Editing Geology (section)

==Applied geology==
[[File:Panning on the Mokelumne.jpg|thumb|upright|Man panning for [[gold]] on the [[Mokelumne]]. [[Harper's Weekly]]: How We Got Gold in California. 1860 ]]

===Economic geology===
{{Main|Economic geology}}

Economic geology is a branch of geology that deals with aspects of economic minerals that humankind uses to fulfill various needs. Economic minerals are those extracted profitably for various practical uses. Economic geologists help locate and manage the Earth's [[natural resource]]s, such as petroleum and coal, as well as mineral resources, which include metals such as iron, copper, and uranium.

====Mining geology====
{{Main|Mining}}
[[Mining geology]] consists of the extractions of mineral and ore resources from the Earth. Some resources of economic interests include [[gemstone]]s, [[metal]]s such as [[gold]] and [[copper]], and many minerals such as [[asbestos]], [[Magnesite]], [[perlite]], [[mica]], [[phosphate]]s, [[zeolites]], [[clay]], [[pumice]], [[quartz]], and [[silica]], as well as elements such as [[sulfur]], [[chlorine]], and [[helium]].

====Petroleum geology====
[[File:Mudlogging.JPG|thumb|Mud log in process, a common way to study the [[lithology]] when drilling oil wells]]
{{Main|Petroleum geology}}
[[Petroleum geologist]]s study the locations of the subsurface of the Earth that can contain extractable hydrocarbons, especially [[petroleum]] and [[natural gas]]. Because many of these reservoirs are found in [[sedimentary basin]]s,<ref>{{Cite book |author=Selley |first=Richard C. |title=Elements of petroleum geology |publisher=Academic Press |year=1998 |isbn=978-0-12-636370-8 |location=San Diego, California}}</ref> they study the formation of these basins, as well as their sedimentary and tectonic evolution and the present-day positions of the rock units.

===Engineering geology===
{{Main|Engineering geology|Soil mechanics|Geotechnical engineering}}
Engineering geology is the application of geological principles to engineering practice for the purpose of assuring that the geological factors affecting the location, design, construction, operation, and maintenance of engineering works are properly addressed. Engineering geology is distinct from [[geological engineering]], particularly in North America.
[[File:New water well opens in Shant Abak DVIDS92609.jpg|thumb|upright|A child drinks water from a [[well]] built as part of a hydrogeological humanitarian project in [[Kenya]].]]

In the field of [[civil engineering]], geological principles and analyses are used in order to ascertain the mechanical principles of the material on which structures are built. This allows tunnels to be built without collapsing, bridges and skyscrapers to be built with sturdy foundations, and buildings to be built that will not settle in clay and mud.<ref>{{Cite book |isbn=978-0-534-55144-5 |author=Das, Braja M. |year=2006 |publisher=Thomson Learning|location=England |title=Principles of geotechnical engineering}}</ref>

===Hydrology===
{{Main|Hydrogeology}}

Geology and geological principles can be applied to various environmental problems such as [[stream restoration]], the restoration of [[brownfields]], and the understanding of the interaction between [[natural habitat]] and the geological environment. Groundwater hydrology, or [[hydrogeology]], is used to locate groundwater,<ref name="Hamilton, Pixie A. 1995 217">{{Cite journal |doi=10.1111/j.1745-6584.1995.tb00276.x |title=Effects of Agriculture on Ground-Water Quality in Five Regions of the United States |year=1995 |author=Hamilton, Pixie A. |journal=Ground Water |volume=33 |pages=217–226 |last2=Helsel |first2=Dennis R. |issue=2 |bibcode=1995GrWat..33..217H |url=https://zenodo.org/record/1230722 |access-date=2020-08-29 |archive-date=2020-10-31 |archive-url=https://web.archive.org/web/20201031082104/https://zenodo.org/record/1230722 |url-status=live }}</ref> which can often provide a ready supply of uncontaminated water and is especially important in arid regions,<ref>{{Cite journal |doi=10.1080/07900629948916 |title=Water Scarcity in the Twenty-first Century |year=1999 |author=Seckler, David |journal=International Journal of Water Resources Development |volume=15 |issue=1–2 |pages=29–42 |last2=Barker |first2=Randolph |last3=Amarasinghe |first3=Upali|bibcode=1999IJWRD..15...29S }}</ref> and to monitor the spread of contaminants in groundwater wells.<ref name="Hamilton, Pixie A. 1995 217"/><ref>{{Cite journal |doi=10.1111/j.1745-6584.1988.tb00397.x |title=Arsenic in Ground Water of the Western United States |year=1988 |author=Welch, Alan H. |journal=Ground Water |volume=26 |pages=333–347 |last2=Lico |first2=Michael S. |last3=Hughes |first3=Jennifer L. |issue=3|bibcode=1988GrWat..26..333W }}</ref>

