Featured Research

from universities, journals, and other organizations

Midwest Geologists Offer New Look At Ancient Continental Collisions

Date:
November 22, 2000
Source:
University Of Cincinnati
Summary:
A team of geologists has accumulated extensive evidence that contradicts a previous view of how the continents which formed Gondwana collided and came apart to form what is now North and South America.

Cincinnati -- A team of geologists has accumulated extensive evidence that contradicts a previous view of how the continents which formed Gondwana collided and came apart to form what is now North and South America.

University of Cincinnati geologist Warren Huff will explain the evidence during a talk Tuesday, Nov. 14 during the annual meeting of the Geological Society of American in Reno, Nevada. Huff has been working with Dennis Kolata of the University of Illinois and Stig Bergstrom of Ohio State for several years to collect and analyze deposits from ancient volcanoes.

The deposits, known as K-bentonites, were formed after massive volcanism in the Ordovician Period roughly 450 million years ago. By tracking these deposits across continents, Huff and his collaborators can reconstruct how the ancient land masses moved.

A previous model (Dalziel et al., 1994) concluded that the continents which became North and South America went through a massive collision, before moving apart into their present-day locations. "We don't agree with that model," said Huff. "Technically, it's possible, but in the time frame we're considering, it doesn't make much sense. "

For example, Huff explained that fossil evidence indicates South America went through an Ice Age at the end of Ordovician. However, the previous model requires the South American land mass to be nearly at the equator during that time.

Huff and his colleagues don't dispute that a collision occurred. The massive volcanism which produced the deep K-bentonite beds is clear evidence that land masses were crunching together. "The question is...what was colliding with what? We believe it was a group of very small terrains much like the western Pacific today where island chains are moving toward mainland Asia. Bits and pieces attached over time."

The strongest evidence for the "bits and pieces" approach comes from the Argentine Precordillera where bentonites have been recovered from dozens of sites. The Precordillera formed before the Andes and contains fossils which are similar to those found in North America, but very different from those found elsewhere in South America.

In the revised model, the Precordillera land mass could have come from North America or simply been in a similar environment (tropical to semi-tropical).

If it did break or rift away from the North American land mass (known as Laurentia), Huff said the rift must have occurred well before the mid-Ordovician collisions. He also noted that the rifting would be consistent with what's known about the eastern United States.

"It's a very broken up continent," said Huff. "The Appalachians stop abruptly near Birmingham, Alabama. Part of the Appalachians are probably part of Africa today. The east coast has a history of this kind of fracturing."

Huff's work is supported by the National Science Foundation and conducted in collaboration with CONICET, a scientific consortium in Argentina.


Story Source:

The above story is based on materials provided by University Of Cincinnati. Note: Materials may be edited for content and length.


Cite This Page:

University Of Cincinnati. "Midwest Geologists Offer New Look At Ancient Continental Collisions." ScienceDaily. ScienceDaily, 22 November 2000. <www.sciencedaily.com/releases/2000/11/001120073210.htm>.
University Of Cincinnati. (2000, November 22). Midwest Geologists Offer New Look At Ancient Continental Collisions. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2000/11/001120073210.htm
University Of Cincinnati. "Midwest Geologists Offer New Look At Ancient Continental Collisions." ScienceDaily. www.sciencedaily.com/releases/2000/11/001120073210.htm (accessed October 23, 2014).

Share This



More Earth & Climate News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) — Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins