The continental South Armenian Block - part of the Anatolide-Tauride South Armenian microplate - of Gondwana origin rifted from the African margin after the Triassic and collided with the Eurasian margin after the Late Cretaceous. During the Late Cretaceous, two northward dipping subduction zones were simultaneously active in the northern Neo-Tethys between the South Armenian Block in the south and the Eurasian margin in the north: oceanic subduction took place below the continental Eurasian margin and intra-oceanic subduction resulted in ophiolite obduction onto the South Armenian Block in the Late Cretaceous. The paleolatitude position of the South Armenian Block before its collision with Eurasia within paleogeographic reconstructions is poorly determined and limited to one study. This earlier study places the South Armenian Block at the African margin in the Early Jurassic. To reconstruct the paleolatitude history of the South Armenian Block, we sampled Upper Devonian-Permian and Cretaceous sedimentary rocks in Armenia. The sampled Paleozoic rocks have likely been remagnetized. Results from two out of three sites sampled in Upper Cretaceous strata pass fold tests and probably all three carry a primary paleomagnetic signal. The sampled sedimentary rocks were potentially affected by inclination shallowing. Therefore, two sites that consist of a large number of samples (>. 100) were corrected for inclination shallowing using the elongation/inclination method. These are the first paleomagnetic data that quantify the South Armenian Block's position in the Tethys ocean between post-Triassic rifting from the African margin and post-Cretaceous collision with Eurasia. A locality sampled in Lower Campanian Eurasian margin sedimentary rocks and corrected for inclination shallowing, confirms that the corresponding paleolatitude falls on the Eurasian paleolatitude curve. The north-south distance between the South Armenian Block and the Eurasian margin just after Coniacian-Santonian ophiolite obduction was at most 1000. km.
Bibliographical noteFunding Information:
The field work and analyses were supported by the Darius Programme. The authors would specifically like to thank the coordination and support of E. Barrier and M.F. Brunet. MJMM would like to thank the Henri Poincaré Postdoctoral Fellowship under which this research was carried out at the Observatoire de la Côte d'Azur (Nice). The authors would like to thank the following persons for their assistance in the field: Gayané Asatryan, Musegh Mkrtchyan, Sargis Vardanyan and drivers Hayro, Marat and Stephan. We also thank the staff at the Institute for Rock Magnetism at the University of Minnesota and especially Mike Jackson and Dario Bilardello for their help in carrying out and interpreting part of the rock magnetic measurements and Douwe van Hinsbergen for providing the paleogeographic reconstruction of the major continents. UK would like to acknowledge Ivan Gabrielyan and Tigran Lorsabyan for their help during a first reconnaissance field work. The authors would like to thank the Editor (Laurent Jolivet), John Geissman and Aral Okay for their helpful comments and constructive reviews, as well as three reviewers of an earlier version of this manuscript: Jérôme Gattacceca, Rob van der Voo and an anonymous reviewer.
- Collision zone
- Inclination shallowing
- Lesser Caucasus
- South Armenian Block
- Tethys reconstructions