Nona Gagnidze | Ilia State University (original) (raw)

Papers by Nona Gagnidze

Research paper thumbnail of Felsitic Magmatizm and Thorium - Bismuth Ore Mineralization in the Greater Caucasus Kakheti Segment, Georgia

Research paper thumbnail of Geology and Mineral Occurrences of the Eastern Greater Caucasus, Georgia Segment

The eastern part of the Caucasus orogen,termed the Georgian segment, is mainly underlain by highl... more The eastern part of the Caucasus orogen,termed the Georgian segment, is mainly underlain by highly deformed Lower-Middle Jurassic shales, sandstones, and volcaniclastic rocks, and cut by numerous intrusive bodies of various compositions. All units contain a variety of mineral deposit types and their surrounding zones of hydrothermal alteration. Detailed geological and metallogenic research, after 30 years stagnation, has led to important new information regarding the evolution of this region. Three main stages of magmatic activity are now clearly distinguished, the oldest magmatism comprises early Jurassic events, related to extensional tectonism, with volcanism and subvolcanic plutonism that ranged from rhyolitic, through dacitic and andesitic, and to basaltic. Additional extensional processes (in the Bajocian time) were characterized by intrusion of a gabbro and diorite dike system into slightly older late Early Jurassic-early Middle Jurassic formations. The final magmatic event w...

Research paper thumbnail of Ore mineral deposition in black shale inthe Ssouthern Slpe of the Greater Caucasus

Research paper thumbnail of “Mythical” gold sands of Svaneti (Caucasus, Georgia) and argonouts expedition purpose

Research paper thumbnail of Volcanogenic Deposits of Non-ferrous Metals in the Lesser Caucasus and Eastern Pontides

Journal of Geological Research, 2021

The paper presents brief characteristics of geological environments of ore deposit occurrences in... more The paper presents brief characteristics of geological environments of ore deposit occurrences in Turkey, Georgia and Armenia. They can be attributed to Kuroko-type deposits, being distinguished by the character of ore accumulation. To the west, in Turkey, there are epigenetic and hydrothermal-sedimentary copper-zinc deposits that were formed in deep restricted basinal settings. An example of the latter is the Chayeli deposit.To the east, in the Caucasus, we have predominantly only epigenetic deposits. Besides, in the Bolnisi mining district (Georgia) there is the Madneuli deposit which represents an example of polyformational deposit. Here, within the restricted territory, have been concentrated:barite, barite-polymetallic, gold-bearing secondary quartzite, large-scale stockworks of copper ores. Judged by the 87Sr/86Sr ratios, some volcanites which are spatially associated with ores, might have been products of the “differentiation” of undepleted mantle, or other magmas that were g...

Research paper thumbnail of Geological Framework and Thorium Resources Exploration Condition of Georgia (The Caucasus)

The Caucasus represents a Phanerozoic collisional orogeny, that formed along the Eurasian North c... more The Caucasus represents a Phanerozoic collisional orogeny, that formed along the Eurasian North continental margin, extends over 1200 km from the Caspian to Black Sea. Georgian republic is situated in the central part of Caucasus Region. Here are marked 3 ore occurrences of thorium : 1-in the Greater Caucasus (Th concentrations vary between 51g/t 3882g/t); 2in the Dzirula massif (Th concentrations vary between 117 g/t -266 g/t); 3in Vakijvari orefield (Th concentrations vary between 185 g/t 428 g/t). Based on these data thorium ore occurrences found in Georgia should be treated as prospective resources.

Research paper thumbnail of Zircons U-Pb Geochronology of the Ore-BearingPlutons of Adjara-Trialeti Folded Zone, LesserCaucasus and Analysis of the Magmatic Processes

