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Heterostructured Calcium Carbonate Microspheres with Calcite Equatorial Loops and Vaterite Spherical Cores

Heterostructured Calcium Carbonate Microspheres with Calcite Equatorial Loops and Vaterite Spherical Cores | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

It takes two different functional additives to produce the title structures. The proposed mechanism based on the nonclassical particle-mediated crystallization of calcium carbonate demonstrates the individual and cooperative effects of the polymer poly(sodium 4-styrenesulfonate) and small folic acid molecules on the formation of heterostructures at different reaction stages.

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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
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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

Ath Godelitsas's insight:

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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Volcano-tectonic evolution of the polygenetic Kolumbo submarine volcano/Santorini (Aegean Sea)

Volcano-tectonic evolution of the polygenetic Kolumbo submarine volcano/Santorini (Aegean Sea) | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Four to five vertically stacked circular and cone-shaped units consisting mainly of volcaniclastics build the Kolumbo underwater volcano which experienced its first eruption > 70 ka ago and its last explosive eruption 1650 AD, 7 km NE of Santorini volcano (southern Aegean Sea).

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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
Ath Godelitsas's insight:

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
Ath Godelitsas's insight:

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
Ath Godelitsas's insight:

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
Ath Godelitsas's insight:

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.
Ath Godelitsas's insight:

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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New light source shines at Brookhaven National Laboratory

New light source shines at Brookhaven National Laboratory | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Energy Secretary Moniz dedicates new facility
Ath Godelitsas's insight:

Prospects were looking bright today at the Department of Energy’s (DOE’s) Brookhaven National Laboratory in Upton, New York. Secretary of Energy Ernest Moniz dedicated the lab’s new $912 million National Synchrotron Light Source II (NSLS-II), which will be the brightest synchrotron light source in the United States and—within a certain energy range—the world.

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Study Finds Deep Ocean is Source of Dissolved Iron in Central Pacific : Woods Hole Oceanographic Institution

Study Finds Deep Ocean is Source of Dissolved Iron in Central Pacific : Woods Hole Oceanographic Institution | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
A new study led by scientists at the Woods Hole Oceanographic Institution (WHOI) points to the deep ocean as a major source of dissolved iron in the central Pacific Ocean. This finding highlights the vital role ocean mixing plays in determining whether deep sources of iron reach the surface-dwelling life that need it to survive.
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