Latitude:                         40° 16' 67"N

Longitude:                      80° 07' 36"W

Quadrangle:                    Canonsburg 7 1/2'

Age:                                 Permian

Formation(s):                  Dunkard Group, Lower Washington Formation, Lower Member, sandstone channel just above coal horizon, Waynesburg sandstone (?).

Purpose:                         This site provides easy access to a interesting sandstone channel.

Park in parking lot south of K Mart, near hill side in back of building. Walk to outcrop on hill side. Parking available for motor coach. Recommended for all age groups.

(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. Stay on this highway through the Fort Pitt tunnels. Go a total of 8.0 mi. and exit onto I-79 south. Go to the Canonsburg Exit. Bear right at the exit and at the stop light at the end of the exit ramp, go left. Go 1.2 miles to the intersection with Rt. 19.  Turn left (north) on Rt. 19. Go 1.6 miles and turn right into the parking lot of the KMart shopping center. Drive to the right (south) side of the complex and pull around back to the outcrops.

See map and figures.

Here is a well exposed sandstone channel in the lower portion of the Washington Formation. Common rip-up clasts in the base of the channel sand indicate basal erosion as the channel prograded over pre-existing sediment. The channel contain some good examples of cross-bedding and a sharp erosional base.

Geologic History: Environment of Deposition:

The Lower Waynesburg formation represents the upper delta plain environment that extends into a regional basin that is being filled from the rising Appalachian mountains to the southeast (today's direction) and from highlands to the north (today's direction).

Here are the facies relationships in the Upper Pennsylvanian Uniontown Formation and the Permian Waynesburg Formation in southern Pennsylvanian and Northern West Virginia.  This is from an untitled late 1970's guidebook by A. C. Donaldson (West Virginia University, retired).

Paleogeographic map showing the region during the during Waynesburg sandstone time. Red square is Pittsburgh.

The above two figures show the modern Ganges Delta. Compare with the paleogeographic map above.

Click on the thumbnails below for pictures of the outcrops:

A look down the length of the outcrop showing the shape of the sandstone channel.

Close-up of cross-bedding within the channel.

A view showing the internal structure of the channel.

Close-up of rip-up clast impressions in base of channel sandstone.

A view of the north end of the outcrop showing the termination of the channel sandstone body.

Close-up of nodular gray shales and siltstones below channel at north end of outcrop.

Rare fragmented fossil plants may be found in the shales.

Berryhill, H. L., Jr., Schweinfurth, S. P., and Kent, B. H., 1971, Coal-bearing Upper Pennsylvanian and Lower Permian Rocks, Washington area, Pennsylvania: U. S. Geological Survey Professional Paper 621, 47p.

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.

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

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)