Gravity data are presented for 220 sites covering 180 000 square kilometres in the Prince Charles Mountains area of eastern Antarctica. Bouguer anomalies range from +60 m Gal over the Amery Ice Shelf (near sea level) to -120 m Gal at altitudes above 2000 m on the Antarctic ice cap. Bouguer anomalies correlate with the mass per unit area above sea level in the relation expected for a region in isostatic equilibrium. Smoothed free air anomalies range from +60 to -60 mGal. North-south trending anomalies over the Lambert Glacier and Amery Ice Shelf are thought to be due to a major fault along the Lambert Glacier, and a rift structure under the Amery Ice Shelf. To the west of these structures the free air anomalies trend mainly east-west.

A short article as a side bar in the Australian Antarctic Magazine published by the Australian Antarctic Division. The sidebar article will accompany a longer article by Lt Peter Waring of the Royal Australian Navy survey team that conducted a multibeam survey in Casey Harbour during season 2013-14

The Archaean cratonic block of the Vestfold Hills, Princess Elizabeth Land is one of only three well-documented examples in East Antarctica. It is characterised by tectonically interlayered tonalitic to granitiC orthogneisses (Mossel gneiss) and garnetiferous paragneisses (Chelnok supracrustal assemblage) as well as sub- ordinate units of predominantly mafic granulite (Tryne meta-volcanics). This sequence is cut by a second suite of orthogneisses (Crooked Lake gneiSS), ranging in composition from gabbro-diorite to tonalite and granite, which was emplaced synchronously with the last major phase of deformation. Cutting the gneisses are several suites of Proterozoic tholeiitic dykes, including a high-Mg suite, which range in age from about 2350 Ma to 1300 Ma. Most dykes are unmetamorphosed, but, in the southwestern part of the VestfoldHills, high-pressure garnet-bearing assemblages developed during a late Proterozoic (about 1100 Ma) thermal event. Granulite facies gneisses that crop out southwest of the Vestfold Block, along the coast of Prydz Bay, show the regional effect of this younger metamorphism and form part of an extensive late Proterozoic high-grade terrain, which makes up much of the East Antarctic Shield. Gneisses in the Rauer Group of Islands, within 30 km of the Vestfold Hills, are lithologically similar (predominantly orthogneisses) to those of the Vestfold Block, and contain metamorphosed relics of Vestfold dykes; however, they include only a minor component derived by remetamorphism of Archaean continental crustal rocks. In contrast, gneisses further to the southwest were mainly derived from aluminous sedimentary protoliths, and are quite different in composition to those of the Vestfold Block and Rauer Group. They do not appear to have been intruded by mafic dykes (mafic granulite is very rare) and apparently represent a Proterozoic cover sequence of similar age to metasedimentary sequences in MacRobertson Land. Intrusion of locally fayalite- bearing granitic rocks took place about 500 Ma ago.

A helicopter survey has mapped gravity and magnetic anomalies and ice thickness over a 100 km by 100 km ice cap area, inland from coastal outcrops of Archaean and Late Proterozoic rocks of the Princess Elizabeth Land coast. The gravity and magnetic anomalies indicate that there is no major change in crustal structure across the boundary between Archaean and Lake Proterozoic rocks. The Archaean rocks of the Vestfold Hills do not extend further inland, but they may extend under Prydz Bay or as a narrow coastal strip under ice inland from the West Ice Shelf, 150 km to the northeast of the Vestfold Hills. Late Proterozoic rocks probably underlie most of the ice cap along the coast.

