David Shengelia

Ivane Javakhishvili Tbilisi State University | TSU · Aleksandre Janelidze Institute of Geology

The Dizi Series is exposed within the Southern Slope zone of the Greater Caucasus, in the core of the Svaneti anticlinorium. It is mainly composed of terrigenous, volcanogenic and carbonate rocks faunisti-cally dated from the Devonian to the Triassic inclusive. Regional and contact metamorphism of the Dizi Series rocks was studied. It is stated tha...

Orthogneissic massifs of the Beshta and Kamenistaya expose in the western part of the Pass subzone of the Main Range structural zone of the Greater Caucasus. Trondhjemitic gneiss is the predominant rock variety and it has gradual transitions to less abundant diorite gneiss. These rocks underwent metamorphism of epidote-amphibolite facies. Ultramafi...

Within the Somkhit-Karabakh tectonic zone (the Lesser Caucasus), preAlpine metamorphites are represented in the Loki, Akhum and Asrikchay massifs, and also occur as blocks in the ophiolite olistostrome of the Amasia-Sevan-Akera belt. Metamorphites of the massifs are similar in composition and P-T conditions of formation (Fig.1). There the following...

Here we report results of U-Pb zircon age data, obtained using LA-ICP-MS, from a total of 14 rocks of the Pass and Elbrus sub-zones of the Main Range Zone of the Greater Caucasus, which differ quite significantly from each other in composition of sedimentary and igneous rocks. Both exotic (detrital) zircons, and those formed within the Greater Cauc...

The Greater Caucasus-the complex geological structure of the Caucasus is an integrated part of the Mediterranean (Alpine-Himalayan) collision orogenic belt. The Dizi series is exposed within the Greater Caucasus Southern Slope zone, in the core of Svaneti anticlinorium. It is composed of faunistically dated from the Devonian to the Triassic inclusi...

The Greater Caucasus-the complex geological structure of the Caucasus is an integrated part of the Mediterranean (Alpine-Himalayan) collision orogenic belt. The Dizi series is exposed within the Greater Caucasus Southern Slope zone, in the core of Svaneti anticlinorium. It is composed of faunistically dated from the Devonian to the Triassic inclusi...

The inliers of Beshta and Mount Kamenistaia pre-Variscan orthognesses are exposed in Western Abkhazia on the Greater Caucasus southern slope in the Beshta and Lashipse river canyons (Fig.1). The Beshta inlier entirely crops out in the Liassic sediments, and that of the Mount Kamenistaia to the North and Northeast are in tectonic contact with the La...

GEOLOGY OF THE LOKI CRYSTALLINE MASSIF (CAUCASUS) (EXPLANATORY NOTE OF THE 1:50 000 SCALE DIGITAL GEOLOGICAL MAP). The explanatory note of the digital geological map of the Loki crystalline massif at a scale of 1:50 000 is of monographic character. It contains an extensive scientific information on the position of geological units and structures, a...

The Loki crystalline massif is exposed in South Georgia and it is an inlier of the pre-Alpine basement within the northern marginal part of the Baiburt-Sevanian terrane. The massif is represented by autochthonous Late Devonian gneissose quartz diorites, allochthonous pre-Upper Paleozoic overthrust sheets of metasediments and metabasites and by Late...

The Loki crystalline massif is exposed in South Georgia and it is an inlier of the pre-Alpine basement within the northern marginal part of the Baiburt-Sevanian terrane. The massif is represented by autochthonous Late Devonian gneissose quartz diorites, allochthonous pre-Upper Paleozoic overthrust sheets of metasediments and metabasites and by Late...

The pre-Alpine Loki crystalline massif is exposed in the northern part of the Baiburt-Sevanian terrane. Its area is 1000km 2. It is represented by metamorphites of greenschist and epidote-amphibolite facies of Paleozoic regional metamorphism and ophiolitic complex of the very low stage of metamorphism. The metamorphites are represented by alumina e...

The Jalovchat intrusive is built up of hornblende gabbros, gabbro-norites and norites. Within the intrusive hornblende-bearing gabbro-pegmatites are widespread. That is a coarse-grained rock with gigantic hornblende crystals. By its unusual composition, the Jalovchat intrusive has no analogue in the Caucasus. However, petrologically and geochemical...

The Loki crystalline massif crops out in the Caucasian region and the geological retrospective represent the northern marginal part of the Baiburt-Sevanian terrain (island arc), bordering with the Paleotethys oceanic basin in the north. The pre-Alpine basement of the massif is built up of Lower-Middle Paleozoic metamorphic complex (metasedimentary...

Orthoclase gabbro intrusive exposes in the Eastern part of the Dzirula crystalline massif of the Central Transcaucasian microcontinent. It is intruded in the Baikal quartz-diorite gneisses as a stock-like body. The intrusive is characterized by heterogeneity of rock composition: variability of mineral content and irregular distribution of rock-form...

The Jalovchat gabbro intrusive is exposed on the northern and southern slopes of Main Range zone of the Greater Caucasus, on an area about 25km2. It is intruded in Precambrian crystalline schists and amphibolites intensively metamorphose them along the contact zone. The intrusive is represented by hornblende-bearing gabbro, gabbro-norites and norit...

