},
	isbn = {00167592},
	url = {https://gsa.confex.com/gsa/2006AM/finalprogram/abstract_115285.htm},
	author = {Brandon J Fleming and David F Boutt and Stephen B Mabee}
}
