Iron isotope composition of aqueous phases of a lowland environment

2016 ◽  
Vol 13 (1) ◽  
pp. 89 ◽  
Author(s):  
Stephan Schuth ◽  
Tim Mansfeldt
Keyword(s):  
Surface Water ◽  
Isotope Composition ◽  
Isotope Analysis ◽  
Fe Oxide ◽  
Fe Oxides ◽  
Fe Isotopes ◽  
Soil Solutions ◽  
Lowland Area ◽  
Different Depths ◽  
Isotope Analyses

Environmental context Iron (Fe) isotope analysis is a powerful tool to understand the transport of Fe within and from soils to rivers. We determined Fe isotopes and Fe concentrations of soil solutions at different depths and found that the Fe isotope compositions are modified owing to adsorption onto Fe oxides, especially in the subsoil. Hence Fe-rich capillary rising groundwater or seeping Fe-rich surface water are depleted in Fe and potentially other metals in Fe oxide-rich soil horizons. Abstract The mobility of iron (Fe) in soils is strongly affected by redox conditions, which also affect Fe input into groundwater and rivers. Stable Fe isotope analyses allow further investigation of Fe translocation processes within, into and out of soils. Soil solutions taken from a Gleysol in a lowland area (NW Germany) at different depths revealed that Fe concentration and isotope ratios strongly varied with abundance of solid Fe oxides. Low δ56Fe values of –1.7 ‰ and minimum Fe concentrations of ~0.2mgL–1 were recorded in soil solutions of Fe-rich horizons. Soil solutions of a Fe-poor horizon, however, yielded higher δ56Fe values (–0.39 ‰) and Fe concentrations of up to 68mgL–1. The water of an adjacent drainage ditch featured δ56Fe values of –1.1 ‰, in strong contrast to +0.60 ‰ of short-range ordered Fe oxide deposits in the ditch bed. We attribute the coupled low δ56Fe values and Fe concentrations to combined adsorption and atom exchange between dissolved Fe and Fe oxides. Consequently Fe oxide-poor horizons had higher δ56Fe values and dissolved Fe concentrations. Outflow of Fe-rich groundwater and surface water during rainfall into rivers is responsible for high δ56Fe for Fe-oxide precipitates and low riverine δ56Fe values.

scholarly journals Properties, processes and regimes of soil solutions and surface waters

2020 ◽  
Vol 175 ◽  
pp. 12022
Author(s):  
Guriyat Podvolotskaya ◽  
Sergey Belopukhov ◽  
Vitaly Savich ◽  
Andrey Sorokin ◽  
Nikolay Tyutrin
Keyword(s):  
Biological Activity ◽  
Surface Water ◽  
Surface Waters ◽  
Pair Correlation ◽  
Rate Of Change ◽  
Water Soluble ◽  
Soil Solutions ◽  
Different Depths ◽  
Different Soils

Soil solutions and the surface waters are characterized by properties, processes and regimes. Soil solutions of different soils and their surface water have different biological activity and change the activity of dissolved stimulants and inhibitors. The object of the study are soil solutions of the main types of soils obtained in the model experiments with the ratio of soils: water equal to 1:1 and 1: 2, soil solutions and surface water in the flooding of soils with water for 1 week – 3 months. The research method consisted in the assessment of pH, Eh, activity of K, NO3, NH4, Ca, Mg by conventional methods, assessment of concentrations of water-soluble compounds extracted from soils by ionite membranes, in the assessment of biological activity of solutions using biotests. The following is suggested for additional evaluation: the using of cation and anion membranes, determination of interrelation between the properties of waters, equation of pair correlation and multiply regression. The informative value of the gradient of surface water concentrations at different distances from the floor of the reservoir, at different depths of the overwatered soils is shown. The mobility of Ca, Mg, Fe, Mn in soils and the content of their water-soluble forms depends on both pH and Eh, whose influence on the content of water-soluble forms of the considered cations shows the effects of synergy and antagonism. The rate of change in the composition of soil solutions during soil flooding depends on a combination of soil properties, temperature, and duration of flooding. Soil solutions of different soils and their surface waters have differentrates.

