Northwestern Glaciated Plateau Section
Appalachian Plateaus Province


Northwestern Glaciated Plateau Section showing geology and shaded relief

The Northwestern Glaciated Plateau Section consists of many broad, rounded uplands cut by long, linear valleys. The uplands have a southeast-oriented linearity that is pronounced in eastern Erie and central Crawford Counties. Elsewhere upland linearity is obscure to absent. The uplands are cut by many flat-floored, narrow to wide valleys that are separated from adjacent uplands by steep slopes on one or both sides of the valley. The valleys are very linear and are oriented north-west-southeast for the most part although some valleys are normal to this orientation. The valley floors are often wetlands. There is frequently a considerable depth of unconsolidated material beneath the valley floor. Local relief between valley floor and the top of an adjacent upland may be up to 600 feet, but is generally less. Local relief on the valley floors and the uplands is less than 100 feet. Elevation ranges from 900 to 2,200 feet. Drainage pattern is dendritic. Bedrock, which is largely covered by glacial deposits, consists of a variety of sandstones, siltstones, shales, as well as some conglomerates and coal. Bedding in the rocks is horizontal. Many of these rocks are rela-tively soft and were easily eroded into linear landforms by the continental glaciers.

The Section occurs in northwestern Pennsylvania and includes all or almost all of Erie, Crawford, Mercer, and Lawrence Counties and parts of Warren, Venango, Butler, and Beaver Counties. Routes along which the Section is well seen are: Interstate 80 in Mercer County and Interstate 79 between Erie and the Section boundary south of Interstate 80; US Route 6 from west of Warren to Ohio; and US Route 322 from west of Franklin to Ohio; Pennsyl-vania Routes 89 north of Titusville, 18 from the Section boundary west of Erie to Beaver County, and 108 in Lawrence County. Other interesting drives on Pennsylvania Routes are: 8 north of Titusville, 19 from Erie to Butler County, 77, 27, and 285 in Crawford County, 208 in Lawrence County, 58, 358, and US Route 62 in Mercer County.

The Section includes Outstanding Geological Features such as: Conneaut Lake, Conneaut Lake Kame, Conneaut Marsh, Dead-ice Terminal Moraine, Drumlins, Grant City Falls, Pikes Rocks, Quakertown Falls, Rock Creek Falls, Springfield Falls, Tamarack Swamp, Titus Bog, and West Liberty Esker. Near Pikes Rocks are: Lottsville Rock City, Nuttles Rocks, Brooks Rocks, and Baker Rocks. Rock Creek Falls occurs in Rock Creek Ravine.

State Parks in the Section include Pymatuning and Maurice K. Goddard.

There are no State Forest Natural Areas in the Section.