This paper reports geochemical characteristics of mafic gneisses and granulites collected from four localities in central Dronning Maud Land to evaluate the tectonic setting of their precursor rocks. Precursor rocks for the mafic gneisses and granulites in central Dronning Maud Land were formed in different geological backgrounds and tectonic settings. The mafic gneisses and granulites in the Schirmacher Hills were derived from basaltic rocks in a back-arc setting. Published U–Pb zircon ages and the geochemical variation of the basement rocks indicate their emplacement between 800 and 650 Ma, close to peak metamorphism. While similar protoliths were recognized in the inland nunataks of Hochlinfjellet, in Filchnerfjella the mafic gneisses/granulites were derived from basaltic rocks formed in marginal continental arcs or island arcs. Highly disturbed trace-element patterns indicate that the metamorphic process influenced the geochemical composition during the prograde metamorphic stage. Our results imply that the outcrops in central Dronning Maud Land with different metamorphic ages contain mafic gneisses/granulites from precursor rocks formed under different tectonic settings.

40Ar/39Ar and U–Pb data from five structural domains constrain the late Neoproterozoic – early Palaeozoic tectonothermal history of the eastern part of the East African–Antarctic Orogen in Sør Rondane. A total of 27 new Ar/Ar ages span 570–474 Ma, roughly corresponding to the age range of three generations of syn- to post-tectonic granitoids. The ages are distinct for the five structural domains. The oldest cooling ages come from the weakly deformed southern part of the SW Terrane of Sør Rondane (SW Terrane S), a sliver of a Tonian island arc, which escaped much of the late Neoproterozoic accretionary deformation. This terrane was intruded by the oldest and largest granitoid complex at c. 640–620 Ma. The oldest Ar/Ar amphibole and biotite ages of 570–524 Ma are from the Main Shear Zone, along the northern margin of the SW Terrane S sliver. It hosts granites of age c. 584–570 Ma strung out along the shear zone. Two younger granitoid phases are recorded in the adjacent four terranes to the west, north and east of the SW Terrane S, and correlate with the younger group of Ar/Ar biotite ages spanning 513–474 Ma. We interpret the magmatic and cooling history of duration > 150 Ma to reflect repeated phases of accretion, magmatism and reactivation, that is, collage-style tectonism, partly pre-dating the incorporation of Sør Rondane into Gondwana. The study area first accreted to the cryptic Valkyrie Craton in Tonian times, was then ‘sandwiched’ between the Kalahari and Indo-Antarctica cratons, and experienced extensional tectonics and elevated heat flux due to lithospheric delamination, which resulted in slow cooling during the Pan-African Orogeny.

Lake Untersee is a perennially ice-covered Antarctic lake that consists of two basins. The deepest basin, next to the Anuchin Glacier is aerobic to its maximum depth of 160 m. The shallower basin has a maximum depth of 100 m, is anoxic below 80 m, and is shielded from convective currents. The thermal profile in the anoxic basin is unusual in that the water temperature below 50 m is constant at 4°C but rises to 5°C between 70 m and 80 m depth, then drops to 3.7°C at the bottom. Field measurements were used to conduct a thermal and stability analysis of the anoxic basin. The shape of the thermal maximum implies two discrete locations of energy input, one of 0.11 W m-2 at 71 m depth and one of 0.06 W m-2 at 80 m depth. Heat from microbial activity cannot account for the required amount of energy at either depth. Instead, absorption of solar radiation due to an increase in water opacity at these depths can account for the required energy input. Hence, while microbial metabolism is not an important source of heat, biomass increases opacity in the water column resulting in greater absorption of sunlight.

An experiment applying controlled meteorological (CMET) balloons near the coast of Dronning Maud Land, Antarctica, in January 2013 is described. Two balloons were airborne for 60 and 106 hours with trajectory lengths of 885.8 km and 2367.4 km, respectively. The balloons carried out multiple controlled soundings on the atmospheric pressure, temperature and humidity up to 3.3 km. Wind speed and direction were derived from the balloon drift. Observations were compared with radiosonde sounding profiles from the Halley Research Station, and applied in evaluating simulations carried out with the weather research and forecasting (WRF) mesoscale atmospheric model. The most interesting feature detected by the CMET balloons was a mesoscale anticyclone over the Weddell Sea and the coastal zone, which was reproduced by the WRF model with reduced intensity. The modelled wind speed was up to 10 m s-1 slower and the relative humidity was 20–40% higher than the observed values. However, over the study period the WRF results generally agreed with the observations. The results suggest that CMET balloons could be an interesting supplement to Antarctic atmospheric observations, particularly in the free troposphere.

The sub-fossil moss Pohlia nutans is recorded from lake sediment cores at Schirmacher Oasis, Dronning Maud Land, Antarctica. It was isolated from 160–162 cm depth of a sediment core. Radiocarbon (14C) dates by accelerator mass spectrometry confirmed its age to be 10.65 kyr bp. The preserved Holocene sub-fossil moss includes delicate leaves, axes and rhizoids and matches perfectly the extant specimens of P. nutans. This is the first record of this sub-fossil from Dronning Maud Land, although the species is common as present-day flora in other parts of the Antarctic. The present status of the moss flora of Schirmacher Oasis is also discussed, including its diversity, ecology and biogeography.

