The occurrence and nature of weathered clasts in the CIROS-1 drill core from McMurdo Sound was recorded. These data showed both associations of weathered material with particular lithofacies and that certain lithologies were preferentially weathered. XRD analysis of weathering rinds from two lithostratigraphic core units suggest that such weathering data can provide evidence of terrestrial palaeoenvironmental conditions that may be otherwise unobtainable.

Field measurements of CO2 exchange were made with an infra-red gas analyser system on lichens at Bailey Peninsula, Wilkes Land, continental Antarctica. It has been demonstrated that Usnea sphacelata, a prominent element of the cryptogamic vegetation of this area, became photosynthetically active at temperatures below 0°C when the thalli were covered by drifted snow. Carbon dioxide uptake was detected down to −10°C. The carbon production during such a ‘frost’ day was considerable for a slow-growing Antarctic lichen. The importance of snow for production in lichens is emphasized. The mechanism of water uptake when the thalli are frozen needs further investigation.

The production of Antarctic Bottom Water is influenced by Ice Shelf Water which is formed due to the modification of shelf water masses under huge ice shelves. The coupling of inflow conditions, thermohaline processes at the ice shelf base and the sub-ice shelf circulation is studied with a two-dimensional thermohaline circulation model which has been developed for a section perpendicular to the ice shelf edge. Different boundary conditions appropriate to the Filchner Ice Shelf regime are considered. The model results indicate that, in general, shelf water is transported toward the grounding line, where at the ice shelf base melting occurs with a maximum rate of 1.5 my−1. Accumulation of ice takes place at the end of the melting zone close to the ice shelf edge with a rate on the order of 0.1 my−1. The location of this accumulation zone determines whether or not the density increase by salt rejection causes an upper circulation cell and the separation of the modified water mass from the ice shelf base at mid-range depth. At the ice shelf edge the simulated temperature, salinity, helium and δ18O values for the temperature minimum layer are typical for Ice Shelf Water. However the sub-ice shelf circulation is highly variable as well as sensitive to changes in boundary conditions. Moderate changes in the characteristics of the inflowing water or in sea-floor topography may double the intensity of the circulation. Non-linear processes in the accumulation zone cause variabilities which can be described by an ice shelf edge oscillator influencing the entire circulation regime.

The lipid composition of natural populations of diatoms in the sea ice at McMurdo Sound was determined during the austral spring bloom of 1985, using and Iatroscan TLC–FID system. The major lipid classes in all samples were polar lipids (including phospholipid, glycolipid and chlorophyll) and triacylglycerol, with lesser proportions of free fatty acids. Total lipid increased through November and early December, reaching a maximum (3300 mg m−2 at Cape Armitage and 1800 mg m−2 at Erebus Ice Tongue) c. one week after the chlorophyll a maxima. This increase was largely attributable to a corresponding increase in triacylglycerol. At the lipid maxima, triacylglycerol/polar lipid ratios in the range 1.0 to 2.5 were observed. The dynamic variations in lipid class abundances indicate that profound changes in the physiology of sea-ice diatoms are occurring throughout the spring bloom. A range of sterols (C26–C30) were detected; 24-methylenecholesterol, brassicasterol and 24-ethylcholesterol were the major sterols at the Cape Armitage and Erebus sites. The similarity of the sterol profiles to those of Antarctic freshwater algal communities strongly indicates diatoms as a more probable source of C29 sterols in the freshwater lakes than cyanobacteria or other algal groups. The hydrocarbons isolated from sea-ice diatoms at all sites were dominated by two unsaturated components, n−C21:6 and a diunsaturated isoprenoid C25 alkene. Until this study, no biological source had been validated for the isoprenoid C25:2 diene, even though it has been detected in many estuarine and coastal sediments.

Chick feeding in common diving petrels (Pelecanoides urinatrix exsul) and South Georgia diving petrels (P. georgicus) was studied on Bird Island, South Georgia. Complete chick meals removed from the proventriculus of adults averaged 25.5 g (n = 32) for common diving petrels (17.6% of adult mass) and 23.3 g (n = 24) for South Georgia diving petrels (20.2% of adult mass); neither contained stomach oils. The sum of the positive mass increments during overnight weighings (SUM) averaged 48.6 g for common diving petrel chicks (n = 78 chick nights) and 41.6 g for South Georgia diving petrel chicks (n = 78 chick nights). Average adult feeding frequencies were 0.95 meals day−1 and 0.92 meals day−1, respectively. Relative meal size in diving petrels was similar to that of other procellariiforms, but SUM averaged about twice that of other petrels. The lower conversion efficiency of meals to body mass in diving petrel chicks reflects the absence of stomach oils in the diet. Higher chick feeding frequency and lower variance in SUM are consistent with the hypothesis that diving petrels forage nearshore on reliable food supply compared with other procellariiforms.

