From Wikipedia, the free encyclopedia
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
[
edit
]
- ^
"Stratigraphy of the layered gabbroic Dufek Intrusion, Antarctica - ScienceBase-Catalog"
.
www.sciencebase.gov
. US:
United States Geological Survey
. Retrieved
2019-02-13
.
- ^
"Page 1 Stratigraphy of the Layered Gabbroic Dufek Intrusion, Antarctica"
(PDF)
. US:
United States Geological Survey
.
- ^
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
.
209
(4460). US: 1014?1017.
Bibcode
:
1980Sci...209.1014B
.
doi
:
10.1126/science.209.4460.1014
.
PMID
17747230
.
S2CID
7156310
.
- ^
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
- ^
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
.