Duncan Mountains

Queen Maud Mountains in the Duncan Mountains which will serve as a transition from the geology of the Shackleton Glacier area to the metasedimentary and metavolcanic basement rocks that occur west of the Scott Glacier. 

Cambrian Henson Marble Taylor Formation Henson Marble Fairweather Formation 

Neoproterozoic to Early Greenlee Formation Duncan Formation 

The Fairweather Formation is younger than the Duncan Formation and was originally described by McCjregor (1965b) as a crushed quartz-sandstone. Stump et al. (1976) classified it as a massive, silicic, porphyritic volcanic rock including nonporphyritic varieties and volcanic breccias. In addition, the Fairweather Formation contains thin beds of marble and chert. Wade and Cathey (1986) considered that the lithologic composition of the Fairweather Formation resembles the Taylor Formation in the Shackleton Glacier area and therefore correlated the two formations as indicated in Table 6.1. 

The area was first visited in 1929 by members of Gould s sledging group and the rock samples they collected were later described by Stewart (1934). Twenty four years later, Linder et al. (1965) mentioned O Brien Peak in their report. The rock samples they collected were dated by Craddock et al. (1964) who reported Rb-Sr whole-rock and mineral dates between 520 30 (microcline) and 450 20 Ma (biotite) which reflect 

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The Transantarctic Mountains between the Shackleton and Axel Heiberg glaciers in Fig. 6.1 are composed primarily of the Granite Harbor Intrusives. Metasedimentary and metavolcanic basement rocks occur only between the Barrett and the Gough glaciers and in the Duncan Mountains located on the coast between the Liv and Strom glaciers. For this reason, we start the presentation of the geology of the... 

Fig. 6.2 The basement rocks that are exposed in the Duncan Mountains consist of the Duncan and Fairweather formations both of which were intruded by the Granite Harbor Intrusives. The contact between the Duncan and Fairweather formations is a fault along which the upthrown side is composed of the Duncan Formation. The Henson Marble on Mt. Henson is considered to be a member of the upper Fairweather Formation (Adapted from Stump 1995)...

Table 6.2 Stratigraphy of the basement rocks in the Duncan Mountains and the Nilsen Plateau of the Queen Maud Mountains (Stump 1985)...

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