SOSSON , M.

We present arguments for an innovative tectonic set-up just prior to the Northern Neotethys obduction event in the NE Anatolian and Lesser Caucasus area. Along the Northern Neotethyan suture (the Ankara–Erzincan–Amasia–Sevan–Akera suture zone), relicts of the northern branch of the Neotethys oceanic domain outcrop as preserved unmetamorphosed...

The ophiolites of NE Anatolia and of the Lesser Caucasus (NALC) evidence an obduction over ∼200 km of oceanic lithosphere of Middle Jurassic age (c. 175–165 Ma) along an entire tectonic boundary (>1000 km) at around 90 Ma. The obduction process is characterized by four first order geological constraints:(1) Ophiolites represent remnants of a...

The reason for obduction, or tectonic transport of oceanic lithosphere onto continents, is investigated by two-dimensional thermo-mechanical numerical modelling based on the geology of the Anatolia–Lesser Caucasus ophiolites. Heating of the oceanic domain and extension induced by far-field plate kinematics appear to be essential for the...

The lithological nature of major interplate boundaries is estimated by a field analysis of a well preserved exhumed subduction channel in the Caucasus Karabakh region. From this field example the subduction channel is a narrow geological object of about 500 m width formed at approximate depth of 10 km along an Andean-type subduction zone. It is...

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The ophiolites of Amasia in the northwestern part of the Sevan-Akera suture zone (Lesser Caucasus, NW Armenia) correspond to a well-preserved example of a major obduction of oceanic lithosphere over the South Armenian continental block. Our mapping evidenced a series of (1) un-metamorphosed gabbroic oceanic crust, (2) serpentinites and a...

The ophiolites of Amasia in the northwestern part of the Sevan-Akera suture zone (Lesser Caucasus, NW Armenia) correspond to a well-preserved example of a major obduction of oceanic lithosphere over the South Armenian continental block. Our mapping evidenced a series of (1) un-metamorphosed gabbroic oceanic crust, (2) serpentinites and a...

Comptes Rendus Géoscience, v. 339, n. 7, p. 482-492, 2007. http://dx.doi.org/10.1016/j.crte.2007.06.002

The Amassia–Stepanavan blueschist-ophiolite complex of the Lesser Caucasus in NW Armenia is part of an Upper Cretaceous-Cenozoic belt, which presents similar metamorphic features as other suture zones from Turkey to Iran. The blueschists include calcschists, metaconglomerates, quartzites, gneisses and metabasites, suggesting a tectonic mélange...

Variscan to Alpine magmatic activity on the North Tethys active Eurasian margin in the Caucasus region is revealed by 40Ar/39Ar ages from rocks sampled in the Georgian Crystalline basement and exotic blocs in the Armenian foreland basin. These ages provide insights into the long duration of magmatic activity and related metamorphic history of...

Tectonics, v. 25, n. 3, p. 22 pp, 2006. http://dx.doi.org/10.1029/2004TC001723

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The morphology of Patia and Mira canyons on the South Colombian convergent margin reflects an interplay between tectonic deformation, sea-level variation and canyon evolution, and provides new insight into the age and location of margin deformation over the last ~ 150 ka. Multibeam bathymetry, seismic, and sedimentary data reveal that...

Investigations of Mass-Transport Deposits (MTDs) and turbidite deposition in the confined North Ecuador subduction trench provide access to paleoseismic information and insights into long-term mechanisms for frontal tectonic erosion at a convergent margin. The studied trench has been the site of four great subduction earthquakes (7.7 ≤ Mw ≤...

Dating radiolarites in the ophiolitic sequences of Alpine mountain belts is important for the geodynamic reconstruction of Neo-Tethys in the Lesser Caucasus.However, radiolarian data from Karabagh are very rare. A moderately well-preserved radiolarian assemblage was obtained from radiolarites that overliepillow lavas cropping out west of the...

Similar geological, petrological, geochemical and age features are found in various Armenian ophiolitic massifs (Sevan, Stepanavan and Vedi). These data argue for the presence of a single large ophiolite unit obducted on the South Armenian Block (SAB). Lherzolite Ophiolite type rock assemblages evidence a Lower–Middle Jurassic slow-spreading...

This article summarizes the geodynamic evolution of the Variscan to Mesozoic Tethyan subduction history, based on a review of geochronological data from Eastern Anatolia and the Lesser Caucasus, and new isotopic ages for the Georgian crystalline basements. The geological history of the basements of Georgia (Transcaucasus) and NE Turkey (eastern...

Journal of Asian Earth Sciences, v. 34, n. 2, p. 135153, 2009. http://dx.doi.org/10.1016/j.jseaes.2008.04.002

This paper investigates the structure of the northern margin of the Ararat depression in a study area in SE Armenia. The depression is a Cenozoic intermontane basin located to the south of the Lesser Caucasus. The purpose is to improve understanding of the basin's structure and origin within a regional tectonic framework which has been...

The Greater Caucasus is Europe's highest mountain belt and results from the inversion of the Greater Caucasus back-arc-type basin due to the collision of Arabia and Eurasia. The orogenic processes that led to the present mountain chain started in the Early Cenozoic, accelerated during the Plio-Pleistocene, and are still active as shown from...