This study presents the first analysis of benthic megafauna and habitats on the Sabrina Coast shelf, East Antarctica, encompassing an area that has been proposed as a Marine Protected Area. Analysis of seabed images indicates that this shelf is comprised of a relatively abundant benthic fauna compared to other parts of the Antarctic shelf, and is dominated by brittle stars, polychaete tubeworms and a range of other sessile and mobile taxa. The distribution of taxa across this shelf is strongly related ( = 0.592) to variations in water depth, latitude, substrate type and the occurrence of phytodetritus. Areas with a high percent cover by phytodetritus are associated with muddy/sandy sediments, with relatively high abundances of mobile holothurians and amphipods, while harder substrates have high abundances of brachiopods, various forms of hard bryozoans, polychaete tubeworms, a range of massive and encrusting sponges and sea whips. Brittle stars, irregular urchins and anemones occur throughout. Variations in substrate type largely reflect the scattered distribution of dropstones, which creates habitat heterogeneity at fine-scales. Several taxa are found only on areas of hard substrate, with most of these taxa showing a broad distribution across the study area, indicating that the density of dropstones is sufficient for most sessile invertebrates to disperse across the region. A few taxa (the hexactinellid sponge Anoxycalyx joubini and branching hydrocorals) show a more restricted distribution. The distribution of hydrocorals may be influenced by their limited dispersal capability, while A. joubini is most likely restricted by water depth. The occurrence of dropstones is associated with significant increases in taxa diversity, abundance and percent biological cover, enhancing the overall diversity and biomass of this ecosystem.

Upper Permian silicified gymnospenn woods from the Bainmedart Coal Measures (Amery Group) near Beaver Lake, East Antarctica, are described as two new species, Australoxylon bainii and A. mondii, on the basis of morphometric and qualitative characters - including ray anatomy, tracheid shape, and cross-field pit structure. Australoxylon mondii has two forms, one of which is characterised by a distinctive ray architecture comprising semidetached rows of ray cells with intervening gaps bridged by sporadic joins. Wood of Vertebraria could not be distinguished from Australoxylon mondii on microanatomical characters, which suggests that these two organ taxa may represent different parts of the same glossopterid plant. Many characters used traditionally in wood taxonomy could not be applied owing to substantial variation or preservational differences both within and between specimens. Three types of presumed biogenic cavities occur in the woods. Coprolite-containing cavities distributed in seasonal bands represent rare evidence for Permian wood-boring arthropods. Other, irregularly distributed cavities and appositions were probably fonned by pathogenic fungi. Growth-ring analysis indicates a markedly seasonal climate with low to moderate interseasonal variation in wood production. Significant intraseasonal influences on growth are also evidenced by numerous false rings.

A well-preserved Late Triassic palynoflora from the upper Flagstone Bench Formation, Prince Charles Mountains, East Antarctica, contains taxa that are also widely distributed in coeval Tethyan Laurasian assemblages. The most common and distinctive of these elements in the present assemblage are: Enzonalasporites vigens, E. densus, cf. Ellipsovelatisporites sp., Minutosaccus crenulatus, cf. Rimaesporites aquilonalis, Ovalipollis ovalis, Samaropollenites speciosus, and Duplicisporites scurrilis. The assemblage is assigned to the Australian Minutosaccus crenulatus Zone, and considered to be of Norian age. Gondwanan palynofloras containing these Laurasian elements are assigned to the Onslow Microflora, which is represented by Middle and Late Triassic palynomorph assemblages from Madagascar, western and northern Australia, East Africa, and Peninsular India. Occurrences of the Onslow Microflora appear to be confined to sediments deposited in palaeolatitudes between about 40o-30oS. As well as climatic controls, we suggest that other factors influenced the distribution of the parent floral communities. In particular, availability of migration pathways along Tethyan coastal plains, that were exposed during periods of sealevel regression, was an important factor controlling the rapid dispersal of certain Triassic plants. Marine influence on the present assemblage is evident by the rare spinose acritarchs, and one specimen of a dinocyst of the Shublikodinium-Rhaetogonyaulax plexus; this is the first record of a Triassic dinocyst from Antarctica.

