Hawaii volcanic lava carries information about the process of planet formation

Today, pedestrians visiting the Kilauea Iki crater in Hawaii only see an almost flat surface with sparse basalt. It looked like asphalt, but in November and December 1959, it emitted an orange glow of new erupting lava.

Currently, an accurate analysis of lava samples taken from craters gives scientists a new tool to regenerate planetary origins. The results of the analysis, conducted by Nicolas Dauphas of the University of Chicago and colleagues, are published in the June 20 issue of Science.

According to Dauphas and co-authors Fang-Zhen Teng of the University of Arkansas and Rosalind T. Helz of the US Geological Survey, the iron isotope test - the insignificant difference of the element shown at the atomic level - can provide information for planetary scientists to know more about the process of forming the crust than they think.

If applied to all types of basalt on Earth and extraterrestrial, including meteorites from Mars and small planets, this method could provide more clear evidence to support the prevailing scientific perspective. that the moon is created after a giant collision between the Earth and another large object.

Because lava in Kilauea Iki crater has cooled and fossilized, the lava iron isotope changes over time. Dauphas said: 'It is like how you put a tray of salt water in the freezer and check what happens to the salt concentration in the water when the rock forms'.

Eruption Hill at Kilauea Iki Crater on Big Island Island in Hawaii.In December 1959, lava sprayed 1900 meters high from this location.Learn lava samples taken from craters, scientists at the University of Chicago and some other places have invented a new tool to recreate planetary origins.(Photo: Steve Koppes)

The finding contradicts the popular notion that isotope variation occurs only at relatively low temperatures, for lighter elements, such as oxygen. But Dauphas and his colleagues were able to determine isotope transformation occurring in magma at a temperature of 1,100 degrees C (2,012 degrees Fahrenheit).

Previous studies on basalt found little or no separation of iron isotopes, but those studies focused on a single slate rather than its individual mineral components. Teng said: 'We analyze not only a slate, but also individual minerals'. Specifically, they analyzed olivine crystals, better known as peridot in the jewelry world.

Science magazine June 20 is the first publication based on data collected and analyzed with the help of a new device in Dauphas's Origin Laboratory. The plasma source mass spectrometer was funded by the National Aeronautics and Space Administration and the University of Chicago, which separated ions (charged particles) according to their mass. These ions are formed in the plasma of the Agon gas inside the device at a temperature of nearly 14,000 degrees Fahrenheit (8,000 degrees K, hotter than the temperature on the sun's surface).

Isotope research has a long history of development at the University of Chicago. Harold Urey, who received the Nobel Prize in Chemistry in 1934, created the executive director of isotope transformation in Chicago in the 1940s and 1950s.

The researchers chose Kilauea Iki to investigate because they had repeatedly drilled the sample when it had cooled over the years. The number of specimens collected makes this lava lake the perfect place to study the change and separation of minerals as well as elements when magma cools and fossils.

Dauphas concluded: 'The results we have achieved open a new path for research. We can now use iron isotopes as indications for magma formation and transformation, which plays an important role in continent formation. '