Both banks of Stonehead Beck expose sections through the sequence. Throughout the mudstones there are numerous nodular wackestone bands. These bands were subject to early lithification and as a consequence helped in the preservation of uncrushed macrofaunas, particularly the ammonoids.
Siderite nodules are present in the barren silty intervals. Bioturbation is generally rare in Stonehead Beck.
This outcrop lies close to the top of Eumorphoceras biozone. As you can see removal of the bed is very easy and has in the past been subject to excessive collecting.
Due to the importance of the site please restrict your collecting and leave the section in a tidy state when leaving.
The Mid-Carboniferous boundary in Stonehead Beck has been defined at the first entry of the conodont Declinognathodus inequalis about 9.4 metres above the Arnsbergian / Chokerian boundary and significantly is marked by a major mass extinction of faunas. The calc-arenite bed that marks the boundary.