Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4692307 | Tectonophysics | 2013 | 15 Pages |
The available biostratigraphic data based on calcareous nannofossil analysis determine the mean ages for the onset of flysch sedimentation (base of transitional beds) of the Ionian unit at ~ 34–35 Ma (external/internal Ionian), and at ~ 41 Ma (middle Ionian). The top of the Ionian flysch at ~ 25 Ma constrains the emplacement of Gavrovo nappe, providing an average duration of at least 11–16 Myr for the flysch sedimentation. Gavrovo flysch deposition started at a mean age of ~ 34 Ma and lasted till ~ 29 Ma (emplacement of Pindos nappe), suggesting an average duration of approximately 5 Myr. Phenomena of synsedimentary tectonism have been reported at the external Ionian unit, indicating that pre-flysch extension of the basin lasted at least 4 Myr. The ~ 6–7 Myr difference of the onset of flysch sedimentation between the external/internal and middle parts of Ionian unit implies evidence for an axial symmetry of the basin before the underthrusting of Mani unit under Pindos nappe.
► Onset of Ionian flysch sedimentation at ~34-35 Ma (external/internal Ionian) and at ~ 41 Ma (middle Ionian), top at ~ 25 Ma. Average duration of at least 11-16 Myrs for flysch sedimentation in the Ionian unit. ► Onset of Gavrovo flysch sedimentation at a mean age of ~ 34 Ma, top at ~ 29 Ma (emplacement of Pindos nappe). Average duration of ~ 5 Myrs for flysch sedimentation in the Gavrovo unit. ► ~ 6-7 Myrs difference of the onset of flysch sedimentation between the external/internal and middle parts of Ionian unit. ► Evidence for an axial symmetry of the Ionian foreland basin before the underthrusting of Mani unit under Pindos nappe.