The Anthracite Upland is the most complex and most studied section
in the state. This area is home to one of Pennsylvania's most
profitable coal fields ever, containing high-grade Anthracite coal.
Mountains are steep-sided and valleys are canoe-shaped, largely due
to its complex folded structure. Other than coal, cyclical
sequences of shale, sandstone, and conglomerate also make up this
region. The rocks are from the Carboniferous period, divided into
the Mississippian and Pennsylvanian periods with almost all of the
coal being mined from Pennsylvanian-aged formations. Along with the
Mazon Creek fossil field in Illinois, a tremendous amount of plant
fossils have been studied from this area. Landsides and acid mine
drainage are two principle hazards of the area. In the past,
underground mine fires have also been a threat. The Centralia Mine
Fire is located within this section.
Exposed by strip mining, the whaleback is quite large and
distinctive. The rocks on top of it are the size of cars.
At the Bear Valley Strip Mine, a sequence of deformational
stages of the Alleghany orogeny can be interpreted from overprinted
structures in rocks of Pennsylvanian age. All of the stages
displayed must be Pennsylvanian or younger but no Mesozoic
deformation is thought to have occurred here. Rocks of the Bear
Valley Strip Mine were deformed at temperatures of 185° to
205°C under an overburden of 3.1 to 5.0 mi (5 to 8 km)
To qualify as a "find", email (do not post online) the answers
to the following questions:
1) Explain what geological structures combined to form the
"whaleback".
2) What is the rock sequence in the Bear Valley strip mine? (ie.
name several of the 7 specific rocks occuring here).
3) Why is the "whaleback" anticline significant in demonstrating
structural geology?
4) UPLOAD a photo clearly showing the "whaleback" in the background
with yourself and GPS.