The Jalovchat gabbro intrusive is exposed on the northern and southern slopes of Main Range zone of the Greater Caucasus, on an area about 25km2. It is intruded in Precambrian crystalline schists and amphibolites intensively metamorphose them along the contact zone. The intrusive is represented by hornblende-bearing gabbro, gabbro-norites and norit...

In the crystalline substrate of the Elbrus subterrane intensively metamorphosed, un-stratified, migmatizated infrastructure and less metamorphosed, un-migmatizated stratified supra-structure built up of mainly mica schists are distinguished distinctly. The oldest formations of the Elbrus subterrane infrastructure are represented by garnet-cordierit...

In the crystalline substrate of the Elbrus subterrane intensively metamorphosed, un-stratified, migmatizated infrastructure and less metamorphosed, un-migmatizated stratified supra-structure built up of mainly mica schists are distinguished distinctly. The oldest formations of the Elbrus subterrane infrastructure are represented by garnet-cordierit...

In the paper petrogenic model of the the Klichi intrusive formation in the Buulgen metamorphic complex is presented. It is shown that the protolith of the Klichi intrusion is represented by hornblende varieties of gabbro-dioritic composition. The intrusion breaks through the Gwandra suite of the Buulgen complex. It was metamorphosed during the Bret...

Late Paleozoic (Sudetian) granitoids within the Caucasus are spread in all outcrops of the pre-Alpine crystalline basement except Miskhan, Akhum and Asrikchay crystalline massifs. In particular, the granitoids crop out: in the southern part of the Scythian Platform and within the Greater Caucasian, Black Sea – Central Transcaucasian and Baiburt-Sev...

Late Variscan granites are widespread in the Dzirula and Khrami crystalline massifs of the Black Sea – Central Transcaucasian terrane (Gamkrelidze & Shengelia 2005). The age of the granites is well-grounded geologically by a number of geologists, but there are solitary isotope-geochronological data on these massifs (Dudauri & Togonidze 1985; Okrosc...

Late Variscan granites are widespread in the Dzirula and Khrami crystalline massifs of the Black Sea – Central Transcaucasian terrane (Gamkrelidze & Shengelia 2005). The age of the granites is well-grounded geologically by a number of geologists, but there are solitary isotope-geochronological data on these massifs (Dudauri & Togonidze 1985; Okrosc...

Late Paleozoic (Sudetian) granitoids within the Caucasus are spread in all outcrops of the pre-Alpine crystalline basement except Miskhan, Akhum and Asrikchay crystalline massifs. In particular, the granitoids crop out: in the southern part of the Scythian Platform and within the Greater Caucasian, Black Sea – Central Transcaucasian and Baiburt-Sev...

Prior to the contact effect of intermediate intrusives the Dizi series was represented by the rocks transformed under epidiagenesis: sandstones rich in strongly dislocated and finely folded coaly-argillaceous matter and in quartz, argillized varieties and limestones. Under the thermal influence of intrusive the sandy- clayey rocks of the Dizi ser...

Variscan regional metamorphism and granitoid magmatism of the Elbrus and Pass subzones of the Main Range structural zone of the Greater Caucasus considerably differ from each other. In particular, Bretonian granitoid magmatism is not manifested in the Pass subzone in contrast to the Elbrus one; composition and conditions of geodynamic formation of...

Within the oceanic area of Tethys, with a typical oceanic crust, in geological past relatively small continental or subcontinental plates (terranes) were situated. The Greater Caucasian, Black Sea - Central Transcaucasian, Baiburt - Sevanian and Iran - Afghanian accretionary terranes, which in geological past represented island arcs or microcontine...

Orthoclase gabbro of the Dzirula crystalline massif incorporates the rocks of different genetic groups: protolith of the gabbroic intrusion, hybrid rock - orthoclase gabbro and leucocratic quartz-feldspar bearing formation. The rocks of all three genetic groups are dated by the U-Pb LA-ICPMS zircon age method. The apparent age of zircon in the prot...

The Caucasus mountain belt has a complex tectono-thermal history that is as yet poorly understood due to the scarcity of reliable geochronological information. Here, we report new monazite and zircon data from the Dzirula massif in the southern Caucasus, which permit development of a model for Variscan LP-HT (low pressure- high temperature) metamor...

The available data on the composition, interrelation, age and formation conditions of the pre-Alpine crystalline basement constituting rocks of the Black Sea-Central Transcaucasian terrane are considered. It is shown that the main stages of regional metamorphism and granite formation are fully corroborated by new U-Pb LA-ICP MS dating. The investig...

According to rare elements content and to geochemical characteristics (Eu/Eu*-Sr/Nd, Rb/Sr-SiO2, Rb/Sr, Sm/Nd, Lan/Ybn), composition of Early Variscan granitoids of the Elbrus and Pass subzones of the Main Range zone of the Greater Caucasus as a whole corresponds to the upper crustal and common crustal granitoids of the other regions of the worl...

We present the first combined analysis of zircon U-Pb and Hf isotopes of intrusive bodies in the Georgian Caucasus that indicates a significant period of magmatism in the Carboniferous. Magmatic zircons of 14 intrusive rocks from the Georgian Caucasus show similar 206Pb/238U ages clustering between 309 and 331 Ma and ɛHf(T) values ranging from -0.1...