Kazakhstania ( kk, Qazaqstaniya), the Kazakh terranes, or the Kazakhstan Block, is a geological region in
Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
which consists of the area roughly centered on
Lake Balkhash
Lake Balkhash ( kk, Балқаш көлі, ''Balqaş kóli'', ; russian: озеро Балхаш, ozero Balkhash) is a lake in southeastern Kazakhstan, one of the largest lakes in Asia and the 15th largest in the world. It is located in the ea ...
, north and east of the
Aral Sea, south of the
Siberian craton
Siberia, also known as Angaraland (or simply Angara) and Angarida, is an ancient craton in the heart of Siberia. Today forming the Central Siberian Plateau, it was an independent continent before the Permian period. The Verkhoyansk Sea, a passive ...
and west of the
Altai Mountains. The
Junggar basin
The Junggar Basin () is one of the largest sedimentary basins in Northwest China. It is located in Xinjiang, and enclosed by the Tarbagatai Mountains of Kazakhstan in the northwest, the Altai Mountains of Mongolia in the northeast, and the Heave ...
in
Xinjiang
Xinjiang, SASM/GNC: ''Xinjang''; zh, c=, p=Xīnjiāng; formerly romanized as Sinkiang (, ), officially the Xinjiang Uygur Autonomous Region (XUAR), is an autonomous region of the People's Republic of China (PRC), located in the northwest ...
,
China, is also part of Kazakhstania, though sometimes referred to as the Junggar Block.
Because the Kazakh terranes merged during the Late Ordovician as part of the
Central Asian Orogenic Belt they are also referred to as the Kazakh Orogen. These terranes are located in what is today
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, north-eastern
Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked co ...
, northern
Kyrgyzstan
Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ...
and south-western
China.
Today Kazakhstania is surrounded by three large, former continents: to the north-east the
Gornostaev Shear Zone separates it from
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...
with which it collided during the
Carboniferous; to the north-west is
Baltica
Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains.
The thick core of Baltica, the East European Craton, ...
which lay adjacent to the Kazakh
Tourgai terrane but far away from Kazakhstania; to the south and east was
Gondwana stretching from the South Pole to the Equator. Not far away from the dispersed Kazakh terranes were
South China,
North China, and
Tarim, but how these continental blocks were positioned relative to Gondwana is not known.
Tectonic evolution
In the Early Palaeozoic the Kazakh
terrane
In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust (geology), crust fragment formed on a tectonic plate (or broken off from it) and Accretion (geology), accreted or "Suture (geology), sutured" to crust lying on another pla ...
s were widely distributed north or northeast of the
Mangyshlak
Mangyshlak or Mangghyshlaq Peninsula ( kk, Маңғыстау түбегі, translit=Mañğystau tübegı; russian: Полуостров Мангышла́к, translit=Poluostrov Mangyshlák) is a large peninsula located in western Kazakhstan. It ...
,
Karakum Karakum may refer to:
*Karakum Desert, a desert in Central Asia
* ''Karakum'' (film), a 1994 Turkmen film
*Karakum Canal, Turkmenistan
* Karakum District, Turkmenistan
See also
* Karakoram, a large mountain range spanning the borders of India, Pak ...
,
Karakorum
Karakorum (Khalkha Mongolian: Хархорум, ''Kharkhorum''; Mongolian Script:, ''Qaraqorum''; ) was the capital of the Mongol Empire between 1235 and 1260 and of the Northern Yuan dynasty in the 14–15th centuries. Its ruins lie in th ...
and
Tarim terranes.
The location, origin, and faunal affinities of these terranes has, however, been the subject of two competing hypotheses: one described these terranes as an enormous
island arc
Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle alon ...
called the Kipchak arc, the other as a series of more or less parallel belts. Faunal analyses indicate that some of the terranes probably originated in Gondwana rather than Baltica or Siberia.
A 2006 analysis of
brachiopod
Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...
s indicated that the
Chu-Ili Mountains must have formed an independent, Peri-Gondwanan terrane in the Late Ordovician located not far from the North and South China
craton
A craton (, , or ; from grc-gre, κράτος "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging an ...
s.
More recent studies suggest that in the Late Ordovician the Kazakh terranes formed an archipelago composed of clusters of island arcs and microcontinents centered on the Equator. Key units in this assemblage were the Boshchekul (in north Kazakhstan), Chingiz-Tarbagatai (east Kazakhstan), and Chu-Ilu (south Kazakhstan) terranes. The Atashu-Zhamshi microcontinent was located in the southwestern margin of the archipelago. A few terranes probably merged as early as the Middle Ordovician but Kazakhstania is very unlikely to have formed a single continent before the end of the period.
[; For a map of the Kazakh terranes see ; For a Late Ordovician reconstruction see ]
During the
Carboniferous and
Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...
, Siberia collided with Kazakhstania to form the
Altai Mountains, later
Baltica
Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains.
The thick core of Baltica, the East European Craton, ...
collided in the
Ural orogeny, creating the basis for most of present-day
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...
.
Commercial importance
Kazakhstania is mainly flat: only in the east near
Karaganda
Karaganda or Qaraghandy ( kk, Қарағанды/Qarağandy, ; russian: Караганда, ) is the capital of Karaganda Region in the Republic of Kazakhstan. It is the fourth most populous city in Kazakhstan, behind Almaty (Alma-Ata), Astan ...
are there mountains, and these only rise to 1,565 metres (5,130 feet) in the
Tarbagatay Range. Although most of Kazakhstania is arid and practically no water flows from the region to the oceans, there is extensive grazing of
cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...
,
sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticated ...
and
camels
A camel (from: la, camelus and grc-gre, κάμηλος (''kamēlos'') from Hebrew or Phoenician: גָמָל ''gāmāl''.) is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. ...
on the grasslands which cover most of the region today. Kazakhstania was too dry for extensive
glaciation
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...
during the
Quaternary. Kazakhstania contains as much as a quarter of the world's proven
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
reserves and is also one of the world's major source of
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
,
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
, and
antimony
Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient t ...
ores. On the southern boundary in the
Turan Depression
The Turan Depression, Turan Lowland or Turanian Basin is a low-lying desert basin region stretching from southern Turkmenistan through Uzbekistan to Kazakhstan.
Geography
The lowland region lies to the east of the Caspian Sea and southeast ...
are large deposits of
natural gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...
.
See also
*
References
Notes
Sources
*
*
*
*
External links
Map of the Kazakhstan Block and surrounding areas
{{Continents of the world
Geology of Kazakhstan
Historical continents
Paleozoic Asia
Carboniferous geology
Permian geology
Geography of Kazakhstan
Geography of Xinjiang
Natural history of Asia