Geochemical Transactions http://scitation.aip.org/ Geochemical Transactions Cell adhesion of Shewanella oneidensis to iron oxide minerals: Effect of different single crystal faces http://link.aip.org/link/?GET/6/77/1&agg=rss Andrew L. Neal, Tracy L. Bank, Michael F. Hochella, Jr., and Kevin M. Rosso<br/> The results of experiments designed to test the hypothesis that near-surface molecular structure of iron oxide minerals influences adhesion of dissimilatory iron reducing bacteria are presented. These experiments involved the measurement, using atomic force microscopy, of interaction forces generate ... [Geochem. Trans. 6, 77 (2005)] published Fri Dec 30, 2005. Secondary mineral formation associated with respiration of nontronite, NAu-1 by iron reducing bacteria http://link.aip.org/link/?GET/6/67/1&agg=rss S. Erin O'Reilly, Janet Watkins, and Yoko Furukawa<br/> Experimental batch and miscible-flow cultures were studied in order to determine the mechanistic pathways of microbial Fe(III) respiration in ferruginous smectite clay, NAu-1. The primary purpose was to resolve if alteration of smectite and release of Fe precedes microbial respiration. Alteration of ... [Geochem. Trans. 6, 67 (2005)] published Mon Oct 24, 2005. Reduction of crystalline iron(III) oxyhydroxides using hydroquinone: Influence of phase and particle size http://link.aip.org/link/?GET/6/60/1&agg=rss Amy J. Anschutz and R. Lee Penn<br/> Iron oxides and oxyhydroxides are common and important materials in the environment, and they strongly impact the biogeochemical cycle of iron and other species at the Earth's surface. These materials commonly occur as nanoparticles in the 3-10 nm size range. This paper presents quantitative result ... [Geochem. Trans. 6, 60 (2005)] published Fri Sep 9, 2005. Polyphosphates as a source of enhanced P fluxes in marine sediments overlain by anoxic waters: Evidence from [sup 31]P NMR http://link.aip.org/link/?GET/6/52/1&agg=rss Poulomi Sannigrahi and Ellery Ingall<br/> Sedimentary phosphorus (P) composition was investigated in Effingham Inlet, a fjord located on the west coast of Vancouver Island in Barkley Sound. Solid-state P nuclear magnetic resonance (NMR) spectroscopy was applied to demineralized sediment samples from sites overlain by oxic and anoxic bottom ... [Geochem. Trans. 6, 52 (2005)] published Wed Jun 22, 2005. Evaporative evolution of a Na--Cl--NO[sub 3]--K--Ca--SO[sub 4]--Mg--Si brine at 95 [degree]C: Experiments and modeling relevant to Yucca Mountain, Nevada http://link.aip.org/link/?GET/6/31/1&agg=rss Maureen Alai, Mark Sutton, and Susan Carroll<br/> A synthetic Topopah Spring Tuff water representative of one type of pore water at Yucca Mountain, NV was evaporated at 95 degrees C in a series of experiments to determine the geochemical controls for brines that may form on, and possibly impact upon the long-term integrity of waste containers and ... [Geochem. Trans. 6, 31 (2005)] published Tue Jun 7, 2005. Deliquescence of NaCl--NaNO[sub 3], KNO[sub 3]--NaNO[sub 3], and NaCl--KNO[sub 3] salt mixtures from 90 to 120 [degree]C http://link.aip.org/link/?GET/6/19/1&agg=rss Susan Carroll, Laura Craig, and Thomas J. Wolery<br/> We conducted reversed deliquescence experiments in saturated NaCl-NaNO-HO, KNO-NaNO-HO, and NaCl-KNO-HO systems from 90 to 120 degrees C as a function of relative humidity and solution composition. NaCl, NaNO, and KNO represent members of dust salt assemblages that are likely to deliquesce and form ... [Geochem. Trans. 6, 19 (2005)] published Mon Apr 11, 2005. Denitrification pathways and rates in the sandy sediments of the Georgia continental shelf, USA http://link.aip.org/link/?GET/6/12/1&agg=rss Cynthia Vance-Harris and Ellery Ingall<br/> Denitrification in continental shelf sediments has been estimated to be a significant sink of oceanic fixed nitrogen (N). The significance and mechanisms of denitrification in organic-poor sands, which comprise 70% of continental shelf sediments, are not well known. Core incubations and isotope trac ... [Geochem. Trans. 