Archive for the ‘People’ Category

New techniques

Dating pinpoints volcanoes that killed half of species, split continents.

New techniques for dating rocks have helped narrow the time frame of a chain of massive volcanic eruptions that wiped out half of the world’s species 200 million years ago, a study said Thursday.

The result is the most precise date yet — 201,564,000 years ago — for the event, which is known as the Triassic-Jurassic extinction event, said the study, published in the journal Science. The event was the fourth mass extinction in the history of our planet.

The eruptions “had to be a hell of an event,” said coauthor Dennis Kent, an expert on paleomagnetism at Columbia University’s Lamont-Doherty Earth Observatory.
They may offer a historic parallel to the human-caused climate change happening today, by showing how sharp increases in carbon dioxide can outpace vulnerable species’ ability to adapt, researchers said.

The new analysis narrows the estimated date from its previous range of up to 3 million years to just 20,000 years at most — a blink of an eye in geological terms.

The eruptions caused an already hot Earth to become even more stifling, killing off plants and animals and making way for the age of the dinosaurs — before they, too, were eventually obliterated some 65 million years ago, possibly by another volcanic event combined with a devastating meteor strike.


A perfect example are the integrated displays. PearsonLloyd had wanted to connect these in a center band to optimize their complexity of articulation. And while this didn’t affect roominess, the band blocked a view into the next row, cutting down on perceived space. So they abandoned the idea. The precise shape of the head/shoulder compartment was honed to accept users of multiple broadness. The lower lumbar adjustments were given massage functions (which sounds like a godsend for anyone who’s gone numb during a long flight). And even the seat textile is wholly custom, bringing in flecks of yellow to warm the otherwise silver sheen. I asked Pearson why many of these pretty obvious improvements hadn’t been made before, why if V-shaped seating is so efficient, it wasn’t simply implemented in the first place? “Simply because design and engineering knowledge evolves,” he responded. “People never arrive immediately at the optimum solution.” Which makes you wonder, with a few more great ideas, how wonderful could Lufthansa’s next new business class be?


Tieken was further encouraged by this possibility when news emerged in 2006 that personnel from the Dickson Mounds Museum found the remains of a bison in the bed of the Illinois River when the river was unusually low.

“It had a similar point embedded in one of the bones,” Tieken said.
The Illinois River finding was dated to the Early Woodland period going back more than 2,000 years, marking it as the earliest evidence of bison hunting in Central Illinois.
Tieken said it’s not uncommon for artifacts from one historic period to be found mixed in with materials from other ancient periods when archaeological sites are unearthed — particularly in stratified areas where several different cultures lived over thousands of years. It’s believed the Adams County drainage ditch items were mixed together when a section of dirt sloughed off the side of the ditch after heavy rains, exposing the archaeological treasures.
Tieken said the bison findings nonetheless have educational value. As it turned out, he said, the carbon dating put the age of the bison remains at between A.D. 1450 and 1470.
“Previously, most researchers believed bison didn’t come into this area until after 1500. So we put that date back at least 50 years,” Tieken said.
A Native American culture known as the Oneota people were living in this area around that time.
“It used to be thought that the Oneota people within Lima Lake were procuring buffalo on hunts to the west. But this (carbon dating results) proves that buffalo were right here in this area,” Tieken said.
In addition, getting a firm date on the bison “adds another time frame and scenario to the whole story down there” at Lima Lake, he said.
Since it was drained of water in the 1930s and converted into farmland, the former site of Lima Lake has been a treasure trove of historical discoveries over the years. Tieken has had a hand in several of those discoveries, which have resulted in three previous carbon-dating evaluations that have added to the local body of knowledge.

For example, one Native American settlement site at the south end of the Lima Lake area has been positively identified to A.D. 78 while another nearby site was dated to A.D. 525.
Even more significantly, a mastodon tooth found in the former Lima Lake bed in 1957 was taken to the U of I five years ago to be dated. Using a new high-tech dating technique, scientists determined the tooth’s actual calendar date was somewhere between 10,891 and 10,854 B.C. At the time, it was the youngest mastodon specimen scientifically dated in North America. Since then, however, a mastodon tooth from Indiana was found to be even younger by about 700 years, Tieken said.
All these discoveries from the Lima Lake area help add to the cultural knowledge base of Adams County, Tieken said.

“This puts things in factual terms as opposed to folklore or old historic tales,” he said. “It’s a living legacy of one particular tract on this huge planet.”