Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4747882 | Cretaceous Research | 2006 | 26 Pages |
The marine succession of the late Early Cretaceous carbonate platform of the eastern Levant was located at the southern border of the Tethyan Ocean. The studied areas of Galilee and the Golan Heights represent a transect across the shallow inner platform. The investigations were focused on carbonate platform biostratigraphy and facies analysis. A precise stratigraphic interpretation of the Upper Barremian–Albian succession was compiled on the basis of the definition of larger benthic foraminifer biozones allowing subdivision of the succession into six well-dated intervals. Detailed analyses of facies and sedimentological parameters allow interpretation of platform development, in connection with platform geometry, as well as relative third-order and second-order sea-level changes. The observed facies patterns reflect a depositional geometry changing from a ramp to a flat-topped platform during Late Barremian–Middle Albian times.Three second-order depositional sequences were recorded in the studied mid-Cretaceous succession of the eastern Levant (MCEL-1 to MCEL-3). The facies analysis clearly indicates their origin in relative sea-level variations. The stratigraphic framework allows biochronostratigraphic calibration of these depositional sequences (MCEL-1: Upper Barremian–Lower Aptian, MCEL-2: uppermost Lower Aptian–middle Upper Aptian, MCEL-3: middle Upper Aptian–Middle Albian) and correlation with stratigraphic charts of local and regional sequences. The second-order sequence boundaries and maximum flooding surfaces correlate with basic sea-level variations recorded on the Arabian Plate, here interpreted as originally eustatically enhanced by subsidence. Tethyan signals are recorded around the Aptian/Albian boundary. A noticeable deepening in the upper Lower Aptian correlates with an extended platform drowning during the Selli Level (Oceanic Anoxic Event 1a: OAE 1a). Orbitolinid beds at this level suggest a deepening facies and a possible response to nutrient enhancement developing at the continental margin during OAE 1a. Eight third-order depositional sequences were observed in the Upper Barremian–Albian interval. They comprise successions of the inner ramp facies from open marine to restricted lagoons or tidal flats. The age and frequency of the Upper Barremian–Lower Aptian sequences correlate with those observed on the Pacific guyots or the Arabian Plate suggesting influence by regional sea-level cycles.