6, 12 (2005)] published Wed Feb 2, 2005. Micro-spectroscopic investigation of selenium-bearing minerals from the Western US Phosphate Resource Area http://link.aip.org/link/?GET/6/1/1&agg=rss Amy L. Ryser, Daniel G. Strawn, Matthew A. Marcus, Jodi L. Johnson-Maynard, Mickey E. Gunter et al.<br/> Mining activities in the US Western Phosphate Resource Area (WPRA) have released Se into the environment. Selenium has several different oxidation states and species, each having varying degrees of solubility, reactivity, and bioavailability. In this study we are investigating the speciation of Se i ... [Geochem. Trans. 6, 1 (2005)] published Fri Jan 28, 2005. Potential contaminants at a dredged spoil placement site, Charles City County, Virginia, as revealed by sequential extraction http://link.aip.org/link/?GET/5/49/1&agg=rss Jianwu Tang, G. Richard Whittecar, Karen H. Johannesson, and W. Lee Daniels<br/> Backfills of dredged sediments onto a former sand and gravel mine site in Charles City County, VA may have the potential to contaminate local groundwater. To evaluate the mobility of trace elements and to identify the potential contaminants from the dredged sediments, a sequential extraction scheme ... [Geochem. Trans. 5, 49 (2004)] published Tue Dec 7, 2004. Effects of aqueous complexation on reductive precipitation of uranium by Shewanella putrefaciens http://link.aip.org/link/?GET/5/41/1&agg=rss Johnson R. Haas and Abraham Northup<br/> We have examined the effects of aqueous complexation on rates of dissimilatory reductive precipitation of uranium by Shewanella putrefaciens. Uranium(VI) was supplied as sole terminal electron acceptor to Shewanella putrefaciens (strain 200R) in defined laboratory media under strictly anaerobic cond ... [Geochem. Trans. 5, 41 (2004)] published Wed Sep 29, 2004. Acid mine drainage biogeochemistry at Iron Mountain, California http://link.aip.org/link/?GET/5/13/1&agg=rss Gregory K. Druschel, Brett J. Baker, Thomas M. Gihring, and Jillian F. Banfield<br/> The Richmond Mine at Iron Mountain, Shasta County, California, USA provides an excellent opportunity to study the chemical and biological controls on acid mine drainage (AMD) generation in situ, and to identify key factors controlling solution chemistry. Here we integrate four years of field-based g ... [Geochem. Trans. 5, 13 (2004)] published Wed Jun 30, 2004. Adatom Fe(III) on the hematite surface: Observation of a key reactive surface species http://link.aip.org/link/?GET/5/33/1&agg=rss Carrick M. Eggleston, Andrew G. Stack, Kevin M. Rosso, and Angela M. Bice<br/> The reactivity of a mineral surface is determined by the variety and population of different types of surface sites (e.g., step, kink, adatom, and defect sites). The concept of "adsorbed nutrient" has been built into crystal growth theories, and many other studies of mineral surface reactivity appea ... [Geochem. Trans. 5, 33 (2004)] published Wed Jun 30, 2004. The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer http://link.aip.org/link/?GET/5/1/1&agg=rss Douglas B. Kent and Patricia M. Fox<br/> We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As) in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: ( ... [Geochem. Trans. 5, 1 (2004)] published Wed Apr 28, 2004. Release of organic nitrogen compounds from kerogen via catalytic hydropyrolysis http://link.aip.org/link/?GET/1/61/1&agg=rss B. Bennett and G. D. Love<br/> High hydrogen pressure pyrolysis (hydropyrolysis) was performed on samples of solvent extracted Kimmeridge Clay Formation source rock with a maturity equivalent to ca. 0.35% vitrinite reflectance. We describe the types and distributions of organic nitrogen compounds in the pyrolysis products (hydrop ... [Geochem. Trans. 