Editing Structural geology (section)

==Use and importance==
The study of geologic structures has been of prime importance in [[economic geology]], both [[petroleum geology]] and [[mining|mining geology]].<ref>{{cite book|last=Russell|first=William L|title=Structural Geology for Petroleum Geologists|publisher=McGraw-Hill|location=New York|year=1955|pages=1|chapter=1. Introduction|chapter-url=https://www.questia.com/PM.qst?a=o&docId=11442903}}</ref> [[Fold (geology)|Folded]] and faulted rock [[stratum|strata]] commonly form traps that accumulate and concentrate fluids such as [[petroleum]] and [[natural gas]]. Similarly, faulted and structurally complex areas are notable as permeable zones for [[hydrothermal]] fluids, resulting in concentrated areas of base and precious metal [[ore]] deposits. Veins of minerals containing various metals commonly occupy faults and fractures in structurally complex areas. These structurally fractured and faulted zones often occur in association with [[Intrusive rock|intrusive]] [[igneous rock]]s. They often also occur around geologic [[reef]] complexes and collapse features such as ancient [[sinkhole]]s. Deposits of [[gold]], [[silver]], [[copper]], [[lead]],  [[zinc]], and other metals, are commonly located in structurally complex areas.

Structural geology is a critical part of [[engineering geology]], which is concerned with the physical and mechanical properties of natural rocks. Structural fabrics and defects such as faults, folds, foliations and [[joint (geology)|joints]] are internal weaknesses of rocks which may affect the stability of human engineered structures such as [[dam]]s, road cuts, [[open pit]] mines and [[Underground mining (hard rock)|underground mines]] or road [[tunnel]]s.

[[Geotechnical]] risk, including [[earthquake]] risk can only be investigated by inspecting a combination of structural geology and [[geomorphology]].<ref>{{cite web|url=http://pubs.usgs.gov/gip/dynamic/tectonics.html|title=Plate tectonics and people|work=USGS}}</ref> In addition, areas of [[Karst topography|karst]] landscapes which reside atop caverns, potential sinkholes, or other collapse features are of particular importance for these scientists. In addition, areas of steep slopes are potential collapse or landslide hazards.

[[Environmental geology|Environmental geologists]] and [[hydrogeology|hydrogeologists]] need to apply the tenets of structural geology to understand how geologic sites impact (or are impacted by) [[groundwater]] flow and penetration.  For instance, a hydrogeologist may need to determine if seepage of toxic substances from waste dumps is occurring in a residential area or if salty water is seeping into an [[aquifer]].

[[Plate tectonic]]s is a theory developed during the 1960s which describes the movement of continents by way of the separation and collision of crustal plates. It is in a sense  structural geology on a planet scale, and is used throughout structural geology as a framework to analyze and understand global, regional, and local scale features.<ref>{{cite journal|first1=Richard F. |last1=Livaccari |first2=Kevin |last2=Burke |first3=A. M. C.|last3=Scedilengör|title=Was the Laramide orogeny related to subduction of an oceanic plateau?|journal=[[Nature (journal)|Nature]]|volume=289|pages=276&ndash;278 | doi=10.1038/289276a0|issue=5795|bibcode = 1981Natur.289..276L |year=1981 |s2cid=27153755 }}</ref>