Koettlitz Group

Blue glaciers is partially ice-free and exposes metasedimentary and metavolcanic rocks of the Koettlitz Group (Adapted from Bull 1962)... 

However, Mortimer (1981) and Findlay et al. (1984) who also worked in the area did not agree with the stratigraphic sequence proposed by Blank et al. (1963). Mortimer (1981) concluded that the Salmon and Miers Marble were the same layer of rock and that the Garwood Lake and the Marshall Formation were also the same unit. Findlay et al. (1984) who remapped basement rocks throughout southern Victoria Land subdivided the Koettlitz Group into the Marshall Formation, the Salmon Marble, and the Hobbs Formation but did not place them in stratigraphic order. 

Fig. 3.15 Three whole-rock samples of marble in the Asgard Formation (Koettlitz Group) define a straight line on the Rb-Sr isochron diagram that yields a date of 840 30 Ma and an initial Sr/ Sr ratio of 0.7080. Date and initial Sr/ Sr ratio calculated by Adams and Whitla (1991) from their own measurements.

The Priestley Formation of the Deep Freeze Range does not correlate with the metasediments of the Robertson Bay Terrane, contrary to a proposal by Nathan and Skinner (1972) who, at that time, had not yet visited the type locality of the Robertson Bay Group in Edisto Inlet (Skinner 1983). It seems more likely that the Priestley Formation is the local representative of the Koettlitz Group of southern Victoria Land because it occupies the same stratigraphic position as the Asgard Formation in the ice-free valleys of southern Victoria Land (McKelvey and Webb 1962 Section 3.1.2) and because both formations contain sedimentary carbonate beds. However, this conjecture has not been confirmed or even tested. 

Fig. 19.20 The Cenozoic volcanic rocks of the McMurdo Volcanic Group in the Wright, Taylor, and Ferrar valleys of southern Victoria Land were erupted between 5.0 and 1.5 Ma (Pliocene), whereas the eruptions in the ice-free valleys north of the Koettlitz Glacier (Fig. 19.19) started at 3.0 Ma and lasted well into the Pleistocene. The eruptions in both areas were subaerial rather than subglacial and occurred after the Transantarctic Mountains of southern Victoria Land had been overridden by the East Antarctic ice sheet (Data from Armstrong 1968 Fleck et al. 1972 Barrett et al. 1992 Wilch et al. 1993b HaU et al. 1993)...

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