Maotianshan Shales
The Maotianshan Shale (English Maotianshan Shales ) are a geological layer assembly from the lower Cambrian of Yunnan, People's Republic of China. Name Awarding type locality is the hill of Maotianshan (Chinese帽 天山, Pinyin Maotianshan ), located in the district of Chengjiang Yuxi prefecture-level city in Kunming. It is to shales of the Yu'anshan - Members of the upper Heilinpu Formation ( former Qiongzhusi Formation), whose ages were determined with 525-520 Ma BP ( 2nd series of the Cambrian and Cambrian average ). They are thus about 10 million years older than the Burgess Shale of Canada. Celebrity have Maotianshan shale obtained for the Konservatlagerstätte contained in them, which was discovered by accident in 1984; latter contains a fossil preserved community, which is extremely diversified and is commonly referred to as Chengjiang Faunengemeinschaft. The Maotianshan slate among the world's 40 Cambrian fossil sites, which can be compared with the findings from the Burgess Shale are distinguished by an exquisite state of preservation usually only very rarely fossilized body tissue and.
Stratigraphy and facies
The Konservatlagerstätte is embedded in 50 meter thick shale feinschichtige of Yu'anshan - Members ( Eoredlichia - Trilobitenzone ). This layer association is widely withstanding, he covered thousands of square miles in eastern Yunnan ( Yangtze craton ) and has promoted in numerous outcrops fossils days. Facies studies suggest that the shales are shallow marine origin, and as fine-grained sediment slurry were in a tropical sea at the shelf edge to the deposition. In addition, sea-level fluctuations and tectonic processes can read. Fossil was obtained in the main benthos, which was periodically covered by turbidity currents - so show most organisms also not made after her death surroundings more. Several carbon-rich horizons documented anoxic conditions likely triggered a mass extinction several times and also contributed to the soft-tissue preservation.
Fossil content
The species diversity of the fossils contained mainly in soft body preservation in Maotianshan Shale is amazing. Among them are algae, jellyfish shaped Metazoa, sponges, Priapuliden, annelidenähnliche worms, echinoderms, arthropods ( with the first trilobites ), Hemichrodata, Chordata, and Agnatha first. Numerous problematic species were discovered, did not pursue likely represent evolutionary sidelines.
Other versions see Chengjiang Faunengemeinschaft