The geology of Georgia is the study of rocks, minerals, water, landforms and geologic history in Georgia. The country is dominated by the Caucasus Mountains at the junction of the Eurasian Plate and the Afro-Arabian Plate, and rock units from the Mesozoic and Cenozoic are particularly prevalent. For much of its geologic history, until the uplift of the Caucasus, Georgia was submerged by marine transgression events. Geologic research for 150 years by Georgian and Russian geologists has shed significant light on the region and since the 1970s has been augmented with the understanding of plate tectonics. [1]
The Georgian Block in the Dzirula Massif is part of the Main Range zone of the Greater Caucasus and the Lesser Caucasus fold system. The south slope of the Greater Caucasus has exposed Paleozoic rocks in the Svaneti Zone, including black shale, phthanite chert, sandstones, turbidites, small amounts of marble and andesite or dacite volcanic rocks. These rocks, which belong to the Dizi Series are up to two kilometers thick and date to the Devonian, Carboniferous and Permian. Weakly metamorphosed Paleozoic sedimentary rocks are also found in the Dzirula Massif—namely, allochthon phyllite that contact Paleozoic granitoids and Precambrian gabbro, amphibolite and serpentinite.
Late Carboniferous and Early Permian conglomerate, sandstone, limestone and argillite are identified by marine fossils. The Dzirula and Khrami massifs contain rhyolite and coal-bearing argillite. [2]
Triassic sediments such as quartz sandstone and siltstone, together with dacite and rhyolite are part of the Dizi Series, with thicknesses of 80 to 500 meters. Jurassic black shales, sandstone, turbidite and rhyolite sequences are up to five kilometers thick. In the Late Jurassic, limestone and marl formed in a shallow marine environment, with alternating layers of basalt-andesite-dacite volcanic rocks exposed on the western edge of the Khrami Massif and in the Lock-Karabakh Zone.
The Early Cretaceous is marked by clastic limestone and greywacke siltstone flysch 750 meters to 1.6 kilometers thick in the Mestia-Tianeti flysch zone. Within the Georgian Block, the crystalline rocks of the Dzirula Massif are overlain by Early Cretaceous rocks 300 to 550 meters thick, primarily limestone but also glauconite sandstone, marl and clay. Elsewhere in the Adjara-Trialeti Zone, calc-alkaline basalt from the Albian is common. Within the Arthvin-Bolsini Block is a 1.2 kilometer sequence of carbonates, shallow water limestones and marl as well as tuff. [3]
In the Cenozoic, greywacke and siltstone flysch, 600 to 850 meters thick, deposited during the Paleocene and Eocene. In the Georgian Block, limestone and marl from this period ranges between 30 and 400 meters thick. Turbidite, and both tholeiite and shoshonite basalt deposited during a Middle Eocene event, up to five kilometers thick. In the Locki Crystalline Massif, basalt, andesite, dacite and rhyolite up to 2.7 kilometers thick overlaps older Cretaceous and Jurassic rocks.
Marl, clay and gravel are hallmarks of the Late Eocene in the Adjara-Trialeti Zone, grading to volcanic rocks in the west. Throughout the Oligocene, layers of gypsum bearing clays intermingled with sandstone and accumulated fish scales. This sequence continued to deposit into the Miocene and is exposed in the Gagra-Djava Zone. Marine molasse deposits with clays, sandstones, conglomerates, limestone and marl were laid down during the Miocene. River terraces, glacial moraines and volcanic rocks from the last 2.5 million years of the Quaternary are present, but erratically distributed. Georgia experienced three periods of glaciation during the Pleistocene. [4]
Northeastern Georgia has asymmetric, isoclinal folding on the southern slope and poorly folded, or monoclinal structures on the northern slope of the Greater Caucasus. Nappe structures are directed toward the south and are evidence of the underthrusting of the Georgian Block beneath the Greater Caucasus. The northern boundary of the Georgian Block is a deep fault, that manifests in the sedimentary cover. To the east, the overlying sedimentary rocks are detached and shifted towards the south, along with the nappes.
The Adjara-Trialeti Zone of the Lesser Caucasus is situated south of the Georgian Block and is anticlinorium with block-fold structures. There is an overthrust nappe along the northern margin of this zone, to the west of the Dzirula Massif. The Artvini-Bolnisi Block has two tectonic units. The gently folded Cenozoic volcanic rocks of the Javakhen Zone contain two seismic faults, associated with lava tubes. The Bolnisi Zone has the Khrami salient horst, with steep folds south of the sedimentary cover. The northeast wedge of the Locki-Karabakh Zone is also situated in Georgia, with crystalline rock from before the Jurassic exposed in the Locki anticlinorium. [5]
Georgia has deposits of iron and manganese ore, as well as rare, small deposits of copper, lead, zinc, tin, cobalt, astatine, and molybdenum. Oil, coal and peat deposits are found in some parts of the country. Barite, calcite, bentonite, diatomite, talc, zeolite, andesite, limestone, dolomite are all used in the chemical industry and some rocks, like chalcedony, spongolite and agate are used for building stones and paint. [6]
The Western Carpathians are an arc-shaped mountain range, the northern branch of the Alpine-Himalayan fold and thrust system called the Alpide belt, which evolved during the Alpine orogeny. In particular, their pre-Cenozoic evolution is very similar to that of the Eastern Alps, and they constitute a transition between the Eastern Alps and the Eastern Carpathians.