Zooplankton was sampled intensively with an RMT 1+8M system in the fjord of Cumberland East Bay, South Georgia during late winter 1983 and summer 1987. In summer, biomass was highest in the surface 20 m, reaching 142 g dw/1000 m3. Copepods dominated the zooplankton comprising 96–99% by numbers, of which 80–90% occurred in the top 100 m of the 265-m water column. The small clausocalanid Drepanopus forcipatus was particulary abundant. With increasing depth the proportion of non-copepod biomass, principally Mysidacea and Amphipoda increased significantly. Biomass throughout the water column in winter was generally 4–5 times lower than in summer although again copepods, and in particular D. forcipatus and members of the Metridinidae, still numerically dominated the plankton. Biomass levels were some 2–3 times greater than those found in Antarctic oceanic regions but were comparable with estimates from some boreal fjords. The mixture of neritic and oceanic species encountered, and the seasonal presence of some gelatinous zooplankton, particularly ctenophores, appears typical of the community structure of many fjord ecosystems.

A terrestrial sequence on Livingston Island, South Shetland Islands, known as the Williams Point Beds contains a well-preserved, diverse fossil flora previously assigned a Triassic age. Because of their supposed age, volcanic provenance and evidence for active volcanism, the Williams Point Beds have occupied a unique position in Gondwana (pre-Jurassic) stratigraphy in the Antarctic Peninsula region. However, a large new collection of plant specimens obtained at Williams Point has yielded several species of angiosperm leaves, which are abundant and occur at all levels within the Williams Point Beds sequence. Thus, a Triassic age is no longer tenable. On the basis of the plants present and published radiometric ages for associated strata, the Williams Point Beds fossil flora is reassigned to the Cretaceous, and there is some evidence for a more restricted Albian–Cenomanian age. This revision of the age of the Williams Point Beds removes all direct evidence for an active Triassic volcanic arc in the Antarctic Peninsula region.

Plant megafossils collected from the previously unexplored English Coast of eastern Ellsworth Land have yielded the first Glossopteris leaves from the Antarctic Peninsula tectonic province. Collecting at Erehwon Nunatak recovered numerous spatulate leaves of consistent morphology, most likely pertaining to one natural species, and described here as Glossopteris erehwonensis sp. nov., as well as fragments of Phyllotheca and Equisetum. The large sample size, the predominance of Glossopteris leaves, the low species diversity, and the lack of characteristic Early Permian (Gangamopteris) and Early Triassic (Dicroidium, Lepidopteris, Pleuromeia) taxa suggest a Permian, probably Late Permian, age for the Erehwon Nunatak beds. These rocks are thus significantly older than any other sedimentary rocks known from Palmer Land and Ellsworth Land. A second flora, collected from Henkle Peak, consists exclusively of the remains of Elatocladus planus, a conifer which probably dominated forests in this area during the Jurassic. The plant megafossils support correlation of the sedimentary rocks with those of the Middle–Late Jurassic Latady Formation of south-eastern Antarctic Peninsula and eastern Ellsworth Land.

The design of a computer-controlled climatic simulation cabinet used for mechanical weathering studies on Antarctic rocks is described. It is argued that if the results of simulations are to be applicable to field situations they should be firmly based on field environmental conditions. Some weathering results from a laboratory simulation based upon microclimatic data collected from the maritime Antarctic are presented and it is shown that they could not have been obtained from field measurements alone. Further simulation studies are required for the Antarctic and it is argued that the nature of Antarctic research is such that it is particularly conducive to this type of approach.

