Latitude:                             40° 28' 10"N

Longitude:                         80° 12' 27"W

Quadrangle:                       Oakdale 7 1/2'

Age:                                            Pennsylvanian

Formation(s):                          Conemaugh Group, Connellsville sandstone

Purpose:                            This site provides an excellent opportunity to view a large, well exposed sandstone channel. 

Outcrop is along the exit ramp from Rt. 60 eastbound, below road level in ravine and on cliff.  Best overall views are from edge of highway and from the opposite side (westbound) of the highway. Parking available for motor coach with strong caution. Get approval from State police for large groups.  Park along side guard rail along exit ramp from main highway. Not recommended for children.

The above map does not show present road configuration.

(Make sure you get an up-to-date PAT Transit schedule:

No PAT Transit service.

From the Cathedral of Learning, Drive 0.7 mi. west on Fifth Avenue. Make a Left on Craft Av. Go 0.1 mi., then make a right onto Blvd. of Allies, go 0.3 mi. then bear right onto entrance ramp to I-376. In Downtown Pittsburgh, bear left to I-279 South. Stay on this highway through the Fort Pitt tunnels. Continue west and bear onto Rt. 60 west toward the airport. Exit at the Clinton Road exit. Turn left at the end of the exit ramp, cross over the Main highway, and then reenter in the eastbound direction. Continue on Rt. 60 eastbound until you reach the next exit. Bear right onto the exit ramp and park along the Guardrail.

See map and figures.

This is actually an outcrop of the combined Connellsville sandstone and Morgantown sandstone with only a small portion of the intervening Clarksburg sequence. The Connellsville sandstone exhibits some spectacular sedimentary structures, including cross-bedding, point-bar structures, and abundant shale and wood fragments in the basal lag. The sharp erosional base of the channel cuts into the underlying layers and locally sits directly on the Little Clarksburg (?) coal. According to Harper (unpublished manuscript) this sandstone was used in the constructionof Rt. 60.

Geologic History: Environment of Deposition:

The Connellsville sandstone is a upper delta plain channel deposit. It has cut through the nearly the entire underlying shale sequence to partially rest on the Morgantown sandstone.

Upper Delta Plain Environment (from Horne and others, 1978).

Typical Section from Upper Delta plain (from Horne and others, 1978).

Click on the thumbnails below for pictures of the outcrops:

A view most of the outcrop from the opposite side of the highway.

A close-up of the west side of the outcrop showing the internal structure and bed distortion within the sandstone channel.

Close-up of the east side of the the outcrop showing the conglomerate at the base of the channel and the split in the Little Clarksburg coal.

Close-up of the base of the sandstone with woody fossil fragments.

Close-up of the sandstone channel sitting directly on the Little Clarksburg coal.

Common fossil wood casts and molds in the basal part of the channel sand. Coal and shales may contain plant fossils and fossil fragments.

Cross, A. T., 1971, The Geology of the Pittsburgh Coal, West Virginia Geological Survey Report of Investigations, No. 10., 99 p.

Edmunds, W. E., Skema, V. W., Flint, N. K., 1999, Pennsylvanian, in Shultz, C. H., ed, The Geology of Pennsylvania, Pennsylvania Geological Survey Special Publication 1, p. 149-169.

Gillespie, W. H., Clendening, J. A., and Pfefferkorn, H. W., 1978, Plant Fossils of West Virginia, West Virginia Geological Survey Educational Series ED-3A, 172p.

Harper, J. A., 1990, Fossil Collecting in the Pittsburgh Area, Pittsburgh Geological Society Guidebook. 50 pages.

Horne, J. C., Ferm, J. C., Caruccio, F. T., and Baganz, B. P., 1978, Depositional models in coal exploration and mine planning in Appalachian region: American Association of Petroleum Geologists Bulletin, v. 62, p. 2379-2411.

Johnson, M. E., 1928, Geology and Mineral Resources of the Pittsburgh Quadrangle, Pennsylvania: Pennsylvania Geological Survey Bulletin A 27, 236 p.

Leighton, H. 1945, The Geology of Pittsburgh and its Environs: A Popular Account of the General Geological Features of the Region: Carnegie Institute Press, 2nd edition, Pittsburgh, PA , 80p.

Shaw, E. W., and Munn, M. J., 1911, Geologic Atlas of the United States: Burgettstown-Carnegie Folio, United States Geological Survey Folio 177 Field Edition, 123p.

Wagner, W. R., and others, 1970, Geology of the Pittsburgh Area: Pennsylvania Geological Survey General Geology Report G 59, 145p.

Click here for  an image of the County Geologic Map (1880)