The sedimentological, chemical and isotopic characteristics of sediment cores from three slightly saline to hypersaline lakes (Highway, Ace and Organic Lakes) and two marine inlets (Ellis Fjord and Taynaya Bay) in the Vestfold Hills, Antarctica have been examined. Sections of the cores deposited in marine environments are characterised by uniform, regularly laminated, fine grained, organic-rich sediments, with uniform organic delta 13C values (-18.0 to 19.4 ppt vs. PDB) and sulfur contents. In contrast, sediments deposited in lacustrine environments are extremely heterogeneous, varying from finely laminated mat-like sequences to poorly sorted clastic-rich sediments. Authigenic monohydrocalcite and aragonite occur in some lake sediments. The delta 13C values of organic matter in the lacustrine sediments exhibit an extremely wide range (-10.5 to -25.3 ppt) that can be related to variations in physico-chemical conditions in the lake waters. Strongly negative organic-delta 13C values coupledwith high sulfur contents are indicative of an anoxic zone in the overlying lake waters, whereas less negative organic-delta 13C values coupled with low sulfur contents are indicative of well-mixed oxic conditions. Particularly high organic-delta 13C values result during high levels of microbial activity in the lakes, due to high rates of photosynthetic CO2 fixation. The large shifts in organic-delta 13C are not necessarily accompanied by any change in macroscopic sedimentological characteristics, illustrating the utility if isotopic investigations in these environments. The delta 13C composition of authigenic carbonate in hypersaline Organic Lake sediments provides a record of changes in palaeoproductivity, while the delta 18O of the carbonate provides information on rates of meltwater input and evaporation in the lake. 14C-dating suggests that Highway Lake was isolated from the sea by isostatic uplift at least 4600 years before present (BP) whereas Organic Lake was isolated at approximately 2700 years BP. Apparent emergence rates calculated from the 14C ages range from 1.0 to 2.1 mm per year. The 'reservoir effect' in the lacustrine and marine environments is variable, but probably does not exceed ~ 1000 years in any of the lakes examined.

Metadata record for data from ASAC Project 492 See the link below for public details on this project. From the abstracts of the referenced papers: Diatom assemblages in two Holocene sediment cores (GC1 and GC2) from the Mac. Robertson Shelf, East Antarctica, are compared with modern sedimentary diatom assemblages from the same area. Open marine deposition commenced in Iceberg Alley (GC1), on the outer continental shelf, greater than 10.7 adj. 14C kyr BP. Chaetoceros resting spores, which may indicate water-column stabilsation from melting glacial and/or sea ice or the maximum summer sea-ice retreat, dominate the diatom assemblage. Approximately 7.5 adj. 14C kyr BP, a sea-ice diatom assemblage was deposited. This assemblage is similar to that being deposited in the surface sediments of the Mac. Robertson Shelf today and suggests that perennial sea ice has persisted in the vicinity of Iceberg Alley since that time. Interbedded within the sea-ice assemblage, however, are Corethron-rich sediment layers that suggest mid- to late-Holocene high-productivity events associated with a climatic optimum. The diatom record from Nielsen Basin (GC2), on the inner continental shelf, is relatively uniform compared to that in GC1. Glacial ice was present over the region c. greater than 5.6 adj. 14C kyr BP and a dissolution diatom assemblage was deposited beneath it. following ice retreat, an ice-edge diatom assemblage was deposited briefly before sea-ice conditions similar to that on the continental shelf today developed. There is no evidence in GC2 for the mid- to late-Holocene high-productivity events identified in GC1. Four diatom assemblages are identified from the surface sediments of Prydz Bay and the Mac. Robertson Shelf using multivariate analysis. A coastal assemblage is characterised by the sea-ice diatoms Fragilariopsis curta, F. angulata, F. cylindrus and Pseudonitzschia turgiduloides. A continental shelf assemblage is characterised by the open-water diatoms Fragilariopsis kerguelensis, Thalassiosira lenuginosa, T. gracilis var. expecta and Trichotoxin reinboldii. The Cape Darnley assemblage contains both sea-ice and open-water diatoms, but all are characteristically large and heavily silicified. Multiple regression has been used to identify the relationships between the diatom assemblages and known environmental variables. There are strong correlations between the coastal, shelf and oceanic assemblages and ecological conditions, including latitude, sea-ice distribution and ocean currents. The Cape Darnley assemblage is thought to represent an assemblage from which the smaller and more lightly silicified species have been removed by current winnowing. The palaeo-depositional environment of inner Prydz Bay, East Antarctica, has been reconstructed for the past 21,320 14C yr B.P., using diatom assemblages and sediment facies from a short, 352 cm long gravity core. Between 21,320 and 11,650 14C yr B.P., compact tillite and diamicton are present in the core, and diatom frustules are rare to absent. These data suggest that an ice sheet grounded over the site during the last glacial maximum. Following glacial retreat, siliceous muddy ooze was deposited, from 11,650 to 2600 14C yr B.P., in an open marine setting. During this stage, diatom frustules are abundant and well preserved, and Thalassiosira antarctica resting spores and Fragilariopsis curta dominate the assemblage. This assemblage suggests open marine deposition in an environment where the spatial and temporal distribution of sea ice is less than today. Since 2600 14C yr B.P., sea-ice and ice-edge diatom species have become more abundant, and neoglacial cooling is inferred. The assemblage is similar to that forming currently in Prydz Bay, where sea-ice is absent (less than 10% cover) for 2-3 months of the year and permanent ice edge and/or multiyear sea ice remains in close proximity to the site.