scholarly journals Ancient Beringian paleodiets revealed through multiproxy stable isotope analyses

2020 ◽  
Vol 6 (36) ◽  
pp. eabc1968
Author(s):  
Carrin M. Halffman ◽  
Ben A. Potter ◽  
Holly J. McKinney ◽  
Takumi Tsutaya ◽  
Bruce P. Finney ◽  
...  
Keyword(s):  
Native Americans ◽  
Stable Isotope ◽  
Tooth Enamel ◽  
Isotope Composition ◽  
Isotope Analysis ◽  
Nitrogen Isotope ◽  
Essential Amino Acids ◽  
Bone Collagen ◽  
Carbon And Nitrogen ◽  
Isotope Analyses

The earliest Native Americans have often been portrayed as either megafaunal specialists or generalist foragers, but this debate cannot be resolved by studying the faunal record alone. Stable isotope analysis directly reveals the foods consumed by individuals. We present multi-tissue isotope analyses of two Ancient Beringian infants from the Upward Sun River site (USR), Alaska (~11,500 years ago). Models of fetal bone turnover combined with seasonally-sensitive taxa show that the carbon and nitrogen isotope composition of USR infant bone collagen reflects maternal diets over the summer. Using comparative faunal isotope data, we demonstrate that although terrestrial sources dominated maternal diets, salmon was also important, supported by carbon isotope analysis of essential amino acids and bone bioapatite. Tooth enamel samples indicate increased salmon use between spring and summer. Our results do not support either strictly megafaunal specialists or generalized foragers but indicate that Ancient Beringian diets were complex and seasonally structured.

scholarly journals Shale gas plays, Neuquén Basin, Argentina: chemostratigraphy and mud gas carbon isotopes insights

2016 ◽  
Vol 46 (suppl 1) ◽  
pp. 181-196 ◽  
Author(s):  
Héctor Adolfo Ostera ◽  
Roberto García ◽  
Daniel Malizia ◽  
Pablo Kokot ◽  
Leonel Wainstein ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Isotope Composition ◽  
Isotope Analysis ◽  
Geochemical Data ◽  
Complex Processes ◽  
Vaca Muerta ◽  
Neuquen Basin ◽  
Neuquén Basin ◽  
Isotope Analyses ◽  
Mixing Of Gases

ABSTRACT: In order to enhance the knowledge of shale objectives from Vaca Muerta and Los Molles Formations in the Neuquén Basin, Argentina, chemostratigraphic and mud gas carbon isotope analyses were performed in two wells from Agua del Cajón and Salitral oilfields (ADC-1016 and NqSa-1148). Geochemical data show restricted levels in both cases to perforate and produce. In ADC-1016 well, Lower Los Molles Formation looks like the most suitable play to be produced. At El Salitral oilfield (NqSa-1148), the best remarkable Vaca Muerta-Quintuco objectives are associated with authigenic elements, in limited horizons. Enhancement of the Quintuco reservoir by deep circulating fluids (thermobaric reservoir) is suggested. Carbon isotope analysis reveals complex processes that affected the gas composition. Addition of microbial methane, biodegradation of ethane-propane and mixing of gases has been recognized. Isotope reversals and presumed water reforming of hydrocarbons have been registered associated with overpressure for Lower Los Molles Formation in the ADC-1016 well, which is pointed out as the most promising shale play in the area. Vaca Muerta gases at Agua del Cajon ADC- 1016 well are associated with the homonymous source. El Salitral 1148 well shows that primary isotope composition in gases from Vaca Muerta shale play and Quintuco reservoir could be associated with a Lower Los Molles source, an aloctonous charge related with the main structures of the area.

