Browsing by Author "Feinberg, Joshua"
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Item Estimating the abundance of iron sulfide minerals in Minnesota freshwater sediments in relation to pore water and sediment chemistry and wild rice growth(2013-10) Cheah, Darren; Myrbo, Amy; Bilardello, Dario; Feinberg, JoshuaEmpirical observations of growth of wild rice (Zizania sp.) in wetlands, lakes, and rivers appear to indicate that higher sulfate concentrations lead to a growth deficiency in wild rice. Many growth locations of wild rice in Northern Minnesota freshwater systems have been affected by sulfate leakage, and are within the vicinity of the Mesabi and Cuyuna Iron Ranges (historic and current iron mining) and the Duluth Complex (proposed copper and nickel mining). The dissolved sulfate is reduced to sulfide by microbes in the sediment, and may be sequestered as iron sulfide minerals (e.g., greigite, Fe3S4, and pyrite, FeS2). These minerals are likely to be concentrated where iron is common in local terrestrial geology; pore water pH, as well as organic matter and water content of bottom sediments, are probably also significant. Samples were collected from over 100 research sites spread widely across Minnesota, including water bodies that are naturally high and low in sulfate and iron, as well as water bodies that display recent sulfate increases due to local mine drainage. Petrographic microscopy was used to identify and qualitatively estimate pyrite abundance, while scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) was employed to determine sediment mineralogy at high magnification. Environmental magnetic analyses were conducted on samples selected based on qualitative abundance of pyrite. Preliminary results reveal that samples associated with mining drainage have elevated magnetic grain concentrations with a larger proportion of high-coercivity minerals (e.g., hematite, Fe2O3, and goethite, FeO(OH)) than those from non-mining sites. These minerals are common products of acid mine drainage, and are formed as Fe-bearing silicate minerals are hydrolyzed during acid leaching. The grain size distributions of magnetic minerals were similar for mining and non-mining sites, although lake samples with higher sulfate concentrations appear to correlate with coarser magnetic minerals. Results from this investigation and previously determined chemical analyses data were statistically compared through simple regression analysis, correlation matrix analysis, and Pearson correlation coefficient calculations.Item FORC Analysis of Natural Anisotropic Magnetic Systems(2015-07) Feinberg, JoshuaPresented at the "2015 First Order Reversal Curve (FORC) Workshop" held at the University of Minnesota on Thursday, July 23, 2015.Item Groundwater chemistry data, real-time temperature, elevation, and specific conductance for MN Wells 668848 and 668849 (May 2021 - May 2024)(2024-05-07) McDaris, John; Feinberg, Joshua; Wiest, Nicholas; mcda0030@umn.edu; McDaris, John; University of Minnesota Department of Earth and Environmental SciencesFull water chemistry analysis data from two wells (668848, 668849) adjacent to Williamson Hall on the East Bank Campus of the University of Minnesota, Twin Cities. Water samples were taken ~quarterly in conjunction with a PhD project led by McDaris. Feinberg and Wiest assisted in sample collection and interpretation. The wells were also instrumented with in situ sensors measuring groundwater temperature, elevation, and specific conductance. Measurements from these sensors were taken multiple times per hour for three years.Item IRM Quarterly, Volume 16, Number 4 (Winter 2007). Cover article: Electron Holography and Rock Magnetism(University of Minnesota. Institute for Rock Magnetism, 2007) Feinberg, JoshuaItem IRM Quarterly, Volume 19, Number 4 (Winter 2009-2010). Cover article: New Low-Temp Probe for 3-Axis Magnetic Measurements(University of Minnesota. Institute for Rock Magnetism, 2010) Bowles, Julie; Solheid, Peat; Jackson, Mike; Feinberg, Joshua; Moskowitz, BruceItem IRM Quarterly, Volume 24, Number 2 (Summer 2014). Cover article: The iron that binds: The unexpectedly strong magnetism of high-temperature ceramic cements commonly used in rock magnetic experiments(University of Minnesota. Institute for Rock Magnetism, 2014) Khakhalova, Evgeniya; Feinberg, JoshuaItem IRM Quarterly, Volume 25, Number 3 (Fall 2015). Cover article: The IRM at 25: A Quarter Century of Community-Based Research and Education(University of Minnesota. Institute for Rock Magnetism, 2016-03) Moskowitz, Bruce; Banerjee, Subir; Feinberg, Joshua; Jackson, Mike; Solheid, Peat; Bilardello, DarioItem IRM Quarterly, Volume 25, Number 4 (Winter 2015). Cover article: Adding Geochemistry to the IRM Toolkit: Acquisition of a Portable X-ray Fluorescence Spectrometer(University of Minnesota. Institute for Rock Magnetism, 2016-04) Frahm, Ellery; Feinberg, JoshuaItem IRM Quarterly, Volume 28, Number 3 (Fall 2018). Cover article: Commonly used experimental parameters for acquisition of anhysteretic remanent magnetization (ARM) and its anisotropy (AARM): Results and recommendations from a rock magnetic community survey(University of Minnesota. Institute for Rock Magnetism, 2018-11) Biedermann, Andrea; Bilardello, Dario; Jackson, Mike; Chadima, Martin; Feinberg, JoshuaItem Program for the 2015 "Workshop on Digital Topographic Analysis"(2015-05-18) Monnier, Gilliane; Feinberg, Joshua; Hayes, Katherine