Emmanuel Skourtsos

FORAMINIFERA, ALGAE AND CARBONATE MICROPROBLEMATICA FROM THE LATE WUCHIAPINGIAN/DZHULFIAN (LATE PERMIAN) OF PELOPONNESUS (GREECE)

The origin of late Permian olistoliths found in the Glypia Cenozoic flysch must be seeked in regions located to the east of the Parnon Mountain and in units that were more internal to Pindos Unit, especially in the islets of Karavia in the Argolis Gulf, and the Episkopi Formation in Hydra Island, that display probably the largest outcrops of this age. The most interesting olistolith is a bioclastic grainstone. It yields about forty taxa of algae, microproblematica, smaller foraminifers and fusulinids, that are briefly described. Three markers generally not co-occurring are locally associated: Paradunbarula ( Shindella ) shindensis , Hemigordiopsis cf. luquensis and Colaniella aff. minima . The age of the Paradunbarula ( Shindella ) biozone is most probably late Wuchiapingian/Dzhulfian, although other datings have been proposed from late Capitanian to late Changhsingian. Due to this dating of the Shindella zone, the coexistence of the first Colaniella with the last Hemigordiopsis are not late Capitanian/Midian in age, but late Wuchiapingian. The similarities of the Greek microfauna with that of South China and southeastern Pamirs, are incompatible with a larger Paleotethys but support the paleogeographic reconstructions which indicate a close location of these geographic units (Pangea B).

Structure and evolution of the western Corinth Rift, through new field data from the Northern Peloponnesus

Abstract Extensional structures with geometrical and kinematic features analogous to the known Gulf of Corinth faults, are found further to the south of what is considered to be the southern margin of the of Proto-Corinth Gulf, reaching south to the northern flanks of Mt Mainalon. This mountain front is marked by the North Mainalon Fault Zone, which comprises a series of normal fault segments with NNE dips. Assuming a listric or ramp-flat geometry for the North Mainalon Fault Zone, it could flatten at a depth of 6–8 km, underneath Mt Khelmos. Its southern, shallow part has been truncated by NNE- and NNW-trending faults, which may be linked to northward propagation of the east–west extension in the Southern Peloponnesus, causing further uplift in the central and northern Peloponnesus, while its deeper part is still active and may reach further north and sole onto the hypothesized detachment zone beneath the Gulf of Corinth.

Glacial history of Mt Chelmos, Peloponnesus, Greece

Abstract Mt Chelmos in the Peloponnesus was glaciated by a plateau ice field during the most extensive Pleistocene glaciation. Valley glaciers radiated out from an ice field over the central plateau of the massif. The largest glaciations are likely to be Middle Pleistocene in age. Smaller valley and cirque glaciers formed later and boulders on the moraines of these glacial phases have been dated using 36Cl terrestrial cosmogenic nuclide exposure dating. These ages indicate a Late Pleistocene age with glacier advance/stabilization at 40–30 ka, glacier retreat at 23–21 ka and advance/stabilization at 13–10 ka. This indicates that the glacial maximum of the last cold stage occurred during Marine Isotope Stage 3, several thousand years before the global Last Glacial Maximum (Marine Isotope Stage 2). The last phase of moraine-building occurred at the end of the Pleistocene, possibly during the Younger Dryas.

Egio earthquake (15 June 1995): An episode in the neotectonic evolution of Corinthiakos Gulf

Abstract Egio earthquake (15 June 1995) produced a series of destructive geological surficial effects in northern Peloponnessos and southern Sterea Hellas. After a brief review on the current opinions on the tectonic regime of the area has been made, we give a description of these effects, focusing mainly on the fractures along the Egio fault. Then, we present a model to interpret the earthquake activity of 15 June 1995; finally a discussion concerning the extensional tectonic regime of the area is made based on seismic data, the geometry of onshore and the recently described offshore faults.

Late Wuchiapingian (Late Dzhulfian, early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon, central–eastern Peloponnesus, Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.

Building up or out? Disparate sequence architectures along an active rift margin—Corinth rift, Greece

Early Pleistocene synrift deltas developed along the southern Corinth rift margin were deposited in a single, dominantly lacustrine depocenter and were subject to the same climate-related base-level and sediment supply cyclicity. Two synrift deltas, just 50 km apart, show markedly different sequence geometry and evolution related to their location along the evolving border fault. In the west, strongly aggradational fan deltas (>600 m thick; 2–4 km radius) deposited in the immediate hanging wall of the active border fault comprise stacked 30–100 m thick stratal units bounded by flooding surfaces. Each unit evolves from aggradational to progradational with no evidence for abrupt subaerial exposure or fluvial incision. In contrast, in the central rift, the border fault propagated upward into an already deep lacustrine environment, locating rift-margin deltas 15 km into the footwall. The deltas here have a radius of >9 km and comprise northward downstepping and offlapping units, 50–200 m thick, that unconformably overlie older synrift sediments and are themselves incised. The key factors driving the marked variation in sequence stratigraphic architecture are: (1) differential uplift and subsidence related to position with respect to the border fault system, and (2) inherited topography that influenced shoreline position and offshore bathymetry. Our work illustrates that stratal units and their bounding surfaces may have only local (<10 km) extent, highlighting the uncertainty involved in assigning chronostratigraphic significance to systems tracts and in calculating base-level changes from stratigraphy where marked spatial variations in uplift and subsidence occur.