Klonk
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Klonk, southwest of Prague, Czech Republic, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the Devonian and Silurian periods on the geologic time scale. Klonk was the first formally agreed upon GSSP, having been ratified by the International Union of Geological Sciences in 1972.[1]
The boundary is defined immediately below the first appearance of the graptolite Monograptus uniformis. The section consists of limestone beds and calcareous shales.
[edit] References
- Ogg, James. GSSP for the Silurian - Devonian Boundary. Retrieved on 2006-07-02.