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Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience
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Birnessite (δ-MnO2) Mediated Degradation of Organoarsenic Feed Additive p-Arsanilic Acid

Birnessite (δ-MnO2) Mediated Degradation of Organoarsenic Feed Additive p-Arsanilic Acid | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

A common soil metal oxide, birnessite (δ-MnO2), was found to mediate its degradation with fast rates under acidic conditions. Experimental results indicate that adsorption and degradation of p-ASA on the surface of δ-MnO2 were highly pH dependent, and the overall kinetics for p-ASA degradation and formation of precursor complex could be described by a retarded first-order rate model.

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Agromining: Farming for Metals in the Future?

Agromining: Farming for Metals in the Future? | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Phytomining technology employs hyperaccumulator plants to take up metal in harvestable plant biomass. Harvesting, drying and incineration of the biomass generates a high-grade bio-ore. We propose that “agromining” (a variant of phytomining) could provide local communities with an alternative type of agriculture on degraded lands; farming not for food crops, but for metals such as nickel (Ni).

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Flash glass: Lightning inside volcanic ash plumes create glassy spherules

Flash glass: Lightning inside volcanic ash plumes create glassy spherules | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Surface tension shapes lightning-melted ash into balls
Ath Godelitsas's insight:

A team sifting through ash samples collected downwind after eruptions at Alaska’s Mount Redoubt in 2009 and Iceland’s Eyjafjallajökull in 2010 found such spherules, the first attributed to volcanic eruptions. (Similar spherules can be formed in a variety of extreme circumstances, from bomb explosions to extraterrestrial impacts). See also: http://geology.gsapubs.org/content/early/2015/02/26/G36255.1

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The “Picasso of low-temperature geochemistry” has died: Robert Berner, 1935-2015

The “Picasso of low-temperature geochemistry” has died: Robert Berner, 1935-2015 | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
The “Picasso of low-temperature geochemistry” has died
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Effect of Fulvic Acid Surface Coatings on Plutonium Sorption and Desorption Kinetics on Goethite

Effect of Fulvic Acid Surface Coatings on Plutonium Sorption and Desorption Kinetics on Goethite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors investigated the effects of FA on Pu(IV) sorption/desorption onto goethite in two scenarios: when FA was (1) initially present in solution or (2) found as organic coatings on the mineral surface. A low pH was used to maximize FA coatings on goethite.

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Spectroscopic Evidence of Uranium Immobilization in Acidic Wetlands

Spectroscopic Evidence of Uranium Immobilization in Acidic Wetlands | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The objective of this work was to study molecular mechanisms responsible for high U retention by Savannah River Site (SRS) wetland sediments under varying redox and acidic (pH = 2.6–5.8) conditions using U L3-edge X-ray absorption spectroscopy.

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Metal Stable Isotope Signatures as Tracers in Environmental Geochemistry

Metal Stable Isotope Signatures as Tracers in Environmental Geochemistry | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers.
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Muonium in Stishovite: Possible Existence of Neutral Atomic Hydrogen in the Earth's Deep Mantle

Muonium in Stishovite: Possible Existence of Neutral Atomic Hydrogen in the Earth's Deep Mantle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors present Muon Spin Rotation experiments on SiO2 stishovite, which is an archetypal high-pressure mineral. Positive muon (which can be considered as a light isotope of proton) implanted in stishovite was found to capture electron to form muonium (corresponding to neutral hydrogen).

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X-ray machine opens new frontier

X-ray machine opens new frontier | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Researchers in Palo Alto in the US state of California are working with the most powerful X-ray laser in the world.
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Bringing high tech down to earth

Bringing high tech down to earth | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

Understanding legacy phosphorus (P) build-up and draw-down from long-term fertilization is essential for effective P management. Using replicated plots from Saskatchewan, Canada, with P fertilization from 1967 to 1995 followed by either P fertilization or P cessation (1995–2010), soil P was characterized in surface and subsurface layers using sequential fractionation, P K-edge X-ray absorption near-edge structure (XANES) and solution 31P nuclear magnetic resonance (P NMR) spectroscopy.

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Expeditionen in die Sahara – dem Klimawandel auf der Spur

http://www.gfe.uni-koeln.de/?p=1374 Aufzeichnung des Gesellschaft für Erdkunde Vortragsabend vom 20.11.2014. Dr. Stefan Kröpelin, Universität zu Köln Bis Mit...
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Key trace minerals greatly strengthen teeth

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The authors showed—using atom probe tomography, x-ray absorption spectroscopy, and correlative techniques—that in unpigmented rodent enamel, Mg2+ is predominantly present at grain boundaries as an intergranular phase of Mg-substituted amorphous calcium phosphate (Mg-ACP).

