Featured Research

from universities, journals, and other organizations

Clinker geochronology, the first glacial maximum, and landscape evolution in the northern Rockies

Date:
June 28, 2011
Source:
The Geological Society of America
Summary:
Scientists have developed and successfully carried out a novel, extraordinary technique for learning how efficiently river channels cut and increase local topographic relief: They have used the exposure of "clinker" deposits in combination with highly refined dating techniques.

Peter W. Reiners of the University of Arizona and colleagues have developed and successfully carried out a novel, extraordinary technique for learning how efficiently river channels cut and increase local topographic relief: They have used the exposure of "clinker" deposits in combination with highly refined dating techniques.

Clinkers are baked coals; baking naturally occurs in shallow depths (tens of meters) and when the clinkers are exhumed during erosion and the development of topographic relief, they are resistant and the rate of exposure can be timed using the U-Th/He isotopic system found in zircons within the clinkers.

In this application, the Reiners and colleagues determined aspects of the pace of recent evolution of Powder River Basin in northern Wyoming and southern Montana. Ages of in-situ clinkers range from as old as 1.1 million years to as young as 10,000 years, but most formed in one of the last three interglacial periods, reflecting either changes in fluvial downcutting caused by glacial-interglacial cycles or other climatic effects on rates of natural coal burning. Clinker deposits atop a broad terrace in the northern part of the Powder River Basin provide a maximum age of 2.6 plus or minus 0.2 million years for terrace formation.

This corresponds to the onset of major Northern Hemisphere glaciation interpreted from marine records, suggesting that the terrace formed by lateral erosion of the landscape as rivers were overwhelmed with sediment during the earliest Plio-Pleistocene glacial episode. The overall correlation of clinker ages with elevation above local base level suggests generally increasing incision and topographic relief in the Basin over at least the last one million years, at rates of ~0.1-0.3 km/million years.


Story Source:

The above story is based on materials provided by The Geological Society of America. Note: Materials may be edited for content and length.


Journal Reference:

  1. Peter W. Reiners, Catherine A. Riihimaki, Edward L. Heffern. Clinker geochronology, the first glacial maximum, and landscape evolution in the northern Rockies. GSA Today, 2011; 4 DOI: 10.1130/G107A.1

Cite This Page:

The Geological Society of America. "Clinker geochronology, the first glacial maximum, and landscape evolution in the northern Rockies." ScienceDaily. ScienceDaily, 28 June 2011. <www.sciencedaily.com/releases/2011/06/110628094820.htm>.
The Geological Society of America. (2011, June 28). Clinker geochronology, the first glacial maximum, and landscape evolution in the northern Rockies. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2011/06/110628094820.htm
The Geological Society of America. "Clinker geochronology, the first glacial maximum, and landscape evolution in the northern Rockies." ScienceDaily. www.sciencedaily.com/releases/2011/06/110628094820.htm (accessed August 1, 2014).

Share This




More Earth & Climate News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
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:
from the past week

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