Geology Times
Recent News |  Archives |  Tags |  About |  Newsletter |  Submit News |  Earthquakes |  Subscribe to GeologyTimes.com RSS Feed Subscribe


More Articles
Compound protects brain cells after traumatic brain injuryCompound protects brain cells after traumatic brain injury

Mice and men share a diabetes geneMice and men share a diabetes gene

Slimy fish and the origins of brain developmentSlimy fish and the origins of brain development

Microbes evolve faster than ocean can disperse themMicrobes evolve faster than ocean can disperse them

Penn team studies nanocrystals by passing them through tiny poresPenn team studies nanocrystals by passing them through tiny pores

Arctic sea ice helps remove CO2 from the atmosphereArctic sea ice helps remove CO2 from the atmosphere

Can tapioca replace corn as the main source for starch sweeteners?Can tapioca replace corn as the main source for starch sweeteners?

Antifreeze proteins in Antarctic fish prevent both freezing and meltingAntifreeze proteins in Antarctic fish prevent both freezing and melting

Sandia magnetized fusion technique produces significant resultsSandia magnetized fusion technique produces significant results

Violent origins of disc galaxies probed by ALMAViolent origins of disc galaxies probed by ALMA

'Jaws' lived in Doncaster'Jaws' lived in Doncaster

Two-dimensional electron liquidsTwo-dimensional electron liquids

Sharks in acidic waters avoid smell of foodSharks in acidic waters avoid smell of food

American-made wind turbine bladesAmerican-made wind turbine blades

Nature's designs inspire research into new light-based technologiesNature's designs inspire research into new light-based technologies

When rulers can't understand the ruledWhen rulers can't understand the ruled

Hey1 and Hey2 ensure inner ear 'hair cells' are made at the right time, in the right placeHey1 and Hey2 ensure inner ear 'hair cells' are made at the right time, in the right place

Is a gluten-free diet enough to control the complications of celiac disease?Is a gluten-free diet enough to control the complications of celiac disease?

X-ray imaging paves way for novel solar cell productionX-ray imaging paves way for novel solar cell production

Childhood mentors have positive impact on career successChildhood mentors have positive impact on career success

Blood-cleansing biospleen device developed for sepsis therapyBlood-cleansing biospleen device developed for sepsis therapy

Missing piece found to help solve concussion puzzleMissing piece found to help solve concussion puzzle

Biologists delay the aging process by 'remote control'Biologists delay the aging process by 'remote control'

Bombarded by explosive waves of information, scientists review new ways to process and analyze Big DataBombarded by explosive waves of information, scientists review new ways to process and analyze Big Data

Program earns kudos for improving grades, retaining studentsProgram earns kudos for improving grades, retaining students

Geography matters: Model predicts how local 'shocks' influence U.S. economyGeography matters: Model predicts how local 'shocks' influence U.S. economy

A healthy lifestyle adds years to lifeA healthy lifestyle adds years to life

Identified for the first time what kind of explosive has been used after the detonationIdentified for the first time what kind of explosive has been used after the detonation

Copied from nature: Detecting software errors via genetic algorithmsCopied from nature: Detecting software errors via genetic algorithms

Isthmus of Panama formed as result of plate tectonics (7/31/2008)

Tags:
plate tectonics, central america

Paleogeographic reconstructions of Central America for (A) 20 Ma and (B) 15 Ma.
Paleogeographic reconstructions of Central America for (A) 20 Ma and (B) 15 Ma.
Contrary to previous evidence, a new University of Florida study shows the Isthmus of Panama was most likely formed by a Central American Peninsula colliding slowly with the South American continent through tectonic plate movement over millions of years.

The study, co-authored by Florida Museum of Natural History researchers Michael Kirby, Douglas Jones and Bruce MacFadden, is published in the July 30 issue of PLoS ONE, the online journal of the Public Library of Science. The study uses geologic, chemical and biologic methods to date rocks and fossils found in sides of the Gaillard Cut of the Panama Canal. The results show that instead of being formed by rising and subsiding ocean levels or existing as a string of islands as scientists previously believed, the Isthmus of Panama was first a peninsula of southern Central America before the underlying tectonic plates merged it with South America 4 million years ago.

"Scientists knew Panama was a North American peninsula, possibly as early as 19 million years ago because fossils that are closely related to North American land mammals, such as rhinos, horses, peccaries and dogs have been found in the Panama Canal during ongoing maintenance," said Kirby, lead author of the study. "But we were not certain when this peninsula first formed and how long it may have existed."

