GSSP for the Devonian-Carboniferous Boundary


Definition:

The base of the Carboniferous System, Mississippian Sub-System and Tournaisian Stage is defined at the base of Bed 89 in Trench E' at La Serre, France. It coincides with the first appearance of the conodont Siphonodella sulcata within the evolutionary lineage from Siphonodella praesulcata to Siphonodella sulcata.


Location:

The La Serre section is located in the southeastern Montagne Noire, Departement Hérault, District of Cabrières, southern France. Artificial trench E', which averages 80cm in depth on the southern slope of La Serre Hill, is about 125m south of the hilltop (252m), about 525m east of La Roquette farmhouse, 2.5km northeast of the village of Fontès. (sheet 1:25,000 Pézenas XXVI/44, 1-2, x = 682.55, y = 140.12).
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Sedimentology:

The rocks in trench E' are part of a geologic unit named "Klippen of Cabrières". The youngest Devonian and earliest Carboniferous beds are characterized by a sequence of predominantly biodetrital oolitic limestone within a pelagic matrix of shale and cephalopod bearing calcilutites.
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Primary Markers:

First appearance of the conodont Siphonodella sulcata within the evolutionary lineage from Siphonodella praesulcata to Siphonodella sulcata at the base of Bed 89 in trench E'.

Secondary Markers:

Trilobites:
Belgibole abruptirhachis, Archegonus (Phillibole) and Carbonocoryphe occur in Bed 89.

Other Locations around the World:

Trilobite Belgibole abruptirhachis occurs immediately above the Hangenberg Schiefer interval in various cephalopod-bearing sections from the Renish Slate Mountains (Germany), the Holy Cross Mountains (Poland) and the Carnic Alps (Austria).

References:

Paproth, E., Feist, R., and Flaijs, G., 1991. Decision on the Devonian-Carboniferous boundary stratotype. Episodes 14/4, p. 331 - 336.