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Articles 1 - 30 of 58

Full-Text Articles in Physical Sciences and Mathematics

Impact Of Biochar Amendments On The Quality Of A Typical Midwestern Agricultural Soil, David A. Laird, Pierce Fleming, Dedrick D. Davis, Robert Horton, Baiqun Wang, Douglas L. Karlen Aug 2019

Impact Of Biochar Amendments On The Quality Of A Typical Midwestern Agricultural Soil, David A. Laird, Pierce Fleming, Dedrick D. Davis, Robert Horton, Baiqun Wang, Douglas L. Karlen

Douglas L Karlen

Biochar, a co-product of thermochemical conversion of lignocellulosic materials into advanced biofuels, may be used as a soil amendment to enhance the sustainability of biomass harvesting. We investigated the impact of biochar amendments (0, 5, 10, and 20 g-biochar kg− 1 soil) on the quality of a Clarion soil (Mesic Typic Hapludolls), collected (0–15 cm) in Boone County, Iowa. Repacked soil columns were incubated for 500 days at 25 °C and 80% relative humidity. On week 12, 5 g of dried and ground swine manure was incorporated into the upper 3 cm of soil for half of the columns. Once …

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Biochar Impact On Nutrient Leaching From A Midwestern Agricultural Soil, David Laird, Pierce Flemming, Baiqun Wang, Robert Horton, Douglas Karlen Aug 2019

Biochar Impact On Nutrient Leaching From A Midwestern Agricultural Soil, David Laird, Pierce Flemming, Baiqun Wang, Robert Horton, Douglas Karlen

Douglas L Karlen

Application of biochar to highly weathered tropical soils has been shown to enhance soil quality and decrease leaching of nutrients. Little, however, is known about the effects of biochar applications on temperate region soils. Our objective was to quantify the impact of biochar on leaching of plant nutrients following application of swine manure to a typical Midwestern agricultural soil. Repacked soil columns containing 0, 5, 10, and 20 g-biochar kg− 1-soil, with and without 5 g kg− 1 of dried swine manure were leached weekly for 45 weeks. Measurements showed a significant decrease in the total amount of N, P, …

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Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui Oct 2018

Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui

Ying Cui

The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant−soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus. The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils …

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Multivariate Spectral Analysis Of Crism Data To Characterize The Composition Of Mawrth Vallis, Melissa Luna Mar 2018

Multivariate Spectral Analysis Of Crism Data To Characterize The Composition Of Mawrth Vallis, Melissa Luna

Melissa Luna

No abstract provided.

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Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker Sep 2016

Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker

Xiaoyang Zhang

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age,aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the MODIS sensors. …

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Lower Lakes Carbon Project: The Aquatic Vegetation Contribution To Carbon Pools, Leigh A. Sullivan, Nicholas J. Ward, Richard T. Bush, Alicia Hidden, Diane M. Fyfe, Michelle Bush, Crystal A. Maher Jul 2016

Lower Lakes Carbon Project: The Aquatic Vegetation Contribution To Carbon Pools, Leigh A. Sullivan, Nicholas J. Ward, Richard T. Bush, Alicia Hidden, Diane M. Fyfe, Michelle Bush, Crystal A. Maher

Adjunct Professor Richard T Bush

No abstract provided.

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Lower Lakes Carbon Project: The Aquatic Vegetation Contribution To Carbon Pools, Leigh A. Sullivan, Nicholas J. Ward, Richard T. Bush, Alicia Hidden, Diane M. Fyfe, Michelle Bush, Crystal A. Maher Jul 2016

Lower Lakes Carbon Project: The Aquatic Vegetation Contribution To Carbon Pools, Leigh A. Sullivan, Nicholas J. Ward, Richard T. Bush, Alicia Hidden, Diane M. Fyfe, Michelle Bush, Crystal A. Maher

Dr Nicholas J Ward

No abstract provided.

