Clay haloes preserve ancient fossils: an Infrared view

A UK-US collaboration has shed light on the preservation of ancient microfossils. As outlined in Interface Focus, the presence of kaolinite haloes surrounding the tiny fossils is believed to have kept destructive bacteria at bay, stopping decay. The small molecular differences of the clay around the fossils called for the Synchrotron IR microbeam.

Fossils that are over 500 million years old are extremely rare because early organisms were microscopic, only the thickness of a hair, and lacked hard parts that can resist decay. To understand how these early organisms could be preserved, IR microspectroscopy was performed using the Multimode InfraRed Imaging and Microspectroscopy (MIRIAM) beamline at Diamond Light Source. IR microanalysis allowed researchers to identify at the micron scale the minerals surrounding 800–1,000 million-year-old microfossils, and it was determined that an aluminium-rich clay known as kaolinite was responsible for their preservation. Kaolinite was previously shown to be toxic to bacteria, so its presence prevented the early organisms from being destroyed.

These observations suggest that the early fossil record might be biased to regions that are rich in kaolinite, such as the tropics. Moreover, the lack of animal fossils in these samples, despite having favourable fossilisation conditions demonstrates that animals were yet to evolve 800 million years ago.

Read more on the Diamond Light Source website

Image: Light microscopy images (left) indicating the position of the microfossils (red boxes) and Synchrotron-based IR maps (right) showing the compositional variation of the clay around the fossil (as ratio of 3694 cm^-1 band vs the M-OH region). 

Credit: Data taken at MIRIAM beamline B22 at Diamond.

Scientists discover new forms of feldspars

High-pressure experiments reveal unknown variants of common mineral

In high-pressure experiments, scientists have discovered new forms of the common mineral feldspar. At moderate temperatures, these hitherto unknown variants are stable at pressures of Earth’s upper mantle, where common feldspar normally cannot exist. The discovery could change the view at cold subducting plates and the interpretation of seismologic signatures, as the team around DESY scientist Anna Pakhomova and Leonid Dubrovinsky from Bayerisches Geoinstitut in Bayreuth report in the journal Nature Communications.Feldspars represent a group of rock forming minerals that are highly abundant on Earth and make up roughly 60 per cent of Earth’s crust. The most common feldspars are anorthite, (CaSi2Al2O8), albite (NaAlSi3O8), and microcline (KAlSi3O8). At ambient conditions, the aluminium and silicon atoms in the crystal are each bonded to four oxygen atoms, forming AlOand SiO4 tetrahedra.

Read more on the DESY website

Image : The crystal structure of the feldspar anorthite under normal conditions (left) and the newly discovered high-pressure variant (right). Under normal conditions, the silicon and aluminium atoms form tetrahedra (yellow and blue) with four oxygen atoms each (red). Under high pressure polyhedra with five and six oxygen atoms are formed. Calcium atoms (grey) lie in between. The black lines outline the so-called unit cell, the smallest unit of a crystal lattice. 

Credit : DESY, Anna Pakhomova

Using soil to combat climate change

Researchers are using synchrotron light to better understand the impact of climate change on more than three trillion metric tonnes of soil carbon around the world.

Using the Canadian Light Source (CLS) at the University of Saskatchewan, scientists from across the United States investigated the plant root mechanisms that control long-term storage of carbon in deep soil. Their findings will have ramifications for global industries such as agriculture, which have touted the benefits of carbon sequestration as their contribution to fighting climate change.

“The significance of our work is we not only show that plants are conduits of carbon into the soil, but the roots also regulate how much carbon the deep soil can store or lose,” said Dr. Marco Keiluweit, a biogeochemist at the Stockbridge School of Agriculture in the University of Massachusetts.

