Definition: A volcano created by geologically excreted liquids and gases, although there are several different processes which may cause such activity. Temperatures are much cooler than igneous processes.
Definition: Sediment is an environmental substance comprised of any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bedor bottom of a body of water or other liquid.
Definition: A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)