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Assessment And Behaviour Of Secondary Iron(Iii) Minerals In Acid Sulphate Soil Materials, Chamindra Vithana Nov 2015

Assessment And Behaviour Of Secondary Iron(Iii) Minerals In Acid Sulphate Soil Materials, Chamindra Vithana

Chamindra Vithana

This study examined two aspects of acidity generating secondary Fe(III) minerals (i.e. schwertmannite and jarosite) in acid sulfate soils (ASS) environments: i) accurate identification and quantification, and ii) improving our understanding of their behaviour in ASS.The study showed that current assessment methods have a number of limitations and are not reliable for accurate estimation of both minerals in ASS environments. The study also showed that in natural environments, these minerals can behave in a manner different to current conceptual understanding. The broad implication of this study was identification of the need for development of improved management techniques for ASS.

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Controls On Trace Metal Authigenic Enrichment In Reducing Sediments: Insights From Modern Oxygen-Deficient Settings, Susan Little, Derek Vance, Timothy Lyons, James Mcmanus Sep 2015

Controls On Trace Metal Authigenic Enrichment In Reducing Sediments: Insights From Modern Oxygen-Deficient Settings, Susan Little, Derek Vance, Timothy Lyons, James Mcmanus

James McManus

Any effort to reconstruct Earth history using variations in authigenic enrichments of redox-sensitive and biogeochemically important trace metals must rest on a fundamental understanding of their modern oceanic and sedimentary geochemistry. Further, unravelling the multiple controls on sedimentary enrichments requires a multi-element approach. Of the range of metals studied, most is known about the behavior of Fe, Mn, and Mo. In this study, we compare the authigenic enrichment patterns of these elements with a group whose behavior is not as well defined (Cd, Cu, Zn, and Ni) in three oxygen-poor settings: the Black Sea, the Cariaco Basin (Venezuela), and the …

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Microbial Utilization Of Abiogenic Carbon And Hydrogen In A Serpentinite-Hosted System, Susan Lang, G. Früh-Green, S. Bernasconi, M. Lilley, G. Proskurowski, S. Méhay, D. Butterfield Jun 2015

Microbial Utilization Of Abiogenic Carbon And Hydrogen In A Serpentinite-Hosted System, Susan Lang, G. Früh-Green, S. Bernasconi, M. Lilley, G. Proskurowski, S. Méhay, D. Butterfield

Susan Q. Lang

No abstract provided.

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Serpentinization, Carbon, And Deep Life, M. Schrenk, W. Brazelton, Susan Lang Jun 2015

Serpentinization, Carbon, And Deep Life, M. Schrenk, W. Brazelton, Susan Lang

Susan Q. Lang

No abstract provided.

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Elevated Concentrations Of Formate, Acetate And Dissolved Organic Carbon Found At The Lost City Hydrothermal Field, Susan Lang, D. Butterfield, M. Schulte, D. Kelley, M. Lilley Jun 2015

Elevated Concentrations Of Formate, Acetate And Dissolved Organic Carbon Found At The Lost City Hydrothermal Field, Susan Lang, D. Butterfield, M. Schulte, D. Kelley, M. Lilley

Susan Q. Lang

No abstract provided.

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Stable Isotope Analysis Of Organic Carbon In Small (Μg C) Samples And Dissolved Organic Matter Using A Gasbench Preparation Device, Susan Lang, S. Bernasconi, G. Früh-Green Jun 2015

Stable Isotope Analysis Of Organic Carbon In Small (Μg C) Samples And Dissolved Organic Matter Using A Gasbench Preparation Device, Susan Lang, S. Bernasconi, G. Früh-Green

Susan Q. Lang

No abstract provided.

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Sources And Cycling Of Carbon In Continental, Serpentinite-Hosted Alkaline Springs In The Voltri Massif, Italy, E. Schwarzenbach, Susan Lang, G. Früh-Green, M. Lilley, S. Bernasconi, S. Méhay Jun 2015

Sources And Cycling Of Carbon In Continental, Serpentinite-Hosted Alkaline Springs In The Voltri Massif, Italy, E. Schwarzenbach, Susan Lang, G. Früh-Green, M. Lilley, S. Bernasconi, S. Méhay

Susan Q. Lang

No abstract provided.

