Geometry and structural evolution of the Mesohellenic Trough (Greece): a new approach

Abstract

The Mesohellenic Trough (MHT) is an elongate basin parallel to the Hellenide isopic zones that extends from southern Albania through northern Greece. The basin developed from Mid-Late Eocene to Mid-Late Miocene time related to Alpine orogenic processes. Structural and kinematic evidence shows that the MHT developed in response to successive tectonic events, involving isostatic crustal flexure, strike-slip and normal faulting, all related to inferred oblique convergence of the Apulian and Pelagonian microcontinents. The Mesohellenic Trough evolved as a piggyback basin above westward-emplacing ophiolites and higher Pelagonian units. This differs from previous interpretations that envisaged foreland flexure related to backthrusting, or subsidence associated with asymmetrical flexure, or normal faulting. The first stage of basin development during the Mid-Late Eocene was contemporaneous with the final emplacement of Pindos oceanic units and culminated in deformation and uplift of Eocene strata. The second phase was dominated by strikeslip faulting during Oligocene-Early Miocene time. The third stage was characterized by low-angle normal faulting at the eastern boundary of the MHT during the Early-Late Miocene. The evolution of the sedimentary basin ended around Late Miocene time, followed by rapid uplift and marine regression. A compressional event occurred during the latest Miocene. Finally, extensional tectonics affected the area from the Late Miocene to .the present.

The Mesohellenic Trough and the Paleogene Thrace Basin on the Rhodope Massif, their Structural Evolution and Geotectonic Significance in the Hellenides

“…Structural evolution: Numerous structural data, accrued from observations on geometry of kinematics, overprinted criteria, stratigraphic relationships and correlation between various structures, show that the basin experienced a complicated history with different tectonic episodes (T1-T5) (Figures 2-4) [11,12]. These events took place in semi-ductile to brittle conditions from Middle Eocene to Quaternary time.…”

“…Dextral strike-slip faults of NW-SE to NNW-SSE orientation controlled the subsidence and evolution of the basin from Early to Late Oligocene. [5][6][7]11]. Numbers in circles (1) indicate the timing (T1) and the locations of the tectonic events where these are recognized and was estimated the corresponding stress tensor (Figures 6-9).…”

“…Geodynamically, the MHT evolved as a piggyback basin in a foreland setting above westward-emplacing ophiolites and higher Pelagonian units [6,8,11,22] while great importance is given to the role of strike-slip faults in the structural evolution of the MHT [11,12]. Successive stages and changing tectonic regimes recognised in the MHT formation are met in strike-slip basins, while experiencing alternating periods of extension and compression.…”

“…The Mesohellenic Trough (MHT) in NW Greece [5][6][7][8][9][10][11][12] and the Thrace Basin (THB) in NE Greece [13][14][15][16][17], including its possible continuation into the Axios Basin (AXB) [18], constitute two large late to synorogenic Tertiary molassic-type basins in the Hellenides ( Figure 1). …”

Sustainable water resources management through the use of GIS technology

“…2). The molassic sediments are not folded, but they present Eastward slopes, as a result of the tectonic movements since Miocene (Vamvaka et al, 2004). Few faults with NE-SW direction are found in molassic sediments (Savoyat & Monopolis, 1972;Mavridis & Kelepertzis, 1993). )…”