Zircons of the major ore-bearing plutons (Merisi, Namonastrali, Vakijvari, Zoti, Okros- Ghele and... more Zircons of the major ore-bearing plutons (Merisi, Namonastrali, Vakijvari, Zoti, Okros- Ghele and Rkviana) of the Adjara-Trialeti Paleogene folded zone of the Lesser Caucasus were dated by the U-Pb method using the Laser Ablation ICP-MS tool at the isotope laboratory of the Department of Earth Sciences at the National Taiwan University. The results are almost identical and are as follows: Merisi (diorite), sm. #12Ge-03=43.42±0.61 Ma; Merisi (syenite) sm.#12Ge- 04=42.78±0.65 Ma; Namonastrali (diorite) sm. #12Ge-05=42.42±0.5 Ma; Namonastrevi (diorite) sm.#12Ge-06=42.03±0.83 Ma; Vakijvari (syenite) sm.#12Ge-13=43.26±0.74 Ma; Zoti (syenite) sm. #12Ge-15 =43.86±0.43 Ma; Zoti (gabbro) sm.#12Ge-16=46.77±0.81 Ma; Okros-Ghele (syenite) sm. #12Ge=19-44.34±0.55 Ma; Rkviana (gabbro) sm. #12Ge-21=44.85±0.59 Ma. Based on the analysis of the results, it is obvious that the ore bearing plutons of the Adjara-Trialeti zone were intruded through the volcanic-sedimentary rocks within a short time inter...

Research paper thumbnail of Ore Mineralization of Active Paleomargins of Continents (on the Example of Alpine Metallic Deposits of Caucasus and Pontides)

Metallogenic features of Pontides – Lesser Caucasus microplates (part of active paleomargin of Eu... more Metallogenic features of Pontides – Lesser Caucasus microplates (part of active paleomargin of Eurasian microplate are determined by copper, copper-molibdenium porphyry, iron-scarn, volcanic nonferrous, precious metals, auriferous and manganese ore deposits. Their orebearing fluid systems occurred consistently on various stages of development of the region and were correlated with geological processes on the border of convergental and divergental interaction of mic¬roplates. The above mentioned types of ore deposits display clear areal and temporary bonds with certain composites of lithogeodynamic complexes (which are presented in mountain folding systems of relics of ancient geomorphological structures) - geological formations. Different geologic-genetical models are suggested for each type of deposits, characterizing possible sources of ore substance, causes of rise and functions of fluid systems, in addition to ore formation environment. It may be said that different genetic grou...

Research paper thumbnail of Field Trip Guide of the Fourth Plenary Conference of the UNESCO IGCP pr.610, Tbilisi, Georgia

Research paper thumbnail of Ore-Forming Processes and Ore Occurrences of the Eastern Greater Caucasus Georgian Segment

In the Eastern Greater Caucasus Georgian segment Lower-Middle Jurassic shales and sandstones expe... more In the Eastern Greater Caucasus Georgian segment Lower-Middle Jurassic shales and sandstones experienced crush, hydrothermal alteration and ore mineralization processes. At some hydrothermally altered areas mainly copper-pyrrhotitic and pyrite-polymetallic ores were formed. Already known ore occurrences were studied and, at the same time, new and interesting ore occurences were discovered in the hydrothermally altered zone in the r. Stori canyon (Bendena,Gelia, and enriched with Th zone) and pyrite-polymetallic ore mineralization at the village Lechuri. The latter should be of great interest, since it shows lots of similarities to Filizchay pyrite-polymetallic deposit by its geologic position and mineralogical-geological parameters, which makes necessary further detailed study of the area. It should be noted that at some areas, on the result of conducted research, for the first time the increased concentrations of Au (at Artana and Tebulo ore fields) were reported. At Tebulo ore fie...

Research paper thumbnail of Felsitic Magmatism and Thorium-Bismuth Mineralization in the Greater Caucasus KakhetiSegment, Georgia

The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-A... more The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-Asian North continental margin between the Black and Caspian Seas and is extended over 1200 km distance between the Black and Caspian seas, and considered as a terrane of the first order, which is accreted to the south margin of the Euroasian continent. The Kakheti segment is located on the eastern part of the southern slope of the Greater Caucasus and is mainly formed of strongly folded Lower Jurassic clay-shales and mafic volcanic-sedimentary formations. According to geophysical data these sediments are located on oceanic or transitional crust. Ore mineralization is related to hydrothermally altered zones, which are significantly enriched by rare metals – thorium and bismuth, and also by gold, copper, zinc, lead and cobalt.

Research paper thumbnail of Gold Potential of Georgia

The authors’ aim was determination of estimated gold resources on the basis of the geological dat... more The authors’ aim was determination of estimated gold resources on the basis of the geological data analysis. The following methods were used for calculation of resources: parameters of ore bodies at gold occurrences, data of geochemical anomalies, geological evidence indicating existence of ore bodies in the depth. The territory of Georgia includes part of the Alpine-Himalayan mountain-fold belt, which is a result of interaction of the Scythian and South Caucasus microplates geologically developed in the marginal area of the Eurasian continent. Four gold bearing complexes are found on the territory of Georgia: 1) Activated in Middle Jurassic south Caucasus microcontinent slope and slope root zones, which are built by Palaeozoic Middle-Early Jurassic marginal sea flischoid-terrigenous sediments (potential in Middle Jurassic deposits in granite stocks Lukhra and in carbonaceous suite Arshira, Lasilli, on Svaneti ridge; 2) The Greater Caucasus southern slope suture zone (“main thrusts”...

