Under the Famennian, the Frasnian consists, from top to bottom, of nodular gray shale, and mica rich in fossils such as Cyrtospirifer verneuili, Spirigera concentrica, Atrypa reticularis, Orthis striatula, Productus subaculeatus, and Acervularia pentagona.
Below this are gray limestone-built beds, rich in corals such as Phacellophyllum caespitosum, Thamnopora boloniensis, alternating with black shale and nodular limestone containing Cyrtospirifer verneuilli and Phacellophyllum caespitosum.
These beds issue from siltation of the biostromes present in the Frasnian epoch, 370 million years ago.
Under the Famennian, the Frasnian consists, from top to bottom, of nodular gray shale, and mica rich in fossils such as Cyrtospirifer verneuili, Spirigera concentrica, Atrypa reticularis, Orthis striatula, Productus subaculeatus, and Acervularia pentagona. Below this are gray limestone-built beds, rich in corals such as Phacellophyllum caespitosum, Thamnopora boloniensis, alternating with black shale and nodular limestone containing Cyrtospirifer verneuilli and Phacellophyllum caespitosum. These beds issue from siltation of the biostromes present in the Frasnian epoch, 370 million years ago.
Carrière des Nerviens Regional Nature Reserve