Adare Peninsula

The Adare Peninsula was first visited by Carsten Borchgrevink and his men who wintered over in two huts on Ridley Beach (Section 1.3). In 1911/12 the huts were used again by Scott(s Northern Party led by Victor Campbell (Section 1.4.3). The remains of these huts still stand on Ridley Beach (McIntosh and Kyle 1990b). Descriptions of the geology of the Adare Peninsula and of the petrology of the volcanic rocks were published by Harrington et al. (1967), Hamilton (1967,1972), Jordan (1981), and by LeMasuiier et al. (1983). 

Armstrong (1978) reported a K-Ar date of 2.27 0.5 Ma corrected by McIntosh and Kyle (1990a) to the new decay constants of Steiger and JSger (1977) using 

Adare Peninsula, HaUett Peninsula, Daniell Peninsula, Coulman Island, and the Possession Islands. The Cenozoic volcanic rocks in these areas are located adjacent to and may have been deposited on top of the low-grade metasedimentary rocks of the Robertson Bay Group of early Paleozoic age (Section 4.5) (Adapted from Gair et al. (1969)) 

The total-alkali and silica concentrations of three rock samples from the Adare Peninsula are classified in Fig. 16.36 as a basanite, a phonolite, and a trachyte (McIntosh and Kyle 1990b). Additional chemical analyses by Hamilton (1972), Smith (1964), David et al. (1896), and unpublished data by P.R. Kyle and W.C. McIntosh demonstrate a continuous spectrum of rock types on the Adare Peninsula from SiO = 42% to 67%. The presence of large volumes of palagonitic tuff breccias and pillow breccias on the Adare Peninsula and elsewhere in the Hallett volcanic province led Hamilton (1972) to conclude that these rocks were erupted through ice at a time when the East Antarctic ice sheet had expanded. This interpretation was supported by the presence of abundant glacial erratics on the northern end of the Adare Peninsula (Priestley 1923). 

Apparently, the volcanic rocks on the Adare Peninsula were erupted subaeriaUy rather than subgla-cially although the basal flows may have come in contract with snow and meltwater in a periglacial enviromnent. After the main phase of the eruption, the East Antarctic ice sheet probably did advance from the west and deposited the glacial erractics that cover the northern part of the Adare Peninsula. 

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The Possession Islands, between 71°53 S, 171°14 E and 71°58 S, 171°07 E, in Fig. 16.35 are located 8 km off the coast of Cape McCormick and Cape Roget on the southern end of the Adare Peninsula. They consist of a group of nine small islands and sea stacks composed of Cenozoic alkali-rich volcanic rocks described... 

Fig. 16.41 The Sr/ Sr ratios of the Cenozoic volcanic rocks on the islands off the coast of Victoria Land are lower than those on the mainland. The islands included here are Franklin, Coulman, Possession, Scott, and Balleny. The volcanoes on the mainland are Melbourne, Vulcan HiUs, Overlord, and The Pleiades, as well as the DanieU, HaUett, and Adare peninsulas (Data from Jones and Walker (1972) and Hart and Kyle (1993))...

The volcanoes along the Ross-Sea coast of northern Victoria Land collectively form the Hallett volcanic province in Fig. 16.35. This province includes the Adare, Hallett, and Daniell peninsulas, and Coulman Island. Volcanic rocks of Cenozoic age also occur on the Possession Islands and at a few vents on the mainland west of the major volcanic complexes named above (McIntosh and Kyle 1990a). 

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