Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience
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New insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece

New insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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We report on integrated geomorphological, mineralogical, geochemical and biological investigations of the hydrothermal vent field located on the floor of the density-stratified acidic (pH ~ 5) crater of the Kolumbo shallow-submarine arc-volcano, near Santorini. Kolumbo features rare geodynamic setting at convergent boundaries, where arc-volcanism and seafloor hydrothermal activity are occurring in thinned continental crust. Special focus is given to unique enrichments of polymetallic spires in Sb and Tl (±Hg, As, Au, Ag, Zn) indicating a new hybrid seafloor analogue of epithermal-to-volcanic-hosted-massive-sulphide deposits. Iron microbial-mat analyses reveal dominating ferrihydrite-type phases, and high-proportion of microbial sequences akin to "Nitrosopumilus maritimus", a mesophilic Thaumarchaeota strain capable of chemoautotrophic growth on hydrothermal ammonia and CO2. Our findings highlight that acidic shallow-submarine hydrothermal vents nourish marine ecosystems in which nitrifying Archaea are important and suggest ferrihydrite-type Fe3+-(hydrated)-oxyhydroxides in associated low-temperature iron mats are formed by anaerobic Fe2+-oxidation, dependent on microbially produced nitrate.

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Coherently aligned nanoparticles within a biogenic single crystal: A biological prestressing strategy

Coherently aligned nanoparticles within a biogenic single crystal: A biological prestressing strategy | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Eocene greenhouse climate revealed by coupled clumped isotope-Mg/Ca thermometry

Eocene greenhouse climate revealed by coupled clumped isotope-Mg/Ca thermometry | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

Reconstructing the degree of warming during geological periods of elevated CO2 provides a way of testing our understanding of the Earth system and the accuracy of climate models. We present accurate estimates of tropical sea-surface temperatures (SST) and seawater chemistry during the Eocene (56–34 Ma before present, CO2 >560 ppm). This latter dataset enables us to reinterpret a large amount of existing proxy data. We find that tropical SST are characterized by a modest warming in response to CO2. Coupling these data to a conservative estimate of high-latitude warming demonstrates that most climate simulations do not capture the degree of Eocene polar amplification. Past greenhouse periods with elevated atmospheric CO2 were characterized by globally warmer sea-surface temperatures (SST). However, the extent to which the high latitudes warmed to a greater degree than the tropics (polar amplification) remains poorly constrained, in particular because there are only a few temperature reconstructions from the tropics. Consequently, the relationship between increased CO2, the degree of tropical warming, and the resulting latitudinal SST gradient is not well known. Here, we present coupled clumped isotope (Δ47)-Mg/Ca measurements of foraminifera from a set of globally distributed sites in the tropics and midlatitudes. Δ47 is insensitive to seawater chemistry and therefore provides a robust constraint on tropical SST. Crucially, coupling these data with Mg/Ca measurements allows the precise reconstruction of Mg/Casw throughout the Eocene, enabling the reinterpretation of all planktonic foraminifera Mg/Ca data. The combined dataset constrains the range in Eocene tropical SST to 30–36 °C (from sites in all basins). We compare these accurate tropical SST to deep-ocean temperatures, serving as a minimum constraint on high-latitude SST. This results in a robust conservative reconstruction of the early Eocene latitudinal gradient, which was reduced by at least 32 ± 10% compared with present day, demonstrating greater polar amplification than captured by most climate models.

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Volcanic crystals as time capsules of eruption history

Volcanic crystals as time capsules of eruption history | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Comparison between Cr zoning and major element zoning on a clinopyroxene antecryst from the 1974 eccentric eruption at Mt. Etna.
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Sequestration of Antimony on Calcite Observed by Time-Resolved Nanoscale Imaging

Sequestration of Antimony on Calcite Observed by Time-Resolved Nanoscale Imaging | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Sb(V) forms a precipitate, whereas Sb(III) needs to be oxidized to Sb(V) before being incorporated in the new phase. Scanning-electron microscopy and Raman spectroscopy allowed identification of the precipitates as two different calcium–antimony phases (Ca2Sb2O7). This coupled dissolution–precipitation process that occurs in a boundary layer at the calcite surface can sequester Sb as a solid phase on calcite.
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Pb2+-Calcite Interactions under Far-from-Equilibrium Conditions: Formation of Micro Pyramids and Pseudomorphic Growth of Cerussite

Pb2+-Calcite Interactions under Far-from-Equilibrium Conditions: Formation of Micro Pyramids and Pseudomorphic Growth of Cerussite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Nanoscale geochemical and geomechanical characterization of organic matter in shale

Nanoscale geochemical and geomechanical characterization of organic matter in shale | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors demonstrate the first application of atomic force microscopy-based infrared spectroscopy (AFM-IR) to measure the chemical and mechanical heterogeneity of OM in shale at the nanoscale, orders of magnitude finer than achievable by traditional chemical imaging tools such as infrared microscopy.
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Rare earth element geochemistry characteristics of seawater and porewater from deep sea in western Pacific

Rare earth element geochemistry characteristics of seawater and porewater from deep sea in western Pacific | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

Deep-sea sediments contain high concentrations of rare earth element (REE) which have been regarded as a huge potential resource. Understanding the marine REE cycle is important to reveal the mechanism of REE enrichment.