Cores from lakes and the shallow marine were taken for investigation of palaeoclimate through proxies such as grain size, TOC, C:N:S and diatoms. The cores have been 14-C dated with some sheel fragments having been analysed using Amino Acid geochronology. The full postglacial record, plus till and pre-glacial sediments, were recovered from two marine cores at 10.3 and 12 m depth in the sediment respectively. These cores are presently (2000) being analysed. Contact the Chief Investgator for queries about these samples or the project, ASAC1071 - 'Palaeoenvironments of the East Antarctic coast between 50E and 120E'. The fields in this dataset are: core number station-employ lake/marine basin latitude longitude water depth (m) date gear recovery (cm) liner (cm) potsdam storage

This data set describes the toxicity of marine sediment spiked with undispersed diesel and diesel dispersed with Dasic Slickgone to the Antarctic ophiuroid Ophiura crassa. In 4 experiment ophiuroids were exposed for 10 days with daily observations of the movement of the animals as an indication of health. This work falls under the umbrella project ASAC_2201. The fields in this dataset are: Concentration SAB Time Animals Moving

This data set describes the toxicity of marine sediment spiked with undispersed diesel and diesel dispersed with Dasic Slickgone. The temperate heart urchin species Echinocardium cordatum was exposed for 10 days to each contaminant with daily observations of the degree of burial of the animals. The data for this project was collected as part of the umbrella project ASAC_2201. The fields for this dataset are: Date Time Urchin Buried Alive Salinity Dissolved Oxygen pH Temperature

Detailed sedimentary information and palaeontological samples were collected from Battye Glacier Formation, of the Pagodroma Group in the Prince Charles Mountains, an area where little information is presently available. The mid to Upper Cenozoic Pagodroma Group provides direct evidence for past changes in climate and glacial environments from deep within the Antarctic continent. Evidence from several geological formations in the Pagodroma Group, many of them fossil-bearing, will help to determine the history of fluctuations in climate and the size of the East Antarctic Ice Sheet (EAIS). This will provide baseline data to help validate the predictive numerical models of ice sheet dynamics. There is a clear need to study the response of the EAIS to past times of global warming. Periods of significance include times when atmospheric CO2 levels were similar to today (Poore and Sloan 1996). Another key time interval is during the late Neogene, prior to the development of Northern Hemisphere glaciation, which has largely governed Antarctic Ice Sheet volume changes during the Quaternary (Clapperton and Sugden 1990; Mabin 1990; Huybrechts 1990, 1992). An important aspect of the research is to build onto the geological data-set collected by ODP Leg 119, 120 and 188 in Prydz Bay. These operations have concentrated on the periphery of Antarctica and, therefore, record ice sheet retreat and advance at its outer-limits. The Pagodroma Group provides significant information about ice sheet variation at its the inner reaches. Together, these data-sets will shape our understanding of major fluctuations of the ice sheet through the Cenozoic, and will assist and test the models developed to predict ice sheet behavior in the future. Direct geological evidence for climatic conditions and the extent of the ice sheet during times of glacial retreat can be obtained only from onshore geological records, such as the Pagodroma Group. This is important given the current warming trends, expected ice sheet retreat and global sea-level rise, and general lack of geological data from onshore Antarctica for predicting the effects of this on the EAIS. Fieldwork was conducted during November - December (2000). A number of significant findings were made from the Amery Oasis: 1) New outcrops of the glacio-marine Battye Glacier Formation were located and mapped. Up to 800 m of geological section was logged and sampled. Similar Antarctic records have only been made available through expensive international drilling efforts around the Antarctic shelf. This project highlights that there are extensive records exposed on land, that can be studied for a fraction of the cost of off-shore marine geoscience. 2) Unique diatomaceous marine mudstone deposits were discovered (~9 m thick). This is the most diatomaceous (up to 12% biogenic silica), in situ marine deposit that has have been found from inland Antarctica. Diatom biostratigraphy indicates that the formation is middle - late Miocene in age. 3) In situ and articulate marine mollusc fossil horizons were discovered. These occur over a lateral distance of ~ 1km and provide undisputable evidence for a major ice sheet retreat in the past. 4) Three erratics containing marine mollusc fossils were discovered. These erratic are potentially Cretaceous in age (Stilwell, pers. comm.). This is the first marine sediment of this age found in the Lambert Graben catchment. Eleven pdf figures are available for download from the provided URL. Also included is a text file which explains what each of the figures are. Furthermore, two excel spreadsheets of data are also available. The two excel spreadsheets in the download directly relate to the paper Whitehead, et al (2003). Some explanatory notes for the excel files are: Qualitative assessment of fossil preservation vf = very fragmented with a few intact specimens seen per traverse of a microscope slide. mf = moderately fragmented with an intact specimen seen every few fields of view (at 600x magnification). See Whitehead et al (2003) for more information. Qualitative fossil abundance, where X = (present) one valve (Diatom valves)/fossil seen during entire examination. R = (rare) greater than 3 valves/fossils seen during all microscope traverses on slide. F = (few) greater than 1 valve/fossil per 10 microscope fields of view (at 600x magnification). C = (common) valves/fossils in each microscope field of view (at 600x magnification). The fields in this dataset are: Stratigraphic Intervals Samples Opal% McLeod Beds Bed A clasts Fossil Preservation Benthic Diatom Abundance Species Bardin Bluffs Formation Fisher Bench Formation Diatoms

