Fang-Zhen Teng, assistant professor of geosciences and a member of the Arkansas Center for Space and Planetary Sciences, Nicholas Dauphas of the department of geophysical sciences and a member of the Enrico Fermi Institute at the University of Chicago, and Rosalind T. Helz of the U.S. Geological Survey report their findings in the June 20 issue of the journal Science.
The researchers examined iron isotopes in basalt samples from the Kilauea Iki lava lake on the main island of Hawaii. Isotopes have the same chemical properties but different weights, so some processes cause what looks like the same material to behave differently – often separating the two. Such separation can tell scientists something about how the material containing the isotopes formed.
However, until now scientists thought that such isotope fractionation only occurred at low temperatures and with elements of low molecular weight. Because of the heat and iron’s molecular weight, scientists thought that the process that formed basalts did not separate iron isotopes.
“There is a huge dispute on this topic,” Teng said. “Our research shows that there is clearly fractionation.”
Teng likens the change in iron isotopic composition in basalts to the baking of a cake: With a cake, you start out with certain ingredients, but the baking process changes the ingredients and their proportions within the cake. In the same way, the process that makes basalt magma through partial melting of the mantle peridotites, or rocks, changes the iron isotope compositions.
Past studies have examined basalts, but found little or no separation of iron isotopes. However, no one was studying the individual minerals found within a basaltic rock.
“We analyzed not only the whole rocks, but the separate minerals,” Teng said. The minerals examined showed a significant separation of iron isotopes, in contrast to the whole rocks. The researchers looked at olivine crystals, better known as peridot in the jewelry world, which formed and sank as the lava lake cooled.
“This research gives scientists a new tool to investigate the question of planetary differentiation,” said Dauphas. If basalts from the moon or Mars have similar iron isotope separation, it suggests that they formed through heat processes similar to those on Earth. However, if rocks from these planetary bodies do not have iron isotope separation, it suggests that they were formed in a different way.
The next project by Teng, who teaches in the J. William Fulbright College of Arts and Sciences, will be to study the isotopic composition of iron in lunar basalts returned by the Apollo missions.CONTACT:
Melissa Lutz Blouin | newswise
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
Modeling magma to find copper
13.01.2017 | Université de Genève
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Power and Electrical Engineering
18.01.2017 | Materials Sciences
18.01.2017 | Life Sciences