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Generation of porphyry copper deposits by gas-brine reaction in volcanic arcs

Generation of porphyry copper deposits by gas-brine reaction in volcanic arcs | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Most of the world/'s copper comes from porphyry ore deposits. Laboratory experiments suggest that these deposits form in a two-stage process over thousands of years, from the interaction between sulphur-rich gases and metal-rich brines.
Ath Godelitsas's insight:

The authors draw on observations of modern subduction zone volcanism to propose an alternative process for porphyry copper formation. They suggest that copper enrichment initially involves metalliferous, magmatic hyper-saline liquids, or brines, that exsolve from large, magmatic intrusions assembled in the shallow crust over tens to hundreds of thousands of years. In a subsequent step, sulphide ore precipitation is triggered by the interaction of the accumulated brines with sulphur-rich gases, liberated in short-lived bursts from the underlying mafic magmas.

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Mechanisms of Sb(III) Oxidation by Pyrite-Induced Hydroxyl Radicals and Hydrogen Peroxide

Mechanisms of Sb(III) Oxidation by Pyrite-Induced Hydroxyl Radicals and Hydrogen Peroxide | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Sb(III) can be oxidized to Sb(V) in the presence of pyrite, which will greatly influence the fate of Sb(III) in the environment.

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How does your crystal grow? A commentary on Burton, Cabrera and Frank (1951)

How does your crystal grow? A commentary on Burton, Cabrera and Frank (1951) | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

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Distribution and partitioning of major and trace elements in pyrite-bearing sediments of a Mediterranean coastal lagoon

Distribution and partitioning of major and trace elements in pyrite-bearing sediments of a Mediterranean coastal lagoon | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The formation of iron sulphide minerals exerts significant control on the behaviour of trace elements in sediments. In this study, three short sediment cores, retrieved from the remote Antinioti lagoon (N. Kerkyra Island, NW Greece), are investigated concerning the solid phase composition, distribution, and partitioning of major (Al, Fe) and trace elements (Cd, Cu, Mn, Pb, and Zn).

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NASA | Satellite Tracks Saharan Dust to Amazon in 3-D

For more information: http://www.nasa.gov/content/goddard/nasa-satellite-reveals-how-much-saharan-dust-feeds-amazon-s-plants For the first time, a NASA satel...
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Atom Exchange between Aqueous Fe(II) and Structural Fe in Clay Minerals

Atom Exchange between Aqueous Fe(II) and Structural Fe in Clay Minerals | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors used an enriched isotope tracer approach to simultaneously trace Fe atom movement from the aqueous phase to the solid (57Fe) and from the solid into the aqueous phase (56Fe).

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Aggregation, Dissolution, and Transformation of Copper Nanoparticles in Natural Waters

Aggregation, Dissolution, and Transformation of Copper Nanoparticles in Natural Waters | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Nano-Cu and Cu(OH)2 aggregated rapidly to >103 nm while the aggregate size of nano-CuO averaged between 250 and 400 nm. Aggregate size for both nano-Cu and nano-CuO showed a positive correlation with ionic strength with a few exceptions. Aggregate size did not correlate well with sedimentation rate, suggesting sedimentation was influenced by other factors.

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Coupled Redox Transformation of Chromate and Arsenite on Ferrihydrite

Coupled Redox Transformation of Chromate and Arsenite on Ferrihydrite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS) were used to determine the composition of the adsorbed layer on Fh during and after exposure to solution-phase Cr(VI) and As(III).

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Earth's Phosphides in Levant and insights into the source of Archean prebiotic phosphorus

Earth's Phosphides in Levant and insights into the source of Archean prebiotic phosphorus | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Seven minerals from the ternary Fe-Ni-P system have been identified with five of them, NiP2, Ni5P4, Ni2P, FeP and FeP2, previously unknown in nature.

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▶ Drone aerial footage of the Canadian Light Source synchrotron

This footage was taken January 2015 at sunrise over the Canadian Light Source synchrotron in beautiful Saskatoon, Saskatchewan.
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2015 ADRIAN SMITH LECTURE | Earth and Environmental Sciences

Join the Dept. of Earth and Environmental Science Mar 11 for the 2015 Adrian Smith Lecture in geochemistry. http://t.co/HhkjRizGOA
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Modulation of oxygen production in Archaean oceans by episodes of Fe(II) toxicity

Modulation of oxygen production in Archaean oceans by episodes of Fe(II) toxicity | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Earth/'s initial oxygenation took several hundred million years. Experiments and geochemical modelling suggest that early photosynthetic marine microbes may have been repeatedly stressed by Fe(II) delivered by submarine volcanism.
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The authors test the hypothesis that the upwelling of Fe(II)-rich, anoxic water into the photic zone during the late Archaean subjected oxygenic phototrophic bacteria to Fe(II) toxicity. In laboratory experiments, they found that supplying Fe(II) to the anoxic growth medium housing a common species of planktonic cyanobacteria decreased both the efficiency of oxygenic photosynthesis and their growth rates.

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Sulphur geodynamic cycle

Sulphur geodynamic cycle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry.
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