Neogene‒Quaternary Mountain Building of the Greater Caucasus and the Role of the Pshekha–Adler and Terek–Aragvi Transverse Fault Zones

Our study of the structure of Ciscaucasian local foredeeps, and in particular the study of molasses, allowed us to clarify the history of the most recent orogeny in the Greater Caucasus. The asynchronous appearance of boulder–pebble alluvium in Ciscaucasian foredeeps, corresponding to different segments of the mountain system, recorded the onset of the formation of the Caucasus mountain relief and enabled us to identify the stages of its segmental uplift: (i) pre-Sarmatian, formation of the Caucasus land mass; (ii) Sarmatian‒Cimmerian, slow collisional orogeny and formation of mid-mountain topography; (iii) Pliocene‒Quaternary, Late-collisional acceleration of uplift and formation of high-mountain topography. The crystalline core of the orogen was exposed in the Central Caucasus region during the Late Sarmatian‒Maeotian. Our study examines the role of large transverse fault zones in Caucasian orogeny and presents new structural, geomorphological, and tectonophysical data on the structure of the Pshekha–Adler and Terek–Aragvi fault zones. We have identified the Terek–Aragvi transeverse fault zone for the first time in the structure of the Greater Caucasus. In the Ciscaucasus and Transcaucasia, the identified fault zones delimit local piedmont troughs and control the distribution of the Maeotian, Pontian, Akchagylian, and Apsheronian marine basins. This article provides a data review and presents the results of study of the structure, recent kinematics, and stress-strain state of the Pshekha–Adler and Terek–Aragvi transverse fault zones.