Very little information is available on the geomorphology of areas surrounding Australian Antarctic stations. This type of information is generally collected during geological surveys. This metadata record gathers a range of descriptive geomorphological information of various nature: -Habitat surveys were conducted in the season 2002-2003 in the Windmill Islands in parallel with bird nest mapping (reported in metadata record BIRDSCASEY0203) in order to study selection of nest sites by a range of species. Habitat was described in the survey sites searched for bird nests following various methods (described in BIRDSCASEY0203). Information is stored as GIS files (Arcview 3.2) -polygon shapefile gathering all the geomorphological units. -line shapefile describing habitat along transects used for searching bird nests -polygon shapefile describing habitat in small 25*25m quadrats used for searching bird nests -A collection of 1309 digital photos showing the sites searched for bird nests indexed by grid site number. Plus another set of 194 photos showing region of the Windmill Islands or bird nests more in detail -A set of Digital Elevation Models (DEM) covering the entire Windmill Islands area generated separately for 18 regions. -200m*200m grid created from the coverage of ice-free areas (Aerial photography 93-94) providing site numbers for the photographic database -A series of Black and White aerial Photos (500 m, Zeiss, 1994) scanned at high resolution for the purpose of substrate study. See the word document in the file download for more information. This work has been completed as part of ASAC project 1219 (ASAC_1219). The fields in this dataset are: Date Boulderbig Bouldsmall Baresubst Morsed Scree Snowcover Permice Slope Aspect Photonumber Sitedotid Comments

Antarctic sediments and sea-ice are important regulators in global biogeochemical and atmospheric cycles. These ecosystems contain a diverse range of bacteria whose biogeochemical roles remains largely unknown and which inhabit what are continually low temperature habitats. An integrated molecular and chemical approach will be used to investigate the coupling of microbial biogeochemical processes with community structure and cold adaptation within coastal Antarctic marine sediments and within sea-ice. Overall the project expects to make an important contribution to our understanding of biological processes within low temperature habitats. DATA SET ORGANISATION: The dataset is organised on the basis of publication and is organised on the basis of the following sections: 1. SEDIMENT SAMPLES and ISOLATES Samples collected are described in terms of location, type and where data were obtained chemical features. The designation, source, media used for cultivation and isolation and availability of sediment and other related isolates are provided. Samples included are from the following locations: Clear Lake, Pendant Lake, Scale Lake, Ace Lake, Burton Lake, Ekho Lake, Organic Lake, Deep lake and Taynaya Bay (Burke Basin), Vestfold Hills region; and the Mertz Glacier Polynya region. 2. BIOMASS and ENZYME ACTIVITY DATA Biomass, numbers and extracellular enzyme activity data are provided for Bacteria and Archaea populations from Mertz Glacier Polynya shelf sediments. 3. FATTY ACID and TETRAETHER LIPID DATA Phospholipid and tetraether lipid data are provided for Mertz Glacier Polynya shelf sediments. Whole cell fatty acid data are provided for various bacterial isolates described officially as new genera or species. 4. RNA HYBRIDISATION DATA RNA hybridisation data for Mertz Glacier Polynya sediment samples is provided, including data for oligonucleotide probes specifc for total Bacteria, Archaea, the Desulfosarcina group (class Deltaproteobacteria, sulfate reducing bacterial clade), phylum Planctomycetes, phylum Bacteroidetes (Cytophaga-Flavobacterium-Bacteroides), class Gammaproteobacteria, sulfur-oxidizing and related bacteria (a subset of class Gammaproteobacteria) and Eukaryota. 5. PHYLOGENETIC DATA 16S rRNA gene sequence data are indicated including aligned datasets for three clone libraries derived from the Mertz Glacier Polynya including GenBank accession numbers. Sequence accession numbers are provided for Vestfold Hills lake sediment samples. In addition GenBank numbers are provided for denaturing gradient gel electrophoresis band sequence data from Mertz Glacier Polynya shelf sediment. Other forms of this DGGE data (banding profile analysis) are available in reference Bowman et al. 2003 (AAD ref 10971).