Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience
7.5K views | +2 today
Follow
Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience
Your new post is loading...
Your new post is loading...
Scooped by Ath Godelitsas
Scoop.it!

Surface alteration mechanism and topochemistry of iron in tremolite asbestos

Surface alteration mechanism and topochemistry of iron in tremolite asbestos | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

With the aim to shed a light on this mechanism, two tremolite samples, one from Italy (Castelluccio) and one from USA (Maryland), immersed in a buffer solution (pH 7.4) with H2O2 were characterized by a multi-technique approach.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

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
Ath Godelitsas's insight:

A particular focus lies on a discussion of processes (redox transformations, complexation, sorption, precipitation, dissolution, evaporation, diffusion, biological cycling) which are able to induce metal stable isotope fractionation in environmental systems.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Transient liquid water and water activity at Gale crater on Mars

Transient liquid water and water activity at Gale crater on Mars | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Liquid water on equatorial Mars is inconsistent with large-scale climatic conditions. Humidity and temperature measurements by the Curiosity rover support the formation of subsurface liquid brines by hydration of perchlorates during the night.
Ath Godelitsas's insight:

Perchlorates are widespread on the surface of Mars and it is expected that liquid brines are abundant beyond equatorial regions where atmospheric humidity is higher and temperatures are lower.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

NASA's Curiosity rover finds astronauts could farm water on Mars - space - 13 April 2015 - New Scientist

NASA's Curiosity rover finds astronauts could farm water on Mars - space - 13 April 2015 - New Scientist | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
NASA's Curiosity rover has found evidence of a liquid water cycle on Mars, and harnessing this could one day make drinking water for astronauts
more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Impacts of Aqueous Mn(II) on the Sorption of Zn(II) by Hexagonal Birnessite

Impacts of Aqueous Mn(II) on the Sorption of Zn(II) by Hexagonal Birnessite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

XAS results show that Zn(II) adsorbs as tetrahedral and octahedral triple-corner-sharing complexes at layer vacancy sites when reacted with birnessite in the absence of Mn(II). Addition of aqueous Mn(II) causes no discernible change in Zn(II) surface speciation at pH 6.5, but triggers conversion of adsorbed Zn(II) into spinel Zn(II)1–xMn(II)xMn(III)2O4 precipitates at pH 7.5. This conversion is driven by electron transfer from adsorbed Mn(II) to structural Mn(IV) generating Mn(III) surface species that coprecipitate with Zn(II) and Mn(II).

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Liquid–Liquid Phase Separation in Aerosol Particles: Imaging at the Nanometer Scale

Liquid–Liquid Phase Separation in Aerosol Particles: Imaging at the Nanometer Scale | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors report results of chemical imaging experiments using environmental scanning electron microscopy (ESEM) and scanning transmission X-ray microscopy (STXM) to investigate the LLPS of micrometer-sized particles undergoing a full hydration-dehydration cycle.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Hydrothermal influence on nearshore sediments of Kos Island, Aegean Sea, Greece

Hydrothermal influence on nearshore sediments of Kos Island, Aegean Sea, Greece | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The Kos-Nisyros volcanic centre is a long-active, Plio-Pleistocene magmatic system in the subduction zone along the easternmost edge of the active Hellenic volcanic arc in the Aegean Sea. Although today there are signs of relative quiescence in volcanic activity, active onshore fumaroles and shallow-sea hydrothermal vents persist on, amongst others, the island of Kos. The present study explores the large-scale imprint of hydrothermally sourced heavy metals and nutrients on the island’s coastal marine environment, based on geochemical data collected in September 2007 from hydrothermal waters and surficial nearshore sediments (<10 m water depth) at several vents in the Bros Thermi and Kephalos Bay hydrothermal fields.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae

Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors demonstrate the combination of fluorescence and ptychography for imaging frozen-hydrated specimens at cryogenic temperatures, with excellent structural and chemical preservation.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Exploring the potential of phyllosilicate minerals as potassium fertilizers using sodium tetraphenylboron and intensive cropping with perennial ryegrass

Exploring the potential of phyllosilicate minerals as potassium fertilizers using sodium tetraphenylboron and intensive cropping with perennial ryegrass | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Biotite and vermiculite can be directly applied as a promising and sustainable alternative to the use of classical K fertilizers, illite can be utilized in combination with soluble K fertilizers, whereas muscovite, phlogopite and smectite may not be suitable for plant growth.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Redox cycling of Fe(II) and Fe(III) in magnetite by Fe-metabolizing bacteria

Ath Godelitsas's insight:

The authors show through magnetic and spectroscopic measurements that the phototrophic Fe(II)-oxidizing bacterium Rhodopseudomonas palustris TIE-1 oxidizes magnetite (Fe3O4) nanoparticles using light energy.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Experimental diagenesis of organo-mineral structures formed by microaerophilic Fe(II)-oxidizing bacteria

Experimental diagenesis of organo-mineral structures formed by microaerophilic Fe(II)-oxidizing bacteria | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Twisted stalks are organo-mineral structures produced by some microaerophilic Fe(II)-oxidizing bacteria at O2 concentrations as low as 3 μM.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Can clays ensure nuclear waste repositories?

