Wisconsin Range

The Shackleton Glacier (84°35 S, 176°20 W) marks the southern limit of the central Transantarctic Mountains as defined in Fig. 3.1. It is also the northern limit of the Queen Maud Mountains which extend along the strike of the Transantarctic Mountains to the Reedy Glacier and to the Wisconsin Range of the Horlick Mountains located at about 86°S and 125°W. 

Modal and Chemical Compositions and Rb-Sr Systematics of the Wyatt Formation, Scott-Glacier Area and Wisconsin Range, Transantarctic Mountains... 

Chemical Compositions of Whole-Rock Samples of the Wyatt Formation from the Scott Giacier Area (Minshew, 1967) and from the Wisconsin Range of the Horiick Mountains in Percent by Weight (Analyst Sam Botts, US Geological Survey)... 

A 235, Wyatt Formation, Mt. Gardiner, Scott Glacier B F-64-61, Wyatt Formation, Metavolcanic Mountain, Wisconsin Range... 

McLeUand D (1967) Geology of the basement complex, Thorvald Nilsen Mountains, Antarctica. MSc thesis. University of Nevada, Reno, NV Minshew VH (1965) Potassium-aigon age from a granite at Mt Wilbur, Queen Maud Range, Antarctica. Science 150 741-743 Minshew VH (1967) Geology of the Scott Glacier rmd Wisconsin Range areas, central Transantarctic Mountains, Antarctica. Ph.D. dissertation. The Ohio State University, Columbus, OH... 

Ray PT (1973) Rubidium-strontium age determinations of intrusive apUte and pegmatite dikes in the Wisconsin Range of the Horiick Mountains, Antarctica. MSc thesis. The Ohio State University, Columbus, OH RoweU AJ, Evans KR, McKenna LW III (1993) Cambrian and possibly Proterozoic strata in the Transantarctic Mountains north of the Leverett Glacier. Antarctic J US 28(5) 35-37... 

Fig. 7.1 The north-facing escarpment of the Wisconsin Range of the Horlick Mountains is composed primarily of granitic basement rocks. This photograph was taken on January 9,1965,...

The basement rocks of the Wisconsin Range in Fig. 7.4 are similar to those of the Queen Maud Mountains (Chapter 6) and are generally correlated with the... 

LaGorce and Wyatt formations and with the Granite Harbor Intrusives. Sills and dikes of the Ferrar Dolerite are rare in the Wisconsin Range, in contrast to the Transantarctic Mountains between southern Victoria Land and the Amundsen Glacier where numerous dolerite sills occur within the Beacon Supergroup. 

Fig. 7.3 Camp Ohio II on the McCarthy Glacier which is a tributary to the Reedy Glacier in the Wisconsin Range of the Horlick Mountains. The person standing next to the Polaris...

Fig. 7.4 The geology of the Wisconsin Range and of the Long Hills is dominated by the Granite Harbor Intrusives of the Wisconsin Range Batholith. These granitic rocks intruded the metasedimentary rocks of the LaGorce Formation and the metavolcanic rocks of the Wyatt Formation, both of which also...

Fig. 7.5 Silica-variation diagram of whole-rock samples of the Wyatt Formation in the Wisconsin Range of the Horlick Mountains. The x represents a sample of the porphyritic quartz monzonite (Data from Minshew 1967 Faure unpublished in Appendix 7.8.1)...

Fig. IJ The hornblende migmatite that occurs on Spear Nunatak south of Metavolcanic Mountain in Fig. 7.6 may be the oldest rock unit in the Wisconsin Range, but its stratigraphic position cannot be determined in the field because it is not in contact with other rocks and it has not been dated by isotopic methods (Murtaugh 1969). An attempt by Faure (unpublished) to date this specimen failed because its Rb/Sr ratio was too low (Photo by G. Faure)...

Even more problematic is the hornblende migmatite on Spear Nunatak which is composed of layers of hornblende and of quartz-plagioclase (andesine) that have been folded and metamorphosed to the amphibolite facies (Fig. 7.7). Murtaugh (1969) considered the migmatites to be the oldest rocks in the Wisconsin Range and Minshew (1967) tentatively correlated them to the Nimrod Group of the Miller Range (Section 5.1.1). 

The granitic basement rocks of the Wisconsin Range Batholith are the dominant lithology in the Quartz Hills and Caloplaca Hills west of Reedy Glacier (Fig. 7.4). They also form the main part of the exposed basement rocks east of the Reedy Glacier and extend east as far as the Long Hills. These granitic basement... 

The Wisconsin Range Batholith contains several textural varieties of granitic rocks which Murtaugh (1969) described as ... 

The bulk of the Wisconsin Range Bathohth is composed of foliated and massive porphyroblastic facies. The tourmaline-bearing granite occurs on Savage Nunatak (Fig. 7.6) and is illustrated in Fig. 7.8. The tourmaline occurs in the form of ovoid rosettes up to... 

Fig. 7.8 Equigranular and unfoliated granitoid of the Wisconsin Range Batholith on Savage Nunatak containing rosettes of black tourmaline surrounded by haloes of light-colored granitic rock (Photo by G. Faure)...

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