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Purification Of Fire Derived Markers For Μg Scale Isotope Analysis (Δ13c, Δ14c) Using High Performance Liquid Chromatography (Hplc), M. Gierga, M. Schneider, D. Wiedemeier, Susan Lang, R. Smittenberg, I. Hajdas, S. Bernasconi, M. Schmidt Jun 2015

Purification Of Fire Derived Markers For Μg Scale Isotope Analysis (Δ13c, Δ14c) Using High Performance Liquid Chromatography (Hplc), M. Gierga, M. Schneider, D. Wiedemeier, Susan Lang, R. Smittenberg, I. Hajdas, S. Bernasconi, M. Schmidt

Susan Q. Lang

No abstract provided.

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Dissolved Organic Carbon In Ridge-Axis And Ridge-Flank Hydrothermal Systems, Susan Lang, D. Butterfield, M. Lilley, H. Johnson, J. Hedges Jun 2015

Dissolved Organic Carbon In Ridge-Axis And Ridge-Flank Hydrothermal Systems, Susan Lang, D. Butterfield, M. Lilley, H. Johnson, J. Hedges

Susan Q. Lang

No abstract provided.

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Nitrates In Karst Systems: Comparing Impacted Systems To A Relatively Unimpacted System, Julie C. Angel, Eric Wade Peterson Dec 2014

Nitrates In Karst Systems: Comparing Impacted Systems To A Relatively Unimpacted System, Julie C. Angel, Eric Wade Peterson

Eric Wade Peterson

Karst aquifers are highly susceptible to contamination because of the connection with surface water. Nitrate contamination is common; with most karst aquifers exhibiting some degree of impact. This work assesses the potential impacts of anthropogenic activities on the Horn Hollow Valley (HHV) in Carter County Kentucky. HHV is a karst aquifer system that appears to be minimally impacted by nitrate and chloride contamination. Sampling of the HHV area was conducted from June 2005 to November 2006. Nitrate as nitrogen (NO3-N) concentrations were between 0.13 to 1.54 mg/L; chloride concentrations ranged from 1.43 to 66.3 mg/L. Impact from anthropogenic sources are …

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Possible Sources For Nickel And Chromium In The Middle Part Of The Fillmore Formation In West-Central Utah, Rachel Nyznyk, Benjamin Dattilo Jul 2014

Possible Sources For Nickel And Chromium In The Middle Part Of The Fillmore Formation In West-Central Utah, Rachel Nyznyk, Benjamin Dattilo

Benjamin F. Dattilo

Nickel and chromium are not commonly found in carbonate or mixed carbonate depositional environments. All lithologies from a 100-meter section in the middle part of the Lower Ordovician Fillmore Formation at a single locality, the “Pyramid Section”, contain anomalous levels of nickel and chromium. Preliminary data has also shown that there is significantly more nickel in the matrix of two FPCs (range of 0.22 – 0.24 ppm) from the pyramid section than found in the other lithologies at that section (0.05 – 0.10 ppm). However, at a separate locality, “Section C”, in the lower part of the Fillmore Formation neither …

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Integrating Bio-, Chemo-, Chrono-, Gamma-Ray, Litho-, And Sequence Stratigraphy In The Upper Cambrian And Lower Ordovician: Progress Toward A Comprehensive Stratigraphic Framework, James Miller, Benjamin Dattilo, Raymond Ethington, Kevin Evans, Rebecca Freeman, James Loch, John Repetski, Robert Ripperdan, Anthony Runkel, John Taylor Jul 2014

Integrating Bio-, Chemo-, Chrono-, Gamma-Ray, Litho-, And Sequence Stratigraphy In The Upper Cambrian And Lower Ordovician: Progress Toward A Comprehensive Stratigraphic Framework, James Miller, Benjamin Dattilo, Raymond Ethington, Kevin Evans, Rebecca Freeman, James Loch, John Repetski, Robert Ripperdan, Anthony Runkel, John Taylor