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School on Novel Experimental Methodologies for Synchrotron Radiation. Andreas Karydas, Director

Interview to Andreas-Germanos Karydas (International Atomic Energy Agency) one of the directors of the "School on Novel Experimental Methodologies fo
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Lecture: Arsenic contamination of groundwaters

Lecture given by Prof. Dr. Lenny H.E. Winkel (ETH Zurich, Switzerland), 2017 EAG Distinguished Lecturer, Institute of Geography and Earth Sciences, Eötvö
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DESY News: Clay mineral waters Earth's mantle from the inside - Deutsches Elektronen-Synchrotron DESY

DESY News: Clay mineral waters Earth's mantle from the inside - Deutsches Elektronen-Synchrotron DESY | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Role of critical metals in the future markets of clean energy technologies

Role of critical metals in the future markets of clean energy technologies | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Silver most critical element causing market bottlenecks. • Further critical elements: In, Te, PGM, REE. • Need for developing substitutions for the critical metals. • Need for new renewable energy technologies not dependent on critical elements.
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Speleothem record of climatic changes in the northern Aegean region (Greece) from the Bronze Age to the collapse of the Roman Empire

Speleothem record of climatic changes in the northern Aegean region (Greece) from the Bronze Age to the collapse of the Roman Empire | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Interconnections of human occupation and climate shifts from the Bronze Age until the demise of the Roman Empire are investigated, based on the first high resolution isotope record of a stalagmite from northern Aegean region (Skala Marion Cave, Thassos Island, Greece).
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Peridotite weathering is the missing ingredient of Earth’s continental crust composition

Peridotite weathering is the missing ingredient of Earth’s continental crust composition | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors show that chemical weathering of Ni- and Cr-rich, undifferentiated ultramafic rock equivalent to ~1.3 wt% of today’s continental crust compensates for low Ni and Cr in formation models of the continental crust.
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New paper by colleagues from @UniBonn: ultra-high pressure and ultra-reduced minerals in ophiolites may form by lightning strikes

New paper by colleagues from @UniBonn: ultra-high pressure and ultra-reduced minerals in ophiolites may form by lightning strikes | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Geochemical Perspectives Letters is a new journal of the European Association of Geochemistry.
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Cooperative and Inhibited Adsorption of d-Ribose onto Brucite [Mg(OH)2] with Divalent Cations

Cooperative and Inhibited Adsorption of d-Ribose onto Brucite [Mg(OH)2] with Divalent Cations | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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World’s oldest known oxygen oasis discovered | University Tübingen

World’s oldest known oxygen oasis discovered | University Tübingen | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Rock Found in Egypt is Unlike Anything Ever Seen in Our Solar System

Scientists at the University of Johannesburg say the Hypatia stone found in Egypt in 1996 contains materials never seen before in our solar system and ma
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Palaeodeserts - Climate Change and Hominin Evolution in the Arabian Desert

Palaeodeserts - Climate Change and Hominin Evolution in the Arabian Desert | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Opposite effects of dissolved oxygen on the removal of As(III) and As(V) by carbonate structural Fe(II)

Opposite effects of dissolved oxygen on the removal of As(III) and As(V) by carbonate structural Fe(II) | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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X-ray diffraction and infrared spectroscopic analyses indicated that crystalline parasymplesite (Fe(II)3(AsO4)2·8H2O) was formed when As(V) was removed under anoxic conditions, while an amorphous Fe-As-containing precipitate was formed when As(III) was removed under oxic conditions.
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Magnetotactic bacteria as a new model for P sequestration in the ferruginous Lake Pavin

Magnetotactic bacteria as a new model for P sequestration in the ferruginous Lake Pavin | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Magnetotactic bacteria (MTB) are a phylogenetically and metabolically diverse group of bacteria biomineralising intracellular magnetites and/or greigites and moving along magnetic field lines.
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PANalytical's timeline. More than a century of experience.

PANalytical has become one of the top two suppliers for analytical X-ray instrumentation, applications and services in the world. With its own X-ray tub
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An essential role for continental rifts and lithosphere in the deep carbon cycle

An essential role for continental rifts and lithosphere in the deep carbon cycle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
The continental lithosphere is a vast store for carbon. The carbon has been added and reactivated by episodic freezing and re-melting throughout geological history. Carbon remobilization can lead to significant variations in CO2 outgassing and release in the form of magmas from the continental lithosphere over geological timescales.
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Trace Element Compositions and Defect Structures of High-Purity Quartz from the Southern Ural Region, Russia

Trace Element Compositions and Defect Structures of High-Purity Quartz from the Southern Ural Region, Russia | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

The analytical combination of cathodoluminescence (CL) microscopy and spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and trace-element analysis by inductively coupled plasma mass spectrometry (ICP-MS) revealed that almost all investigated quartz samples showed very low concentrations of trace elements (cumulative concentrations of <50 ppm with <30 ppm Al and <10 ppm Ti) and low abundances of paramagnetic defects, defining them economically as “high-purity” quartz (HPQ) suitable for high-tech applications.

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When water meets iron at Earth's core–mantle boundary

When water meets iron at Earth's core–mantle boundary | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

Abstract.Hydrous minerals in subducted crust can transport large amounts of water into Earth's deep mantle.

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When water meets iron at the core–mantle boundary, they react to form an interlayer with an extremely oxygen-rich form of iron, iron dioxide, together with iron hydride.
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