Research paper thumbnail of Mineral Occurrences of the Eastern Greater Caucasus, Georgia

Research paper thumbnail of Magmatizm and Mineral Occurrences of the Eastern Greater Caucasus Georgian Segment

Magmatism and Mineral Occurrences of the Eastern Greater Caucasus, Georgian Segment N. GAGNIDZE, ... more Magmatism and Mineral Occurrences of the Eastern Greater Caucasus, Georgian Segment N. GAGNIDZE, A.OKROSTSVARIDZE, K. AKIMIDZE, S. L. CHUNG Ilia state University, Tbilisi 0162, Georgia, (*correspondence:nonagagnidze@gmail.com) Javakhishviuli State University, Tbilisi 0138, Georgia (okrostsvari@gmail.com) 3 Institute of Earth Science, Academia Sinica, Taipei 11529, Taiwan (sunlin@earth.sinica.edu.tw)

Research paper thumbnail of Late Miocene Volcanic Ash Layers of the Inter-Mountain Depression of the Eastern Caucasus: The Products of the Megacaldera Explosion?

The Caucasus is a central segment of the Mediterranean Alpine-Himalayan collisional orogenic syst... more The Caucasus is a central segment of the Mediterranean Alpine-Himalayan collisional orogenic system and consists of the Greater and Lesser Caucasus orogens and intermountain depression. There are numerous layers of volcanic ashes in the late Miocene marine sediments (dated paleontologically) of the Eastern Caucasus intermountain depression. The ashes consist primarily of hornblende, pyroxene, and volcanic glass (Skhirtladze, 1964). The thickness of the layers varies between 5 m to several decimeters, while their distribution area is wide and includes the Kartli and Kakheti regions in Georgia and the western region of Azerbaijan

Research paper thumbnail of Felsic Magmatism and Th-Bi Mineralitation in the Greater Caucasus Kakheti Region, Georgia

The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-A... more The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-Asian North continental margin between the Black and Caspian Seas, and is accreted to the south margin of the Euroasian continent. The Kakheti region is located on the eastern part of the southern slope of the Greater Caucasus and is mainly formed of strongly folded Lower Jurassic clay-shales and mafic volcanic-sedimentary formations. Ore mineralization is related to hydrothermally altered zones, which are significantly enriched in rare metals – thorium and bismuth, and also in gold, zinc, lead and cobalt. The studied area is underlain with highly deformed Lower-Middle Jurassic sediments and volcaniclastic rocks, associated with numeorus intrusive bodies. The rocks contain variety of mineralization types and hydrothermal alteration. The largest outcrop of felsic hypo-abyssal dykes is Speroza massif, which has a lenticular shape with a length of 14 km. It represnets the area of mesothermal...

Research paper thumbnail of The Volcanogenic Deposits of Non-Ferrous Metals of Paleoisland Arc Environment Associated with Wall Rock Alterations of Host Rocks and Problems of Ore Genesis (On the Example of Ore Districts in Georgia, Armenia and Turkey)