Benjamin F. Dattilo

Chronostratigraphic classification of the Laurentian Upper Cambrian and Lower Ordovician is based on strata in Utah, Nevada, Missouri, Minnesota, Wisconsin, and Alberta. Biozonations are based on strata there as well as in Texas and Oklahoma. Regional trilobite zonations vary somewhat because of facies influence and periods of regional endemism; the zonation is quite different in slope deposits. Conodont zonation begins in the middle Upper Cambrian; many taxa occur in a variety of facies and are cosmopolitan, so zones can be correlated across Laurentia and globally. Calcitic brachiopod zones established in Oklahoma have been identified in other areas where faunas have …

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Microbe-Mineral Relationships And Biogenic Mineral Transformations In Actively Venting Deep-Sea Hydrothermal Sulfide Chimneys, Tzihsuan J. Lin May 2014

Microbe-Mineral Relationships And Biogenic Mineral Transformations In Actively Venting Deep-Sea Hydrothermal Sulfide Chimneys, Tzihsuan J. Lin

TZIHSUAN J LIN

This dissertation uses a combination of microbiology, mineralogy, and geochemistry to understand dissimilatory iron reduction in hyperthermophilic archaea and the role and potential impact of these and other vent microorganisms within active deep-sea hydrothermal vent chimneys. The central objective of the dissertation is to determine if mineral composition and chimney type are among the primary determinants of microbial community composition and hyperthermophilic, dissimilatory iron reducer growth, in addition to other environmental factors such as nutrient availability, temperature, pH, and chlorinity. This is done using samples and organisms collected from the Endeavour Segment of the Juan de Fuca Ridge in the …

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Locating Cryptotephra In Sediments Using Fluid Imaging Technology, Robert D'Anjou, Nicholas L. Balascio, Raymond S. Bradley Jan 2014

Locating Cryptotephra In Sediments Using Fluid Imaging Technology, Robert D'Anjou, Nicholas L. Balascio, Raymond S. Bradley

Raymond S Bradley

We report a new approach to locate and quantify cryptotephra in sedimentary archives using a continuously-imaging Flow Cytometer and Microscope (FlowCAM_). The FlowCAM rapidly photographs particles flowing in suspension past a microscope lens and performs semi-automated analysis of particle images. It has had primarily biological applications, although the potential sedimentological applications are numerous. Here we test the ability of this instrument to image irregularly shaped, vesicular glass shards and to screen sediment samples for the presence of cryptotephra. First, reference samples of basalt and rhyolite tephra (sieved <63>microns) were analyzed with the FlowCAM, demonstrating the ability of the instrument to …

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231pa/230th Evidence For A Weakened But Persistent Atlantic Meridional Overturning Circulation During Heinrich Stadial 1, Louisa Bradtmiller, J. Mcmanus, L. Robinson Dec 2013

231pa/230th Evidence For A Weakened But Persistent Atlantic Meridional Overturning Circulation During Heinrich Stadial 1, Louisa Bradtmiller, J. Mcmanus, L. Robinson

Louisa I. Bradtmiller

No abstract provided.

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Isotopes Of Carbon In A Karst Aquifer Of The Cumberland Platea Of Kentucky , Usa, Lee J. Florea Dec 2013

Isotopes Of Carbon In A Karst Aquifer Of The Cumberland Platea Of Kentucky , Usa, Lee J. Florea

Lee J Florea, PhD, P.G.

In this study, the concentration and isotopic composition of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) are measured in the karst groundwater of the Otter Creek watershed of the Cumberland Plateau of Kentucky, USA. Comparisons among these data and with the geochemistry of carbonate and gypsum equilibrium reactions reveal that DOC concentration is inversely related to discharge, multiple reaction pathways provide DIC with isotopic enrichment that may be directly related to mineral saturation, and oxidation of reduced sulfur is possible for dissolution. DOC is derived from C3 vegetation with an average δ13CDOC of ‒27‰. DIC in groundwater is …

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Preliminary Summary Of Water Resource Investigations During 2012 At Timpanogos Cave National Monument, Utah, Lee J. Florea, Chelsie R. Dugan, Camille Mckinney Nov 2013

Preliminary Summary Of Water Resource Investigations During 2012 At Timpanogos Cave National Monument, Utah, Lee J. Florea, Chelsie R. Dugan, Camille Mckinney

Lee J Florea, PhD, P.G.

