Jetty Oasis, Jetty Peninsula, Prince Charles Mountains, Mac Robertson Land, Eastern Antarctica, Antarcticai

Regional Level Types
Jetty Oasis	Oasis
Jetty Peninsula	Peninsula
Prince Charles Mountains	Mountain Range
Mac Robertson Land	- not defined -
Eastern Antarctica	Region
Antarctica	Continent

Jetty Oasis is a large area naturally free of snow and ice in the Jetty Peninsula. It includes the Russian (formerly Soviet) Soyuz Station (see coordinates).

Permian sediments containing specimens of petrified woods crop out just to the north of the station. A ca. 13-km-long belt of shield rocks, intruded by dykes and pipes of alkaline-ultramafic rocks, crops out to the east; a long moraine is situated to the northwest.

The Permian sedimentary rocks outcropping near Soyuz Station consists of carbonaceous shales and coals (to 20 centimeters thick). Fragments of petrified wood consisting of siderite and minor pyrite occur with coal in permafrost 0.7 kilometer north of the station. Cellular structure is well preserved in some specimens. Leaf and stem impressions were found in sandstone immediately overlying coal at two localities, one 350 m west of the petrified wood locality (presumably the same coal bed) and a second 2 km north of Soyuz. The Permian sediments around Soyuz resemble the Bainmedart Coal Measures of the Amery Group in which carbonaceous slate, coal, and fossils are present.


Ultramafic alkaline plugs and dykes intruded the shield rocks as the result of rifting during Upper Mesozoic. According to K–Ar dating, their age is Early Cretaceous (Laiba et al., 1987). The ultramafic alkaline plugs are 15 to 200 metres across, while the dikes reach 180 m in length and up to 2 m in thickness. The stocks have two- and sometimes three-phase structure determined by successive emplacement of the following phases (from early to late): (1) tuffisite breccia (tuffisites); (2) alkaline picrite and melanephelinite; (3) polcenites (not always occur). Lamproites and lamproite-like rocks contain ~20–25% olivine, 1–2% pyroxene, and 5% Ti-bearing magnetite. The content of phlogopite is strongly variable and may reach 10–15%, whereas carbonates (including secondary ones) amount 10–20%, and even more than 30–40% in the most altered varieties. Accessory minerals are apatite, ilmenite, monazite, pyrite, and others.

All rocks contain diverse mantle xenoliths: olivine melanephelinite and alkaline picrite in particular contain a profusion of mantle xenoliths. The xenoliths are very variable in size and reach 40–50 cm in diameter. The suite of xenoliths is representative of a broad section of the upper mantle, and includes deep-seated garnet lherzolite as well as samples of the shallower mantle, such as spinel lherzolite, harzburgite, and dunite.



Note on the alternative names: the official name for both oasis and peninsula is Jetty (given in 1956 by Australian National Antarctic Research Expeditions). This toponym is written as Джетти by Russians. As the Russian group of letters "дж" is transliterated into English as "dzh", the toponym resulting from the English translation of Russian papers is usually Dzhetti. The toponym "Dzetti", which does not exists, is a typo appeared only in Kogarko et al. (2007). Later it has been transliterated as "Дзетти" only in the Russian articles and websites (e.g. http://druza.web.ru/) that cited the work of these authors.

Other Regions, Features and Areas containing this locality

References