Ferrière, J., Chanier, F., Reynaud, J., Pavlopoulos, A., Ditbanjong, P. and Coutand, I. 2013.   Evolution of the Mesohellenic Basin (Greece) : a synthesis. In: (Ed.) Emmanuel Skourtsos, The Geology of Greece - Part II, Journal of the Virtual Explorer, Electronic Edition, ISSN 1441-8142, volume 45, paper 1.

Evolution of the Mesohellenic Basin (Greece) : a synthesis

Jacky Ferrière

UFR Sciences Terre, UMR 8217, Lille University, 59655 Villeneuve d’Ascq, Cedex, France

Frank Chanier

UFR Sciences Terre, UMR 8217, Lille University, 59655 Villeneuve d’Ascq, Cedex, France

Jean-Yves Reynaud

UFR Sciences Terre, UMR 8217, Lille University, 59655 Villeneuve d’Ascq, Cedex, France

Andreas Pavlopoulos

Mineralogy-Geology, Agricultural University of Athens, Iera odos 75, 11855, Athens, Greece

Pitaksit Ditbanjong

UFR Sciences Terre, UMR 8217, Lille University, 59655 Villeneuve d’Ascq, Cedex, France

Isabelle Coutand

Department of Earth Sciences, 3015, 1355 Oxford street, Dalhousie University, Halifax, N.S., Canada


This article is an attempt to synthesize the knowledge about the Mesohellenic Basin (MHB), based upon available literature and also unpublished data. We focus on our interpretation but also mention alternative ones. The MHB is an orogenic basin of general importance, because of (i) its large size (300km along strike, and 150km in Greece) ; (ii) its location in the middle part of the Hellenic chain (between the Pindos accretionary prism and the Pelagonian upper unit) ; (iii) its large-scale piggyback setting. It has also a regional interest because of its Late Eocene-Middle Miocene age, a period of the Hellenic orogen which remains poorly understood.

The MHB fill is dominated by siliciclastic submarine deposits emplaced by gravity processes. After two main successive tectonic events, the deposits show a continued deepening during late Eocene (Krania basin) and Oligocene (MHB basin s.s.) times. Then, the Miocene series are characterized by shallower coarser-grained (early Miocene) or more calcareous (middle Miocene) sediments.

Water depth overall increases towards the north. In the Miocene, the southern MHB limit extends beyond the Meteora area, beneath the present-day Trikala plain. We consider that the piggyback setting is a key to the evolution of the MHB. Tectonics primarily controlled subsidence and the regime of sedimentation, therefore overprinting the effect of eustatic changes. The MHB infill reflects the timing and nature of understhrusted tectonic units : (i) in the Late Eocene, during the easy subduction of the thin Pindos basin crust and the development of the Pindos accretionary prism in the external zones, subsidence in the MHB is localized in contrasted and likely small areas inherited from heterogeneities of the internal zones, namely the boundaries of the Pelagonian Indentor (PI); (ii) in the Oligo-Miocene, subsidence is generalized in the strike of the chain, due to collision of the thicker crusted Gavrovo-Tripolitsa block of the external zones.

In the Oligo-Miocene MHB, subsidence is first strong (Eptachorion marls), and then migrates to the east, progressively or stepping over structural highs as the Theopetra-Theotokos Structure (TTS) in front of the PI. In the Miocene, sediment supply is abruptly transferred from the Pindos accretionary prism to the Pelagonian hinterland, in response to a severe uplift of the Pelagonian domain notably the Pelagonian Indentor (Meteora conglomerates).

While the collision is recorded as a major compressional phase at the Eocene-Oligocene boundary, most of the following tectono-sedimentary evolution reflects processes at the subduction plane, which remain hypothetical (tectonic erosion, underplating…). Also, the importance of strike-slip motion of some faults on the basin evolution remain matter of debate.

Our ongoing research on the MHB is focused on the chronostratigraphic assessment of sediment supply, based on thermochronology and basin modeling.

Keywords: Greece, Mesohellenic Basin, Cenozoic, Hellenides, Syntectonic sedimentation, Piggyback Basin, Forearc Basin

Table of Contents

The MHB: geological setting
The Mesohellenic Basin: definition and overview
Evolution of ideas about the MHB
The sedimentary fill of the MHB
Knowledge limits
The main lithological formations and their boundaries
Facies map of the MHB
The upper Lutetian-upper Eocene Formations
Rizoma Fm
Krania Fm
Interpretation: transgression above a post-tectonic, irregular paleotopography
The Oligocene Eptachorion Formation
Facies of the base
From turbidites to shelf marls
Interpretation : rapid and widespread subsidence of the MHB
The Upper Oligocene (?) - Lowermost Miocene Tsarnos - Pentalofon Formation
The lower part: Taliaros or Tsarnos formation
The main part: Pentalofon Formation
Age of the Pentalofon Formation
Interpretation: raise of Pelagonian supply and rapid infilling
The Lower Miocene (p.p.) Tsotyli Formation
The Tsotyli deposits
Interpretation: shift of subsidence to the east
The Lower to Middle (p.p) Miocene Ondria and Orlias formations
The Ondria Formation
The Orlias Formation
Interpretation: final marine stage
Synthesis of stratigraphic data
Overall evolution of water depth
Evolution of depositional slopes
Eastward migration of sediment sources
Eastward migration of subsidence
Eustatic versus tectonic controls
Tectonic development of the MHB
General overview
The southwestern border of the MHB
Deformation within Oligocene series
Structures in other formations on the SW border of the MHB
The eastern border of MHB
Eastern border structures in the northern Segment
Eastern border structures in the southern Segment
The Theopetra – Theotokos Structure: synsedimentary tectonic activity in the southern MHB
Description of the Theopetra – Theotokos Structure (TTS)
Origin of the TTS
Tranverse structures across the MHB
Krania sub-basin
Other transverse structures
Discussion on along strike lateral displacements
Tectonic development of the MHB
Tectonic structures
Chronology of deformation
Discussion on the MHB evolution
Controls on sedimentation
Tectonic control on sedimentation
Eustatism control on sedimentation
Discussion on geodynamic interpretations
Discussion on mechanism of basin development
Evolution of the MHB and successive geodynamic settings
Pre-MHB setting
Lutetian to Late Eocene small confined basins
Latest Eocene compressional episode
The first elongated major basin:the western MHB
Oligocene initial development of the large MHB
The first major sedimentary change in the main MHB: coarse grained deposits linked to an eastern uplift (Pentalofon Fm, Latest Oligocene – Early Miocene)
The second stage of large basin: the western MHB
The final stage of MHB development: Ondria – Orlias Formations
The present-day MHB