Editing Bethel Park, Pennsylvania (section)

===Geology===
The exposed rocks in Bethel Park are mostly composed of [[sandstone]], [[limestone]], [[shale]], and a few [[coal]] layers (Redstone, Waynesburg, Washington, etc.). The ages of the exposed rocks bracket the late [[Pennsylvanian (geology)|Pennsylvanian]] epoch ([[Gzhelian]] age; approximately 303 million years ago) near the lowest elevations, and [[Cisuralian|Early Permian]] period ([[Asselian]] age; approximately 297 million years ago) near the highest parts of the southern part of Bethel Park (e.g. Rocky Ridge). These sedimentary rocks were deposited as the sea level rose and fell along an ancient coastline (with the region alternating between delta, shallow lake, and shallow sea), and finally being uplifted with the formation of the [[Appalachian Mountains]].

Bethel Park is underlain by the Pennsylvania-age Monongahela Formation.  The Monongahela Formation consists of the Uniontown member and the underlying Pittsburgh member, and the base is the [[Pittsburgh coal seam]].  Much of southern Allegheny County is undermined, and the PADEP indicates that all of Bethel Park was undermined.<ref>{{cite web | url=http://www.dep.state.pa.us/dep/deputate/minres/bmr/msipage/Municipality%20Mine%20Maps/Allegheny_County/bethel_park_municipality.pdf | title=Municipality of Bethel Park, Allegheny County |website=Pennsylvania Department of Environmental Protection | date=2005-11-15 | archive-url=https://web.archive.org/web/20080227215223/http://www.dep.state.pa.us/dep/deputate/minres/bmr/msipage/Municipality%20Mine%20Maps/Allegheny_County/bethel_park_municipality.pdf | archive-date=2008-02-27 }}</ref>

A portion of the area is underlain by the [[Pittsburgh Coal Company|Pittsburgh Terminal No. 8 Mine]] (Cortis and others, 1975), which was commonly known as the "H" Mine and the Coverdale Mine.  The mine opened around 1920.<ref>{{cite web| url =http://patheoldminer.rootsweb.com/allh1.html| title="Coal Miners Memorial: "H" Mine, (Pittsburgh Terminal No. 8 Mine) (Coverdale Mine), Coverdale, Bethel Park, Allegheny County, PA" |author1=Washlaski, R.A. |author2=R.P. Washlaski |author3=P.E. Starry, Jr. | year=2007}}</ref>  The historic operations of the Coverdale Mine are apparent on a Bridgeville 7.5-minute topographic map.  A "Mine Dump" is shown adjacent to the Montour Railroad tracks and South Park Road.  Coal was mined through vertical shafts accessing inclined slopes following the dip of the [[Pittsburgh coal seam]].  Mine voids in the inclined slope resulted from the practice of [[room and pillar]] mining during the early 20th century.  The Coverdale Mine is closed and largely unflooded.<ref>{{cite web| url =http://www.hrc.nrcce.wvu.edu/final/DonovanDD.pdf | title=Long-Term Changes in Water Chemistry as a Result of Mine Flooding in Closed Mines of the Pittsburgh Coal Basin, USA. | work=Proceedings of 6th International Conference for Acid Rock Drainage, Cairns, Qld., Australia, July 12–18, 2003 |author1=Donovan, J.J. |author2=B R Leavitt |author3=E Werner | year=2003 | pages=869–875 }}</ref>