Checked content

File:North america basement rocks.png

North_america_basement_rocks.png(484 × 429 pixels, file size: 13 KB, MIME type: image/png)

North American cratons and basement rocks.

As radiometric ages were determined for the shield-like rocks on the continents which were either exposed at the surface, underlay the flat rocks, or were within the interior of the mountain belts, patterns of age intervals were determined. These old rocks have been called the "basement". This has been interpreted to mean that the continents had somehow grown by development of rock assemblages with these characteristic age parameters. The expanding continental nuclei are part of the "craton" which consist of both exposed and buried basement rocks.

Source

Public domain This image is in the public domain because it contains materials that originally came from the United States Geological Survey, an agency of the United States Department of the Interior. For more information, see the official USGS copyright policy.

български | català | Deutsch | English | español | eesti | suomi | français | galego | italiano | 한국어 | македонски | മലയാളം | Nederlands | polski | português | русский | Türkçe | 中文(香港)‎ | 中文(简体)‎ | +/−

USGS logo green.svg

http://rst.gsfc.nasa.gov/Sect2/14strprv.jpg or http://instruct.uwo.ca/earth-sci/300b-001/14strprv.gif

English Wikipedia, original upload 22 April 2005 by Berkut

History

Originally uploaded by User:SEWilco as Image:North america basement rocks.jpg. Replaced when this better version found.


derivative works

Derivative works of this file:

The following pages on Schools Wikipedia link to this image (list may be incomplete):

Learn more about Schools Wikipedia

SOS Children's Villages has brought Wikipedia to the classroom. Our 500 Children's Villages provide a home for thousands of vulnerable children. Beyond our Villages, we support communities, helping local people establish better schools and delivering effective medical care to vulnerable children. Sponsoring a child is the coolest way to help.