1, 61 (2004)] published Fri Mar 5, 2004. An experimental investigation of geochromatography during secondary migration of petroleum performed under subsurface conditions with a real rock http://link.aip.org/link/?GET/1/54/1&agg=rss Steve Larter, Berni Bowler, Ed Clarke, Colin Wilson, Brian Moffatt et al.<br/> An understanding of the size of petroleum secondary migration systems is vital for successful exploration for petroleum reserves. Geochemists have suggested that compositional fractionation of petroleum accompanying the migration process (geochromatography) can potentially be used to infer distances ... [Geochem. Trans. 1, 54 (2004)] published Fri Mar 5, 2004. Pyrite surface interaction with selected organic aqueous species under anoxic conditions http://link.aip.org/link/?GET/1/47/1&agg=rss Joakim Bebie and Martin A. A. Schoonen<br/> The interaction between low-molecular weight organic compounds and pyrite under anoxic conditions has been studied using a combination of electrophoresis and batch sorption experiments. The results suggest that acetate, carbamide, ethylamine, formamide, purine, D-ribose, and adenine, as well as the ... [Geochem. Trans. 1, 47 (2004)] published Fri Mar 5, 2004. Molecular mechanics and quantum mechanical modeling of hexane soot structure and interactions with pyrene http://link.aip.org/link/?GET/1/41/1&agg=rss J. D. Kubicki<br/> Molecular simulations (energy minimizations and molecular dynamics) of an n-hexane soot model developed by Smith and co-workers (M. S. Akhter, A. R. Chughtai and D. M. Smith, Appl. Spectrosc., 1985, 39, 143; ref. 1) were performed. The MM+ (N. L. Allinger, J. Am. Chem. Soc., 1977, 395, 157; ref. 2) ... [Geochem. Trans. 1, 41 (2004)] published Fri Mar 5, 2004. Carbon isotopic evidence for the catalytic origin of light hydrocarbons http://link.aip.org/link/?GET/1/38/1&agg=rss Frank D. Mango<br/> The molecular proportionality between C and C isomers reported recently (F. D. Mango, Geochim. Cosmochim. Acta, 2000, 64, 1265; ref. 1) is probably the strongest evidence for catalysis yet published. It implicates two cyclopropane-like precursors, [S] and [S] (where S denotes any substrate), of simi ... [Geochem. Trans. 1, 38 (2004)] published Fri Mar 5, 2004. Polar non-hydrocarbon contaminants in reservoir core extracts http://link.aip.org/link/?GET/1/34/1&agg=rss B. Bennett and S. R. Larter<br/> A geochemical investigation of oils in sandstone core plugs and drill stem test oils was carried out on samples from a North Sea reservoir. A sample of diesel used as a constituent of the drilling fluids was also analysed. The aliphatic and aromatic hydrocarbons and polar non-hydrocarbons were isola ... [Geochem. Trans. 1, 34 (2004)] published Fri Mar 5, 2004. Effect of temperature and illumination on pyrite oxidation between pH 2 and 6 http://link.aip.org/link/?GET/1/23/1&agg=rss Martin Schoonen, Alicia Elsetinow, Michael Borda, and Daniel Strongin<br/> The effect of heat and illumination with visible light on the oxidation of pyrite with dissolved molecular oxygen in solutions between pH 2 and 6 has been investigated using a combination of surface science experiments and batch oxidation experiments. The rate of the oxidation of pyrite is strongly ... [Geochem. Trans. 1, 23 (2004)] published Fri Mar 5, 2004. Theoretical studies on metal thioarsenites and thioantimonides: synergistic interactions between transition metals and heavy metalloids http://link.aip.org/link/?GET/1/16/1&agg=rss J. A. Tossell<br/> Recently we established that the ternary complex, CuAsS(SH)(OH) has an unusually high stability and makes a large contribution to the total concentrations of both Cu and As in sulfidic solutions equilibrated with Cu and As sulfide minerals. This ternary complex has an unusual structure, containing a ... [Geochem. Trans. 1, 16 (2004)] published Fri Mar 5, 2004.