Featured Research

from universities, journals, and other organizations

Nanometer-scale Complexity, Growth, And Diagenesis In Desert Varnish

Date:
March 4, 2008
Source:
Geological Society of America
Summary:
Finely layered coatings, rich in manganese and iron and commonly called desert varnish, are common on rocks in desert environments worldwide. These coatings have been the subject of intense scientific debate and extensive research, owing to their potential for indicating past climates, for dating geological surfaces, and, via artwork carved in varnish, for providing information about ancient cultures.

Finely layered coatings, rich in manganese and iron and commonly called desert varnish, are common on rocks in desert environments worldwide. These coatings have been the subject of intense scientific debate and extensive research, owing to their potential for indicating past climates, for dating geological surfaces, and, via artwork carved in varnish, for providing information about ancient cultures.

Related Articles


The full scientific potential of desert varnish can only be realized through a rigorous probing of the physico-chemical variables and fundamental properties of varnish components, especially its mineralogical components.

Determining the mineralogy of the manganese- and iron-bearing materials is challenging because the minerals are extremely fine grained, generally down to nanometer-sized, and often poorly crystalline.

In addition, the thin film-like nature of varnish on rock makes separating and studying it difficult. Garvie et al. used novel sample preparation methods, high-resolution electron microscopy, and spectroscopic imaging to provide novel insights into desert varnish structure, mineralogy, and chemistry.

The spectroscopic imaging shows nanometer-scale separation of manganese- and iron-bearing phases, possibly reflecting differing degrees of chemical oxidation. A suite of late-grown manganese and iron phases commonly occur also, together with sparse barium and strontium sulfates, and rare, entrained, carbonaceous particles.

These data demonstrate that varnish remains a mineralogically and structurally active system. They furthermore suggest that there must be strict climate controls on varnish growth.

 This research by Laurence Garvie et al., Center for Meteorite Studies, School of Earth and Space Exploration, Arizona State University was published in the March issue of Geology, Pages 215-218.


Story Source:

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


Cite This Page:

Geological Society of America. "Nanometer-scale Complexity, Growth, And Diagenesis In Desert Varnish." ScienceDaily. ScienceDaily, 4 March 2008. <www.sciencedaily.com/releases/2008/02/080229183457.htm>.
Geological Society of America. (2008, March 4). Nanometer-scale Complexity, Growth, And Diagenesis In Desert Varnish. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/2008/02/080229183457.htm
Geological Society of America. "Nanometer-scale Complexity, Growth, And Diagenesis In Desert Varnish." ScienceDaily. www.sciencedaily.com/releases/2008/02/080229183457.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Aquaponics Turn Suburban Industrial Park Into Farmland: Hume

Aquaponics Turn Suburban Industrial Park Into Farmland: Hume

The Toronto Star (Jan. 27, 2015) — Ancient techniques of growing greens with fish and water are well ahead of Toronto bylaws. Video provided by The Toronto Star
Powered by NewsLook.com
Storm Slams New England, Spares Mid-Atlantic

Storm Slams New England, Spares Mid-Atlantic

AP (Jan. 27, 2015) — A howling blizzard with wind gusts over 70 mph heaped snow on Boston along with other stretches of lower New England and Long Island on Tuesday, but failed to live up to the hype in Philadelphia and New York City. (Jan. 27) Video provided by AP
Powered by NewsLook.com
Mexico's Volcano of Fire Erupts Again

Mexico's Volcano of Fire Erupts Again

Reuters - News Video Online (Jan. 26, 2015) — A huge plume of smoke shoots into the air as activity in Mexico&apos;s Volcano of Fire picks up again. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Time Lapse: Snow, Frost Piling Up in New York's Times Square

Time Lapse: Snow, Frost Piling Up in New York's Times Square

Reuters - US Online Video (Jan. 26, 2015) — Video shows the accumulation of snow and frost in New York City&apos;s Times Square over five hours on Monday. Time Lapse (no reporter narration). Video provided by Reuters
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