GEOLOGIC SETTING

The Latady Group in the southern Antarctic Peninsula is a Jurassic sequence deposited initially in rift basins associated with the early stages of Gondwana breakup (Early and Middle Jurassic). Deposition continued in the Late Jurassic in a larger back-arc basin that formed either in response to subduction along the western margin of the peninsula or thermal relaxation (Willan and Hunter 2005). Rocks of the Latady Group crop out between eastern Ellsworth Land and the southern Black Coast (Figure 1). They comprise a thick (~2.8–6 km) sequence of minor terrestrial, shallow water, and fossiliferous marine sandstones and mudstones (Laudon et al. 1969; Williams et al. 1972; Dalziel and Elliot 1973; Suarez 1976; Quilty 1978; Smellie 1981; Rowley and Williams 1982; Laudon et al. 1983; Rowley et al. 1983; Vaughan and Storey 2000, Vaughan et al. 2002; Hikuroa 2005; Willan and Hunter 2005). Strata of the Witte Nunataks and Hauberg Mountains Formations (Latady Group), crop out in the Witte Nunataks, and the Hauberg Mountains, southern part of Mount Hirman, and Quilty Nunataks respectively (Willan and Hunter 2005, figures 2, 4, 5c,d and Figure 1.3).