About Konkian/Sarmatian Boundary of Georgia Based on Foraminifera

2020

The Sarmatian deposits in the vicinity of the town of Mtskheta were studied by palynological method. All layers of the section contain pollen and spores. Of great interest is the presence of palynomorphs in Upper Sarmatian deposits, a large part of which on the territory of Kartli is represented by continental sediments. Sarmatian deposits are widely distributed on the territory of Eastern Georgia (Fig.1). By faunistical and lithological data they are divided into three substages: Volhinian, Bessarabian and Khersonian. On the territory of Kartli the Lower Sarmatian is conformably bedding on the Konkian deposits and is represented by clayey sediments with intercalations of limestones and sandstones. Lower Sarmatian is characterized well by fauna [1]. The deposits of Middle Sarmatian are comfortably bedding on Lower Sarmatian. They are represented by blue-grayish or green-grayish clays with rich fauna of mollusks [1]. In the Kartli depression the Upper Sarmatian is represented by fres...

Bulletin of the Georgian National Academy of Sciences, 2012

The results of palynological and microfaunistical investigations of the Sarmatian deposits of Eastern Georgia are given. The similarity in dynamics of terrestrial and marine biocenosis is established.

Proceedings of the Georgian Academy of Sciences, Biological series B, 2009

The foraminifers and palynomorphs from the Late Cenozoic in Eastern and Western Georgia were studied in more than 45 sections. The evolution of the foraminifers is traced and development stages are distinguished for the Sarmatian and the Meotian. The landscape-phytocenological method allows interpreting the evolution of vegetation depending on climatic fluctuations. Common turning-points in the development of marine and terrestrial biocoenoses are recognized and connected with changes in paleogeography and depositional environments in the region of today's Caucasus during the Late Cenozoic.

2019

The Tethys Ocean was closed in Georgia only in the Late Cenozoic. Geophysical study has led to a detailed model of the deep crustal structure of the region that includes areas of twolayered as well as three-layered continental crust. The thickness of the crust varies from 30 to 60 km, with significant lateral variations in the sedimentary layer (0–25 km). Geological, paleobiogeographical and paleogeographical data supported by paleomagnetic studies indicate the existence of several tectonic units in Georgia and adjoining regions that have distinctive geological histories. Their position against the African and Eurasiatic continents provides a reason for grouping them into Northern Tethyan and Southern Tethyan domains. The magmatic evolution of the North Tethyan domain is featured by major events corresponding to the Pacific and Mediterranean type stages of Tethyan development. Late Cenozoic magmatic complexes are exposed along the boundaries of the main terrains of the region. The c...

2021

The foraminifera of the Miocene deposits of the Black Sea-Caspian region were studied by many paleontologists, most importantly Bogdanowicz (1965), Didkovsky (1966), Dzhanelidze (1970), Dzhanelidze et al. (1985). The foraminifera of Sarmatian s.l. and Meotian deposits of Western Georgia were the subject of investigations of Maissuradze (1966, 1971, 1980, and 1988). The foraminifera of Sarmatian s.l. deposits of Eastern Georgia were studied by Koiava (2004, 2006 b). The Sarmatian s.l. deposits are widely distributed on the territory of Georgia. They are characterized by frequent changes of facies, which was the main factor that influenced the composition of foraminiferal fauna. During the late Cenozoic, several stages in the development of foraminifera can be distinguished (Koiava et al., 2008; Koiava et al., 2017). The characteristics of these stages are given below. The Volhynian commonly overlies conformably the Konkian deposits and is represented by argillo-arenaceous facies (sands, clays). In the shallow water deposits of the lower part of Volhynian are dominant: Elphidium macellum (Fichtel & Moll), E. crispum (Linnaeus), E. obtusum (d'Orbigny), E. hauerinum (d'Orbigny), E. angulatum (Egger), Elphidiella artifex (Serova). In lesser numbers of specimens occur: Ammonia aff. beccarii (Linnaeus), Nonion tumidulus Pishvanova, N. bogdanowiczi Voloshinova, Sinuloculina consobrina (d'Orbigny), Varidentella reussi reussi (Bogdanowicz), V. reussi sartaganica (Krasheninnikov), Affinetrina guriana (Dzhanelidze), Porosononion martkobi (Bogdanowicz), P. subgranosum (Egger) and others (Maissuradze, Koiava 2011 a). In deeper argillaceous deposits of the same age are found: Varidentella reussi reussi (Bogdanowicz), V. reussi sartaganica (Krasheninnikov), Sinuloculina consobrina (d'Orbigny), Affinetrina guriana (Dzhanelidze), Cycloforina karreri (Reuss), Quinqueloculina collaris (Gerke & Issaeva), 12 Spiroloculina okrojantzi Bogdanowicz, Articulina problema Bogdanowicz, A. tamanica Bogdanowicz. Commonly it is possible to see also thin-shelled, comparatively small Nonion tumidulus Pishvanova, N. bogdanowiczi Voloshinova, Porosononion martkobi (Bogdanowicz), P. subgranosum (Egger), Fissurina aff. marginata (Montagu) and statoliths of crustaceans Sarmysis sarmaticus (Khalilov). Both facies are characterized by layers with Varidentella reussi and are attributed to the stage I. The upper part of Volhynian is also characterized by different assemblage the composition of which is dependent on lithology or depth of the basin where the sediments accumulated. In near-shore deposits the species of Nonion, Elphidium, and Porosononion dominate. In deeper-water deposits miliolids dominate: Articulina, Varidentella, Sinuloculina, Cycloforina, Affinetrina and also, rarely, Nonion and Porosononion. In complexes of this age the first endemic species and subspecies are found: Sinuloculina consobrina sarmatica (Gerke), Cycloforina karreri ovata (Serova), Varidentella complanata (Gerke & Issaeva), Articularia articulinoides (Gerke & Issaeva), Fissurina cubanica (Bogdanowicz), F. elongata (Pobedina, Voroshilova, Rybina & Kuznetsova). The number of percentage of miliolids and elphidiids are different. In the West, the miliolids are dominant but in the East elphidiids (Nonionidae and Elphidiidae) prevail. The complex of foraminifera in the Bessarabian is composed of the following species: Affinetrina voloshinovae voloshinovae (Bogdanowicz), A. voloshinovae eldarica Maissuradze, Koiava & Spezzaferri, A. voloshinovae pecteniformis (Bogdanowicz), Cycloforina karreri (Reuss), Sinuloculina angustioris (Bogdanowicz), Varidentella complanata (Gerke & Issaeva), V. reussi costulata Maissuradze, Koiava & Spezzaferri, Spiroloculina okrojantzi Bogdanowicz, S.

