glomeroporphyritic Applied to those phenocrysts which have attached together to form clusters set within a finer-grained groundmass. The phenocryst clusters can form by the aggregation of separate crystals suspended in a melt or by partial disaggregation of crystal accumulations on the walls of the magma chamber.
More From encyclopedia.com
Septum , septum (pl. septa) A cross wall or partition. 1. A morphological term used particularly with reference to the Cephalopoda, whose shells are divided i… Caldera , Caldera A caldera is a large, usually circular depression at the summit of a volcano . Most calderas are formed by subsidence or sinking of the centr… Hydrothermal Systems (geology) , magma chamber A region, postulated to exist below the Earth's surface, in which magma is received from a source region in the deep crust or upper man… chamber , cham·ber / ˈchāmbər/ • n. 1. a hall used by a legislative or judicial body. ∎ the body that meets in such a hall. ∎ any of the houses of a legislatur… Cloud Chamber , cloud chamber cloud chamber, device used to detect elementary particles and other ionizing radiation. A cloud chamber consists essentially of a close… Whittaker Chambers , Whittaker Chambers Whittaker Chambers In 1948 TIME magazine editor Whittaker Chambers (1901-1961) testified that in the 1930s he helped organize a Co…
About this article
Updated About encyclopedia.com content Print Article
You Might Also Like