Visnyk of Taras Shevchenko National University of Kyiv. Geology, 2017

ВУЛКАНОГЕННЫЕ МЕСТОРОЖДЕНИЯ ЦВЕТНЫХ МЕТАЛЛОВ ПАЛЕООСТРОВОДУЖНЫХ СООРУЖЕНИЙ И ПРОБЛЕМЫ ГЕНЕЗИСА РУ... more ВУЛКАНОГЕННЫЕ МЕСТОРОЖДЕНИЯ ЦВЕТНЫХ МЕТАЛЛОВ ПАЛЕООСТРОВОДУЖНЫХ СООРУЖЕНИЙ И ПРОБЛЕМЫ ГЕНЕЗИСА РУД (на примере рудных обьектов Грузии, Армении и Турции) (Рекомендовано членом редакційної колегії д-ром геол.-мінерал. наук, проф. В.М. Загнітком) Цель: изучение околорудного пространства вулканогенных месторождений цветных металлов палеоостроводужных сооружений (на примере Маднеульского месторождения) и определение условий их формирования с использованием геохимических и термобарогеохимических исследований. Методы: выполнено картирование карьера Маднеульского месторождения, определены содержания редких и рассеянных элементов на приборе ICP-MS, в Геологической службе США и Кавказском институте минерального сырья проведены термобарогеохимические исследования и определён изотопный состав кислорода и водорода в рудах. Результаты: выявлены структурные особенности месторождения, характер околорудного пространства, определён минеральный состав метасоматитов и доказана многоэтапность формирования месторождений. Научная новизна: высказаны соображения о генезисе вулканогенных месторождений альпийских палеоостроводужных сооружений с учётом выполненных авторами термобарогеохимических исследований, а также с привлечением существующих в научном мире представлений о генезисе месторождений. Практическая значимость: описанные особенности околорудного пространства могут быть с успехом использованы в других регионах в процессе поисков месторождений вулканогенного класса.

Research paper thumbnail of Field investigation of the mythical “Gold Sands” of the ancient Colchis Kingdom and modern discussion on the Argonauts’ expedition

Research paper thumbnail of Magmarizm and Ore Occurrences of the Kakheti and Tusheti Regions, Greater Caucasus, Georgia Republic

Journal of Geological Resource and Engineering, 2018

Kakheti and Tusheti regions (Eastern Graeter Caucasus), of the Georgia Republic are mainly underl... more Kakheti and Tusheti regions (Eastern Graeter Caucasus), of the Georgia Republic are mainly underlain by highly deformed Lower-Middle Jurassic shales, sandstones, and volcaniclastic rocks, intruded by numerous intrusive bodies of various compositions. All units contain a variety of ore mineral deposit types and their surrounding zones of hydrothermal alteration. Continued geological and metallogenic researches in the past 30 years have led to important new information regarding the evolution of this region. Three main stages of magmatic activity are now clearly distinguished. Oldest magmatism comprises Early Jurassic events, related to extensional tectonism, which ranged from rhyolitic, through dacitic and andesitic, and to basaltic magma. Additional extensional processes (in Bajocian) were characterized by intrusion of a gabbro and diorite dike system into recently deposited late Early Jurassic-early Middle Jurassic formations. The final magmatic event was associated with Middle Jurassic folding and uplift during which multiphase diorite plutons were emplaced. Related intense hydrothermal activity was responsible for important polymetallic mineralization, with more than 100 recognized outcropping ore occurrences. A detailed study of 11 of these ore occurrences has indicated anomalous concentrations of gold, thorium, yttrium, cobalt, cadmium, and bismuth. In addition, several new and potentially significant ore mineral occurrences were discovered.

Research paper thumbnail of Geological Framework and Mineral Occurrences in the Georgia Segment Eastern Greater Caucasus

Episodes, 2016

/XXXXX The eastern part of the Caucasus orogen, termed the Georgian segment, is mainly underlain ... more /XXXXX The eastern part of the Caucasus orogen, termed the Georgian segment, is mainly underlain by highly deformed Lower-Middle Jurassic shales, sandstones, and volcaniclastic rocks, and cut by numerous intrusive bodies of various compositions. All units contain a variety of mineral deposit types and their surrounding zones of hydrothermal alteration. Detailed geological and metallogenic research, after 30 years stagnation, has led to important new information regarding the evolution of this region. Three main stages of magmatic activity are now clearly distinguished. The oldest magmatism comprises early Jurassic events, related to extensional tectonism, with volcanism and subvolcanic plutonism that ranged from rhyolitic, through dacitic and andesitic, and to basaltic. Additional extensional processes (in Bajocian times) were characterized by intrusion of a gabbro and diorite dike system into slightly older late Early Jurassicearly Middle Jurassic formations. The final magmatic event was associated with Middle Jurassic folding and uplift during which multiphase diorite plutons were emplaced. Intense hydrothermal activity related to this latest magmatism was responisble for important polymetallic mineralization including more than 100 historically recognized outcropping occurrences. A detailed study of 11of the more significant of these occurrences has indicated anomalous concentrations of base metals as well as gold, thorium, yttrium, cobalt, cadmium, and bismuth. In addition, several new and potentially significant mineral occurrences were discovered, including two designated here as Gelia and Lechuri.

