NODULE - 3 reference results
nodule: see concretion.
The Columbia Electronic Encyclopedia Copyright © 2004.
Licensed from Columbia University Press
Licensed from Columbia University Press
In geology, a rounded mineral concretion that is distinct from, and may be separated from, the formation in which it occurs. Nodules usually are elongated and have a knobby irregular surface; they are generally oriented parallel to the bedding. Chert and flint, clay ironstone, and phosphorites commonly occur as nodules. Manganese-rich nodules are found on the ocean floor.
Learn more about nodule with a free trial on Britannica.com.
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Copyright © 2009, Dictionary.com, LLC. All rights reserved.