Posted on 08/08/2011 7:58:48 PM PDT by decimon
Boulder, CO, USA - An international team of researchers has found the strongest evidence yet that parts of North America and Antarctica were connected 1.1 billion years ago, long before the supercontinent Pangaea formed.
"I can go to the Franklin Mountains in West Texas and stand next to what was once part of Coats Land in Antarctica," said Staci Loewy, a geochemist at California State University, Bakersfield, who led the study. "That's so amazing."
Loewy and her colleagues discovered that rocks collected from both locations have the exact same composition of lead isotopes. Earlier analyses showed the rocks to be the exact same age and have the same chemical and geologic properties. The work, published online (ahead of print) in the September issue of the journal Geology, strengthens support for the so-called SWEAT hypothesis, which posits that ancestral North America and East Antarctica were joined in an earlier supercontinent called Rodinia.
The approximately 1.1 billion year old North American Mid-continent Rift System extends across the continent from the Great Lakes to Texas. Volcanic rocks associated with the rift, which appears to represent an aborted tectonic attempt to split the ancestral North American continent of Laurentia, are well exposed in the Keweenaw Peninsula of the Upper Peninsula of Michigan from which they take their name, the Keweenawan large igneous province. The rift extends in the subsurface beneath Minnesota, Iowa, Nebraska, Kansas and Oklahoma to the Franklin Mountains near El Paso, Texas where related rocks are exposed.
(Excerpt) Read more at geosociety.org ...
Traveling Texas ping.
Cool. Love the Franklin Mountains...especially when they’re clear (no pollution haze).
I wonder if they found my watch that I lost in Antarctic?
Just joking. It was in the washing machine.
I know the Franklins, been there a couple of times. Really cool to look down over old El Paso and into Juarez beyond, especially at night. I’ve camped at the state park there and sat around listening to Norteno music coming out of Mexico, enjoying a nice adult beverage. Good mountain bike trail down there.
TTIUWM.
(maps.)
Whoah. Dude, where’s my continent?
Srsly, Thanks.
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| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
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Thanks decimon. Finders keepers. |
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This is pretty cool stuff. But what’s even cooler is that 1.1 billion years ago, somebody thought to name a super-continent, Rodinia.
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