Klonk

Klonk is a hill near the village of Suchomasty, Czech Republic, about 35 kilometers southwest of Prague. He represents a geological locality of international importance

The steep slope in 1972 set as the GSSP (Global Boundary Stratotype Section and Point) for the boundary between the ages of Silurian and Devonian. The GSSP method, which first came to use in Klonk, is a method of Chronostratigraphy that are defined in binding form geological periods and their limits using reference profiles. After a selection process in the years 1969-1971, in which eligible areas in Europe, Nevada and Morocco were investigated, put the " Silurian - Devonian Boundary Committee " the Barrandian as the type area and clunk as boundary - stratotype for the two age fixed. The result was approved in Montreal of the International Commission on Stratigraphy 1972.

Klonk met the requirements of the new system especially true because the profile is not disturbed by orographic or tectonic processes. The layers are formed as a sequence of limestones and shales, thus can be observed particularly well. To define the Silurian - Devonian boundary fossils are used. As an index fossil is the Graptolith Monograptus uniformis, of importance are the trilobite Warburg Ella rugulosa and conodonts Icriodus woschmidti and Angochitina chlupaci.

To protect the locality 1977, a national natural monument was proclaimed in Klonk. It is 8.9 acres in size and lies at an altitude 322-418 m nm at the northern end of the slope. The site is not publicly accessible.