Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience
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What Kind of Iron is in the Southern Ocean?

What Kind of Iron is in the Southern Ocean? | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

The samples were analyzed using scanning transmission X-ray microscopy (STXM). STXM combines microscopy with spectroscopy, allowing the researchers to distinguish a number of different iron species and compounds in particles of different shapes and sizes.

 

See also: http://www.sciencemag.org/content/338/6111/1199.abstract

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The most common forms of iron are Fe(II) and Fe(III). There’s plenty of highly oxidizing Fe(III) in sea water but it’s insoluble, and life has developed special mechanisms to absorb it. Fe (II) is readily soluble and easily taken up by plants and bacteria but sparse in sea water, except when freshly dumped there by continental run-off or wind-blown dust. Most dust is in the form of magnetite, however, a compound of both Fe(II) and Fe(III). The researchers tested their particles for pure Fe(II), pure Fe(III), mixtures of these two with other materials (including aluminum), and magnetite. They found that the iron solubulity of their samples ranged over three orders of magnitude. Then they compared the predominant kinds of iron in a region with the pattern of summertime chlorophyll, that is, phytoplankton growth.

 

See also: http://www.sciencemag.org/content/338/6111/1199.abstract

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Gold and uranium concentration in the Carbon Leader Reef, Witwatersrand Supergroup, South Africa

Gold and uranium concentration in the Carbon Leader Reef, Witwatersrand Supergroup, South Africa | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
High-resolution scanning- and transmission-electron microscopy of pyrobitumen-hosted uraninite reveal that uraninite grains are highly porous aggregates of uniformly sized nanocrystals, and that many of their pores are filled by native gold.
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Antimony and Arsenic Behavior during Fe(II)-Induced Transformation of Jarosite

Antimony and Arsenic Behavior during Fe(II)-Induced Transformation of Jarosite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Jarosite can be an important scavenger for arsenic (As) and antimony (Sb) in acid mine drainage (AMD) and acid sulfate soil (ASS) environments.
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Adsorption of Selenium and Strontium on Goethite

Adsorption of Selenium and Strontium on Goethite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Goethite, as one of the most thermodynamically stable and commonly occurring natural iron oxy-hydroxides, promisingly retains these elements.
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Chiral acidic amino acids induce chiral hierarchical structure in calcium carbonate

Chiral acidic amino acids induce chiral hierarchical structure in calcium carbonate | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Chiral structures are formed in numerous processes including biomineralization of calcium carbonate.
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Chiral, vaterite toroidal suprastructure having a ‘right-handed’ (counterclockwise) spiralling morphology is induced by L-enantiomers of Asp and Glu, whereas ‘left-handed’ (clockwise) morphology is induced by D-enantiomers, and sequentially switching between amino-acid enantiomers causes a switch in chirality
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Seawater cycled throughout Earth/'s mantle in partially serpentinized lithosphere

Seawater cycled throughout Earth/'s mantle in partially serpentinized lithosphere | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors show that water and halogen enrichment is unexpectedly associated with trace element signatures characteristic of dehydrated oceanic crust, and that the most incompatible halogens have relatively uniform abundance ratios that are different from primitive mantle values.
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Two-stage opening of the Dover Strait and the origin of island Britain

Two-stage opening of the Dover Strait and the origin of island Britain | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors combine analysis of a regional high-resolution bathymetric grid of the central and eastern English Channel shelf that includes new multibeam sonar data from the Dover Strait, with new high-resolution seismic-reflection data to investigate how the Strait was formed.
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Lecture: Speleothems as paleoclimate indicators

Lecture given by Prof. Miryam Bar-Matthews at the Institute for Geological and Geochemical Research, Hungarian Academy of Sciences, as part of the EA
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Nanoscience in the Earth and Environmental Sciences Workshop @goldschmidt2017

Nanoscience in the Earth and Environmental Sciences Workshop @goldschmidt2017 | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
A Pre-Meeting Workshop In Association with the Goldschmidt 2017 Conference Dates: August 12-13, 2017 Conveners: David Mogk, Montana State University (USA); Michael Hochella, Virginia Tech/PNNL (USA); Nancy Healy
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Mineralogists identify a group of minerals that owe their existence to human activity

Mineralogists identify a group of minerals that owe their existence to human activity | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
No other species in Earth's history has left a mark on the planet as profound and lasting as Homo sapiens. So much so that scientists are increasingly making a case for designating a new geological time period: the Anthropocene
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Journey to Mars Webinar (March2017)

Journey to Mars Webinar featuring NASA Astromaterials Research and Exploration Scientist Doug Ming from the NASA Johnson Space Center in Houston, TX.
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Secrets hidden by the Fibonacci Number and Phi (Φ)

Secrets hidden by the Fibonacci Number and Phi (Φ) | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

The Fibonacci numbers are the sequence of numbers defined by the linear recurrence equation.

 

The plot above shows the first 511 terms of the Fibonacci sequence represented in binary, revealing an interesting pattern of hollow and filled triangles (Pegg 2003). A fractal-like series of white triangles appears on the bottom edge, due in part to the fact that the binary representation of ends in zeros. Many other similar properties exist.

