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Molasses of foredeeps are important indicators of the newest orogenic uplifts, as well as the source of data on climate and landscape changes. One of the fullest sections of Neogene–Quaternary deposits is studied in valleys of the Belaya, Pshekha, and Psekups rivers at the junction of the Western and Northwestern Caucasus with the Eastern Kuban and Western Kuban foredeeps. The formation of the deposits corresponds to the main evolution stages of the Great Caucasus orogen, as well as the foredeeps. A summary of extensive published and original tectonostratigraphic materials has shown that the lowland and then hilly relief in an axial zone of Western Caucasus existed at least from the Middle Miocene. At the same time, the northern flank of the present-day orogen and the foredeeps were located at sea level and were repeatedly flooded by the seas up to the Kuyalnikian (Piacenzian–Gelasian) time, and the Western Kuban Foredeep was flooded even later. The main data on stratigraphy of the upper molasses and Pliocene–Quaternary tectonic movements of the region are based on facies analysis and bio- and magnetostratigraphic studies of the Upper Pliocene–Lower Pleistocene Belorechensk Formation. Its sedimentation started at the beginning of the Kuyalnikian as a result of an increase in the energy of mountain rivers due to the uplift of the riverheads. It is stated that the minimum average rate of uplift of the Western Caucasus in the basin of the Belaya River is 0.8 mm/year over last 4 mln years with acceleration up to 1.7 mm/year from the beginning of the Calabrian. The Belorechensk Formation includes three subformations, which successively become coarser clastic and correspond to the main stages of the accumulation of upper molasses in the Late Pliocene and Early Pleistocene during the intensification of uplifts and landscape-climate changes of Western Caucasus and Ciscaucasia. [ABSTRACT FROM AUTHOR]

The results of a comparative analysis of the structure and history of the Neogene–Quaternary development of 18 intermontane basins in Northern Armenia and Eastern Turkey are presented. The research is based on expeditionary works carried out by the authors in 2012–2023 and supplemented by published materials from other researchers. Paleontological, magnetostratigraphic, and radioisotope data on the stratigraphy of the basins are analyzed. The comparison made it possible to identify four stages of basin development, expressed by the type of sedimentation: (i) marine sedimentation; (ii) predominantly lacustrine accumulation of fine-grained clastic material transported from low uplifts; (iii) lacustrine–alluvial sedimentation with a significant proportion of coarse material carried down from neighboring uplifts: (iv) involvement of the basins in the total uplift of the region, which in most basins is expressed by increased incision of watercourses into previously emerged landforms and in the Sevan depression is combined with ongoing lacustrine–alluvial sedimentation. Consistent rejuvenation of stages (i)–(iii) of basin development in the northern direction is revealed, caused by the growth and northward expansion of uplift of the Taurus Ridge in the process of its thrusting onto the Arabian Plate. At the same time, development of the basins revealed the impact of tectonic events in the Middle and South Caspian. It was expressed in the Early Pliocene by an unconformity and the appearance of coarse-clastic rocks, reflecting the increasing contrast of vertical movements between the Caucasian and Caspian regions, and at the end of the Late Pliocene by penetration of waters of the Akchagylian transgression of the Caspian Sea into some basins. These features of the development of the basins did not depend on differences in their origin, which was governed by the influence of several factors. Among them, the main ones were movements on faults as a result of the interaction of lithospheric blocks, and subsidence, caused by movements of sublithospheric masses, expressed by volcanism. Secondary roles were played by the behavior of the ophiolitic substrate and the tectonovolcanic damming of river valleys. [ABSTRACT FROM AUTHOR]

