Re-Evaluation of the Ionian Basin Evolution during the Late Cretaceous to Eocene (Aetoloakarnania Area, Western Greece)

Elena Zoumpouli,Avraam Zelilidis,Chrysanthos Botziolis,Vasiliki Zygouri,George Iliopoulos,Angelos G Maravelis

doi:10.3390/geosciences12030106

Elena Zoumpouli, Avraam Zelilidis + Show 4 more

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https://doi.org/10.3390/geosciences12030106

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Abstract

Field investigation, Microfacies analysis, and biostratigraphy have been carried out in the central parts of the Ionian Basin (Aetoloakarnania area, Western Greece) in order to decipher the depositional environments that developed during the accumulation of the Upper Cretaceous to Eocene carbonate succession. Three different Standard Microfacies types (SMF) have been observed, corresponding to two different depositional environments (Facies Zones or FZ) of a platform progradation. The three SMF types which occur in the study area during the Upper Cretaceous to Eocene are: 1. SMF 3 that includes mudstone/wackestone with planktic foraminifera and radiolaria, corresponding to toe-of-slope (FZ: 3), 2. SMF 4, which can be classified as polymict clast-supported microbreccia, indicating a toe-of-slope-slope environment (FZ: 4) and 3. SMF 5 which is characterized by allochthonous bioclastic breccia and components deriving from adjacent platforms and which reflects a slope environment. Microfacies analysis provided evidence of a change in the origin of sedimentary components and biota showing the transition from toe-of-slope to slope, as well as a change in organism distribution.

Highlights

The Ionian zone has been the focus of numerous studies for a long time —most dealing with its biostratigraphy and lithostratigraphy—providing an abundance of information on the palaeogeographical evolution of the Ionian basin [1,2,3,4]
According to Karakitsios [2,20] and Zelilidis et al [3] the depositional system of the Ionian basin was subdivided into three successions: the pre-rift succession, consisting of lower to middle Triassic evaporites and Upper Triassic to Lower Jurassic limestones, the syn-rift succession, consisting of Lower to uppermost Jurassic deposits and the post rift succession, consisting of Cretaceous to Eocene deposits, and which was further subdivided into two sub-stages, the Lower Cretaceous and the Upper Cretaceous to the lower Eocene sub-stage, respectively
Microfacies analysis and biostratigraphy results indicate that the Maastrichtian carbonate sequence is represented by the three different Microfacies types Standard Microfacies types (SMF) 3, SMF 4 and SMF 5, corresponding to two different depositional environments/Facies Zones

Summary

Introduction

The Ionian zone has been the focus of numerous studies for a long time —most dealing with its biostratigraphy and lithostratigraphy—providing an abundance of information on the palaeogeographical evolution of the Ionian basin [1,2,3,4]. The main Ionian zone, in general, has been studied by Aubouin [7], IGRS-IFP [8], Bornovas [9], Bernoulli and Renz [10], BP [11], Karakitsios and Tsaila Monopolis [12], Karakitsios et al [13], Skourtsis-Coroneou et al [14] and Zelilidis et al [3,15]. According to Karakitsios [2,20] and Zelilidis et al [3] the depositional system of the Ionian basin was subdivided into three successions: the pre-rift succession, consisting of lower to middle Triassic evaporites and Upper Triassic to Lower Jurassic limestones, the syn-rift succession, consisting of Lower to uppermost Jurassic deposits and the post rift succession, consisting of Cretaceous to Eocene deposits, and which was further subdivided into two sub-stages, the Lower Cretaceous and the Upper Cretaceous to the lower Eocene sub-stage, respectively. According to Bourli et al [16], due to the regional tectonic activity, the syn-rift and post-rift stages should be considered as parts of the same Jurassic to early Eocene syn-rift episode

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