English: Weathered black shales disconformably overlying limestones in the Devonian of Kentucky, USA.

The rocks in the upper and middle parts of the photo are weathered black shales of the New Albany Shale, a Devonian-aged formation in Kentucky, Indiana, Illinois, and eastern Missouri. The unit is dominated by dark-colored marine mudshales of Late Devonian age. These black shales were deposited in a moderately deep, anoxic seafloor environment. This was a widespread lithofacies during the Late Devonian's Global Anoxia Event. The New Albany Shale is equivalent to the Ohio Shale, the Antrim Shale, and the Chattanooga Shale in surrounding states.

The basal New Albany here is the Blocher Member - it consists of dolomitic black shales (dolosiltites, actually). The fissile nature of Blocher rocks is due to post-depositional compaction. Blocher beds are rich in organic carbon and have been homogenized by bioturbation.

The rocks in the lower left part of the picture are the Middle Devonian North Vernon Limestone, which is part of a widespread sheet of Devonian carbonates that extends from New York State to the Midwest. The North Vernon Limestone represents deposition in a subtropical, shallow-water, carbonate platform environment. The limestone here is fossiliferous, with decent-sized camerate crinoid columnals. An encrinite bed is present in the top-preserved North Vernon.

Just above the top of the North Vernon Limestone is a thin, lensoidal lag unit with phosphatic nodules, glauconitic pellets, and conodonts.

The New Albany-North Vernon contact represents missing time - such stratigraphic boundaries are called unconformities, which are surfaces of erosion and/or non-deposition of sediments. This is a disconformity, with horizontal sedimentary rocks above and below the contact, which here has noticeable paleotopography. A paleosinkhole was visible here when the cut was fresh.

Oxidative weathering of pyrite (FeS2 - iron sulfide; "fool's gold") at the New Albany-North Vernon boundary has produced iron oxide minerals such as reddish-brown hematite and yellowish-brown limonite. The iron oxides have stained the underlying rocks via descending meteoric waters (rain and runoff). The end result is a "bleeding unconformity".

Stratigraphy: lowermost-preserved New Albany Shale (uppermost Givetian Stage to lower Frasnian Stage, uppermost Middle Devonian to lower Upper Devonian) disconformably over the Beechwood Member of the North Vernon Limestone (Givetian Stage, upper Middle Devonian)

Locality: roadcut along the western side of the south-bound entrance ramp to Interstate 65 at the Route 245-Interstate 65 interchange, north-northeast of Belmont & south of Sherpherdsville, south-central Bullitt County, north-central Kentucky, USA (37° 55' 24.45" North latitude, 85° 41' 18.33" West longitude)