Posted on 06/07/2010 7:29:10 PM PDT by SunkenCiv
A large proportion of the zircons found in Jurassic-era sandstones throughout a Texas-sized portion of the Colorado Plateau originated in the Appalachians, previous analyses have shown. Those erosion-resistant mineral grains were carried westward by an immense river, deposited on floodplains and then stirred back up innumerable times before ending up in massive dune fields that later solidified into western sandstones, says William R. Dickinson, a geologist at the University of Arizona in Tucson.
In their attempt to trace the transcontinental river system, the researchers took a 20-kilogram hunk of Michigan sandstone from one of those quarries and then extracted and analyzed its zircons. About 40 percent of zircons in the sample were between 905 million and 1.3 billion years old, and about 10 percent were between 285 and 510 million years old. Most if not all of these zircons probably eroded from the northern Appalachians, the researchers suggest. The overall age distribution of zircons from the Michigan sample is strikingly similar to those found in the sandstones of the Colorado Plateau, a hint that all of the zircons eroded from the same sources.
(Excerpt) Read more at sciencenews.org ...
Immigrants from the East -- Zircon grains found in Jurassic-era sandstones of the Colorado Plateau (including rocks of Utah's Zion National Park, shown here) were carried by a massive river that drained the Appalachians and flowed through Michigan, a new study suggests. [USGS]
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Maybe they wuz sploded thare by wun uv dem comet thingies.
LLS
The Zircons hailing from the Bronx
That’s where Cubic Zirconium rings are born!
Not true Jack. The cubic form of zirconium is made by humans in laboratories. Gem zircons on the other hand occur naturally in several colors -- blue, white, yellow, red, etc. -- and the white ones were long used as diamond substitutes because of their "fire" and brilliance.
Zircon also has unique properties that make it very useful in dating ancient rocks. See Zircon in Geochronology
We need to recreate on of those rivers for when the Mississippi region floods. They could use that excess water out west.
LOL! Yes, I know.
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