English: Conglomerate from the Pennsylvanian of Ohio, USA.

This rock is from the lowermost Pottsville Group, a Pennsylvanian-aged, cyclothemic succession in eastern Ohio that contains nonmarine shales, marine shales, siltstones, sandstones, coals, marine limestones, and chert ("flint"). The lower Pottsville dates to the late Early Pennsylvanian. The upper part dates to the early Middle Pennsylvanian. The Lower-Middle Pennsylvanian boundary is apparently somewhere near the Boggs Member (?).

At this southern Ohio site, the basal Pottsville is a spectacular quartz-pebble conglomerate, with a quartzose sandstone unit above it, plus coal and sandstone and shale above that.

In eastern and northeastern Ohio, the conglomeratic base of the Pottsville Group is called the Sharon Conglomerate (a.k.a. Sharon Sandstone; Sharon Formation; Sharon Member). The literature points out that the Sharon elsewhere in Ohio is not directly correlatable with the conglomerate exposed at this site near Jackson, Ohio. Thus, it has been suggested that the unit at this locality be referred to as the "Sharon" Conglomerate.

Here, the rocks are generally massive (= non-bedded) quartz-pebble conglomerates. Other clast lithologies and sizes are also present, including angular shale clasts, angular sandstone clasts (both derived from erosion of the underlying Logan Formation of Early Mississippian age), rounded to irregularly-shaped ironstone clasts, rounded quartz sandstone pebbles, rounded quartzite pebbles, and rounded silicified limestone pebbles. A very unusual clast type present at this outcrop is ferruginous, pyrite-cemented and hematite-cemented, quartz-pebble conglomerate (= conglomerate in conglomerate ! ).

The rusty coloration in this rock sample is from iron oxide.

Stratigraphy: "Sharon" Conglomerate, lowermost Pottsville Group, Lower Pennsylvanian

Locality: Jackson North Outcrop - roadcut along the southwestern side of Rt. 35, immediately southeast of the Rt. 35-Lloyds Bridge Road intersection (the northwestern intersection - there are two of them), north of the town of Jackson, northwest-central Jackson County, southern Ohio, USA (39° 06’ 32.94” North latitude, 82° 40’ 39.99” West longitude)