Research paper thumbnail of Felsitic Magmatizm and Thorium - Bismuth Ore Mineralization in the Greater Caucasus Kakheti Segment, Georgia

Research paper thumbnail of Geology and Mineral Occurrences of the Eastern Greater Caucasus, Georgia Segment

The eastern part of the Caucasus orogen,termed the Georgian segment, is mainly underlain by highl... more The eastern part of the Caucasus orogen,termed the Georgian segment, is mainly underlain by highly deformed Lower-Middle Jurassic shales, sandstones, and volcaniclastic rocks, and cut by numerous intrusive bodies of various compositions. All units contain a variety of mineral deposit types and their surrounding zones of hydrothermal alteration. Detailed geological and metallogenic research, after 30 years stagnation, has led to important new information regarding the evolution of this region. Three main stages of magmatic activity are now clearly distinguished, the oldest magmatism comprises early Jurassic events, related to extensional tectonism, with volcanism and subvolcanic plutonism that ranged from rhyolitic, through dacitic and andesitic, and to basaltic. Additional extensional processes (in the Bajocian time) were characterized by intrusion of a gabbro and diorite dike system into slightly older late Early Jurassic-early Middle Jurassic formations. The final magmatic event w...

Research paper thumbnail of Ore mineral deposition in black shale inthe Ssouthern Slpe of the Greater Caucasus

Research paper thumbnail of “Mythical” gold sands of Svaneti (Caucasus, Georgia) and argonouts expedition purpose

Research paper thumbnail of Volcanogenic Deposits of Non-ferrous Metals in the Lesser Caucasus and Eastern Pontides

Journal of Geological Research, 2021

The paper presents brief characteristics of geological environments of ore deposit occurrences in... more The paper presents brief characteristics of geological environments of ore deposit occurrences in Turkey, Georgia and Armenia. They can be attributed to Kuroko-type deposits, being distinguished by the character of ore accumulation. To the west, in Turkey, there are epigenetic and hydrothermal-sedimentary copper-zinc deposits that were formed in deep restricted basinal settings. An example of the latter is the Chayeli deposit.To the east, in the Caucasus, we have predominantly only epigenetic deposits. Besides, in the Bolnisi mining district (Georgia) there is the Madneuli deposit which represents an example of polyformational deposit. Here, within the restricted territory, have been concentrated:barite, barite-polymetallic, gold-bearing secondary quartzite, large-scale stockworks of copper ores. Judged by the 87Sr/86Sr ratios, some volcanites which are spatially associated with ores, might have been products of the “differentiation” of undepleted mantle, or other magmas that were g...

Research paper thumbnail of Geological Framework and Thorium Resources Exploration Condition of Georgia (The Caucasus)

The Caucasus represents a Phanerozoic collisional orogeny, that formed along the Eurasian North c... more The Caucasus represents a Phanerozoic collisional orogeny, that formed along the Eurasian North continental margin, extends over 1200 km from the Caspian to Black Sea. Georgian republic is situated in the central part of Caucasus Region. Here are marked 3 ore occurrences of thorium : 1-in the Greater Caucasus (Th concentrations vary between 51g/t 3882g/t); 2in the Dzirula massif (Th concentrations vary between 117 g/t -266 g/t); 3in Vakijvari orefield (Th concentrations vary between 185 g/t 428 g/t). Based on these data thorium ore occurrences found in Georgia should be treated as prospective resources.

Research paper thumbnail of Zircons U-Pb Geochronology of the Ore-BearingPlutons of Adjara-Trialeti Folded Zone, LesserCaucasus and Analysis of the Magmatic Processes

Zircons of the major ore-bearing plutons (Merisi, Namonastrali, Vakijvari, Zoti, Okros- Ghele and... more Zircons of the major ore-bearing plutons (Merisi, Namonastrali, Vakijvari, Zoti, Okros- Ghele and Rkviana) of the Adjara-Trialeti Paleogene folded zone of the Lesser Caucasus were dated by the U-Pb method using the Laser Ablation ICP-MS tool at the isotope laboratory of the Department of Earth Sciences at the National Taiwan University. The results are almost identical and are as follows: Merisi (diorite), sm. #12Ge-03=43.42±0.61 Ma; Merisi (syenite) sm.#12Ge- 04=42.78±0.65 Ma; Namonastrali (diorite) sm. #12Ge-05=42.42±0.5 Ma; Namonastrevi (diorite) sm.#12Ge-06=42.03±0.83 Ma; Vakijvari (syenite) sm.#12Ge-13=43.26±0.74 Ma; Zoti (syenite) sm. #12Ge-15 =43.86±0.43 Ma; Zoti (gabbro) sm.#12Ge-16=46.77±0.81 Ma; Okros-Ghele (syenite) sm. #12Ge=19-44.34±0.55 Ma; Rkviana (gabbro) sm. #12Ge-21=44.85±0.59 Ma. Based on the analysis of the results, it is obvious that the ore bearing plutons of the Adjara-Trialeti zone were intruded through the volcanic-sedimentary rocks within a short time inter...

