Replacement of benthic communities in two Neoproterozoic–Cambrian subtropical-to-temperate rift basins, High Atlas and Anti-Atlas, Morocco.

Martedì 9 Aprile, ore 13 Aula C 

Presso il dipartimento di Scienze della Terra, il prof. Sèbastien Clausen terrà un seminario dal titolo:
"Replacement of benthic communities in two Neoproterozoic–Cambrian subtropical-to-temperate rift basins, High Atlas and Anti-Atlas, Morocco"

Abstract: 

The 'Cambrian explosion' is often introduced as a major shift in benthic marine communities with a decline of microbial consortia related to the diversification of metazoans and development of bioturbation ('Agronomic Revolution'). Successive community replacements have been reported along with ecosystem diversification and increase in guild complexity from Neoproterozoic to Cambrian times. This process is recorded worldwide but with regional diachroneities, some of them directly controlled by the geodynamic conditions of sedimentary basins. The southern High Atlas and Anti-Atlas of Morocco record development of two rifts, Tonian–(?)early Cryogenian and latest Ediacarian–Cambrian in age,separated by the onset of the Pan-African Orogeny. his tectonically controlled, regional geodynamic change layed a primary control on pattern and timing of benthic ecosystem replacements. Successive benthic communities include microbial consortia, archaeocyathan-thromboid reefal complexes, chancelloriid-echinoderm-sponge meadows, and deeper offshore echinoderm-dominated communities.

Keywords: palaeoecology, evolution, biofabrics, abiotic controls, biotic controls, microbialite, reefs, echinoderms.