Kazakhstania
Kazakhstania (
, 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, north-eastern Uzbekistan, northern Kyrgyzstan and south-western China.[1] Today Kazakhstania is surrounded by three large, former continents: to the north-east theTectonic evolution
In the Early Palaeozoic the Kazakh terranes were widely distributed north or northeast of the Mangyshlak, Karakum, Karakorum and Tarim terranes.[3] 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 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.[4] A 2006 analysis of brachiopods 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 cratons.[5]
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.[6]
During the
Commercial importance
Kazakhstania is mainly flat: only in the east near
See also
References
Notes
- ^ Popov & Cocks 2017, Introduction, pp. 323, 325
- ^ Popov & Cocks 2017, Late Ordovician Global Geography, pp. 325–327
- ^ Torsvik & Cocks 2009, pp. 8–9
- ^ Popov & Cocks 2006, p. 247
- ^ Popov & Cocks 2006, p. 254
- ^ Popov & Cocks 2017, Abstract; For a map of the Kazakh terranes see Popov & Cocks 2006, Fig. 1, p. 248; For a Late Ordovician reconstruction see Percival et al. 2011, Fig. 1, p. 414
Sources
- Percival, I. G.; Popov, L. E.; Zhan, R. B.; Ghobadi Pour, M. (2011). "Patterns of origination and dispersal of Middle to Late Ordovician brachiopods: examples from South China, East Gondwana, and Kazakh terranes". In Gutiérrez-Marco, J. C.; Rábano, I.; García-Bellido, D. (eds.). Ordovician of the World. Cuadernos del Museo Geominero. Vol. 14. Madrid: Instituto Geológico y Minero de Espana. pp. 413–419. ISBN 9788478408573. Retrieved 27 December 2017.
- Popov, L. E.; Cocks, L. R. M. (2006). "Late Ordovician brachiopods from the Dulankara Formation of the Chu‐Ili Range, Kazakhstan: their systematics, palaeoecology and palaeobiogeography". Palaeontology. 49 (2): 247–283. S2CID 129492176.
- Popov, L. E.; Cocks, R. M. (2017). "Late Ordovician palaeogeography and the positions of the Kazakh terranes through analysis of their brachiopod faunas" (PDF). Acta Geologica Polonica. 67 (3): 323–380. . Retrieved 27 December 2017.
- Torsvik, T. H.; Cocks, L. R. M. (2009). "The Lower Palaeozoic palaeogeographical evolution of the northeastern and eastern peri-Gondwanan margin from Turkey to New Zealand". Geological Society, London, Special Publications. 325 (1): 3–21. S2CID 128490493. Retrieved 27 December 2017.