Pyrite-filled burrow (?) in limestone in the Pennsylvanian of Ohio, USA.

The Pottsville Group is 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 (?).

The Boggs Member is a relatively thin stratigraphic interval in the Pottsville Group. It typically consists of marine fossiliferous limestones, dominated by brachiopods and crinoid ossicles. Significant lateral and vertical lithologic variation is present - the Boggs interval ranges from being a fossiliferous limestone to an intraclastic limestone to a chert to a dolostone. In places, it has a relatively high component of disseminated pyrite. In other places, it is relatively rich in black manganese oxide(s).

Minerals observed in the Boggs Limestone interval: calcite, dolomite, glauconite, goethite, gypsum, limonite, pyrite, sphalerite, turgite, vivianite, wad.

This limestone has a slightly discolored structure (from near-upper left to the bottom of the photo) that is a possible trace fossil (burrow) (?). The filling is dominated by small, subrounded pyrite masses (click on the photo to zoom in and look around).

Stratigraphy: Boggs Member, middle Pottsville Group, lower Atokan Stage, lower Middle Pennsylvanian

Locality: ravine below the southern side of Rt. 208 (= Dresden-Adamsville Road), east of the town of Dresden, Madison Township, Muskingum County, eastern Ohio, USA (= locality of Stout, 1918, p. 74, lines 8-13)

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