===Paleoclimatology===
{{Main|Paleoclimatology}}

Geologists also obtain data through stratigraphy, [[boreholes]], [[core sample]]s, and [[ice core]]s. Ice cores<ref>{{Cite journal |author=Barnola |first1=J. M. |last2=Raynaud |first2=D. |last3=Korotkevich |first3=Y. S. |last4=Lorius |first4=C. |year=1987 |title=Vostok ice core provides 160,000-year record of atmospheric CO2 |journal=Nature |volume=329 |issue=6138 |pages=408–414 |bibcode=1987Natur.329..408B |doi=10.1038/329408a0 |s2cid=4268239}}</ref> and sediment cores<ref>{{Cite journal |author=Colman |first1=S. M. |last2=Jones |first2=G. A. |last3=Forester |first3=R. M. |last4=Foster |first4=D. S. |year=1990 |title=Holocene paleoclimatic evidence and sedimentation rates from a core in southwestern Lake Michigan |journal=Journal of Paleolimnology |volume=4 |issue=3 |pages=269 |bibcode=1990JPall...4..269C |doi=10.1007/BF00239699 |s2cid=129496709}}</ref> are used for paleoclimate reconstructions, which tell geologists about past and present temperature, precipitation, and [[sea level]] across the globe. These datasets are our primary source of information on [[global climate change]] outside of instrumental data.<ref>{{Cite journal |last1=Jones |first1=P. D. |last2=Mann |first2=M. E. |date=6 May 2004 |title=Climate over past millennia |url=http://www.meteo.psu.edu/holocene/public_html/shared/articles/JonesMannROG04.pdf |url-status=live |journal=Reviews of Geophysics |volume=42 |issue=2 |page=RG2002 |bibcode=2004RvGeo..42.2002J |doi=10.1029/2003RG000143 |archive-url=https://web.archive.org/web/20190411223135/http://www.meteo.psu.edu/holocene/public_html/shared/articles/JonesMannROG04.pdf |archive-date=11 April 2019 |access-date=28 August 2015 |doi-access=free}}</ref>

===Natural hazards===
[[File:GCRockfall.JPG|thumb|Rockfall in the Grand Canyon]]
{{Main|Natural hazard#Geological hazards}}
Geologists and geophysicists study natural hazards in order to enact safe [[building code]]s and warning systems that are used to prevent loss of property and life.<ref>[http://www.usgs.gov/hazards/ USGS Natural Hazards Gateway]. {{Webarchive|url=https://web.archive.org/web/20100923133848/http://www.usgs.gov/hazards/|date=2010-09-23}}. usgs.gov.</ref> Examples of important natural hazards that are pertinent to geology (as opposed those that are mainly or only pertinent to meteorology) are:
{{columns-list|colwidth=22em|
* [[Avalanche]]s
* [[Earthquake]]s
* [[Flood]]s
* [[Landslide]]s and [[debris flow]]s
* [[River channel migration]] and [[Avulsion (river)|avulsion]]
* [[Rockfall]]s
* [[Sinkhole]]s
* [[Soil liquefaction]]
* [[Subsidence]]
* [[Tsunami]]s
* [[Volcano]]es
}}