scholarly journals Sunda arc mantle source δ18O value revealed by intracrystal isotope analysis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Frances M. Deegan ◽  
Martin J. Whitehouse ◽  
Valentin R. Troll ◽  
Harri Geiger ◽  
Heejin Jeon ◽  
...  
Keyword(s):  
Mantle Source ◽  
Secondary Ion Mass Spectrometry ◽  
Isotope Composition ◽  
Isotope Analysis ◽  
Sunda Arc ◽  
Mid Ocean Ridge ◽  
Plumbing Systems ◽  
Ocean Ridge ◽  
Secondary Ion ◽  
Magma Plumbing

AbstractMagma plumbing systems underlying subduction zone volcanoes extend from the mantle through the overlying crust and facilitate protracted fractional crystallisation, assimilation, and mixing, which frequently obscures a clear view of mantle source compositions. In order to see through this crustal noise, we present intracrystal Secondary Ion Mass Spectrometry (SIMS) δ18O values in clinopyroxene from Merapi, Kelut, Batur, and Agung volcanoes in the Sunda arc, Indonesia, under which the thickness of the crust decreases from ca. 30 km at Merapi to ≤20 km at Agung. Here we show that mean clinopyroxene δ18O values decrease concomitantly with crustal thickness and that lavas from Agung possess mantle-like He-Sr-Nd-Pb isotope ratios and clinopyroxene mean equilibrium melt δ18O values of 5.7 ‰ (±0.2 1 SD) indistinguishable from the δ18O range for Mid Ocean Ridge Basalt (MORB). The oxygen isotope composition of the mantle underlying the East Sunda Arc is therefore largely unaffected by subduction-driven metasomatism and may thus represent a sediment-poor arc end-member.

Factors affecting 13C/12C ratios of inland halophytes. I. Controlled studies on growth and isotopic composition of Puccinellia nuttalliana

1986 ◽  
Vol 64 (11) ◽  
pp. 2693-2699 ◽  
Author(s):  
Robert D. Guy ◽  
David M. Reid ◽  
H. Roy Krouse
Keyword(s):  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Isotope Analysis ◽  
Research Problem ◽  
Carbon Isotope Composition ◽  
Stable Carbon ◽  
Factors Affecting ◽  
Plant Parts ◽  
High Level ◽  
Puccinellia Nuttalliana

Studies on various factors affecting the growth and stable carbon isotope composition of the graminaceous C3 halophyte Puccinellia nuttalliana (Schultes) Hitch. were initiated as a step towards interpreting δ13C variations in nature. For isotope analysis, combustion at 900 °C resulted in higher CO2 yield than at 550 °C but did not affect δ13C values. Differences in δ13C between leaves of different insertion level were unimportant, but roots were about 1‰ more positive than shoots. Trends in δ13C with salinity were the same in all plant parts. Depressions of growth by NaCl or Na2SO4 were similar, but plants grown in Na2SO4 displayed a greater shift in δ13C relative to controls. Growth rates were affected more by salinity than were previously reported photosynthetic rates. At typical salinities, δ13C changed linearly with salinity. The supply of nitrate to stressed and unstressed plants had no important influence on δ13C. Growth in polyethylene glycol produced δ13C values consistent with a high level of stress. After a salinity step-up, changes in δ13C were complete within 10 days. During winter, data were found to be heavily influenced by unintentional, human-respired CO2 enrichment. This represents a potentially serious research problem in laboratories of temperate climes.

scholarly journals Methane dynamics in different boreal\\newline lake types

2008 ◽  
Vol 5 (4) ◽  
pp. 3457-3496 ◽  
Author(s):  
S. Juutinen ◽  
M. Rantakari ◽  
P. Kortelainen ◽  
J. T. Huttunen ◽  
T. Larmola ◽  
...  
Keyword(s):  
Surface Water ◽  
Shallow Lakes ◽  
Nutrient Concentrations ◽  
Temperature Ranges ◽  
Lake Status ◽  
Different Depths ◽  
Ch4 Concentration ◽  
The Mean ◽  
Annual Flux ◽  
The Eu