This manuscript considers the hydrology and geochemistry of water resources within Timpanogos Cave National Monument in American Fork, Utah. In particular, data are presented for five cave pools within the Monument and the American Fork River that flows through the Monument. Two independent dye trace attempts in this study have not established a connection between the surface near the canyon rim at the south border of the Monument and the cave pools or the river. Ion chemistry of the pools reveals elevated sulfate concentrations. Analysis of sulfate and other reaction products suggests the possibility of combined carbonic and sulfuric acids …

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Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward Oct 2013

Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward

Dr Nicholas J Ward

This thesis examines sulfide oxidation in 4 physically and mineralogically diverse acid sulfate soil (ASS) materials collected from coastal floodplain sites in north-eastern New South Wales. The aim of this study is to gain further understanding of the process of sulfide oxidation in ASS materials, which will allow improved and more effective management strategies to be applied to these materials. The process of sulfide oxidation was examined using laboratory incubation experiments. The oxidation of pyrite was the primary cause of initial acidification of the ASS materials studied. Although the acid volatile sulfur fraction increased in concentration by an order of …

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Investigations Into The Potential For Hypogene Speleogenesis In The Cumberland Plateau Of Southeast Kentucky, U.S.A., Lee J. Florea Jul 2013

Investigations Into The Potential For Hypogene Speleogenesis In The Cumberland Plateau Of Southeast Kentucky, U.S.A., Lee J. Florea

Lee J Florea, PhD, P.G.

This manuscript offers preliminary geochemical evidence that investigates the potential for hypogene speleogenesis in the Cumberland Plateau of southeastern Kentucky, U.S.A. The region was traditionally considered a classic example of epigenic karst, but new insights have uncovered tantalizing observations that suggest alternatives to simple carbonic acid speleogenesis. Such first-order observations have included natural petroleum seeps at the surface and in caves, occasional cave morphologies consistent with action of hypogene fluids, and prolific gypsum within cave passages. To this point, geochemical data from caves and springs verify carbonic acid as the primary dissolutional agent; however, these same analyses cannot rule out …

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Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson May 2013

Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson

Alexandra M Simpson

No abstract provided.

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Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson May 2013

Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson

Alexandra M Simpson

No abstract provided.

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Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton May 2013

Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Associate Professor Edward D Burton

Schwertmannite and jarosite are considered as less soluble ironhydroxy sulfate minerals which are present in highly acidic environments (pH < 3). These minerals release acidity in the long run as they weather by hydrolysis [1]. However, 1M KCl extraction of soil samples (Clarence and Quartz) spiked with those two minerals showed that schwertmannite has some acidity that may be readily available.

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Hydro-Geochemical Coupling In Seawater Inundation Acid Sulfate Soils: Mobilisation Of Arsenic And Hysteresis In Iron And Sulfur Cycling, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan May 2013

Hydro-Geochemical Coupling In Seawater Inundation Acid Sulfate Soils: Mobilisation Of Arsenic And Hysteresis In Iron And Sulfur Cycling, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan

Associate Professor Edward D Burton

A large-scale field trial indicates that tidal seawater inundation of coastal acid sulfate soils (CASS) stimulates iron and sulfate reducing conditions, leading to the generation of internal alkalinity and greatly decreasing soil / groundwater acidity. This remediation technique can be considered highly effective from the relatively narrow perspective of decreasing acidity and raising pH. However, a broader perspective reveals that tidal seawater inundation initiates complex and tightly coupled hydrological and geochemical processes within sediments and porewaters. These processes have had a profound effect on the mobilisation, redistribution and transformation of Fe minerals in the landscape (Johnston et al., 2011a) – …

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