Sövit

Sövit is a medium to coarse-grained igneous rock that is counted among the carbonatites . Together with the fine-grained alvikite it forms the rock group of calcite carbonatites .

etymology

Sövit was named after its type locality , Söve , located in the Fen complex in Telemark ( Norway ) .

Initial description

Sövit was scientifically described for the first time in 1921 by Waldemar Christofer Brøgger .

mineralogy

3-inch Sövi handpiece from Magnet Cove carbonatite , Arkansas

The main mineral of Sövit is by definition calcite , which is represented with more than 50 percent by volume. Biotite and apatite are secondary constituents , and amphibole , magnetite , melilite , monticellite , olivine , phlogopite , pyroxene , pyrite , pyrochlore and fluorite also appear as accessories .

Varieties

The following types of rock are known from Sövit:

• Aegirin-Sövit
• Amphibole Sövit (especially sodium amphibole)
• Apatite Sövit
• Biotite Sövit
• Mica Sövit
• Klinopyroxen-Sövit
• Magnetite-Sövit (especially pyroxene-biotite-magnetite-Sövit)
• Melilith-Sövit
• Monticellit-Sövit
• Nepheline Sövit
• Olivine Sövit
• Phlogopite Sövit
• Pyroxen -Sövit: Hollait . Is made up of 55 percent by volume of pyroxene and contains calcite and nepheline .

Silicosövites have less than 50 percent by volume calcite.

Kåsenite is a Sövitic melteigite , which consists of calcite, aegirin-augite , nepheline and apatite.

Chemical composition

The following table illustrates the chemical composition of some Sövite:

Weight%	Average savit Amba Dongar	Phlogopit-Sövit Kaiserstuhl	Silicate-rich Sövit Alnön
SiO 2	2.97	2.08	16.20
TiO 2	0.09	0.04	0.80
Al 2 O 3	0.16	0.49	7.05
Fe 2 O 3	2.63	3.60	10.99
MnO	0.50	0.30	0.50
MgO	0.99	1.21	3.38
CaO	49.34	49.51	35.68
Na 2 O	0.04	0.40	0.56
K 2 O	0.06	0.51	0.92
P 2 O 5	1.69	1.62	0.95
CO 2	39.76	37.06	22.20
SO 3		2.29
BaO	0.41
SrO	0.69	1.16

Occurrence

• Angola :
  • Bonga
• Australia :
  • Cummins Range
• Brazil
  • Jacupiranga - Hauterivian - 131 million years BP
  • Serra Negra , Minas Gerais
  • Tapira
• Germany :
  • Altvogtsburg and Schelingen in the Kaiserstuhl - 18 to 13 million years old BP - Burdigalium to Serravallian
  • Laacher See
• Finland :
  • Siilinjärvi - Rhyacium - 2094 million years BP
  • Sokli - Frasnium - 365 million years BP
• India :
  • Amba Dongar in Gujarat - Danium - 65.5 million years old BP
• Canada :
  • British Columbia :
    • Aley
  • Ontario :
    • Argor
    • Lackner Lake
    • Manitou Island
    • Mortinson Lake
    • Nemegosenda Lake
    • Prairie Lake
  • Québec :
    • Oka carbonatite complex - Albium - 109 million years BP
• Kenya :
  • Homa Bay
  • Lay the Hills
  • Ruri (Ruri-South)
• Malawi :
  • Chilwa
  • Kangan customer
  • Tundulu
• Mongolia :
  • Lugiingol
  • Mushgai-khudag
• Namibia :
  • Thick Willem - Ypresium - 49 million years BP
  • Kalkfeld
• Norway :
  • Söve in the Fen area of ​​Telemark (type locality) - Cambrian - 539 million years BP
  • Stjernøy
• Zambia :
  • Nkombwa Hill
• Sweden :
  • Smedsgården on Alnön - Ediacarium - 560 million years old BP
• South Africa :
  • Phalaborwa - Orosirian - 2047 million years BP
  • Sandhead drif
• Tanzania :
  • Nachendezwaya
• Turkey :
  • Kizilcaşren
• Uganda :
  • Budeda Hill
  • Bukusu
  • Tororo
• United States of America :
  • Arkansas :
    • Magnet Cove Carbonatite
  • Wyoming :
    • Bear Lodge , Bear Lodge Mountains

Individual evidence

1. ^ Brögger, WC: The igneous rocks of the Kristianiag region. IV. The Fen area in Telemark, Norway . In: Skrifter udgit av Videnskabsselskabet i Kristiania. I. Math.-Nat. Class . tape 9 , 1921, pp. 1-408 .
2. ↑ Jörg Keller: Carbonatitic volcanism in the Kaiserstuhl alkaline complex: Evidence for highly fluid carbonatitic melts at the earth's surface . In: Journal of Volcanology and Geothermal Research . tape 9 , no. 4 , March 1981, ISSN  0377-0273 , p. 423-431 , doi : 10.1016 / 0377-0273 (81) 90048-2 .