Shackleton Range and Theron Mountains

In this way, the Shackleton Range completes a trend that began in the Thiel Mountains and continued in the Pensacola Mountains both of which are inCTeasingly displaced from the subduction zone along which the Ross Orogen formed by compression from east to west at about 500 Ma. However, Clarkson (1982) reported that the Cambro-Ordovician rocks at the western end of the Shackleton Range strike north and south. 

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The Beacon rocks occur not only in southern Victoria Land in Fig. 10.4 but characterizes the Transantarctic Mountains from northern Victoria Land to the Ohio Range of the Horlick Mountains. They continue from there to the far-eastern mountains described in Chapter 8 including the Pensacola Mountains, the Shackleton Range, the Theron Mountains, and even the Kottas Mountains on the coast of the Weddell Sea in Queen Maud Land (Poscher 1989 Barrett 1991). 

StephensonPJ (1966) Geology. 1. Theron Mountains, Shackleton Range, and Wichaway Nunataks. Commonwealth Trans-Antarctic Expedition 1955-1958. Science Rept No 8 1-79 Storey BC (1996) Microplates and mantle plumes in Antarctica. Terra Antartica 3(2) 91-102... 

The Thiel and Pensacola mountains were mapped by geologists of the US Geological Survey (Schmidt and Ford 1969). The geologic map of the Shackleton Range was published by Clarkson (1982) and by Clarkson et al. (1995) based on field work of geologists from many countries. The Theron Mountains were discovered and described by members of the Commonwealth Trans-Antarctic Expedition (1955-1958 Section 1.5.4 Stephenson 1966). 

The Kirkpatrick Basalt does not occur in the Queen Maud, Horlick, Thiel, and Pensacola mountains. Exposures of basalt in the Shackleton Range have not been correlated with the Kirkpatrick Basalt However, sills of Ferrar Dolerite do occur in the Whichaway Nunataks (Brewer 1989), in the Theron Mountains (Blundell and Stephenson 1959 Brewer et al. 1987, 1992). In addition, basalt magma pooled in a large magma chamber in the crust beneath the Pensacola Mountains where it differentiated into the layered gabbro complex of the Dufek intrusion (Ford and Kistler 1980). 

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