SEDIMENTATION ON THE TRIPOLITZA PLATFORM OF THE LOWER CRETACEOUS TO CENOMANIAN SEQUENCE IN CENTRAL CRETE (GREECE)

The Tripolitza zone of the Hellenic orogen is closely related to the s outh Tethys passive margin. It represents the internal part of the Gav rovo-Tripolitza platform which crops out in the central-south Peloponn ese, Crete and the south-east Aegean islands. From bottom to top, the Tripolitza sequence is composed of Triassic elastic sediments (Tyros b eds), Triassic to upper Eocene platform carbonates and a elastic flysc h series. In the present paper the sedimentation and stratigraphy of t he Lower Cretaceous to Cenomanian carbonate succession of the Tripolit za zone in central Crete, are investigated. The basal beds consist of 100 m of laminated to brecciated dolomites with some intercalations of micritic limestones which are interpreted as peritidal deposits. They are of Early Cretaceous, probable Banemian age. They are overlain by 150 m of carbonates, which represent a shelf-lagoonal facies with sea- level fluctuations from upper subtidal to upper intertidal conditions. Influence of the open sea is observed towards the top of this series, dated as early Aptian on the basis of a fairly rich microfauna. The A ptian continues with 130 m of stromatolitic dolomites and dolomite bre ccia of intertidal to supratidal environments and 45 m of limestones r eflecting a subtidal environment. A shallow water, subtidal limestone facies 15 m thick containing gastropods and rudists probably constitut e the base of the Albian formation. It is followed by a regressive ser ies 240 m thick. This is composed of laminated limestones and dolomite s, gradually becoming stromatolitic dolomites with dolomite breccia in tercalations. This regressive carbonate sedimentation took place durin g the Aptian p.p.(?)-Albian-early Cenomanian. Sedimentation during the middle-late Cenomanian had a transgressive character. The succession is characterized by the presence of rudist-reef facies as well as of l ow-energy subtidal-lagoonal facies. The latter are expressed by limest ones with intercalations of dolomites. Locally, the microfauna and mic roflora are rich and of high diversity.