The Pyrenees are a 430-kilometre-long, roughly east–west striking, intracontinental mountain chain that divide France, Spain, and Andorra. The belt has an extended, polycyclic geological evolution dating back to the Precambrian. The chain's present configuration is due to the collision between the microcontinent Iberia and the southwestern promontory of the European Plate. The two continents were approaching each other since the onset of the Upper Cretaceous (Albian/Cenomanian) about 100 million years ago and were consequently colliding during the Paleogene (Eocene/Oligocene) 55 to 25 million years ago. After its uplift, the chain experienced intense erosion and isostatic readjustments. A cross-section through the chain shows an asymmetric flower-like structure with steeper dips on the French side. The Pyrenees are not solely the result of compressional forces, but also show an important sinistral shearing.
The geology of Germany is heavily influenced by several phases of orogeny in the Paleozoic and the Cenozoic, by sedimentation in shelf seas and epicontinental seas and on plains in the Permian and Mesozoic as well as by the Quaternary glaciations.
The geology of Belarus began to form more than 2.5 billion years ago in the Precambrian, although many overlying sedimentary units deposited during the Paleozoic and the current Quaternary. Belarus is located in the eastern European plain. From east to west it covers about 650 kilometers while from north to south it covers about 560 kilometers, and the total area is about 207,600 square kilometers. It borders Poland in the north, Lithuania in the northwest, Latvia and Russia in the north, and Ukraine in the south. Belarus has a planar topography with a height of about 160 m above sea level. The highest elevation at 346 meters above sea level is Mt. Dzerzhinskaya, and the lowest point at the height of 80 m is in the Neman River valley.
The geology of Bosnia & Herzegovina is the study of rocks, minerals, water, landforms and geologic history in the country. The oldest rocks exposed at or near the surface date to the Paleozoic and the Precambrian geologic history of the region remains poorly understood. Complex assemblages of flysch, ophiolite, mélange and igneous plutons together with thick sedimentary units are a defining characteristic of the Dinaric Alps, also known as the Dinaride Mountains, which dominate much of the country's landscape.
The geology of Sweden is the regional study of rocks, minerals, tectonics, natural resources and groundwater in the country. The oldest rocks in Sweden date to more than 2.5 billion years ago in the Precambrian. Complex orogeny mountain building events and other tectonic occurrences built up extensive metamorphic crystalline basement rock that often contains valuable metal deposits throughout much of the country. Metamorphism continued into the Paleozoic after the Snowball Earth glaciation as the continent Baltica collided with an island arc and then the continent Laurentia. Sedimentary rocks are most common in southern Sweden with thick sequences from the last 250 million years underlying Malmö and older marine sedimentary rocks forming the surface of Gotland.
The geology of North Macedonia includes the study of rocks dating to the Precambrian and a wide array of volcanic, sedimentary and metamorphic rocks formed in the last 541 million years.
The geology of Kazakhstan includes extensive basement rocks from the Precambrian and widespread Paleozoic rocks, as well as sediments formed in rift basins during the Mesozoic.
The geology of Laos includes poorly defined oldest rocks. Marine conditions persisted for much of the Paleozoic and parts of the Mesozoic, followed by periods of uplift and erosion. The country has extensive salt, gypsum and potash, but very little hydrocarbons and limited base metals.
The geology of Afghanistan includes nearly one billion year old rocks from the Precambrian. The region experienced widespread marine transgressions and deposition during the Paleozoic and Mesozoic, that continued into the Cenozoic with the uplift of the Hindu Kush mountains.
The geology of Kyrgyzstan began to form during the Proterozoic. The country has experienced long-running uplift events, forming the Tian Shan mountains and large, sediment filled basins.
The geology of Uzbekistan consists of two microcontinents and the remnants of oceanic crust, which fused together into a tectonically complex but resource rich land mass during the Paleozoic, before becoming draped in thick, primarily marine sedimentary units.
The geology of Thailand includes deep crystalline metamorphic basement rocks, overlain by extensive sandstone, limestone, turbidites and some volcanic rocks. The region experienced complicated tectonics during the Paleozoic, long-running shallow water conditions and then renewed uplift and erosion in the past several million years ago.
The geology of Turkmenistan includes two different geological provinces: the Karakum, or South Turan Platform, and the Alpine Orogen.
The geology of Bulgaria consists of two major structural features. The Rhodope Massif in southern Bulgaria is made up of Archean, Proterozoic and Cambrian rocks and is a sub-province of the Thracian-Anatolian polymetallic province. It has dropped down, faulted basins filled with Cenozoic sediments and volcanic rocks. The Moesian Platform to the north extends into Romania and has Paleozoic rocks covered by rocks from the Mesozoic, typically buried by thick Danube River valley Quaternary sediments. In places, the Moesian Platform has small oil and gas fields. Bulgaria is a country in southeastern Europe. It is bordered by Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east.
The geology of Romania is structurally complex, with evidence of past crustal movements and the incorporation of different blocks or platforms to the edge of Europe, driving recent mountain building of the Carpathian Mountains. Romania is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders the Black Sea to the southeast, Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, and Moldova to the east.
The geology of Slovakia is structurally complex, with a highly varied array of mountain ranges and belts largely formed during the Paleozoic, Mesozoic and Cenozoic eras.
The geology of Greece is highly structurally complex due to its position at the junction between the European and African tectonic plates.
The geology of Montenegro includes sedimentary and volcanic rocks from the Paleozoic through the Cenozoic, deposited atop poorly understood crystalline basement rock.
The geology of Italy includes mountain ranges such as the Alps, the Dolomites and the Apennines formed from the uplift of igneous and primarily marine sedimentary rocks all formed since the Paleozoic. Some active volcanoes are located in Insular Italy.
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