UW Associate Professor Mike Cheadle holds a core sample from the Samail Ophiolite,
a large slab of oceanic crust that was pushed on top of the continental crust in Oman
in the Middle East. Cheadle is participating in the Oman Drilling Project, the goal
of which is to learn more about oceanic crust and Earth’s mantle. (Eiichi Takazawa,
Niigata University, Japan, Photo)
Space is vast and mysterious, and the majority of it is unexplored. So are the oceans
on Earth: While they cover most of the surface, what goes on underneath them is mostly
unknown.
University of Wyoming geology and geophysics Associate Professor Mike Cheadle is working
to contribute to the knowledge of what happens within the oceans with his research
on oceanic crust and Earth’s mantle.
“Oceans cover 71 percent of the earth’s surface, but we don’t actually know much about
what goes on beneath them, because it’s so hard to get there,” Cheadle says.
One way to circumvent the difficulties of accessing the sea floor is to study ophiolites
-- portions of oceanic crust that have been geologically pushed on top of the continental
crust. Cheadle is a participant in the Oman Drilling Project, the goal of which is
to learn more about oceanic crust and Earth’s mantle by drilling samples of rocks
from the Samail Ophiolite. More than 200 scientists worldwide have contributed to
the project.
“The best place in the world where you’ve got a piece of ocean crust -- that was once
below miles of water that has been geologically pushed up on the continent -- is in
a country called Oman in the Middle East,” Cheadle says. “We can find fewer good examples
in places like Oregon and in California, but it turns out Oman is literally the biggest
piece of ocean crust that’s been pushed up on the continents in the world.”
The scientific drill ship Chikyu was where Cheadle and other scientists examined the
Samail Ophiolite samples. (Mike Cheadle Photo)
After samples were drilled and collected from Oman, they were transported to the scientific
drill ship Chikyu for examination. Cheadle was one of 30 scientists involved in describing
and cataloguing the samples. Now, he is studying those samples using more in-depth
techniques to learn how oceanic crust forms.
“We can do various geological techniques to look at things like chemistry, and we
cut things into thin sections that you can look at under the microscope to spend time
trying to understand how it’s all working,” Cheadle says.
The findings from Oman are just one part of Cheadle’s overall research regarding oceanic
crust, but he believes they will contribute to understanding not only that formation,
but also other geological questions, such as what the boundary between the crust and
the Earth’s mantle is like.
Cheadle will discuss his work with the Oman Drilling Project in a session at the American
Geophysical Union’s fall meeting Dec. 10-14 in Washington, D.C.
