Recognition of stratigraphic sequences in carbonate platform and slope deposits: empirical models based on microfacies analysis of Palaeogene deposits in southeastern Spain

The functional morphology and life style of foraminifers can be used to det ermine their former position on the platform and to detect upwards shallowi ng and deepening trends in sedimentary sequences. The sequential analysis o f the Palaeogene platform deposits of Alicante proved to be greatly enhance d by the use of the palaeoecology of foraminifers. On the basis of this ana lysis, three different empirical models for platform accommodation cycles c ould be designed. a ramp model, distinctive for the Lower Eocene, a combine d ramp-rimmed model, characteristic for the Middle and Upper Eocene, and a rimmed model representative for Oligocene cycles. The change in platform ty pe through time is thought to be a response to climate-related changes in g rowth-potential of hermatypic corals. Possible criteria to distinguish syst ems tracts in slope deposits on their foraminiferal and clast content are p ut to the test in a slope section, with positive results. From the correlat ion of the southern Spanish Palaeogene cycles with Eurasian-African plate-b oundary events along the Pyrenees, and with Antarctic glaciations, it can b e concluded that the majority of the cycles are tectonically controlled wit h glacio-eustatic contributions since the Middle/Late Eocene boundary. (C) 2000 Elsevier Science B.V. All rights reserved.