Yamato Belgica complex

from Wikipedia, the free encyclopedia

The Yamato-Belgica complex is considered to be a Late Neoproterozoic to Cambrian orogenic terran in Queen Maud's East Antarctic land . It consists of the Yamato and Belgica Mountains , which are of magmatic origin and have been metamorphically impressed.

Naming

The Yamato Mountains (Mountains of Great Peace) were named after the Japanese Antarctic Research Expedition, which carried out geomorphological and geological surveys in this area between 1968 and 1977 . The mountain range was previously discovered by a Belgian Antarctic expedition (1959 to 1961) and photographed from the air in early October 1960. It was named after the Belgian Queen Fabiola Mora y Aragón in The term Yamato Mountains has established itself in the specialist literature.

The Belgica Mountains also owe their discovery to a Belgian Antarctic expedition that took place between 1957 and 1958. The name of the mountain range was given by the Belgica expedition ship, the first Belgian Antarctic expedition from 1897 to 1899.

Location and extent

The Yamato Belgica Complex (YBK) is located in the central-eastern Queen Maud Land (Dronning Maud Land) and extends from the Sôya Coast to the east on Lützow-Holm Bay and southwest to the Sør Rondane Mountains. The Sôya Coast represents the western section of the Lützow-Holm complex . The YBK is divided into the northern Yamato Mountains ( Queen Fabiola Mountains ) and the south-western Belgica Mountains . The highest point in the Yamato Mountains is Mount Fukushima , while Mount Victor is the highest point in the Belgica Mountains at 2590 meters.

Rocks and metamorphoses

The YBK consists mainly of felsic orthogneiss and plutonic rocks , which were caused by tectonic events. They are characterized by widespread granite - and syenite - intrusions with smaller proportions of metamorphic rocks amphibolithischer facies of quartzite - feldspatischer and intermediate composition. Rocks of the granulite facies are rarer . Some of them are contained in a syenitic intrusiva.

The age dating comes mainly from zirconia data, which are between 1,000 and 500 mya , with the exception of one location that is approximately 2,500 mya. Quartz monzonite and granitic gneiss from the Yamato Mountains gave an age of 535 mya, which is considered to be the time of the amphibolite facies metamorphosis and magmatism. This period corresponds to the Kuunga orogeny, when between approx. 600 and 500 mya East Antarctica and the African Kaapvaal craton collided and which led to the formation of the greater continent of Gondwana . The metamorphic processes in the Vijayan Complex and Wanni Complex of Sri Lanka correlate with those in the YBK and Rayner Province (see → Sri Lanka ).

Although not enough data are yet available to determine the Proterozoic-Cambrian history of the YBK, the lack of data older than 1,000 mya suggests juvenile earth crust formation as island arch terranos in the late Mesoproterozoic , similar to the Sør Rondane Mountains in west-central Dronning Maud Country. This stands in clear contrast to the Lützow-Holm complex, which is also an island arch, but was built much earlier.

Web links

  • Kazuyuki Shiraishi, Yoshikuni Hiroi, Yoichi Motoyoshi and Keizo Yanai: Plate tectonic development of Late Proterozoic paired metamorphic complexes in eastern Queen Maud Land, East Antarctica. In: Advanced Earth and Space Science, Geophysical Monograph Series, 01 January 1987. doi: 10.1029 / GM040p0309 , alternative
  • K. Shiraishi, DJ Ellis, Y. Hiroi, CM Fanning, Y. Motoyoshi and Y. Nakai: Cambrian Orogenic Belt in East Antarctica and Sri Lanka: Implications for Gondwana Assembly. In: The Journal of Geology, Coverage: 1893-2015, (Vol. 1, No. 1 - Vol. 123, No. 6). link
  • Yusuke Takamura, Toshiaki Tsunogae, M. Santosh and YukiyasuTsutsumi: Detrital zircon geochronology of the Lützow-Holm Complex, East Antarctica: Implications for Antarctica – Sri Lanka correlation. In: Geoscience Frontiers Volume 9, Issue 2, March 2018, Pages 355-375. doi: 10.1016 / j.gsf.2017.08.006 , alternatively

Individual evidence

  1. ↑ M. Satish-Kumar, T. Hokada, T. Kawakami and Daniel J. Dunkley: Geosciences research in East Antarctica (08E - 608E): present status and future perspectives. In: Geological Society, London, Special Publications, 308, 1-20, 1 January 2008. doi: 10.1144 / SP308.1 , alternative
  2. ↑ Takanobu Sawagaki and Kazuomi Hirakawa: Erosion of Bedrock by Subglacial Meltwater, Soya Coast, East Antarctica. In: Geografiska Annaler, Series A, Physical Geography 1997, A (A): 223-238. PDF
  3. ^ Joseph G. Meert: A synopsis of events related to the assembly of Eastern Gondwana. In: Tectonophysics 362 (1): 1-40 • February 2003. doi: 10.1016 / S0040-1951 (02) 00629-7 , alternative
  4. ↑ Kazuyuki Shiraishi, Yoshikuni Hiroi, Yoichi Motoyoshi and Keizo Yanai: Plate Tectonic Development of Late Proterozoic Paired Metamorphic Complexes in Eastern Queen Maud Land, East Antarctica. In: Advanced Earth and Space Sience, Geophysical Monograph Series, 01 January 1987. doi: 0.1029 / GM040p0309 , alternative