05.07.2009

Altering the form of a substance from solid to gaseous. The process through which ice goes directly into a vapor without passing through the liquid state.

or,

A frozen substance sublimates when it passes directly into the gas phase without first becoming liquid

A tectonic process that occurs at the boundary of two converging plates, whereby oceanic crust slides below continental crust into the mantle and causes melting that results in a zone of volcanism along that boundary

An oil and gas development project is sub-commercial if the degree of commitment is not such that the accumulation is expected to be developed and placed on production within a reasonable time frame which is usually limited to around 5 years

A type of coal that is dull black and has less moisture than lignite. Subbituminous is generally used to produce steam for electricity generation

Variety of sandstone in which 25% percent of the sand grains are composed of feldspar