The central and western Transantarctic Mountains appear to be divided longitudinally by one or more terrane boundaries that separate two regions characterized by different Lower Palaeozoic successions. Re-examination of the upper Beardmore Glacier area and reinterpretation of its Early Palaeozoic stratigraphy emphasizes the strong similarity between it and the Byrd Group outcrops in the area between the Byrd and Nimrod glaciers. This similarity demonstrates that for several hundred kilometres the Cambrian succession of an inboard region is largely devoid of volcanic rocks but includes fossiliferous Lower Cambrian platformal limestones that are overlain unconformably by coarse basin-fill deposits. The latter probably include beds of Middle and perhaps early Late Cambrian age that were themselves deformed prior to the Devonian. Erratic blocks indicate that comparable successions may have been developed as far west as the Whichaway Nunataks. The inferred geological history of this part of the continental margin, which is commonly regarded as autochthonous, stands in contrast to that of more outboard regions where thick volcanic sequences occur in expanded stratigraphic sections that include shallow-marine Middle and Late Cambrian deposits. We consider that these regions, predominantly the Queen Maud and Theil mountains and the Neptune Range of the Pensacola Mountains, constitute one or more displaced crustal blocks. The boundary between them and the inboard sequence adjacent to the craton is probably a series of large strike-slip faults that may have been initiated during the Early Palaeozoic and have been active episodically since then.

The family Acanthonotozomatidae is widely distributed, especially in the Antarctic Ocean. Although many acanthonotozomatids are very conspicuous (they are relatively large and often armoured with teeth on tergites and appendages) very little is known about their biology (Just 1978, Coleman 1989).

The southernmost exposures of Mesozoic dolerites in Coats Land, the Omega dolerites, occur at Whichaway Nunataks. The dolerites are geochemically indistinguishable from the Theron Mountains' dolerites. In both regions high- and low-Ti compositions occur with trace element signatures more akin to island-arc magmas than within-plate tholeiites. From a preliminary Sr isotopic study the Omega dolerites can be classified as Ferrar type. The existence of Ferrar type material in these nunataks suggest that the boundary between the Ferrar and Weddell Sea sub-provinces occurs within the Theron Mountains.

A normal mode approach is used to model the behaviour of a linearly-damped, elastic, ice beam floating on a fluid foundation and subjected to a random distributed loading. As an example, two loading regimes are considered to act on the Erebus Glacier Tongue, McMurdo Sound: broad bandwidth (‘white noise’) loading, and an ocean wave-type pressure distribution beneath the tongue. For white noise input, the root mean square (rms) deflexion is found to good accuracy within the first few modes, but the rms bending moment increases with the number of modes included in the summation due to the unlimited frequency content of the forcing. Solutions for the rms deflexion and bending moments quickly converge to their mathematical limit after six modes when the forcing is due to ocean waves. A local maximum in rms bending moment near the end of the beam confirms that waves may be important as a mechanism for iceberg calving.

A detailed profile of the ice fabric, the deuterium content and the sodium concentration of a 1.64 m long, first-year sea-ice core from Breid Bay, near Syowa station (Antarctica), is described. The core consists mainly of frazil ice (77%), a common feature observed in recent extended studies of the first-year sea-ice cover in the Weddell Sea area. Neither snow ice, nor platelet ice is present. The remainder of the core consists of congelation ice. The typical substructure of ice plates/brine lamellae occurs only at the bottom of the core. Otherwise fine-grained congelation ice is ‘sandwiched’ between layers of frazil. It lacks the intracrystalline substructure but shows a strong textural elongation and c-axis clustering in the horizontal plane. The evolution processes of the first-year sea-ice cover in Breid Bay are analysed. The dynamical component, demonstrated to play a major role in the eastern Weddell Sea, seems to be of minor importance in this area, where thermodynamics satisfactorily explains the isotopic, chemical and textural characteristics of the core. It is proposed that the topmost part of the core consists of frazil ice produced by wind- and wave-induced turbulence. Once a consolidated ice cover is provided, the growth proceeds at a slower rate, through congelation ice formation and frazil ice production, initiated by thermohaline convection processes in the water column. The lower alternate layers of fine grained congelation ice and frazil ice could result from cyclic thermal and salinity regimes at the ice-water interface, connected with the major meteorological events of the year.

Trachyandesite lava flows and trachytic dykes exposed at ‘Gandalf Ridge’ and near Lake Morning on the northern slopes of Mount Morning represent the oldest exposed volcanic rocks in the Erebus volcanic province of the McMurdo Volcanic Group. Conventional whole rock K-Ar age determinations show the rocks are mid-Miocene, ranging between 14.6 and 18.7 Ma. North–south trending faults, which parallel the Transantarctic Mountains, cut the dated dykes. The faults are probably part of a broad fault zone which bounds the uplifted Transantarctic Mountains and the down-dropped Ross Sea/Ross Ice Shelf embayment.