The recently inaugurated Belgian Princess Elisabeth Station has been built in the Sør Rondane Mountains (Dronning Maud Land). The construction site is situated close to the Utsteinen Nunatak (71°57′S, 23°20′E), on a granite ridge. Prior to the survey and construction activities, the site had been subject to limited or no direct human impacts. Therefore, a biological inventory has been started for future evaluations of human impacts in the area. This study presents the cyanobacterial diversity of ten samples from the Utsteinen ridge, the Utsteinen Nunatak in the vicinity of the station's site and the more distant Ketelersbreen Dry Valley. All samples were taken before the station was built and were studied by light microscopy and Denaturing Gradient Gel Electrophoresis. Two strains were also isolated. Two different phenol-based extraction methods, with and without detergent-based steps, were tested to improve the quality of molecular detection from these environmental samples. We observed high cyanobacterial diversity (ten morphotypes and 13 operational taxonomic units) in comparison to other Antarctic terrestrial locations and a widespread distribution pattern within the Sør Rondane Mountains area. This might reflect the habitat similarities and/or the easy local dispersal capabilities of microorganisms within the region. The high diversity and proportion of potential endemic (46%) operational taxonomic units, of which 23% were newly described, suggest that this area could have acted as a biological refuge during past glaciations.

The lichen and moss collections by G.T. Bowra in Heimefrontfjella in 1963–64 are redetermined. These are the only plant collections made in Heimefrontfjella prior to a Swedish expedition in 1991–92. Taxonomical and nomenclatural improvements have resulted in several changes. A total of 16 lichens and two mosses were found.

New apatite fission-track (AFT) ages from Heimefrontfjella and Mannefallknausane indicate that the Mesoproterozoic basement and Permian sedimentary cover rocks were heated to c. 100°C during the Mesozoic. Heating was due to the burial by up to 2000 m of Jurassic lavas at c. 180 Ma, when the area was affected by the Bouvet/Karoo hot spot. Near the developing coastline, the lava pile was quickly eroded and in part deposited on the continental shelf as pebbly and coarse-grained volcaniclastic sandstones. The AFT data indicate that farther inland the lava pile was not eroded until c. 100 Ma, and the Palaeozoic unconformity between the Mesoproterozoic basement and Permo–Carboniferous sedimentary rocks as a reference plane remained at temperatures of c. 80°C. Formation of an up to 800 m b.s.l. deep graben in from Heimefrontfjella as well as flexural uplift and rapid denudational cooling of the not extended crust from Heimefrontfjella southwards occurred at c. 100 Ma. It is speculated that a period of major plate reorganisation and new rifting at c. 100 Ma is responsible for affecting a much wider continental margin as far inland as Heimefrontfjella and producing a total relief in excess of 3500 m.

Large-scale bedrock morphology and relief of two key areas, the Jutulsessen Nunatak and the Jutulstraumen ice stream are used to discuss glascial history and landscape development in western and central Dronning Maud Land, Antarctica. Two main landform components were identified: well-defined summit plateau surfaces and a typical alpine glacial landscape. The flat, high-elevation plateau surfaces previously were part of one or several continuous regional planation surfaces. In western Dronning Maud Land, overlying cover rocks of late Palaeozoic age show that the planation surface(s) existed in the early Permian, prior to the break-up of Gondwana. A well-develoment escarpment, a mega landform typical for passive continental margins, bounds the palaeosurface remnants to the north for a distance of at least 700 km. The Cenozoic glacial landscape, incised in the palaeosurface and escarpment, is exemplified by Jutulsessen Nunatak, where a c. 1.2 km deep glacial valley system is developed. However, the prominent Penck-Jutul Trough represents some of the deepest dissection of the palaeosurface. This originally tectonic feature is today occupied by the Jutulstraumen ice stream. New topographic data show that the bed of the Penck-Jutul Trough is situated 1.9±1.1 km below sea level, and that the total landscape relief is at least 4.2 km. Today's relief is a result of several processes, including tectonic faulting, subaerial weathering, fluvial erosion, and glacial erosion. It is probable that erosion by ice streams has deepened the tectonic troughs of Dronning Maud Land since the onset of ice sheet glaciation in the Oligocene, and continues today. An attempt is made to identify major events in the long-term landscape development of Dronning Maud Land, since the break-up of the Gondwana continent.

Moisture sources for snow falling in Dronning Maud Land (DML), Antarctica, are calculated for 1998 using three dimensional 5-days backward air parcel trajectories. The drilling site of the European Project on Ice Coring in Antarctica (EPICA) in DML is chosen as the main arrival point (75.0°S, 0.01°E). A distinction is made between trajectories with and without snowfall at arrival. Of the snowfall trajectories, 40–80% are located in the Atlantic Ocean within four days before arrival. Evaporation along these trajectories is largest three to four days before arrival. The air parcels are then located between 40° and 60°S in the Atlantic Ocean where surface temperatures range between 0° and 20°C. A case study for May 1998 shows that when snow falls exceptionally high temperatures and wind speeds prevail in the atmospheric boundary layer. The position of the trajectories in the boundary layer suggests a source region for this event between 40° and 50°S and 20° and 60°W in the Atlantic Ocean, where sea surface temperatures vary between 5° and 15°C.