 

The Fibonacci numbers give the number of pairs of rabbits months after a single pair begins breeding (and newly born bunnies are assumed to begin breeding when they are two months old), as first described by Leonardo of Pisa (also known as Fibonacci) in his book Liber Abaci. Kepler also described the Fibonacci numbers (Kepler 1966; Wells 1986, pp. 61-62 and 65). Before Fibonacci wrote his work, the Fibonacci numbers had already been discussed by Indian scholars such as Gopāla (before 1135) and Hemachandra (c. 1150) who had long been interested in rhythmic patterns that are formed from one-beat and two-beat notes or syllables. The number of such rhythms having beats altogether is , and hence these scholars both mentioned the numbers 1, 2, 3, 5, 8, 13, 21, ... explicitly (Knuth 1997, p. 80).

 

The numbers of Fibonacci numbers less than 10, , , ... are 6, 11, 16, 20, 25, 30, 35, 39, 44, ... (OEIS A072353). For , 2, ..., the numbers of decimal digits in are 2, 21, 209, 2090, 20899, 208988, 2089877, 20898764, ... (OEIS A068070). As can be seen, the initial strings of digits settle down to produce the number 208987640249978733769..., which corresponds to the decimal digits of (OEIS A097348), where is the golden ratio. This follows from the fact that for any power function , the number of decimal digits for is given by .


Via Dr. Stefan Gruenwald
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Evidence for early life in Earth’s oldest hydrothermal vent precipitates

Evidence for early life in Earth’s oldest hydrothermal vent precipitates | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors describe putative fossilized microorganisms that are at least 3,770 million and possibly 4,280 million years old in ferruginous sedimentary rocks, interpreted as seafloor-hydrothermal vent-related precipitates, from the Nuvvuagittuq belt in Quebec, Canada.
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Arsenate and Selenate Scavenging by Basaluminite: Insights into the Reactivity of Aluminum Phases in Acid Mine Drainage

Arsenate and Selenate Scavenging by Basaluminite: Insights into the Reactivity of Aluminum Phases in Acid Mine Drainage | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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In this study, the affinity of basaluminite and schwertmannite for arsenate and selenate is compared, and the coordination geometries of these oxyanions in both structures are reported.
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Impact of Mn(II)-Manganese Oxide Reactions on Ni and Zn Speciation

Impact of Mn(II)-Manganese Oxide Reactions on Ni and Zn Speciation | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Layered Mn oxide minerals (phyllomanganates) often control trace metal fate in natural systems. The strong uptake of metals such as Ni and Zn by phyllomanganates results from adsorption on or incorporation into vacancy sites.
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Bauxite Residue Valorisation and Best Practices Conference (BR2018) – Red Mud Project

Bauxite Residue Valorisation and Best Practices Conference (BR2018) – Red Mud Project | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Nano-Tomography of Porous Geological Materials Using Focused Ion Beam-Scanning Electron Microscopy

Nano-Tomography of Porous Geological Materials Using Focused Ion Beam-Scanning Electron Microscopy | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
This contribution serves as an introduction and overview of FIB-SEM tomography applied to porous materials. on
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Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation

Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors.
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Falcondo Ni-laterite deposit (Dominican Republic) elucidated by means of μXAS

Falcondo Ni-laterite deposit (Dominican Republic) elucidated by means of μXAS | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
In the present paper a set of garnierite samples and the associated Ni-bearing serpentines with characteristic mineral compositions and textures, from the saprolite horizon, were studied by EMPA, μXRF and μXAS.
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Aggregation-induced growth and transformation of β-FeOOH nanorods to micron-sized α-Fe2O3 spindles

Aggregation-induced growth and transformation of β-FeOOH nanorods to micron-sized α-Fe2O3 spindles | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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In this work, the authors studied the hydrothermal growth of akaganeite (β-FeOOH) nanorods and their transformation to micron-sized hematite (α-Fe2O3) spindles using high-resolution cryogenic transmission electron microscopy (cryo-TEM). Only akaganeite particles and hematite spindles were detected in the samples. Further, cryo-electron 3D tomograms show that akaganeite nanorods were aggregated into loose three-dimensional networks with some embedded hematite spindles.
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Researchers pinpoint source of arsenic in Yangtze River

Researchers pinpoint source of arsenic in Yangtze River | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

“Generally, arsenic is a huge problem in Asian groundwater. A recent report estimated more than 19 million people in China are exposed to unsafe arsenic concentrations... Across Asia (as a whole) estimates suggest 100 million to 200 million people are exposed,” said Michael Schaefer from the Earth System Science Department at Stanford University, Stanford, Calif.

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Understanding Uranium Behavior in Sediments | EMSL

Understanding Uranium Behavior in Sediments | EMSL | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Uranium accumulates in oxygen-depleted sediments such as ore deposits, marine basins and contaminated aquifers. Identifying chemical forms of uranium that dominate sediments is key to understanding how this contaminant reacts and moves in sediments.
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Cycles of nutrient trace elements in the Phanerozoic ocean

Cycles of nutrient trace elements in the Phanerozoic ocean | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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