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

Abstract

Based on structural analysis and lithostratigraphic data, as well as geological mapping, the Paleogene part of the Thrace Basin (THB) in NE Greece (including the Paleogene deposits of the Axios Basin, AXB) was compared with the Mesohellenic Trough (MHT) in NW Greece. Both basins are characterized by a thick sedimentary sequence of molassic-type strata (3-5 km thickness) of Tertiary age, overlain unconformably by Miocene-Pliocene and Quaternary deposits. Molassic sedimentation started almost simultaneously in both areas during the Mid-Late Eocene but it finished in different time, in the Mid-Late Miocene for the MHT and the Late Oligocene for the THB, respectively. Sedimentation in THB was also linked with an important calc-alkaline and locally shoshonitic, acid to andesitic magmatism of EoceneOligocene age. We interpreted the MHT as a polyhistory strike-slip and piggy-back basin, above the westwardemplacing Neotethyan ophiolites and Pelagonian units on the cold Hellenic accretionary prism. In contrast to the MHT, the studied portion of the THB evolved as a Paleogene supra-detachment basin above the strongly extended during the Eocene-Oligocene Rhodope metamorphic province. The syn-depositional magmatic products, linked possibly with subduction processes in Pindos or Axios ocean(s). In any case, MHT and THB are related to inferred oblique convergence of the Apulia plate and the internal Hellenic units.

The Geology, Geochemistry, and Origin of the Porphyry Cu-Au-(Mo) System at Vathi, Serbo-Macedonian Massif, Greece

“…Two extensional events were reported by Kilias et al [21]. The oldest is contemporaneous with the Cretaceous amphibolite facies metamorphic event and exhibits an ENE-WSW extensional trend and eastward-trending shears.…”

“…The oldest is contemporaneous with the Cretaceous amphibolite facies metamorphic event and exhibits an ENE-WSW extensional trend and eastward-trending shears. The youngest extensional event occurred during the Late Cretaceous and Middle Eocene (68.5 ± 3.8 to 46.6 ± 3.6 Ma) and continued through to the Miocene [21,32,33]. The faults of this event structurally controlled the intrusions related to the second and the third Cenozoic magmatic events [19,20].…”

“…The Serbo-Macedonian Massif (SMM) in Greece is represented by the Vertiskos Unit that is composed of the following: (i) a sequence of migmatites, gneisses, schists, and thin marble intercalations, and (ii) a sequence of metagabbros, metadiabases, and amphibolites, intercalated with gneisses [17,[21][22][23][24]. Mafic to ultramafic rocks which belong to the Melidonis (1968) and Markoulis (1970).…”

At the crossroads: early Miocene marine fishes of the proto-Mediterranean Sea

“…The MHB was a synorogenic molasse-type basin (Kilias et al, 2015), a separate paleogeographic area from the late Eocene until the middle Miocene, between the internal and external Hellenides, ENE and WSW, respectively. It was a narrow, 300 km long trench, filled with up to 4.5 km of sedi-234 K. Agiadi et al: At the crossroads ments, which have been separated into the Krania, Eptachori, Pentalofos, Tsotyli, and Ondria formations (Brunn, 1956;Wielandt-Schuster et al, 2004;Ferrière et al, 2013;Kilias et al, 2015), deposited parallel to each other (except for the Krania Formation) along the eastern margin of the trough (Kilias et al, 2015). The studied sediments belong to the Pentalofos Formation, consisting in general of upper Chattianlower Miocene sandstones to silty marlstones (Mavridis et al, 1985;Ferrière et al, 2004;Wielandt-Schuster et al, 2004;Kilias et al, 2015).…”

Magnetostratigraphy and Chronology of the Lower Pleistocene Primate Bearing Dafnero Fossil Site, N. Greece

“…The Quaternary physiogeography of the studied area is dominated by the complex ravine system associating the Haliakmon River valley that extends in a northwesterly direction from close the Greco-Albanian borders to the Sarantaporos Mountain [29]. Geotectonically, it is placed along the eastern margins of the Mesohellenic Basin (MHB), an Oligo-Miocene post-orogenic trough with a long detrital sedimentary infill (see [35][36][37]).…”