Die Fossillagerstätte Korbacher Spalte – ihre Entstehung und Einordnung in den Zechstein Nord-Hessens

The fossil deposit known under the name of “Korbacher Spalte” near Korbach in Northern Hessen is one of the rare places where remains of an Upper Permian vertebrate fauna were found. The fauna includes Pareiasaurians, Archosaurs and Therapsids (mammal-like reptiles). Comparable, but considerably better preserved faunas are known from different parts of Pangaea merely in South Africa and in the southern parts of the Ural in Russia. In Werra-Carbonate (Upper Permian formation z1) a fissure was formed that is a few metres wide; its sedimentary deposit still contains heavily fragmented reptile bones. Sedimentological, sedimentpetrographical and geophysical research has proved that the processes that formed the fissure as well as its filling with sediment and fossil fragments were a consequence of rupturing periods and shiftings in terrestrial environment. Because the profile of the local area in the former “Steinbruch Fisseler” was cut off erosively in the course of time an exact dating of the origin of the fissure can´t be taken. The recently found complete profiles of Randkarbonat (z1Ca) to Upper Werra Clay (z1Tb) near Vöhl-Dorfitter and the bore hole near the “Korbacher Spalte” can be regarded as the clue to dating the fissure near Korbach. The formation of the fissure and its filling with sediments and fossil substances can be dated at that very place that is adjoining Randkarbonat (z1Ca) and Upper Werra Clay (z1Tb). The state of preservation of the fossils shows that the “Korbacher Spalte” is no primary fossil deposit. The animals had lived already before the fissure opened, their remains were transported with the sediments into the filling of the fissure. Taking into consideration the paläogeographic and paläoclimatic circumstances at the period of the Werra-Folge the terrestrial reptiles can be brought into correlation as far as fauna, finding place and period is concerned with rare, but well preserved findings contained in Kupferschiefer layers. Thereby the period the reptiles were existing in near the eastern part of the Rhinish Massive can be dated exactly to a certain period. As far as the period of the Kupferschiefer sea in the Frankenberg/Eder –area is concerned there is handed down a flora that served as nourishment for the vertebrates. The growing aridity of the climate during the Werra-Folge led to the withering of the flora and thus cut off the nutritional requirements of the fauna. Animals that perished on the shore of the Kupferschiefer sea were embedded in the seabed and were conserved completely. The animals that died on the Rhinish Massive were first embedded in a primary fossil deposit on the increasingly deserting surface. While the “Korbacher Spalte” was opened, periods of heavy rainfall led to a rearrangement from higher regions to the seashore located in the east. There the fissure of the “Korbacher Spalte” was filled with sediments and with bones having been fragmented by/ in the course of the rearrangement. Consequently the “Korbacher Spalte” is at least a secondary, but probably even a tertiary fossil deposit that contains the rearranged vertebrate fauna of the Kupferschiefer period.