- Radiolarite
-
Radiolarite is a siliceous, comparatively hard, fine-grained, chert-like, and homogeneous sedimentary rock that is composed predominantly of the microscopic remains of radiolarians. This term is also used for indurated radiolarian oozes and sometimes as a synonym of radiolarian earth. However, radiolarian earth is typically regraded by Earth scientists to be the unconsolidated equivalent of a radiolarite. A radiolarian chert is well-bedded, microcrystalline radiolarite that has a well-developed siliceous cement or groundmass.[1]
The Windalia radiolarite is a Cretaceous formation in Western Australia. The formation contains abundant foraminifera, radiolaria and calcareous nanoplankton fossils.[2] Locally the varicolored opaline to chalcedonic radiolarite is mined and used as an ornamental stone termed mookaite.[3]
References
- ^ Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) Glossary of Geology (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. ISBN 0-922152-76-4
- ^ http://www.informaworld.com/smpp/content~content=a795070741~db=all~order=page D. W. Haig, et. al., Mid-Cretaceous calcareous and siliceous microfossils from the basal Gearle Siltstone, Giralia Anticline, Southern Carnarvon Basin, Alcheringa: An Australasian Journal of Palaeontology, Volume 20, Issue 1, 1996, pages 41‑68
- ^ Mookaite at mindat.org
External links
- Radiolarian Ribbon Chert in the Marin Headlands (NPS)
- Chert FAQ - NPS
- Photo of radiolarite in Corsica, France (text in French) retrieved 2009-05-17
This article related to petrology is a stub. You can help Wikipedia by expanding it.
