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| Tucker, Steve, Cain, Dave, Bruce and Christine, Put-In day to Ford Ranges.
Photo © Bruce Luyendyk
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White Ocean of Ice deals
with investigation of plate tectonic history in the Southwestern Pacific. Our
team of geologists sought out information on the separation of the New Zealand
subcontinent on the Pacific Plate from the main continent of Antarctica – the Antarctic
Plate. The result of that separation created the modern South Pacific Ocean
basin.
We knew from oceanographic studies that this sea floor had formed
since about 80 million years ago but we did not know how and when that process
started and led to the drifting of New Zealand away from West Antarctica. Research
in New Zealand by members of our team and many others revealed some facts, but
did they match observations is Antarctica? Those were few and difficult to make.
We decided to go to Antarctica to find answers to these questions. The U.S. National
Science Foundation supported our research.
Our work focused in the Ford Ranges of Marie Byrd Land in
West Antarctica, a location that was believed once joined with New Zealand. We learned
from several lines of evidence that the whole process of plate breakup brewed
for more than twenty million years. It began close to 105 million years ago before
separation took off.
We also studied a very special variety of metamorphic rocks (rocks
transformed by intense heat and pressure) in the Fosdick Mountains of the Ford
Ranges. We found that these rocks had been exhumed from many miles deep in the
Antarctic crust as the plate breakup process got underway. This was a result of
stretching between the plates. Upper levels of crust thinned and allowed the lower
levels to rise up and create the mountains. Research in this mountain range continues
today by geologists at Colorado College.
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