Featured Research

from universities, journals, and other organizations

Andes Mountains Are Older Than Previously Believed

Date:
May 17, 2009
Source:
Smithsonian Tropical Research Institute
Summary:
Much is known about the rise of the central Andes mountains, but a new study of the eastern Andes in Colombia indicates that mountain building began much earlier there.

Sediments that gather at the base of mountains provide important clues about how and when the mountains were formed.
Credit: Carlos Jaramillo, STRI

The geologic faults responsible for the rise of the eastern Andes mountains in Colombia became active 25 million years ago—18 million years before the previously accepted start date for the Andes' rise, according to researchers at the Smithsonian Tropical Research Institute in Panama, the University of Potsdam in Germany and Ecopetrol in Colombia.

Related Articles


“No one had ever dated mountain-building events in the eastern range of the Colombian Andes,” said Mauricio Parra, a former doctoral candidate at the University of Potsdam (now a postdoctoral fellow with the University of Texas) and lead author. “This eastern sector of America’s backbone turned out to be far more ancient here than in the central Andes, where the eastern ranges probably began to form only about 10 million years ago.”

The team integrated new geologic maps that illustrate tectonic thrusting and faulting, information about the origins and movements of sediments and the location and age of plant pollen in the sediments, as well as zircon-fission track analysis to provide an unusually thorough description of basin and range formation.

As mountain ranges rise, rainfall and erosion wash minerals like zircon from rocks of volcanic origin into adjacent basins, where they accumulate to form sedimentary rocks. Zircon contains traces of uranium. As the uranium decays, trails of radiation damage accumulate in the zircon crystals. At high temperatures, fission tracks disappear like the mark of a knife disappears from a soft block of butter. By counting the microscopic fission tracks in zircon minerals, researchers can tell how long ago sediments formed and how deeply they were buried.

Classification of nearly 17,000 pollen grains made it possible to clearly delimit the age of sedimentary layers.

The use of these complementary techniques led the team to postulate that the rapid advance of a sinking wedge of material as part of tectonic events 31 million years ago may have set the stage for the subsequent rise of the range.

"The date that mountain building began is critical to those of us who want to understand the movement of ancient animals and plants across the landscape and to engineers looking for oil and gas," said Carlos Jaramillo, staff scientist from STRI. "We are still trying to put together a big tectonic jigsaw puzzle to figure out how this part of the world formed."

This work was published in the Geological Society of America Bulletin in April 2009.


Story Source:

The above story is based on materials provided by Smithsonian Tropical Research Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mauricio Parra, Andrιs Mora, Carlos Jaramillo, Manfred R. Strecker, Edward R. Sobel, Luis Quiroz, Milton Rueda, and Vladimir Torres. Orogenic wedge advance in the northern Andes: Evidence from the Oligocene-Miocene sedimentary record of the Medina Basin, Eastern Cordillera, Colombia. Geological Society of America Bulletin, 2009; 121 (5-6): 780 DOI: 10.1130/B26257.1

Cite This Page:

Smithsonian Tropical Research Institute. "Andes Mountains Are Older Than Previously Believed." ScienceDaily. ScienceDaily, 17 May 2009. <www.sciencedaily.com/releases/2009/05/090515191558.htm>.
Smithsonian Tropical Research Institute. (2009, May 17). Andes Mountains Are Older Than Previously Believed. ScienceDaily. Retrieved April 21, 2015 from www.sciencedaily.com/releases/2009/05/090515191558.htm
Smithsonian Tropical Research Institute. "Andes Mountains Are Older Than Previously Believed." ScienceDaily. www.sciencedaily.com/releases/2009/05/090515191558.htm (accessed April 21, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Maine Storm Surge Sparks Power Explosions

Raw: Maine Storm Surge Sparks Power Explosions

AP (Apr. 21, 2015) — Police dash cam video shows a series of explosions along the beach in Maine as heavy storm surge soaked electrical transformers. (April 21) Video provided by AP
Powered by NewsLook.com
Searching For The Loch Ness Monster? Try Google Street View

Searching For The Loch Ness Monster? Try Google Street View

Newsy (Apr. 21, 2015) — For the anniversary of the notorious "Surgeon&apos;s Photo" of the Loch Ness monster, Google used Street View to let those online join the search. Video provided by Newsy
Powered by NewsLook.com
Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

AFP (Apr. 21, 2015) — As money runs out at Tacugama Chimpanzee Sanctuary in Sierra Leone, around 85 chimps are facing homelessness. The centre closed when the Ebola epidemic was ravaging the country but now that closure is beginning to look permanent. Video provided by AFP
Powered by NewsLook.com
Solar Plane Completes 6th Leg of Quest to Circumnavigate Globe

Solar Plane Completes 6th Leg of Quest to Circumnavigate Globe

AFP (Apr. 21, 2015) — Solar Impulse 2 lands in the Chinese city of Nanjing, finishing the sixth stage of its landmark 12-leg quest to circumnavigate the globe powered only by the sun. Duration: 00:42 Video provided by AFP
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