>Read more on the Canadian Light Source website

Image: Rhizogenic weathering extract; (full image here)

Preventing heart attacks

Scientists have taken an important step towards finding a potential cure for the disease that causes strokes and heart attacks in seniors and increases the mortality rate of diabetic and chronic kidney disease patients.
Researchers from the University of McGill and SickKids Toronto in collaboration with Universite de Montreal developed a simplified laboratory model that mimics the formation of mineral deposits that harden arteries and leads to these devastating conditions.
They used the Canadian Light Source (CLS) at the University of Saskatchewan to understand the type of minerals that formed and how they develop on the arteries.
“The goal in developing our lab model is that it would help us understand the mineralization process. We can then mimic what happens, and use it to test hypotheses on why the minerals are forming and also test some drugs to find something that can stop it,” said lead researcher Dr. Marta Cerruti.
Her six-member team is focused on the poorly understood process of how minerals form and grow on elastin, a protein on artery walls that provides the elasticity needed for blood flow to the heart, said Cerruti, an associate professor in Materials Engineering at McGill.
The hypothesis is that calcium phosphate-containing minerals form inside the walls of arteries and then calcify into a bone-like substance that narrows arteries and causes them to lose elasticity crucial for blood flow.

>Read more on the Canadian Light Source website

Image: Marta Cerruti (left) and Ophelie Gourgas in a laboratory using a Raman machine.

Research on shark vertebrae could improve bone disease treatment

The U.S. Department of Energy’s Advanced Photon Source (APS) at Argonne National Laboratory has facilitated tens of thousands of experiments across nearly every conceivable area of scientific research since it first saw light more than two decades ago.
But it wasn’t until earlier this year that the storied facility was used to study shark vertebrae in an experiment that one Northwestern University researcher hopes will shed light on the functionality of human bone and cartilage. Shark spines constantly flex when they swim, said Stuart R. Stock, a materials scientist and faculty member of Northwestern’s Feinberg School of Medicine. Yet they remain surprisingly resilient throughout the fish’s lifetime, he said.

Human bones, however, cannot endure the same kind of bending and become more fragile as people age. Stock is using the APS to better understand shark vertebrae’s formation and strength. He wants to know how the animal’s tissue develops and how it functions when the animal swims.

>Read more on the APS at Argonne National Laboratory website

Simulating meteorite impacts in the lab

Scientists monitor the response of feldspar minerals to rapid compression

A US-German research team has simulated meteorite impacts in the lab and followed the resulting structural changes in two feldspar minerals with X-rays as they happened. The results of the experiments at DESY and at Argonne National Laboratory in the US show that structural changes can occur at very different pressures, depending on the compression rate. The findings, published in the 1 February issue of the scientific journal Earth and Planetary Science Letters (published online in advance), will aid other scientist to reconstruct the conditions leading to impact craters on Earth and other terrestrial planets.

>Read more on the PETRA III at DESY website

Image: Scanning electron microscopy image of the micro-structure of albite prior to the rapid compression experiments.
Credit: Stony Brook University, Lars Ehm

Molluscs use thermodynamics to create complex morphologies with exceptional properties

An international team has found how some molluscs create their complex structures.

Their work provides new tools for novel bioinspired and biomimetic bottom-up material design.
Nature serves as a source of inspiration for scientists and engineers thanks to the complex material architectures that make up some living organisms. These materials carry out essential functions, ranging from structural support and mechanical strength, to optical, magnetic or sensing capabilities. One example of this are molluscan shells, made of mineralized tissues organised in mineral-organic hierarchical functional architectures.

Molluscs appeared more than 500 million years ago, and they have developed hard and stiff mineralised outer shells for structural support and protection against predation. Their shells consist of mineral-organic composite structures made of calcium carbonates, mostly calcite and aragonite. The different shells exhibit a large variety of intricate three-dimensional assemblies with superior mechanical properties.

>Read more on the European Synchrotron website

Garnet gemstones contain secrets of our seismic past

Somewhere in the world an earthquake is occurring. In general, it will be a small tremor, an earthquake of magnitude two or lower, which humans cannot even feel. However when a major earthquake occurs, of magnitude 7 or above, it can cause devastating damage, events like tsunamis, and loss of life. These type of quakes, like the 2011 event in Japan and 2015 Nepalese events, happen around 20 times each year worldwide.

Large earthquakes tend to occur in subduction zones, such as the so-called Ring of Fire, where tectonic plates meet and one is bent and forced underneath the other, into the mantle of the earth. As well as leading to earthquakes, subduction also causes the composition and structure of the rock itself to become altered, in a process called high-pressure/low temperature metamorphism.

Metamorphism can take a variety of forms, in a number of different rocks, but one that is of particular interest is a type called rhythmic major-element zoning, in the mineral garnet. If found it can be a sign that subduction has occurred, and it can act as a record of seismicity in the crust of our Earth.