This work contributes to a better knowledge of potentially seismogenic faults of the Georgia Greater and Lesser Caucasus by evaluating the distribution of earthquake foci, active tectonic stress field, kinematics and geometry of main fault planes. We consider all the information coming from field structural geology, geomorphology, seismo-logical data from historical and instrumental catalogues, seismic reflection sections, as well as new focal mechanism solutions. These data enable recognizing some active ENE-WSW reverse faults in the core of the Greater Caucasus that are parallel to the mountain range. At the southernmost front of the Greater Caucasus, a series of main thrusts dipping towards NNE are active, with up to hundreds-km-long segments; along this thrust zone, a potentially locked segment is present, about 90 km long. The studied section of the Lesser Caucasus has active structures along the northern front given by south-dipping thrusts, as well as in the central core where strike-slip and oblique faults coexist. The Transcaucasian depression between the two mountain ranges shows an ongoing inversion tectonics of the central part of the Rioni Basin where active N-to NE-dipping reverse faults are present, accompanied by clear evidence of uplift of a wide area. The data are coherent with a N-S to NNE-SSW contraction of the central-western Greater Caucasus and Lesser Caucasus. Although in general the seismicity decreases westward in terms of number of earthquakes and magnitude, seismological and geological structural data in the Rioni Basin indicate here a Quaternary propagation of deformation towards the west.

Earth Sciences, 2015

Geography is facing new challenges in Georgia. On the one hand, it is related to evaluation of current condition of the country and its geo-ecological issues, and on the other hand, the requirements of practice and the prospects of socioeconomic development. The requirements of practice imply several urgent issues such as new orientation of the land use and the optimal use of the region's natural-resource potential, demographic stability and development of mountainous areas. The prospects of the country's development include the urgent issues such as global environmental problems and prediction of geo-system conditions, development of military geography and planning of environmentally strained areas. In order to present and solve these problems effectively, Georgian School of Geography should play a key role, which will become a prerequisite for its further development.

2012

Two Bronze Age human settlements of the Western Karthaliny Basin (Transcaucasia region, Georgia) were studied using a multidisciplinary approach. Satellite data (Corona, Landsat) and aerial images, as well as new archaeological data and a detailed field survey were applied to the study of the hydrographic evolution of the Kura (Mtkvari) River and of its tributaries; its influence on the archaeological sites scattered between the villages of Natsargora and Agara was also examined. Finally, four stratigraphic profiles were analysed; these are situated along the Kura river and on its tributaries flowing from the Greater Caucasus: the Western and the Eastern Prone.

South Caucasus – Archaeological Context, 2021

Study of past changes in environment and, its effect on human society delivers key information to reconstruct the hystorical past but also to project future changes and their effects. Study focus on South-East Georgia, Caucasus region, which represents natural polygon of long term changes in the environment. Study area represents semi-arid Shiraqi plain in South-East Georgia (see the map below). It is characterized with annual precipitation <600mm and shows open dry steppic landscape today. However, recent data collected using remote sensing and archaeological studies, deliver evidences of early human inhabitation of this area, starting from the Paleolithic and forming a constant chain of active settlement through the time, until sudden abrupt at the end of the Bronze Age. Geomorphologically Shiraqi plane represents 800 sqr. km of almost flat area with average height of 600 m above Sea level, surrounded by chains of mountains creating a natural walls surrounding the plane. There ...