Nature Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! ===Geology=== {{Main|Geology}} Geology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, [[structural geology|structure]], [[Physical property|physical properties]], dynamics, and [[History of the Earth|history]] of [[Earth materials]], and the processes by which they are formed, moved, and changed. The field is a major [[academic discipline]], and is also important for [[mining|mineral]] and [[petroleum geology|hydrocarbon]] extraction, knowledge about and mitigation of [[natural hazard]]s, some [[Geotechnical engineering]] fields, and understanding [[Paleoclimatology|past climates]] and environments. ====Geological evolution==== [[File:Tectonic plate boundaries.png|thumb|left|upright=1.3|Three types of geological [[plate tectonic]] boundaries]] The geology of an area evolves through time as rock units are deposited and inserted and deformational processes change their shapes and locations. Rock units are first emplaced either by [[deposition (geology)|deposition]] onto the surface or intrude into the [[Country rock (geology)|overlying rock]]. Deposition can occur when [[sediment]]s settle onto the surface of the Earth and later [[lithification|lithify]] into [[sedimentary rock]], or when as [[volcanic rock|volcanic material]] such as [[volcanic ash]] or [[lava]] flows, blanket the surface. Igneous [[intrusion]]s such as [[batholith]]s, [[laccolith]]s, [[dike (geology)|dikes]], and [[sill (geology)|sills]], push upwards into the overlying rock, and crystallize as they intrude. After the initial sequence of rocks has been deposited, the rock units can be [[deformation (mechanics)|deformed]] and/or [[metamorphism|metamorphosed]]. Deformation typically occurs as a result of horizontal shortening, [[extension (geology)|horizontal extension]], or side-to-side ([[strike-slip]]) motion. These structural regimes broadly relate to [[convergent boundary|convergent boundaries]], [[divergent boundary|divergent boundaries]], and [[transform boundary|transform boundaries]], respectively, between [[plate tectonics|tectonic plates]]. Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page