Palaeoecology and taxonomy of the macrobenthic fauna from the Upper Cretaceous Ajlun Group, southern Jordan

The Upper Cretaceous Ajlun Group (Cenomanian-Turonian) of southern/south-eastern Jordan has been analysed in 15 detailed sections with thicknesses between 40 m and 200 m. Taxonomic, palaeoecological, taphonomic, and sedimentological aspects were taken into account. During the early Upper Cretaceous the study area was situated at the south-eastern margin of the Tethys Ocean, between the palaeo-shoreline in the south-east and an offshore carbonate platform in the west. Thus, the measured sections include a complete facies succession from terrestrial-dominated environments via marginal marine siliciclastics to an area of carbonate precipitation. So far, very little is known about the fauna and the depositional environment of the group, especially of the transitional marginal marine part. Also, in depth studies of the Cretaceous fauna of southern Jordan are very rare. Therefore, the benthic fauna of the area is described in an extensive taxonomic chapter. It consists of 117 taxa, 77 of which are bivalves, 22 gastropods, 9 echinoids, and 4 corals. The phyla Porifera, Bryozoa, and Brachiopoda are represented by 1 species each. Additionally, at least two species of decapod crustaceans were found. One bivalve species is new: Anthonya jordanica from Cenomanian claystones of the eastern study area. 41 quantitative samples of the benthic invertebrate fauna were grouped into nine associations and three assemblages by means of a Q-mode cluster analysis. These are described as remnants of former communities and their environments are discussed. Salinity and substrate consistency are assumed to have been the most important environmental parameters controlling the faunal distribution. The overall palaeo-environment is discussed on the basis of sedimentological and palaeoecological results. It was primarily influenced by the morphology of the sea floor, sediment supply, and salinity of the sea water.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Würzburg

Year

2002

Author dc:creator

• Berndt, Roman

Contributors dc:contributor

• Fürsich, Franz T.

• Palökologie
• Kreide
• Benthos
• Jordanien
• Cenoman
• Palaeoecology
• Cretaceous
• benthic fauna
• Jordan
• Cenomanian

Repository record source_url

https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/957

OAI identifier oai:identifier

oai:opus.bibliothek.uni-wuerzburg.de:957