Conservation deposit
A conservation deposit is a site of fossils that are particularly well preserved. Fossils are not necessarily particularly common in such sites, but they are mostly complete and / or still show remains of organs that are normally not fossil- preservable ("soft tissue preservation "), original color pigments or other biomarkers . The more or less complete preservation of organic matter is also possible. There are also fossil discovery sites that are both conservation and concentrate storage sites , such as the Geiseltal fossil site .
Well-known conservation stores in Germany are z. B. the Bundenbach slate , the Lower Jurassic Posidonia slate , the Solnhofen limestone , the Messel pit and the porch brickworks . Internationally outstanding conservation deposits include the Burgess Shale in Canada, the Santana Formation in Brazil and the Jehol Group in China.
According to the sedimentological peculiarities that led to this extraordinary fossil conservation, the following types of conservation deposits are distinguished:
- Stagnation deposits
Stagnation deposits are characterized by abiotic (hostile) conditions in the water layers close to the ground and in the sediment close to the surface. Examples are oil shale , black shale and plate limestone .
- Obrution deposits
Obrution deposits (burial deposits) arise when they are suddenly embedded in fine-grained sediment. The benthos , the living organisms living on the ground, is buried before it can break down into individual parts. Examples of obrution deposits are various echinoderma deposits (e.g. Gmünd) and such famous fossil deposits as the Burgess Shale , the Chengjiang Fauna Community and the Bundenbacher Schist .
Conservate traps
Preserve traps consist of a preserving medium, such as asphalt , peat and ice, in which fauna elements are quickly embedded. A well-known example of preservation in ice is the frozen carcass of the steppe bison " Blue Babe " from Alaska .
See also
- Fossilization ( Conservation Section )