Circum-Tethyan carbonate platform evolution during the Palaeogene: the Prebetic platform as a test for climatically controlled facies shifs

Abstract

The distribution of selected shallow-benthic biota at circum-Tethyan carbonate platforms demonstrates an excellent proxy forthe impact of latitudinally controlled cooling and variations in the trophic resources during the Palaeogene. In this study, we link andcompare the spatial distribution and abundance of larger benthic foraminifera and hermatypic corals of Tethyan carbonate successionswith new records from the Prebetic platform in SE Spain. Te succession of the Prebetic platform is dominated by larger benthicforaminifera and coralline red algae throughout the Eocene, whereas corals were not recorded until the Late Eocene. Similar biotic trendswere reported from 10 selected circum-Tethyan carbonate platforms. High-resolution carbon isotopes indicate a decoupling from theglobal carbon cycle during the latest Eocene and Early Oligocene. Tus, a possible scenario is demonstrated by the increasing restrictionof the Prebetic shelf due to the continuing convergence of the Betic domain towards Iberia during the Early Oligocene. Based onprevious studies, we refned earlier established Palaeogene platform stages, which refect the evolution of shallow-benthic communitiesduring the transition from global greenhouse to icehouse conditions. Global cooling led to the recovery of coral communities in thenorthern Tethyan realm during the Bartonian (stage IV). A prominent cooling event at the Bartonian Priabonian boundary, associatedwith the demise of many symbiont-bearing larger foraminifera, caused the proliferation of coral reefs in the northern Tethys and therecovery of corals in the southern Tethys (stage V). Te massive temperature drop related to the Oi-1 glaciation represented the base ofplatform stage VI (Early Oligocene ?). Afer a transient platform crisis during the lowermost Oligocene, coral reefs spread throughoutthe Tethys and proliferated with newly emerged larger benthic foraminifera.