Can clays ensure nuclear waste repositories? | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors have analyzed -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption

Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

The processes that create economic-grade accumulations of metals above magma chambers are unclear. High-temperature laboratory experiments show that rapid reactions between magmatic gases and Earth's crust can trigger efficient metal deposition.

Ath Godelitsas's insight:

The authors use high-temperature laboratory experiments to show that a very rapid chemisorption reaction occurs between sulphur dioxide gas, a principal component of magmatic gas mixtures, and calcic feldspar, an abundant mineral in the arc crust. The chemisorption reaction generates the mineral anhydrite and hydrogen sulphide gas, and triggers deposition of metal sulphides.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Urban soil geochemistry in Athens Greece

Elsevier Audioslides presentation on the paper "Urban soil geochemistry in Athens, Greece: The importance of local geology in controlling the distribution of ...
more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

International Natural Zeolite Association

International Natural Zeolite Association | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
International Natural Zeolite Association
Ath Godelitsas's insight:
International Natural Zeolite Association
more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Dry (Mg,Fe)SiO3 perovskite in the Earth's lower mantle

Dry (Mg,Fe)SiO3 perovskite in the Earth's lower mantle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Combined synthesis experiments and first-principles calculations show that MgSiO3-perovskite with minor Al or Fe does not incorporate significant OH under lower mantle conditions.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Welcome to the Deep Carbon Observatory

A quick overview of the Deep Carbon Observatory, including a survey of the resources available on the DCO community and data portals (https://deepcarbon.net)

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Chabazite: Stable Cation-Exchanger in Hyper Alkaline Concrete Pore Water

Chabazite: Stable Cation-Exchanger in Hyper Alkaline Concrete Pore Water | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Chabazite is typically synthesized in 1 M KOH solutions but also crystallizes in simulated young cement pore water, a pH 13 aqueous solution mainly containing K+ and Na+ cations. Its formation and stability in this medium was evaluated as a function of temperature (60 and 85 °C) over a timeframe of more than 2 years and was also asessed from a mechanistic point of view. Chabazite demonstrates excellent cation-exchange properties in simulated young cement pore water.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

World's largest asteroid impact site could be in Australia

World's largest asteroid impact site could be in Australia | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Not long ago, asteroid impacts weren't considered as a significant factor in the evolution of Earth.
more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Lunar central peak mineralogy and iron content using the Kaguya Multiband Imager

Lunar central peak mineralogy and iron content using the Kaguya Multiband Imager | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
RT @jgrplanets: Lunar central peak mineralogy and iron content using the Kaguya Multiband Imager http://t.co/iDBcFdANXU
more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

‘Iron rain’ fell on early Earth

‘Iron rain’ fell on early Earth | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
What caused Earth’s metal-rich mantle and crust? Iron rain may be the answer.
more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

C-DEBI (Center for Dark Energy Biosphere Investigations)

C-DEBI (Center for Dark Energy Biosphere Investigations) is a National Science Foundation Science and Technology Center led by Drs. Jan Amend (USC).

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Slab stagnation in the shallow lower mantle linked to an increase in mantle viscosity

Slab stagnation in the shallow lower mantle linked to an increase in mantle viscosity | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The main phases of the lower mantle, bridgmanite and ferropericlase, do not show any structural transitions at these depths, so only moderate and smooth viscosity variations are expected with depthto at least ~2,500 km. The reason for slab stagnation, which may also lead to the formation of chemically distinct reservoirs in Earth’s deep mantle, is therefore unclear. The authors have used synchrotron radial X-ray diffraction to measure in situ the deformation behaviour of ferropericlase at pressures of up to 96 GPa.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Tetrahedrally coordinated carbonates in Earth’s lower mantle

Tetrahedrally coordinated carbonates in Earth’s lower mantle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Above 80 GPa, in situ synchrotron infrared experiments show the unequivocal spectroscopic signature of the high-pressure phase of (Mg,Fe)CO3. Using ab-initio calculations, the authors assign the new infrared signature to C–O bands associated with tetrahedrally coordinated carbon with asymmetric C–O bonds. Tetrahedrally coordinated carbonates are expected to exhibit substantially different reactivity than low-pressure threefold coordinated carbonates, as well as different chemical properties in the liquid state.

more...
No comment yet.
Scooped by Ath Godelitsas
Scoop.it!

Goldschmidt 2015 - YouTube

Goldschmidt2015 will be the 25th Goldschmidt conference, and to celebrate it we are returning to beautiful Prague, the same venue as Goldschmidt2011.
more...
No comment yet.