No less than 15–20 sedimentary basins are now known on the Antarctic continental landmass and surrounding continental shelves. Reconstruction of their tectonic and stratigraphic evolution is a specialized task. Owing to the polar position of the continent, the Pacific and Atlantic global geostructures are closely spaced there and the interplay between them is strong enough to result in hybridization of the characteristic tectonic features of the various basins. The present morphostructure of the southern polar region of the Earth is characterized by a prominent circumpolar zoning. Therefore, the sedimentary basins form a gigantic ring along the continental margin, including both the shelf proper and the edge of the continent. Within the ring, the basins are associated with different types of margins successively replacing each other, from the Mesozoic magmatic are in the Pacific segment to the classic passive margin off East Antarctica. The formation of the sedimentary basins in the Antarctic segment of the Pacific mobile belt was a part of a single process of geosynclinal development, whereas on the craton flank the process was superposed on the continental structures by rifting during Gondwana fragmentation. During post-break-up tectonism, continental glaciation played an important part in the formation of the sedimentary basins.

The necessity for uniform reference systems for conventional maps (analogue) and geographic information systems (digital) is discussed. It is recommended that the following scales and projections are used for Antarctic maps: general maps at scales smaller than 1:1 000 000 should use a stereographic projection. Maps up to a scale of 1:1 000 000 should be compiled according to the specifications of the International Map of the World (IMW) 1:1 000 000. Ellipsoids are used as reference surfaces for the various map projections. Differences of the ellipsoidal parameters of the WGS72 and WGS84 systems have to be considered if accuracies better than 10 m are required. Geographic information systems may store data in vector or raster format and in geographic or in geodetic coordinates. For a raster format which is referred to the geographic (spheroidal) grid the term of ‘geographic raster’ is introduced, in contrast to the ‘geodetic raster’ which is referred to a plane cartesian coordinate system. The Institut für Angewandte Geodäsie (IfAG) is establishing the ‘Geocoded Information System Antarctica’ (GIA) using digital satellite image recordings. Internal storage of data in the GIA is in the form of the geodetic raster (and not by spheroidal coordinates). For the scale range 1:250 000 to 1:1 000 000 the size of the raster element is 60 m × 60 m. For smaller scales, satellite image data of a raster width of 240 m × 240 m are preferred.

‘All cartographers' trouble began with the abolition of the flat-Earth theory ’

Upper Jurassic–Lower Cretaceous anoxic mudstones and air-fall ashes of the Nordenskjöld Formation are exposed on the eastern coast of Graham Land. Deformation of the strata has a long history spanning dewatering and lithification and was probably produced in a strike-slip tectonic regime. Available evidence suggests the onset of deformation in the region was during Tithonian times. The strike-slip deformation provides further evidence of a plate boundary along the eastern margin of the peninsula during the break-up of Gondwana and the movement of the crustal blocks of West Antarctica. It may also be related to a change in the spreading history of the Weddell Sea region and be the cause of a major facies change from fine anoxic to coarse clastic sedimentation.

Recent geomorphological research in the ice-free areas of West Antarctica and the subantarctic islands has begun to provide an outline glacial chronology that helps our understanding of the late Quaternary history of ice sheets. However, there is a need for detailed studies of the glacial history of the Antarctic Peninsula area and its offshore islands before a general chronology can be fully reliable. In particular, evidence of Neoglacial glacial fluctuations in the area are imperfectly known in spite of work by Sugden & Clapperton (1977) on island groups in the Scotia Sea, Clapperton et al. (1978) on South Georgiaand Clapperton & Sugden (1982) on Alexander Island. The aim of this note is to present data relating to Holocene glacier fluctuations from the hitherto unstuded Brabant Island (64°15′S, 62°3′W).

A new fossil teleost, belonging to the family Aspidorhynchidae Nicholson & Lydekker, Aspidorhynchus antarcticus sp. nov., was obtained from a block of reworked Upper Jurassic tuffaceous mudstone in the lower (Albian) part of the mid-Cretaceous Whisky Bay Formation of James Ross Island, Antarctic Peninsula. Additional material, assignable to Aspidorhynchus sp., was collected from in situ Upper Jurassic marine rocks (Nordenskjöld Formation) at Longing Gap, northern Antarctic Peninsula. Not only is this the first reported occurrence of the family from Antarctica, it is also the first unequivocal record of Aspidorhynchus outside Europe; prior to this discovery, the genus had only been reported with certainty in marine deposits from the Middle Jurassic to Lower Cretaceous of England, France and Germany. This is the earliest neopterygian fish so far recovered from marine rocks in the Antarctic.