(Press-News.org) Researchers excavating a creek bed in central Texas have found evidence suggesting humans settled in North America some two thousand years earlier than previously estimated.
The findings are reported in the March 25 issue of Science.
Earth scientists at the University of Illinois at Chicago determined the age using an optical dating technique. They linked sediment and mineral samples to human artifacts and tools found in a single stratigraphic layer located below younger, previously dated Paleo-Indian Clovis-culture artifacts.
Texas A&M University anthropologist Michael Waters led the archaeological dig in the Buttermilk Creek complex, near Austin, which has been excavated for years. While artifacts suggesting earlier settlement had been found at the site before, they couldn't be verifiably dated.
UIC earth and environmental sciences professor Steven Forman worked with Waters and a multi-university team of researchers, finding buried beneath the Clovis layer tools such as blades and cores -- technologies unique to the Clovis culture.
Forman gathered about 50 core samples from two sites at Buttermilk Creek for luminescence dating analysis at UIC. Carbon-14 dating couldn't be used to date the pre-Clovis artifact layer because that layer didn't contain any organic matter.
"We dated the sediments by a variety of optical methods," Forman said. "We also dated different mineral fractions as well, and we consistently got the same ages. We looked at the age structure of the sediment by many different ways and got the same answers."
This is the first time that optical dating has been used to constrain a paleoculture within a date range, Forman said.
Luminescence dating, a relatively new technique, measures light energy trapped in minerals such as feldspar and quartz formed centuries ago. Samples must be carefully handled to avoid any exposure to light, which would contaminate the readings. They were analyzed in a darkroom laboratory at UIC.
"We found Buttermilk Creek to be about 15,500 years ago -- a few thousand years before Clovis," Forman said. "It's the first identification of pre-Clovis lithic technology (stone tool technology) in North America."
INFORMATION:
Other authors include Thomas Jennings, Joshua Keene, Jessi Halligan, Charles Hallmark and James Wiederhold of Texas A&M; Lee Nordt and Steven Driese of Baylor University; Joshua Feinberg and Anna Lindquist of the University of Minnesota; and Michael Collins of Texas State University.
An audio podcast on this subject is available at http://bit.ly/fPQeaK.
Photos of Forman available at http://newsphoto.lib.uic.edu/v/Forman+Steven/
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PHILADELPHIA - Researchers at the University of Pennsylvania's Abramson Cancer Center have discovered a novel way of treating pancreatic cancer by activating the immune system to destroy the cancer's scaffolding. The strategy was tested in a small cohort of patients with advanced pancreatic cancer, several of whose tumors shrank substantially. The team believes their findings – and the novel way in which they uncovered them -- could lead to quicker, less expensive cancer drug development.
The authors call the results, published in the March 25 issue of Science, a big ...
COLLEGE STATION, March 24, 2011— New discoveries at a Central Texas archaeological site by a Texas A&M University-led research team prove that people lived in the region far earlier – as much as 2,500 years earlier – than previously believed, rewriting what anthropologists know about when the first inhabitants arrived in North America. That pushes the arrival date back to about 15,500 years ago.
Michael Waters, director of Texas A&M's Center for the Study of First Americans, along with researchers from Baylor University, the University of Illinois-Chicago, the University ...
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Lauren Persha and Arun Agrawal of the University of Michigan and Ashwini Chhatre of the University of Illinois used evidence from more than 80 forest sites in six tropical countries to test how local participation ...
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The 525-million-year-old fossil belongs to a group of tentacle-bearing creatures which lived inside hard tubes. Previously only the tubes have been seen in detail but this new specimen clearly shows the soft parts of the body including tentacles for feeding.
Details of the discovery have been announced today in the journal Current Biology. The study was funded by the Royal Society and the National Natural Foundation ...
The variety on offer at the Foire de Paris means everyone is likely to find something they are interested in at the exhibition, with stands ranging from travel destinations to cooking gadgets.
It runs from April 28th to May 8th 2011 and features three sections: home, leisure and world culture.
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Children with Tourette syndrome could benefit from behavioural therapy to reduce their symptoms, according to a new brain imaging study.
Researchers at The University of Nottingham discovered that the brains of children with Tourette syndrome (TS) develop in a unique way — which could suggest new methods of treating the condition.
The study, published in the journal Current Biology, found that many children with TS experience a 'reorganisation' of the brain structure in their teens, as their brain compensates for the condition and allows them to gain control over their ...