Research paper thumbnail of Ore Mineralization of Active Paleomargins of Continents (on the Example of Alpine Metallic Deposits of Caucasus and Pontides)

Metallogenic features of Pontides – Lesser Caucasus microplates (part of active paleomargin of Eu... more Metallogenic features of Pontides – Lesser Caucasus microplates (part of active paleomargin of Eurasian microplate are determined by copper, copper-molibdenium porphyry, iron-scarn, volcanic nonferrous, precious metals, auriferous and manganese ore deposits. Their orebearing fluid systems occurred consistently on various stages of development of the region and were correlated with geological processes on the border of convergental and divergental interaction of mic¬roplates. The above mentioned types of ore deposits display clear areal and temporary bonds with certain composites of lithogeodynamic complexes (which are presented in mountain folding systems of relics of ancient geomorphological structures) - geological formations. Different geologic-genetical models are suggested for each type of deposits, characterizing possible sources of ore substance, causes of rise and functions of fluid systems, in addition to ore formation environment. It may be said that different genetic grou...

Research paper thumbnail of Field Trip Guide of the Fourth Plenary Conference of the UNESCO IGCP pr.610, Tbilisi, Georgia

Research paper thumbnail of Ore-Forming Processes and Ore Occurrences of the Eastern Greater Caucasus Georgian Segment

In the Eastern Greater Caucasus Georgian segment Lower-Middle Jurassic shales and sandstones expe... more In the Eastern Greater Caucasus Georgian segment Lower-Middle Jurassic shales and sandstones experienced crush, hydrothermal alteration and ore mineralization processes. At some hydrothermally altered areas mainly copper-pyrrhotitic and pyrite-polymetallic ores were formed. Already known ore occurrences were studied and, at the same time, new and interesting ore occurences were discovered in the hydrothermally altered zone in the r. Stori canyon (Bendena,Gelia, and enriched with Th zone) and pyrite-polymetallic ore mineralization at the village Lechuri. The latter should be of great interest, since it shows lots of similarities to Filizchay pyrite-polymetallic deposit by its geologic position and mineralogical-geological parameters, which makes necessary further detailed study of the area. It should be noted that at some areas, on the result of conducted research, for the first time the increased concentrations of Au (at Artana and Tebulo ore fields) were reported. At Tebulo ore fie...

Research paper thumbnail of Felsitic Magmatism and Thorium-Bismuth Mineralization in the Greater Caucasus KakhetiSegment, Georgia

The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-A... more The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-Asian North continental margin between the Black and Caspian Seas and is extended over 1200 km distance between the Black and Caspian seas, and considered as a terrane of the first order, which is accreted to the south margin of the Euroasian continent. The Kakheti segment is located on the eastern part of the southern slope of the Greater Caucasus and is mainly formed of strongly folded Lower Jurassic clay-shales and mafic volcanic-sedimentary formations. According to geophysical data these sediments are located on oceanic or transitional crust. Ore mineralization is related to hydrothermally altered zones, which are significantly enriched by rare metals – thorium and bismuth, and also by gold, copper, zinc, lead and cobalt.

Research paper thumbnail of Gold Potential of Georgia

The authors’ aim was determination of estimated gold resources on the basis of the geological dat... more The authors’ aim was determination of estimated gold resources on the basis of the geological data analysis. The following methods were used for calculation of resources: parameters of ore bodies at gold occurrences, data of geochemical anomalies, geological evidence indicating existence of ore bodies in the depth. The territory of Georgia includes part of the Alpine-Himalayan mountain-fold belt, which is a result of interaction of the Scythian and South Caucasus microplates geologically developed in the marginal area of the Eurasian continent. Four gold bearing complexes are found on the territory of Georgia: 1) Activated in Middle Jurassic south Caucasus microcontinent slope and slope root zones, which are built by Palaeozoic Middle-Early Jurassic marginal sea flischoid-terrigenous sediments (potential in Middle Jurassic deposits in granite stocks Lukhra and in carbonaceous suite Arshira, Lasilli, on Svaneti ridge; 2) The Greater Caucasus southern slope suture zone (“main thrusts”...

