Miller Range
| Miller Range | ||
|---|---|---|
| location | Ross Dependency , Antarctica | |
| part of | Transantarctic Mountains | |
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| Coordinates | 83 ° 15 ′ S , 157 ° 0 ′ E | |
The Miller Range is a mountain range in the Ross Dependency of Antarctica . In the Transantarctic Mountains , it extends from the Nimrod Glacier over a distance of around 80 km to the south along the western flank of the Marsh Glacier .
It is named after the New Zealand geographer Joseph Holmes Miller (1919-1986), who mapped this area as a member of the New Zealand group of the Commonwealth Trans-Antarctic Expedition (1955-1958).
geology
Map with the Nimrod Glacier
Map with the Marsh Glacier in the middle
The Nimrod Group is the most important geological unit within the Miller Range. It allows rare glimpses of the East Antarctic basement . Together with parts of the Shackleton Range , the Terre Adélie Kraton and the Gawler Kraton, it formed the initial crust blocks of the Mawson Craton and the Mawson Continent.
The Nimrod Group forms a heterogeneous metamorphic complex. The rock stock is mainly composed of banded paragneiss of various compositions, mica schist , quartzites , granitic to gabbronitic orthogneiss , ultramafic rock formations and relics of eclogites . The latter indicate subduction processes .
The oldest rocks date between 3,100 and 2,720 mya. Zircons of igneous protoliths are 3,290 to 3,060 mya old. For a detritic quartzitic zircon, an age between 2,500 and 1,700 mya has been proven. This age spectrum correlates with other archaic to paleoproterozoic East Antarctic rocks.
Deformations and metamorphic impressions took place in different degrees and at different times. At 1,730 mya an orthogneiss intruded the rock packages. This period corresponds to the Nimrod-Kimban orogeny, which occurred during the formation of the Mawson craton and the Mawson continent. Between 550 and 475 mya of plutonite extruded during the formation of the Ross orogen .
Web links
- Miller Range in the Geographic Names Information System of the United States Geological Survey (English)
- Miller Range on geographic.org (English)
- GW Grindley and Ian McDougall: Age and correlation of the Nimrod Group and other precambrian rock units in the central Transantarctic Mountains, Antarctica. In: New Zealand Journal of Geology and Geophysics. doi: 10.1080 / 00288306.1969.10420290 , online article
- John W. Goodge: Latest Neoproterozoic basin inversion of the Beardmore Group, central Transantarctic Mountains, Antarctica. In: Tectonics, Vol. 16, No. 4, Pages 682-701, Aug 1997. On-line article
- John W. Goodge, Vicki L. Hansen, Simon M. Peacock, Brad K. Smith and Nicholas W. Walker: Kinematic Evolution of the Miller Range Shear Zone, Central Transantarctic Mountains, Antarctica, and Implications for Neoproterozoic to early Paleozoic Tectonics of the east Antarctic Margin of Gondwana. In: Tectonics, Vol. 12, No. 6, Pages 1460-1478, December 1993. Online article
Individual evidence
- ↑ Miller, Joseph Holmes. Entry in the Encyclopedia of New Zealand (accessed November 7, 2015).
- ^ John W. Goodge and C. Mark Fanning: 2.5 by of punctuated Earth history as recorded in a single rock. In: Geology; November 1999; v. 27; no. 11; p. 1007-1010. PDF
- ^ MH Monroe: Antarctica - Before and After Gondwana. In: Gondwana Research, Volume 19, Issue 2, March 2011, Pages 335-371. doi: 1016 / j.gr.2010.09.003 , alternatively
- ^ John W. Goodge, C. Mark Fanning and Vickie C. Bennett: U – Pb evidence of ∼1.7 Ga crustal tectonism during the Nimrod Orogeny in the Transantarctic Mountains, Antarctica: implications for Proterozoic plate reconstructions. In: Precambrian Research, Volume 112, Issues 3-4, 10 December 2001, Pages 261-288. doi: 10.1016 / S0301-9268 (01) 00193-0 , alternatively
- ^ Anthony J. Reid, Stacey O. McAvaney, and Geoff L. Fraser: Nature of the Kimban Orogeny across northern Eyre Peninsula. In: MESA Journal 51 December 2008. PDF