The canal's maintenance also exposes sediment layers and marine animal fossils, as well as strata of rocks and clay specific to numerous environments, including lagoon, delta, swamp, woodland and dry tropical forest.

Previous studies placed marine sediment as the youngest layers, suggesting the peninsula was submerged before finally joining with South America. The current study revises the time order of strata, however, and concludes that the Panamanian peninsula joined with South America roughly 4 million years ago.

Deep-sea deposits in one sediment layer suggest a short-lived strait may have existed across the Panama Canal Basin between 21 and 20 million years ago," said Jones, director of the Florida Museum of Natural History. "However, these short-lived straits probably had little impact on the long-term evolution of Central America's flora and fauna."

Kirby explained that because of numerous geologic faults resulting from tectonic plate movement that continues today, there is no area in Panama that allows a full view of the strata making up the land.

"We realized there was a problem with our previous understanding of the stratigraphy, or layering of sediments, in Panama," Kirby said.

The authors used alternative methods such as strontium isotope dating of fossils and re-analysis of vertebrate fossils to better determine the geologic sequence of the Canal.

"There's always missing information, like pages out of a book, when it comes to figuring out which layers came first and which were formed later," Kirby added.

Anthony Coates, a staff scientist emeritus at the Smithsonian Tropical Research Institute in Panama who has extensively studied the geological history of the rise of the Central American isthmus, said the study brings together a diverse array of geologic evidence that convincingly suggests Central America was a peninsula and not a group of islands.

"They have made an important contribution to the land-based geologic evidence of the plate tectonic history of the formation of the Isthmus," said Coates, who did not participate in the study. "Their results have important consequences for the nature of the global change engendered by the rise and closure of the isthmus."

One of the major effects of the formation of the Isthmus of Panama was the intensification of the Gulf Stream in the Atlantic Ocean. While the area that is now Panama was still a peninsula, ocean currents moving north along the north coast of South America spilled over to the Pacific Ocean through the wide Central American Seaway, also called the Atrato Seaway. As tectonic plate movement joined the peninsula with South America to form the present-day Isthmus of Panama, equatorial ocean currents between the Atlantic and Pacific were cut off, forcing water northward into the Gulf Stream current.

"The strengthened Gulf Stream, in turn, delivered enough moisture to allow the formation of glaciers across North America," Kirby said.

The complete text of the study is available on the publication's Web site, www.plosone.org/doi/pone.0002791.

Note: This story has been adapted from a news release issued by the University of Florida

Post Comments:

Search

New Articles
Fracking's environmental impacts scrutinized

First eyewitness accounts of mystery volcanic eruption

What set the Earth's plates in motion?What set the Earth's plates in motion?

Meteorite that doomed the dinosaurs helped the forests bloomMeteorite that doomed the dinosaurs helped the forests bloom

How a change in slope affects lava flowsHow a change in slope affects lava flows

Early Earth less hellish than previously thoughtEarly Earth less hellish than previously thought

M 9.0+ possible for subduction zones along 'Ring of Fire,' suggests new study

Wastewater injection is culprit for most quakes in southern Colorado and northern New Mexico

Contaminated water in 2 states linked to faulty shale gas wells

Gas leaks from faulty wells linked to contamination in some groundwater

Asian monsoon much older than previously thoughtAsian monsoon much older than previously thought

Microscopic diamonds suggest cosmic impact responsible for major period of climate change

Seismic gap may be filled by an earthquake near Istanbul

Mystery solved: 'Sailing stones' of Death Valley seen in action for the first time

Living in the shadow of Mauna Loa: A silent summit belies a volcano's forgotten fury



Archives
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007


Science Friends
Agricultural Science
Astronomy News
Biology News
Biomimicry Science
Cognitive Research
Chemistry News
Tissue Engineering
Cancer Research
Cybernetics Research
Electonics Research
Forensics Report
Fossil News
Genetic Archaeology
Genetics News
Microbiology Research
Nanotech News
Parenting News
Physics News


  Archives |  Submit News |  Advertise With Us |  Contact Us |  Links
Use of this site constitutes acceptance of our Terms of Service and Privacy Policy. All contents © 2000 - 2015 Web Doodle, LLC. All rights reserved.