Dufek Intrusion

The Dufek Intrusion is a mafic layered intrusion that was emplaced into present-day Antarctica approximately 183 million years ago.[1][2][3][4] It comprises two outcropping sections called the Dufek Massif and the Forrestal Range that are thought to be connected beneath the Sallee Snowfield.

The Dufek intrusion is associated with large volumes of Jurassic tholeiitic magmatism associated with the breakup of Gondwana. This magmatism stretched from northern Victoria Land to Dronning Maud Land and onwards into Africa and Australia. Stratigraphy within the intrusion includes the 1.8 km thick Dufek Massif section and associated nanataks. This massif section is composed of the 230 m thick Walker Anorthosite, with laminated plagioclase cumulates, overlain by the Aughenbaugh Gabbro. This gabbro consists of laminated plagioclase with and the augite-pigeonite pyroxene cumulus. The upper portion of the intrusion consists of the 1.7 km thick Forrestal Range section, with the Saratoga Gabbro cumulates overlain by the 300 m thick Lexington Granophyre.[5]

References
  1. "Stratigraphy of the layered gabbroic Dufek Intrusion, Antarctica - ScienceBase-Catalog". www.sciencebase.gov. US: United States Geological Survey. Retrieved 2019-02-13.
  2. "Page 1 Stratigraphy of the Layered Gabbroic Dufek Intrusion, Antarctica" (PDF). US: United States Geological Survey.
  3. Behrendt, J. C.; Drewry, D. J.; Jankowski, E.; Grim, M. S. (1980-08-29). "Aeromagnetic and radio echo ice-sounding measurements show much greater area of the dufek intrusion, antarctica". Science. US. 209 (4460): 1014–1017. Bibcode:1980Sci...209.1014B. doi:10.1126/science.209.4460.1014. PMID 17747230. S2CID 7156310.
  4. S.D.Burgess, S.A.Bowring, T.H.Fleming & D.H.Elliot, 2015. High-precision geochronology links the Ferrar large igneous province with early-Jurassic ocean anoxia and biotic crisis. Earth and Planetary Science Letters, ISSN 0012-821X, Vol: 415, Page: 90-99
  5. Ford, Arthur; Himmelberg, Glen (1991). Tingey, Robert (ed.). Geology and crystallization of the Dufek intrusion, in The Geology of Antarctica. Oxford: Clarendon Press. pp. 175–214. ISBN 0198544677.


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