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Satellite view of Antarctica
Courtesy of Molly
Miller |
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In 1985, a group
of Ohio State scientists and collaborators traveled to Antarctica as part
of the National Science
Foundation's Polar Research Program to better understand
the geologic history of the continent. By determining how various rock
layers were deposited, their goal was to distinguish geographical features
such as rivers, swamps and mountains. Of particular interest was a widespread
rock unit consisting of shale with interspersed beds of coarser-grained sandstone.
Geologists who had previously studied the rock were unable to determine whether
this unit was deposited under marine or freshwater conditions, whether a
large lake or the ocean had covered the area. In order to answer this question,
the scientists invited Miller to come along on their next expedition.
Once she arrived in Antarctica and saw
the rocks, Miller quickly determined that the strata had been deposited
in fresh water. She observed that the trace fossils it
contained closely resembled marks made by modern insects,
the dominant bottom-dwelling animals in modern lakes and streams. Miller
documented the existence of huge lakes that would have tempered
the climate
and created a suitable environment for plants and advanced animals such as
reptiles.
Miller found the expedition so exhilarating and the geologic problems so
intriguing that she returned to the Antarctic in 1995 to conduct in-depth
research on the evolution of fresh water animals. She has now made the trek
to the icy continent four times and returns this winter for her fifth expedition “on
the ice.”
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