Titre :

Active tectonics within the NW and SE extensions of the Pambak-Sevan-Syunik fault: Implications for the present geodynamics of Armenia

Auteur(s) :

Ritz, J.F. [Auteur]
Géosciences Montpellier
Avagyan, A. [Auteur]
Institute of Geological Sciences of the National Academy of Sciences of Armenia [IGS NAS RA]
Mkrtchyan, Mushgeh [Auteur]
Géosciences Montpellier
Nazari, H. [Auteur]
Geological Survey of Iran
Blard, P. -H. [Auteur]
Centre de Recherches Pétrographiques et Géochimiques [CRPG]
Karakhanian, A. [Auteur]
Institute of Geological Sciences of the National Academy of Sciences of Armenia [IGS NAS RA]
Philip, Herve [Auteur]
Géosciences Montpellier
Balescu, S. [Auteur]
Histoire, Archéologie et Littérature des Mondes Anciens - UMR 8164 [HALMA]
Mahan, S. [Auteur]
US Geological Survey [Denver]
Huot, S. [Auteur]
Munch, Philippe [Auteur]
Géosciences Montpellier
Lamothe, M. [Auteur]

Titre de la revue :

Quaternary International

Pagination :

61-78

Éditeur :

Elsevier

Date de publication :

2016-02-22

ISSN :

1040-6182

Mot(s)-clé(s) en anglais :

Armenia
Active faults
Pambak-Sevan-Syunik fault
Slip rate
Paleoseismology
Cosmogenic He-3

Discipline(s) HAL :

Planète et Univers [physics]/Sciences de la Terre/Tectonique

Résumé en anglais : [en]

This study analyzes the active tectonics within the northwestern and southeastern extensions of the Pambak-Sevan-Syunik fault (PSSF), a major right-lateral strike-slip fault cutting through Armenia. Quantifying the ...
Lire la suite >This study analyzes the active tectonics within the northwestern and southeastern extensions of the Pambak-Sevan-Syunik fault (PSSF), a major right-lateral strike-slip fault cutting through Armenia. Quantifying the deformations in terms of geometry, kinematics, slip rates and earthquake activity, using cosmogenic 3He, OSL/IRSL and radiocarbon dating techniques, reveal different behaviors between the two regions. Within the northwestern extension, in the region of Amasia, the PSSF bends to the west and splits into two main WNW–ESE trending reverse faults defining a compressional pop-up structure. We estimate an uplift rate and a shortening rate of 0.5 ± 0.1 mm/y and 1.4 ± 0.6 mm/y, respectively. This suggests that most of the ∼2 mm/y right lateral movement of the PSSF seems to be absorbed within the Amasia pop-structure. Within the southeastern extension, the PSSF shows signs of dying out within the Tsghuk Volcano region at the southernmost tip of the Syunik graben. There, the tectonic activity is characterized by a very slow NS trending normal faulting associated with a slight right-lateral movement. Slip rates analyses (i.e. vertical slip rate, EW stretching rate at 90° to the fault, and right-lateral slip rate of ∼0.2 mm/y, ∼0.1 mm/y and ∼0.05 mm/y, respectively) lead to the conclusion that the right lateral movement observed further north along the PSSF is mainly transferred within other active faults further west within the Karabagh (Hagari fault or other structures further northwestwards). Comparing our slip rates with those estimated from GPS data suggests that most of the deformation is localized and seismic, at least within the Tsghuk region. The geometrical and kinematic pattern observed within the two terminations of the PSSF suggests that the fault and its surrounding crustal blocks are presently rotating anticlockwise, as also observed within the GPS velocity field. This is consistent with the recent kinematic models proposed for the Caucasus-Kura-South Caspian region and brings a new insight into the present geodynamics of Armenia.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Collections :

• Histoire Archéologie Littératures des Mondes Anciens (HALMA) - UMR 8164

Source :

Harvested from HAL