Tuesday, 24 February 2015

Orbiculite

Orbiculite








(Orbicular Granite )  Orbicular granite (also known as orbicular rock or orbiculite) is an uncommon plutonic rock type which is usually granitic in composition.

These rocks have unique appearance due to orbicules - concentrically layered, spheroidal structures, probably formed through nucleation around a grain in a cooling magma chamber. 
Almost a third of known orbicular rock occurrences are from Finland. The occurrences are usually very small. 
In New Zealand scattered boulders have been found, this example is from Western Australia.

Please follow this link to read more :- Orbiculite