Orbicular Granite Origin

These rocks have a unique appearance due to orbicules concentrically layered spheroidal structures probably formed through nucleation around a grain in a cooling magma chamber.

Orbicular granite origin. Rapakivi granite obtained commercially spheres up to approx. The origin and age of the orbicular granite gneiss in. The orbicular granitoid formed in situ in a pocket of evolved and volatile rich melt segregated from the surrounding partially crystallized huaco granite possibly via a filter pressing mechanism. The northeast and west coast of tasmania contain large granite batholiths around 360 million years old.

Orbicular granite near trial harbour tasmania australia. This structure is from the mid proterozoic eon and was formed approximately one billion years ago. Other similar sites in finland and chile enjoy the status of protected site. 5 cm actually not a true orbicular granite.

The nature and polygenetic origin of orbicular granodiorite in the lower castle creek pluton northern sierra nevada batholith california arthur gibbs sylvester department of earth science university of california santa barbara california 93106 usa origin and evolution of the sierra nevada and walker lane themed issue 39 24 120 17. The closest site is in namaqualand south africa. The orbicular granite formation is very rare. One of the largest ones is called the heemskirk granite and it is exposed along the shore at trial and granville harbour near the town of zeehan in western.

This paper describes an assemblage and origin of some remarkable orbicular rocks with felsic haloes in a single pipe like exposure in the granodiorite of lower castle creek pluton in the northern sierra nevada batholith these orbicular rocks bear similarities to some of those elsewhere in the sierra nevada moore and lockwood 1973 although they are larger and better developed than most. Orbicular granite also known as orbicular rock or orbiculite is an uncommon plutonic rock type which is usually granitic in composition. Origin in scandinavia found in glacially transported material in lower saxony germany.