Geologists Discover Magma And Carbon Dioxide Combine

Tag : liquid carbon dioxide

This discovery overturns a longtime belief by geologists, whothought that carbon dioxide was incapable of dissolving in magma,said Calvin Barnes, professor of geosciences and lead investigator.
Through a grant from the National Science Foundation, Barnes, AaronYoshinobu, associate professor of geosciences, and doctoral studentYujia Li, discovered that carbon dioxide is released when magmainteracts with rocks such as limestone and marble. The carbondioxide, when combined with the magma, can create more powerfuleruptions.
“The main topic of our research involves magma’sinteraction with rocks that release carbon dioxide,” he said.“Hot magma melts the calcium carbonate-rich rock, and itmixes with magma much like adding an ingredient to something youare cooking to change the consistency or flavor. This forms bubblesand increases the volume of the magma. In turn, it must be pushedout through an eruption in a manner similar to modern explosivevolcanoes in Italy, including Mount Vesuvius.”
The Texas Tech geologists’ research is in collaboration withcolleagues at the University of Trondheim, the Geological Survey ofNorway, and the University of Wyoming. So far their research hasyielded three papers in journals such as the Norwegian Journal ofGeology and Lithos. Several more are pending.
Because searing hot temperatures prevent scientists from observingthese reactions directly, Barnes studied samples from the ancientCaledonian fold belt in Norway – Scandinavia’sequivalent of the Appalachian Mountains of North America.
Erosion has exposed the layers of magma that solidified withinearth’s crust when the Caledonian fold belt was formed,Barnes said. Through chemical analysis, he and Li confirmed thatcarbon dioxide not only is released when magma encounters calciumcarbonated-based rocks, but also that a great deal of calciumdissolves in the magma and equal amounts of carbon dioxide arereleased. Just as carbon dioxide causes a soft drink to fizz, thiscaused the magma to bubble and expand until it reached the point oferuption.
Barnes’ research coupled with new experiments done byresearchers in France and Italy has shown that the contamination ofmagma by carbonate not only is possible, but also it is capable ofexplaining many of the unusual characteristics of modern volcanoessuch as Vesuvius, an active volcano located east of Naples, Italy,and the Alban Hills, located southeast of Rome.
He said that both the Alban Hills and Vesuvius produce unusuallyhigh amounts of carbon dioxide during eruptions because the crustbeneath these volcanoes contains calcium carbonate-based limestonerocks.
Through their research, they can better understand eruptions andcalculate the amounts of carbon dioxide released during volcanicactivity. Understanding these concepts is important from a publicsafety standpoint since cities and towns are close by activevolcanoes.
“It’s useful because a volcanic eruption gives you asnapshot of what is happening beneath Earth’s surface,”Barnes said.