Lesser Caucasus

 

 

Neo-Tethys closure and oroclinal bending in the Lesser Caucasus (Armenia and Georgia)

 

 

There is ongoing collaboration between Maud Meijers (previously Postdoctoral Fellow at the Université de Nice – Sophia Antipolis) and a large multi-disciplinary research team with scientists from several countries to study the geology of the Lesser Caucasus (Georgia, Armenia).

The Lesser Caucasus region has been shaped by ongoing Africa-Eurasia convergence. One of the main goals in this project is to reconstruct the former Tethyan realm for this region in terms of its rifting, subduction and collision history. The geological evolution in the present-day Lesser Caucasus is characterized by the accretion of a microcontinent  ̶  the South Armenian Block (SAB)  ̶  to the southern Eurasian margin in the latest Cretaceous to possibly lower Eocene. Convergence between the SAB and the Eurasian margin was accommodated by several subduction zones that were at times simultaneously active. After SAB-Eurasia collision, Arabia-Eurasia collision continued to drive shortening in the Caucasus region.

Prof. Shota Adamia and Dr. Bezhan Asanidze looking out over beautifully exposed Miocene-Pliocene sequences near David Gareji monastery close to the boarder with Azerbaijan. Generally outcrops in the Lesser Caucasus are less well exposed, especially the sub-tropical stretch of Georgia along the Black Sea coast can be challenging for a geologist.

 

The paleolatitude position of the SAB between its moment of rifting from the African margin and its collision with the Eurasian margin is essentially unconstrained. Paleomagnetism is a tool to provide quantitative paleolatitude constraints. Bazhenov and Burtmann (2002) have shown that the convex arc-shaped geometry of the Lesser Caucasus between the SAB and the former Eurasian margin is an orocline. The age of formation of this orocline is however unknown. The two main goals of our project are 1) to provide paleolatitude constraints for the SAB to improve reconstructions of the Tethyan realm and 2) to constrain the timing of orocline formation using paleomagnetism.

 

 


The main collaborators in this project are:


Marc Sosson, Yann Rolland and Marc Hässig – Université de Nice - Sophia Antipolis (France)
Brigitte Smith – Université de Montpellier II (France)
Lilit Sahakyan, Araik Grigoryan, Ara Avagyan – National Academy of Sciences of Armenia, Yerevan (Armenia)
Shota Adamia – NODIA Institute of Geophysics, Tbilisi (Georgia)
Nino Sadradze – Djanelidze Institute of Geology, Tbilisi (Georgia)
Bezhan Asanidze – Caucasian Institute of Mineral Resources, Tbilisi (Georgia)
Uwe Kirscher – LMU Munich (Germany)
Daniel Pastor Galán, Cor Langereis, Renzo Degenaar (MSc, started 2012), Marily Mensink (BSc 2011) – Utrecht University (the Netherlands)
Carla Müller – independent researcher

 

Field works and laboratory analyses were funded by the Darius Program