With improving accessibility to Antarctica, the need for proactive protection and management of sites of intrinsic scientific, historic, aesthetic or wilderness value is becoming increasingly important. Environmental protection and conservation practise in the Antarctic is globally unique and is managed by provisions contained within the Antarctic Treaty. Whilst these provisions have been primarily utilised to protect sites of biological or cultural significance, sites of geological or geomorphological significance may also be considered. However, in general, sites of geological and geomorphological significance are underrepresented in conservation globally, and, particularly, in Antarctica. Wider recognition of sites of geological significance in Antarctica can be achieved by development of a geo-conservation register, similar to geological themed inventories developed elsewhere in the world, to promote and recognise intrinsically valuable geological and geomorphological sites. Features on the register that are especially fragile, or otherwise likely to be disturbed, threatened or become vulnerable by human activity, can be identified as such and area management protocols for conservation, under the Antarctic Treaty, can be more readily invoked, developed and substantiated. Area management should mitigate casual souveniring, oversampling and accidental or deliberate damage caused by ill-advised construction or other human activity. The recognition of significant geological and geomorphological features within the Antarctic, and their protection, is identified under the current Australian Antarctic Science Strategic plan (under Stream 2.2; Vulnerability and spatial protection)

Granitic rocks in different terranes and of different ages in the Prince Charles Mountains (PCM) show systematic compositional differences. Archaean granitic basement rocks of the southern PCM have compositions unlike those of typical Archaean tonalite- tronhjemite-granodiorite (TTG) terranes and consist mainly of within-plate types, which probably post-date crust formation and early metamorphic events. Unusually HFSE-rich (Zr, Nb, and Y) hornblende-biotite granite gneiss with A-type (anorogenic) affinities was probably derived by fractionation of mafic magma, but other granites represent intracrustal melts. Orthopyroxene-bearing tonalitic to granitic orthogneiss of the c. 1000 Ma high-grade terrane in the northern PCM and adjacent areas includes a large proportion of Y-depleted, Sr-undepleted volcanic arc granitoids, probably derived by melting of a plagioclase-poor mafic source (e.g. amphibolite or eclogite) in a Palaeo- or Mesoproterozoic Andean-type plate margin. Tonalite-granodiorite and mafic to felsic metavolcanic rocks at Fisher Massif also formed in an active continental margin, with an associated island arc, about 1300 million years ago. Most c. 1000 Ma granitoids also have volcanic arc characteristics, but there are significant syn-collision and within-plate types, indicating a polygenetic origin in a high-grade terrane formed at a convergent plate margin. Syn to late-metamorphic orthopyroxene granitoids (charnockites) include HFSE-rich quartz monzonitic varieties, which probably formed by fractionation of mantle-derived magma, and more siliceous granites, which represent high-temperature, predominantly intracrustal melts of dry granulite-facies orthogneiss. These granites are mainly Y-depleted, implying high-pressure melting with residual garnet in crust thickened by continental collision (between Archaean cratons in India and Antarctica) and heated by magmatic underplating. Major Cambrian plutons have A-type features, consistent with melting of dry granulite-facies rocks caused by mafic underplating. Emplacement near the present Lambert Glacier graben suggests an association with internal fracturing that preceded eventual break-up of Gondwana.

Early Archaean ( >3 b.y. old) metapelites from the Napier Complex of East Antarctica are enriched in MgO and depleted in K2O and Rb compared with late Archaean and Proterozoic metapelites, probably reflecting a higher proportion of mafic to ultramafic material and sodic (tonalitic to granodioritic) felsic igneous rocks in the source. A number of the more magnesian are strongly depleted in Cr, Ni, Cu, and V, and may have been formed by metamorphism of sediments derived from hydrothermally altered mafic or ultramafic igneous rocks. There is evidence for metamorphic depletion of Rb relative to K in these high-temperature granulite facies metapelites, many of which have high K/Rb ratios, and for depletion of U relative to Th in granulite-facies metapelites compared with those of amphibolite facies. The unique occurrence, on a regional scale, of assemblages containing sapphirine + quartz, and osumilite in metapelites of the Napier Complex may be due to their unusual chemical compositions, as well as to exceptionally high temperatures of metamorphism (900-950°C). Such assemblages are found only in the more magnesian rocks (mostly with mg > 0.6) in the Napier Complex, whereas younger metapelites are, with few exceptions, relatively iron-rich. Nevertheless, regional high-grade metamorphism with geothermal gradients sufficiently steep to allow formation of these rare assemblages is likely to have been confined to the Archaean.