Research paper thumbnail of Mineral Occurrences of the Eastern Greater Caucasus, Georgia

Research paper thumbnail of Magmatizm and Mineral Occurrences of the Eastern Greater Caucasus Georgian Segment

Magmatism and Mineral Occurrences of the Eastern Greater Caucasus, Georgian Segment N. GAGNIDZE, ... more Magmatism and Mineral Occurrences of the Eastern Greater Caucasus, Georgian Segment N. GAGNIDZE, A.OKROSTSVARIDZE, K. AKIMIDZE, S. L. CHUNG Ilia state University, Tbilisi 0162, Georgia, (*correspondence:nonagagnidze@gmail.com) Javakhishviuli State University, Tbilisi 0138, Georgia (okrostsvari@gmail.com) 3 Institute of Earth Science, Academia Sinica, Taipei 11529, Taiwan (sunlin@earth.sinica.edu.tw)

Research paper thumbnail of Late Miocene Volcanic Ash Layers of the Inter-Mountain Depression of the Eastern Caucasus: The Products of the Megacaldera Explosion?

The Caucasus is a central segment of the Mediterranean Alpine-Himalayan collisional orogenic syst... more The Caucasus is a central segment of the Mediterranean Alpine-Himalayan collisional orogenic system and consists of the Greater and Lesser Caucasus orogens and intermountain depression. There are numerous layers of volcanic ashes in the late Miocene marine sediments (dated paleontologically) of the Eastern Caucasus intermountain depression. The ashes consist primarily of hornblende, pyroxene, and volcanic glass (Skhirtladze, 1964). The thickness of the layers varies between 5 m to several decimeters, while their distribution area is wide and includes the Kartli and Kakheti regions in Georgia and the western region of Azerbaijan

Research paper thumbnail of Felsic Magmatism and Th-Bi Mineralitation in the Greater Caucasus Kakheti Region, Georgia

The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-A... more The Greater Caucasus represents a Phanerozoic collisional orogen which is formed along the Euro-Asian North continental margin between the Black and Caspian Seas, and is accreted to the south margin of the Euroasian continent. The Kakheti region is located on the eastern part of the southern slope of the Greater Caucasus and is mainly formed of strongly folded Lower Jurassic clay-shales and mafic volcanic-sedimentary formations. Ore mineralization is related to hydrothermally altered zones, which are significantly enriched in rare metals – thorium and bismuth, and also in gold, zinc, lead and cobalt. The studied area is underlain with highly deformed Lower-Middle Jurassic sediments and volcaniclastic rocks, associated with numeorus intrusive bodies. The rocks contain variety of mineralization types and hydrothermal alteration. The largest outcrop of felsic hypo-abyssal dykes is Speroza massif, which has a lenticular shape with a length of 14 km. It represnets the area of mesothermal...

Research paper thumbnail of The Volcanogenic Deposits of Non-Ferrous Metals of Paleoisland Arc Environment Associated with Wall Rock Alterations of Host Rocks and Problems of Ore Genesis (On the Example of Ore Districts in Georgia, Armenia and Turkey)