The loess-paleosol sequence of the Alma-Peschanoe section located in the west of the Crimean Peninsula is analyzed. A comprehensive analysis of morphological, physicochemical, and some other features enables us to identify eight paleosols formed under different conditions. The supposed age of the loess-paleosol sequence was determined by the paleofaunal analysis based on the discovery of a tooth from the mouse Micromys cf. bendae. According to the data obtained, the formation of paleosols at the initial stage was rhythmical under dry and moderately warm conditions. The paleosols were formed according to the steppe type of soil formation (Kastanozems in the WRB). Later, the climate changed towards an increase in temperature and humidity, and two red-brown polygenetic paleosols were formed. Their formation was gradual under conditions from arid to hot humid subtropical climate; at the optimal stages of soil evolution, the soils were formed according to the fersiallitic type (Nitisols). At the final stages, paleosols were formed under sharp changes in the regimes of moistening—drying. The studied red paleosols may be presumably assigned to the Sevastopol stratigraphic horizon. The studies performed enable us to characterize the landscape-climatic conditions and to elaborate a concept of the genesis of the soil cover in the Early Pliocene. [ABSTRACT FROM AUTHOR]

The Late Pliocene Gilbert-type delta is described in the western Erzurum Basin (NE Turkiye) and its position in the Late Cenozoic development of the basin is defined. The Erzurum Basin originated no later than Late Miocene between two Mesozoic ophiolite zones, continuing the Izmir–Ankara–Erzincan suture. In the Late Miocene–Pliocene, the basin was filled with fine-grained clastic and carbonate sediments of lacustrine-lagoon type. The Gilbert-type delta formed at the top of these deposits in the western part of the basin. The delta consists of 11 wedge-shaped bodies of clay, silt, sand, and gravel that were deposited as foresets of different phases of the delta development. The foreset bodies are dipping at 5° to 35° E. Some bodies underwent soft sediment deformation. The delta deposits are dated to Late Pliocene based on remains of small mammals and molluscs, palynological, and magneto-stratigraphic analysis. The delta eroded surface is overlain by alluvial pebbles dated to Early Pleistocene by archaeological finds. The Erzurum Basin is the westernmost member in a row of intermontane basins that continues to the east with the Pasinler, Horasan, and Agri basins that are drained by the Araxes River and its tributaries. It is likely that the paleo-Araxes River spread to the west in Late Pliocene and the studied delta was formed by its upper reaches that flowed into the water body of the Erzurum Basin. The delta deposits were covered by coarse alluvium in Early Pleistocene when the Erzurum Basin was tectonically isolated from the Araxes drainage system. In the latest Early Pleistocene or early Middle Pleistocene, the paleo-Araxes upper reaches were captured by the Euphrates River upper reaches that drain the Erzurum Basin now. The Upper Miocene and Pliocene deposits of the Erzurum, Pasinler, and Horasan Basins are similar and were accumulated in a single basin of sedimentation. Therefore, it can be assumed that the deposits of the upper Pliocene, containing the Akchagylian marine biota in the Horasan Basin, extended into the Erzurum Basin. However, the assumption that the upper reaches of the Euphrates River and the Erzurum Basin were the channel, through which the open sea biota entered the Akchagylian basin, is very unlikely for two reasons. Firstly, the Erzurum basin was limited by the described delta of the river, which flowed into it from the west. Secondly, the upper reaches of the Euphrates penetrated into the Erzurum Basin after the completion of the Akchagylian stage of sedimentation. [ABSTRACT FROM AUTHOR]

This article presents new data obtained as a result of field research in 2022 on the Sevan intermountain depression in Armenia. The emergence of the Sevan intermountain depression in the Miocene was associated with the development of the Sevan almond-shaped structure, which is bounded by the right-lateral Pambak‒Sevan‒Syunik fault zone in the northeast, the Garni zone in the southwest, and the Arpa‒Zangezur zone in the south. Within the Sevan almond-shaped structure, the strike-slip structures of Lesser Sevan (the western part of Lake Sevan) and the Gavar almond-shaped structure, the Gavar horst, a number of faults, as well as extension zones were formed, including the southern part of Greater Sevan (the eastern part of Lake Sevan) and the axial zone of the Geghama Range. The development of the Sevan intermountain depression continued in the Pliocene under the influence of the uplift of the Lesser Caucasus and the Armenian Highlands. We have summarized the available data on the geological structure and geodynamics of the Sevan intermountain depression; we present the obtained data on the stratigraphy of the Pliocene–Quaternary deposits and their position, and show that during the Akchagyl transgression at the Pliocene–Pleistocene boundary, marine sedimentary accumulations did not occur in the Sevan intermountain depression. [ABSTRACT FROM AUTHOR]