>Read more on the Diamond Light Source website

NSRRC User, Jennifer Kung elected as a MSA Fellow

First female scientist ever awarded MSA fellowship in Asia.

NSRRC user, Jennifer Kung is among the 11 new elected fellows for 2018, announced by the Mineralogical Society of America (MSA) Council at its Fall Council Meeting in Seattle, WA, USA. She is the only recipient from Taiwan, as well as the first female scientist ever awarded MSA fellowship in Asia.

Prof. Kung is an Associate Professor in Earth Science at National Cheng-Kung University. She runs “Mineral and Rock Physics Lab” to investigate the behaviors of earth materials under high pressure and high temperature using the knowledge of crystal chemistry, mineral physics to understand the interior of the Earth. The major research methods she employs include X-ray diffraction, vibrational spectroscopy and ultrasonic measurements in conjunction with high pressure facilities, like large volume high pressure apparatus or diamond anvil.


Identification of a mineral that until now was only present in meteroites

X-ray microdiffraction experiments were done to determine the crystalline structure of chladniite

Researchers from the Institute of Materials Science of Barcelona (ICMAB-CSIC), the Autonomous University of Barcelona (UAB), and the National University of Córdoba (Argentina), in collaboration with researchers of the ALBA Synchrotron, have identified a mineral in the region of Córdoba (Argentina), until now only observed in meteorites.

The study, published in European Journal of Mineralogy, affirms that the mineral is chladniite, a complex phosphate belonging to the fillowite group, which contains sodium, calcium, magnesium and iron, and has a trigonal structure. It has been found in a pegmatite, an igneous (magmatic) rock, formed from the slow cooling and solidification of magma.

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Speedy X-Ray Detector Arrives at NSLS-II

Advanced detector fuels discovery by allowing users to collect massive datasets in less time.

The National Synchrotron Light Source II (NSLS-II), a DOE Office of Science User Facility at the U.S. Department of Energy’s Brookhaven National Laboratory, is a truly international resource. Geoscientists from Australia and France recently trekked across the globe to aim NSLS-II’s tiny, intense beams of x-ray light at thin samples of nickel-rich mineral gathered from a mine in far-off Siberia. They scanned these slices of geological material to see what other chemical elements were associated with the nickel. The group also examined slices of minerals grown in a lab, and compared results from the two sample suites to learn how massive metal deposits form.

Their experiment was the first to use a newly installed x-ray detector, called Maia, mounted at NSLS-II’s Submicron Resolution X-Ray Spectroscopy (SRX) beamline. Scientists from around the world come to SRX to create high-definition images of mineral deposits, aerosols, algae—just about anything they need to examine with millionth-of-a-meter resolution. Maia, developed by a collaboration between NSLS-II, Brookhaven’s Instrumentation Division and Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO), can scan centimeter-scale sample areas at micron scale resolution in just a few hours—a process that used to take weeks.

Chemistry at the protein-mineral interface

The nucleation site of iron mineral in human L ferritin revealed by anomalous -ray diffraction

Iron ions have crucial functions in every living organism being essential for cellular respiration, DNA synthesis, detoxification of exogenous compounds, just to provide a few examples. However, the redox properties of iron ions can also cause the occurrence of deleterious free-radicals. For these reasons, when unnecessary, iron must be kept in appropriate forms unable to cause damage. Nature evolved a special protein cage, called ferritin, consisting of 24 subunits arranged to form a hollow sphere with an internal diameter of about 80 Å where mineralized iron is stored, generally under the form of insoluble ferric oxides.

In mammals, two types of subunits build-up the 24-mer ferritins: the ‘heavy’ (H) and the ‘light’ (L). These subunits differ not only in molecular weight (21.2 kDa for H and 20.0 kDa for L) but, mainly, in function. The H subunit is able to catalyze the rapid oxidation of Fe2+ to Fe3+ followed by transfer in the storage cavity. On the contrary, the L-chain does not possess catalytic activity, but it is still able to mineralize ferric ions upon spontaneous oxidation by dioxygen of captured Fe2+. Despite the intensive research on ferritin chemistry, the mechanisms of iron oxidation and storage to form mineral nanoparticles inside the ferritin cavity are still to be fully established.

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