Visnyk of Taras Shevchenko National University of Kyiv. Geology, 2017

ВУЛКАНОГЕННЫЕ МЕСТОРОЖДЕНИЯ ЦВЕТНЫХ МЕТАЛЛОВ ПАЛЕООСТРОВОДУЖНЫХ СООРУЖЕНИЙ И ПРОБЛЕМЫ ГЕНЕЗИСА РУ... more ВУЛКАНОГЕННЫЕ МЕСТОРОЖДЕНИЯ ЦВЕТНЫХ МЕТАЛЛОВ ПАЛЕООСТРОВОДУЖНЫХ СООРУЖЕНИЙ И ПРОБЛЕМЫ ГЕНЕЗИСА РУД (на примере рудных обьектов Грузии, Армении и Турции) (Рекомендовано членом редакційної колегії д-ром геол.-мінерал. наук, проф. В.М. Загнітком) Цель: изучение околорудного пространства вулканогенных месторождений цветных металлов палеоостроводужных сооружений (на примере Маднеульского месторождения) и определение условий их формирования с использованием геохимических и термобарогеохимических исследований. Методы: выполнено картирование карьера Маднеульского месторождения, определены содержания редких и рассеянных элементов на приборе ICP-MS, в Геологической службе США и Кавказском институте минерального сырья проведены термобарогеохимические исследования и определён изотопный состав кислорода и водорода в рудах. Результаты: выявлены структурные особенности месторождения, характер околорудного пространства, определён минеральный состав метасоматитов и доказана многоэтапность формирования месторождений. Научная новизна: высказаны соображения о генезисе вулканогенных месторождений альпийских палеоостроводужных сооружений с учётом выполненных авторами термобарогеохимических исследований, а также с привлечением существующих в научном мире представлений о генезисе месторождений. Практическая значимость: описанные особенности околорудного пространства могут быть с успехом использованы в других регионах в процессе поисков месторождений вулканогенного класса.

Research paper thumbnail of Field investigation of the mythical “Gold Sands” of the ancient Colchis Kingdom and modern discussion on the Argonauts’ expedition

Research paper thumbnail of Magmarizm and Ore Occurrences of the Kakheti and Tusheti Regions, Greater Caucasus, Georgia Republic

Journal of Geological Resource and Engineering, 2018

Kakheti and Tusheti regions (Eastern Graeter Caucasus), of the Georgia Republic are mainly underl... more Kakheti and Tusheti regions (Eastern Graeter Caucasus), of the Georgia Republic are mainly underlain by highly deformed Lower-Middle Jurassic shales, sandstones, and volcaniclastic rocks, intruded by numerous intrusive bodies of various compositions. All units contain a variety of ore mineral deposit types and their surrounding zones of hydrothermal alteration. Continued geological and metallogenic researches in the past 30 years have led to important new information regarding the evolution of this region. Three main stages of magmatic activity are now clearly distinguished. Oldest magmatism comprises Early Jurassic events, related to extensional tectonism, which ranged from rhyolitic, through dacitic and andesitic, and to basaltic magma. Additional extensional processes (in Bajocian) were characterized by intrusion of a gabbro and diorite dike system into recently deposited late Early Jurassic-early Middle Jurassic formations. The final magmatic event was associated with Middle Jurassic folding and uplift during which multiphase diorite plutons were emplaced. Related intense hydrothermal activity was responsible for important polymetallic mineralization, with more than 100 recognized outcropping ore occurrences. A detailed study of 11 of these ore occurrences has indicated anomalous concentrations of gold, thorium, yttrium, cobalt, cadmium, and bismuth. In addition, several new and potentially significant ore mineral occurrences were discovered.

Research paper thumbnail of Geological Framework and Mineral Occurrences in the Georgia Segment Eastern Greater Caucasus

Episodes, 2016

/XXXXX The eastern part of the Caucasus orogen, termed the Georgian segment, is mainly underlain ... more /XXXXX The eastern part of the Caucasus orogen, termed the Georgian segment, is mainly underlain by highly deformed Lower-Middle Jurassic shales, sandstones, and volcaniclastic rocks, and cut by numerous intrusive bodies of various compositions. All units contain a variety of mineral deposit types and their surrounding zones of hydrothermal alteration. Detailed geological and metallogenic research, after 30 years stagnation, has led to important new information regarding the evolution of this region. Three main stages of magmatic activity are now clearly distinguished. The oldest magmatism comprises early Jurassic events, related to extensional tectonism, with volcanism and subvolcanic plutonism that ranged from rhyolitic, through dacitic and andesitic, and to basaltic. Additional extensional processes (in Bajocian times) were characterized by intrusion of a gabbro and diorite dike system into slightly older late Early Jurassicearly Middle Jurassic formations. The final magmatic event was associated with Middle Jurassic folding and uplift during which multiphase diorite plutons were emplaced. Intense hydrothermal activity related to this latest magmatism was responisble for important polymetallic mineralization including more than 100 historically recognized outcropping occurrences. A detailed study of 11of the more significant of these occurrences has indicated anomalous concentrations of base metals as well as gold, thorium, yttrium, cobalt, cadmium, and bismuth. In addition, several new and potentially significant mineral occurrences were discovered, including two designated here as Gelia and Lechuri.