Open Session - SWISS GEOSCIENCE MEETINGs

Hellenides, they can be correlated with the base of the Pindos Unit which shows Carnian calcareous and terrigenous sediments
with rare intercalation of pillow lava (Fleury, 1980). More proximal sequences can be found at the base of the Tripolitza
Unit (Ravdoucha-Tyros beds) where volcano-sedimentary series are interstratified or followed by calcareous debris-flow,
olistoliths and quartzitic sediments. The blocks are Scythian-Anisian Hallstatt limestones, Anisian radiolarites and
Verrucano-type sandstones. All these Upper Triassic detritic sequences are interpreted to be the synrift deposits of the Pindos
back-arc basin.
In conclusion, the Upper Triassic detrital units in Turkey and adjacent regions record the opening of Paleotethyan back-arc
basins like the Huğlu-Pindos Ocean and the closure of the Paleotethys.
REFERENCES
Bernoulli, D., de Graciansky, P.-C. & Monod, O., 1974: The extension of the Lycian Nappes (SW Turkey) into the southeastern
Aegean Islands, Eclogae Geologicae Helvetiae, 67(1), 39-90.
Koepke, J., Seidel, E. & Kreuzer, H., 2002. Ophiolites on the southern Aegean islands Crete, Karpathos and Rhodes;
composition, geochronology and position within the ophiolite belts of the Eastern Mediterranean, Lithos, 65, 183-203.
Moix, P., Beccaletto, L., Kozur, H.W., Hochard, C., Rosselet, F. & Stampfli, G.M., 2008. A new classification of the Turkish
terranes and sutures and its implication for the paleotectonic history of the region, Tectonophysics, 451(1-4), 7-39.
Fleury, J.-J., 1980. Les zones de Gavrovo-Tripolitza et du Pinde-Olonos (Grèce continentale et Péloponnèse du nord). Evolution
d'une plate-forme et d'un bassin dans leur cadre alpin, Société Géologique du Nord, Publication, 4, 1-473.
1. 0
The Greater Caucasus Tectonics and paleotectonics East of Eden
Mosar Jon*, Kangarli Talat**, Bochud Martin*, Rast Annick*
* Département de Géosciences Université de Fribourg, Chemin du Musée 6, CH-1700 Fribourg
** Geology Institute of Azerbaijan (GIA), National Academy of Sciences, H.Javid Av 29A, Baku AZ1143, AzerbaijanDépartement de
Géosciences Université de Fribourg, Chemin du Musée 6, CH-1700 Fribourg (jon.mosar@unifr.ch)
The Caucasus orogen lies at Europe’s cross-road with Asia and Arabia, and is one of the world’s outstanding Mountain belts.
It consists of the northern foreland basins, the Greater Caucasus, the intramontane basins (Kura-Kartli-Rioni; ≈ 200 m elevation)
and the Lesser Caucasus. North of the Greater Caucasus the deep sedimentary Terek and Kuban basin (> 6000 m; up to
1,600 m elevation) forms the transition to the Scythian platform. The Greater Caucasus is Europe’s highest and youngest
mountain range with Mt. Elbrus culminating at 5642m, and rock uplift of more than 8,000 m in the last 2 Myr. The intramontane
basin is one of the world’s earliest sites of human society with 1.8 Ma old humanoid remains of Dmanisi (Georgia).
The Lesser Caucasus with lower topography (≈ 3000 m), is a zone of important volcanic and seismic activity. In the East and
West, the Caucasus topography is bound by two very deep basins, the South Caspian Sea and the Black Sea, hosting one of
the world’s largest oil and gas provinces.
The presentation will address the tectonics of the Greater Caucasus, mainly along a traverse far east of Dmanisi, the Eden of
1.8-2.0 My old hominids. The overall tectonic setting of the Greater Caucasus corresponds to a doubly verging mountain-belt
with two external fold-and-thrust belts. The main transport direction is to the S. Along the N slopes, N-directed thrusting is
observed and a N-verging foreland fold-and-thrust belt develops. The southern active orogenic front is in, or to the S of, the
Kura-Kartli-Rioni “Molasse” basin. This foreland basin is filled with Tertiary and Quaternary sediments.
The Greater Caucasus corresponds to the inverted Mesozoic Greater Caucasus Basin. The evolution of the margin shows a
passive margin type geometry and is related to the back-arc rift processes resulting from the northward subduction of the
oceanic domains beneath the Lesser Caucasus arc. The evolution of the margin - its successive extensional and inversion
events - is related to the geodynamics of the subduction zone. The sedimentation is influenced by carbonate environment
linked to the platform to the north and volcanic derived sediments coming from the south. Following a series of rifting
events, a number of Jurassic to Cretaceous inversions are characteristic of the Greater Caucasus basin/margin. The basin
forms the connection between the oceanic realms of the Black Sea and the South Caspian Sea. The basin entirely develops
on continental crust.
A major debate concerns the existence of subduction slabs beneath the Caucasus. It is generally admitted that the Lesser
Caucasus is situated above an old slab. An incipient subduction is believed to occur at the northern edge of the Black Sea
and in the central Caspian Sea (Absheron Ridge), the western and eastern extensions of the southern front of the Greater
Caucasus. The Moho plunges from about 40 km beneath the Kura basin to more than 60 km beneath the Greater Caucasus
and rises to 40 km again under the northern foreland basin.
Symposium 1: Structural Geology, Tectonics and Geodynamics