Editing Somerset County, Pennsylvania (section)

==Geology==
Somerset County is situated along the eastern border of the [[Allegheny Plateau]] [[United States physiographic region|physiographic province]], which is characterized by gently [[Fold (geology)|folded]] to flat-lying [[sedimentary rock]]s of middle to late [[Paleozoic]] age. The eastern border of the county is approximately at the [[Allegheny Front]], a geological boundary between the Allegheny Plateau and the [[Ridge-and-Valley Appalachians|Ridge and Valley]] Province (characterized by [[Fold (geology)|folded]] and [[Fault (geology)|faulted]] [[sedimentary rock]]s of early to middle Paleozoic age).<ref>{{cite web|url=http://www.dcnr.state.pa.us/topogeo/maps/map13.pdf |archive-url=https://web.archive.org/web/20011116133635/http://www.dcnr.state.pa.us/topogeo/maps/map13.pdf |archive-date=November 16, 2001 |url-status=dead|title=Geology, Map 13|website=www.dcnr.state.pa.us|access-date=November 29, 2018}}</ref>

The [[Stratigraphy|stratigraphic record]] of sedimentary rocks within the county spans from the [[Devonian]] [[Scherr Formation]] to the [[Pennsylvanian (geology)|Pennsylvanian]] [[Virgilian series|Monongahela Formation]]. Most of these rocks are clastics ([[conglomerate (geology)|conglomerate]], [[sandstone]], [[shale]]), and there is little or no [[limestone]] exposed at the surface. No [[Igneous Rock|igneous]] or [[Metamorphic Rock|metamorphic]] rocks of any kind exist within the county.

[[Structural Geology|Structurally]], Somerset County has many gentle [[Fold (geology)|folds]], the axes of which trend roughly north-northeast. [[Syncline]]s include the Youghiogheny Syncline, New Lexington/Johnstown Syncline, Somerset Syncline, Berlin Syncline, and Wellersburg Syncline (called the George's Creek Syncline in Maryland). The southern end of Wilmore Syncline is at the town of Windber. [[Anticline]]s include the Laurel Hill Anticline, Centerville Dome, Boswell Dome, Negro Mountain Anticline, and an unnamed anticline between the Berlin and Wellersburg Synclines.

The primary mountains within the county are (from west to east) [[Laurel Hill (Pennsylvania)|Laurel Hill]] (which forms part of the western border), [[Negro Mountain]], Meadow Mountain, [[Savage Mountain]], and [[Allegheny Mountain (Pennsylvania)|Allegheny Mountain]]. Negro Mountain also includes [[Mount Davis (Pennsylvania)|Mount Davis]], the highest peak in Pennsylvania. Each mountain trends northeast.

All of Somerset County lies far to the south of the [[terminal moraine]], and thus it was never glaciated.<ref>{{cite news|url=http://www.dcnr.state.pa.us/topogeo/maps/map59.pdf |archive-url=https://web.archive.org/web/20011116140157/http://www.dcnr.state.pa.us/topogeo/maps/map59.pdf |archive-date=November 16, 2001 |url-status=dead|title=Geology, Map 59|newspaper=Pennsylvania Department of Conservation & Natural Resources|access-date=November 29, 2018}}</ref> However, during the [[Pleistocene]] epoch (the Ice Age), [[periglacial]] processes dominated. Most of the county was most likely a [[tundra]] during the Pleistocene. [[Patterned ground]] typical of tundra is still visible at [[Mount Davis (Pennsylvania)|Mount Davis]], although it is somewhat obscured by vegetation.

The main drainages in southwestern Somerset county are the [[Casselman River]] and [[Laurel Hill Creek]] which flow into the [[Youghiogheny River]] along the southwest border. In the northwest, [[Stonycreek River]], [[Shade Creek]], and Quemahoning Creek (which flows into the [[Quemahoning Reservoir]]) are tributaries of the [[Conemaugh River]]. All these drainages are part of the [[Mississippi River]] Watershed. In the southeast, [[Wills Creek (North Branch Potomac River)|Wills Creek]] flows east into Bedford County and then into Maryland where it joins the [[Potomac River]]. Also, the headwaters of the [[Raystown Branch Juniata River|Raystown Branch of the Juniata River]] are to the east of the town of Somerset. Both the Potomac and Juniata rivers are part of the [[Chesapeake Bay]] Watershed.

[[Coal]] fields exist within Somerset County. The coal is entirely [[bituminous]], and much of it has been mined or is being mined by [[Surface mining|Strip mining]]. Most of the coal is within the Main Bituminous Field, which stretched north and west to adjacent counties and southward into Maryland and West Virginia. The rest is within the Georges Creek Field.<ref>{{cite web|url=http://www.dcnr.state.pa.us/topogeo/maps/map11.pdf |archive-url=https://web.archive.org/web/20000918074050/http://www.dcnr.state.pa.us/topogeo/maps/map11.pdf |archive-date=September 18, 2000 |url-status=dead|title=Geology, Map 11|website=www.dcnr.state.pa.us|access-date=November 29, 2018}}</ref>

There are many abandoned mines in the county, and [[acid mine drainage]] is an environmental problem in many areas. Fishless streams exist as a result of the discharge from the abandoned mines. These include parts of the [[Casselman River]], [[Shade Creek]], [[Stonycreek River]], and Quemahoning Creek, as well as many of their tributaries.<ref>[http://bedford.sapdc.org/bedford/lib/bedford/AcidMineDrainage.pdf]{{dead link|date=December 2017|bot=InternetArchiveBot|fix-attempted=yes}}</ref>

There are many small, deep [[natural gas]] fields in the northwestern part of the county.<ref>{{cite web|url=http://www.dcnr.state.pa.us/topogeo/maps/map10.pdf |archive-url=https://web.archive.org/web/20000918074027/http://www.dcnr.state.pa.us/topogeo/maps/map10.pdf |archive-date=September 18, 2000 |url-status=dead|title=Geology, Map 10|website=www.dcnr.state.pa.us|access-date=November 29, 2018}}</ref>