Abstract. This study explores the variability in concentrations of dissolved CH4 and annual flux estimates in the pelagic zone in a statistically defined sample of 207 lakes in Finland. The lakes were situated representatively in the boreal zone, where the mean annual air temperature ranges from −2.8 to 5.9°C. We examined how lake CH4 dynamics related to regional lake types assessed according to the EU water framework directive. Ten lake types were defined on the basis of water chemistry, color, and size. Lakes were sampled for dissolved CH4 concentrations four times per year, at four different depths at the deepest point of each lake. We found that CH4 concentrations and fluxes to the atmosphere tended to be high in nutrient rich calcareous lakes, and that the shallow lakes had the greatest surface water concentrations. CH4 content in the hypolimnion was related to oxygen and nutrient concentrations, and lake depth or area. The surface water CH4 concentration was related to the depth or area of lake. Methane close to the bottom can be viewed as proxy of lake status in terms of frequency of anoxia and nutrient levels. Median CH4 release from randomly selected lakes was 45 mmol m−2 a−1. Shallow lakes had the highest median CH4 effluxes, with the clear shallow lake type having the smallest median. Our data, combined with other studies, suggest that lake surface area could be used for an approximation of CH4 release from lakes. Shallow small lakes common in boreal and arctic landscapes may have disproportional significance with respect to CH4 release.

scholarly journals Oxygen isotope composition of zircons from the Talnakh economic intrusion of the Noril’sk province: first data

2019 ◽  
Vol 489 (2) ◽  
pp. 170-173
Author(s):  
I. Yu. Badanina ◽  
E. A. Belousova ◽  
K. N. Malitch ◽  
S. F. Sluzhenikin
Keyword(s):  
Oxygen Isotope ◽  
Isotope Composition ◽  
Oxygen Isotope Composition ◽  
Primary Magma ◽  
Crustal Component ◽  
Layered Series ◽  
Isotope Data ◽  
Oxygen Isotope Data ◽  
First Results ◽  
Isotope Analyses

This study presents the first results of oxygen isotope analyses (18O) collected on zircons from the Talnakh economic intrusion within the Norilsk province. Zircons from gabbro-diorite, gabbroic rocks of the layered series and plagioclase-bearing wehrlite have similar mantle-like mean 18O values (5,39 0,49; 5,64 0,48 and of 5,28 0,34, respectively), which differ from 18O in zircons from sulfide-bearing melanocratic troctolite with a taxitic texture in the lower part of the intrusion (mean 18O = 6,50 0,98). These new oxygen isotope data support (i) the mantle-derived origin of the primary magma(s), parental to the Talnakh intrusion, and (ii) possible involvement of a crustal component during the formation of sulfide-bearing taxitic-textured rocks.

scholarly journals Iron Oxide Contents in Relation to the Colour of Asnawa Soils

2017 ◽  
Vol 1 (1) ◽  
pp. 89-94
Author(s):  
Sherwan Kafoor
Keyword(s):  
Iron Oxide ◽  
Soil Properties ◽  
Iron Oxides ◽  
Soil Samples ◽  
Visual Methods ◽  
Colour Intensity ◽  
Fe Oxide ◽  
Fe Oxides ◽  
New Formula

Asnawa soils contain high amounts of iron oxides. These minerals apply much influence on different soil properties, of which the most observable is colour. The objective of this study was to conclude if colour of soils measured by visual methods can be parameterized to quantify soil Fe oxides. The examined area was divided to three zones (zone A, zone B and zone C) according to their colour intensity. Forty soil samples were examined for their colour and iron oxide contents. Their colour were ranged between 5YR (H) 2.5 (V/C) to 5YR (H) 5/8 (V/C). The average values of free Fe oxide in the soils of the three zones were 52.1%, 36.8% and 15.9% respectively. A new formula was derived to measure colour intensity. A highly significant correlation was found between colour intensity and concentrations of Fe oxides in the examined soils.

Sign in / Sign up

Export Citation Format

Share Document