Kirkpatrick Basalt, Northern Victoria Land

Meisch A.T., 1969, The constant sum problem in geochemistry. In Merriam D.F. (ed.), Computer applicatiom in the earth sciertces. Plenum Press, New York, pp.. 161-176. Mensing T.M., Faure G., Jones L.M., Bowman J.R. and Hoefs J., 1984, Petrogenesis of the Kirkpatrick basalt, Solo Nunatak, northern Victoria Land Antarctica, based upon isotopic compositions of strontium, oxygen and sulfur. Contrib. Mineral. Petrol., 87, 101-108. 

The volcanoes of the Transantarctic Mountains occur between Cape Hallett in northern Victoria Land and Mount Early (87°04 S, 153°46 W), which is located only 300 km from the South Pole. The volcanic mountains and cinder cones in the Transantarctic Mountains define the McMurdo Volcanic Province which is subdivided into four regions (Kyle 1990). These volcanoes were active in Late Tertiary time starting less than 25 million years ago and continuing to the present as in the case of Mount Erebus. All of them have extruded silica-undersaturated and alkali-rich lavas in marked contrast to the Ferrar Dolerite and Kirkpatrick Basalts of Middle Jurassic age both of which consist largely of silica-saturated tholeiites. These two suites of volcanic rocks are products of quite different petrogenetic processes that nevertheless occurred at different times in the lithospheric mantle underlying the Transantarctic Mountains. The petrogenesis of these different suites of volcanic rocks is the subject of Chapter 12 (Kirkpatrick Basalt) and Chapter 13 (Ferrar Dolerite), and Chapter 16 (Cenozoic Volcanoes). 

Fig. 4.19 The Bowers Terrane occupies the central area of northern Victoria Land flanked by the Wilson Terrane in the west and the Robertson Bay Terrane in the east The major rock types of this segment of the Transantarctic Mountains are identified by capital letters in alphabetical order A = Admiralty Intmsives, B = Beacon Supergroup, BT = Bowers Terrane, G = Granite Harbor Intrusives, P = Galhpoli Porphyries, R = Robertson Bay Group, W = Wilson Group. The Kirkpatrick Basalt has been onritted from this map for the sake of clarity and the Ferrar Dolerite sills are included with the Beacon Supergroup. The Lanterman and Salamander ranges constitute the eastern province of the Wilson Terrane (Adapted from Gair et al. 1969)...

The Exposure Hill Formation of northern Victoria Land occupies the same stratigraphic position as the Mawson Formation in the Allan and Coombs hills of southern Victoria Land. Both formations are composed of volcanic breccias and related pyroclastic rocks that formed at the start of the eruption of the Kirkpatrick Basalt and the intrusion of sills of the Ferrar Dolerite of the Middle Jurassic Ferrar Group which is the subject of Chapter 12. 

Transantarctic Mountains from northern Victoria Land to the Theron Mountains on the coast of the Weddell Sea. In fact, the Beacon rocks characterize the Transantarctic Mountains because they form the peaks and ridges of this enormous mountain range. The Transantarctic Mountains are also shaped by the numerous and voluminous sills of the Ferrar Dolerite and by the related Kirkpatrick Basalt. 

The Exposure Hill Formation occurs at the base of the sheet-like lava flows of Kirkpatrick Basalt that form the Mesa Range of northern Victoria Land and on nearby nunataks most of which are located in the Rennick graben in Fig. 12.6. The deposits of breccia and related pyroclastic rocks occur at Exposure Hill at the southern end of Gair Mesa and at Mt. Fazio and Scarab Peak on Tobin Mesa as well as on Mt. Carson adjacent to the Aeronaut Glacier in Fig. 12.7. hi addition, Elliot et al. (1986a) described a deposit of breccia on Agate Peak located about 26 km east of the northern tip of Pain Mesa (Fig. 12.6). 

Fig. 12.9 The Mesa Range of northern Victoria Land is located along the upper reaches of the Rennick Glacier which flows north to the Oates Coast. The mesas and associated nunataks are composed primarily of basalt flows of the Kirkpatrick Basalt.

Fig. 12.27 Samples of the Kirkpatrick Basalt on Mt. Falla (Queen Alexandra Range) and Storm Peak (Marshall Mountains) range in composition from subalkalic tholeiite basaltic andesites to andesites. Alternatively, the phenocryst compositions identify these rocks as tholeiitic basalts. The high sihca concentrations of these rocks presumably arise from the aphanitic matrix. The chemical compositions of the Kirkpatrick Basalt in the Beardmore Glacier area are similar to the basalt flows of the Mesa Range in northern Victoria Land (Data from Elhot 1970a, 1972 1974 Faure et al., 1982)...

The concentrations of TiO of the basalt flows on Storm Peak in Fig. 12.28 range from greater than 0.4% to less than 2.4% and include both low-Ti and high-Ti varieties. Most of the flows on Storm Peak have intermediate TiO concentrations between 1.0% and 1.6%. In this regard, the flows on Storm Peak in the Queen Alexandra Range differ from the Kirkpatrick Basalt in the Mesa Range of northern Victoria Land where the TiO concentrations have a distinctly bimodal distribution seen in Fig. 12.28. 

Fig. 12.28 The concentrations of TiO of the Kirkpatrick Basalt on Storm Peak in the Marshall Mountains range from greater than 0.4% to less that 2.4% but are not as sharply divided into low-H and high-H suites as the basalt flows on Solo Nunatak and Pain Mesa of northern Victoria Land (Data from EUiot 1970a, 1972 Faure et al. 1982 Mensing et al. 1984 Mensing 1987)...

The initial Sr/ Sr and Nd/ Nd ratios of Kirkpatrick Basalt in the Mesa Range of northern Victoria Land in Fig. 12.39 occupy an area in quadrant 4 close to the data cluster of the Tasmanian Dolerite. Therefore, this Sr-Nd isotope mixing diagram confirms... 

Mensing TM (1987) Geology and petrogenesis of the Kirkpatrick Basalt, Pain Mesa and Solo Nunatak, northern Victoria Land, Antarctica Ph.D. dissertation. The Ohio State University, Columbus, OH... 

Brotzu P, Capaldi G, MeUuso L Orsi G (1988) Jurassic Ferrar Dolerites and Kirkpatrick Basalts in northern Victoria Land... 

The Prince Albert Mountains in the northern part of southern Victoria Land consist of a large number of nunataks located on the polar plateau at the heads of Mawson, Harbord, and David glaciers aU of which flow into the Ross Sea. Several of these nunataks are composed of siUs of Ferrar Dolerite although flows of Kirkpatrick Basalt occur on Brimstone Peak (75°48 S, 158°33 E). Molzahn et al. (1996) reported isotope ratios of strontium, neodymium, and osmium as well as trace-element concentrations of five dolerite samples from the nunataks of the Prince Albert Mountains and two basalt samples from Brimstone Peak, including rubidium, strontium, samarium, neodymium, rhenium (Re) and osmium (Os). They also measured isotope ratios of strontium, neodymium, and lead in clinopyroxene and plagioclase of these rocks. 

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