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
Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences