This international workshop has been organized by the Coastal Working Group of the SCAR/IGBP ANTIME program in coordination with ongoing projects which are being supported jointly by the Japan Society for the Promotion of Science (JSPS) and National Science Foundation of the United States (NSF).

 This 4-day Antarctic Ice Margin Evolution (ANTIME) workshop is being hosted by the Japanese National Institute of Polar Research (NIPR) at their Antarctic expedition lodge near Mt. Fuji. Support for this workshop has been provided by the Japan Society for the Promotion of Science (JSPS), Japan Polar Research Association, Fukutake Foundation, National Science Foundation of the United States (NSF), Scientific Committee on Antarctic Research (SCAR) and the International Geosphere-Biosphere Program (IGBP).

 Environmental changes around Antarctica have coincided with global climate variations during the Little Ice Age, mid-Holocene, Last Glacial Maximum, Marine Isotope Stage 3 and Last Interglacial period. However, data from Antarctica - especially coastal areas surrounding the continent -have not been well integrated into climate modelling efforts such as CLIMAP and COHMAP. There also are large uncertainties about the dynamics between sea level and the Antarctic ice sheets during the Late Quaternary.

The purpose of this workshop is to design and implement interdisciplinary research projects that can be conducted in coastal areas around the continent to assess the role of Antarctica in global climate and sea-level changes during the Late Pleistocene and Holocene. This workshop also will include discussions of technological advances (such as portable shallow drilling and innovative geochemical approaches) for generating well-constrained environmental chronologies from emerged marine deposits around the continent. Together, these discussions will contribute to the circumpolar integration of geological, chemical, biological and glaciological perspectives to elucidate climate and sea-level feedbacks with Antarctica.

 **WEDNESDAY, 16 SEPTEMBER 1998**

 Arrival at the National Institute of Polar Research (NIPR)

 **THURSDAY, 17 SEPTEMBER 1998**

 0900 Depart NIPR for Lake Kawaguchi-Ko

1200-1400 Arrival at Lake Kawaguchi-Ko

1400-1530 Registration

1530-1600 "Welcoming Remarks" - (Kazuomi Hirakawa)

1600-1800 "Discussion of Workshop Objectives and Activities" - (Paul Berkman,

Ian Goodwin and Kazuomi Hirakawa)

1800-2130 Dinner and Evening Activity

 **FRIDAY, 18 SEPTEMBER 1998**

 0700-0800 Breakfast

JAPANESE ENVIRONMENTAL RESEARCH IN ANTARCTICA:

 0800-0830 "Research History of Environmental-Related Problems in and around Lützow-Holm Bay, East Antarctica"

- (Yoshio YOSHIDA) 1

ANTARCTIC COASTAL ENVIRONMENTAL VARIABILITY:

 0830-0900 "Circum-Antarctic Coastal Environmental Shifts Reflected by Emerged Marine Deposits During the Late Quaternary"

- ( Paul Arthur BERKMAN) 2

0900-0930 "Stable Isotopes and Quaternary Dating Techniques in the McMurdo Dry Valley Lakes" - (Peter T. DORAN) 4

0930-1000 "Carbon-14 Anomaly of Fresh Water Algae from some Coastal Lakes in Antarctica"

- (Hiroshi AOKI, Hideki WADA, Tsunehiro KAWAI and Toshio NAKAMURA) 6

1000-1030 Break

1030-1100 "Ecology and Paleoecology of Marine-Derived Lakes in the Vestfold Hills, East Antarctica"

- (Zipan WANG, Patrick P. DEPREZ and Paul Arthur BERKMAN) 7

1100-1130 "Forces Driving Historical Changes in High Latitude (77^oS) Marine Glacial Termina"

- (Ross D. POWELL, James N. McINNES and Ian D. GOODWIN) 8

 **FRIDAY, 18 SEPTEMBER 1998**

 1130-1200 Group Discussion

1200-1330 Lunch

 GEOCHEMISTRY AND DATING:

 1330-1400 "Nagoya AMS ¹⁴C Facility and Application to Dating of Molluscs and Lake Sediments in Antarctica"

- (Toshio NAKAMURA, Tomoko OHTA, Hirotaka ODA, Etsuko NIU, Akiko,IKEDA,Hiroshi TAKAHASHI and A.J. Timothy JULL) 10

1400-1430 "How Old are Pre-Holocene Fossil Shells in Antarctic Beaches?" - (Charles P. HART) 12

1430-1500 "Paleoceanographic Contrasts Between Marine Isotope Stage 3 and Holocene Coastal Environments in Lutzow

-Holm Bay, East Antarctica Based on Fossil Foraminifera" - (Atsuo IGARASHI) 13

1500-1530 Break

1530-1600 "Parts of Bunger Hills were Ice Free at Last Glacial Maximum"

-(Damian, B. GORE, Edward RHODES, Dan ZWARTZ, Paul AUGUSTINUS, Michelle LEISHMAN, Eric COLHOUN) 14

1600-1630 "Carbonate Geochemistry in Antarctica Nearshore Marine Environments"

- (Kacey LOHMANN, Paul BERKMAN and Hideki WADA) 15

1630-1700 Group Discussion

1700-1800 Preparations for Break-Out Sessions on Saturday

1800-2130 Dinner and Evening Activity

 **SATURDAY, 19 SEPTEMBER 1998**

 0700-0800 Breakfast

 ICE-SHEET AND SEA-LEVEL HISTORY:

 0800-0830 "Circum-East Antarctic Patterns of Holocene Coastal Emergence, Glacio-Isostasy and Glacial Ice Load"

- (Ian D. GOODWIN) 17

0830-0900 "Some Geomorphological Problems on the Environmental Variability Along the Victoria Land Coast"

- (Kazuomi HIRAKAWA) 18

0930-1000 "Ice-Sheet Reconstruction Using Geomorphic and Geodetic Evidence" - (Dan ZWARTZ) 19

1000-1030 Break

1030-1100 "Age of the Last Glaciation of the Vestfold Hills and Significance for Sea Level Change"

- (Eric A. COLHOUN and Damian B. GORE) 20

1100-1130 "Antarctic Ice-Sheet Contribution to Global Sea-Level Rise in the Holocene"

- (Ólafur INGOLFSSON and Christian HJORT) 22

1130-1200 Group Discussion

 **SATURDAY, 19 SEPTEMBER 1998**

 1200-1330 Lunch

 BREAK-OUT GROUPS:

 1330-1730 Prepare Strategies Regarding Field Work and Data Syntheses for the Science and Implementation Plan

(GROUP 1: Holocene Coastal Environmental Variability / GROUP 2: Paleogeography During the Last

Glacial Cycle)

1730-1800 Discussion of Break-Out Group Progress

1800-2130 Dinner and Evening Activity

 **SUNDAY, 20 SEPTEMBER 1998**

 0700-0800 Breakfast

0800-0930 Complete Break-Out Group Writing Tasks

0930-1030 Final Discussion

1030-2130 Field Trip

 **MONDAY, 21 SEPTEMBER 1998**

 Morning Depart for NIPR from Mt. Fuji / Lake Kawaguchi-ko

Afternoon Arrival at NIPR

Evening Dinner in Itabashi

 **TUESDAY, 22 SEPTEMBER 1998**

 Depart for Home

The Lützow-Holm Bay region was an impacted area before the International Geophysical Year in 1957-58. Therefore, earlier surveys in various scientific fields provided basic information on the environments and their changes. Geomorphology of coastal ice-free areas revealed the history of deglaciation of the ice sheet and relative sea level changes. Timing and patterns of these events are now research subjects of widespread and keen interest. Studies of submarine geology and geomorphology also have been conducted to evaluate ice-sheet fluctuations, but further investigation of submarine topography stratigraphies are necessary for the study of environmental changes. Remnants of raised delta fans, fluvioglacial deposits, periglacial phenomena (such as patterned ground) and marine boulder pavements in coastal ice-free areas all suggest the presence of more abundant meltwater in the Holocene and/or Pleistocene than the present. Changes of the ice-sheet margins also have attracted attention in terms of recent environmental changes. Disappearance of a floating glacier tongue was pointed out using an areal photo from 60 years ago. Changes of the floating tongue of the Shirase Glacier, one of the most rapidly flowing glacial tongues in Antarctica, also has been noted. Monitoring ice-sheet margin fluctuations by satellite imagery and aerial photography is now one of the long-term programs in this region. Other scientific programs in relation to environmental changes also will be discussed briefly.

The circumpolar occurrence of emerged marine macrofossil and sediment deposits from Antarctic coastal will be assessed in relation to Late-Quaternary climate changes. Additional information on the geochemistry of these macrofossils and their surrounding geomorphological settings will be used in these interpretations.

Radiocarbon ages of the macrofossils, which are interpreted in view of the complexities of the Antarctic marine radiocarbon reservoir and resolution of this dating technique, show a bimodal distribution. These data indicate that marine species were inhabiting coastal environments from at least 35,000 to 20,000 yr BP, during Marine Isotope Stage 3 when extensive iceberg calving created a 'meltwater lid' over the Southern Ocean. The uniform absence of emerged calcareous marine fossils from 20,000 to approximately 8500 yr BP coincides with the subsequent advance of the Antarctic ice sheets during the Last Glacial Maximum. Synchronous re-appearance of marine fossils in Antarctic emerged beaches, all of which have Holocene marine-limit elevations an order of magnitude lower than in the Arctic, reflect minimal isostatic uplift around the continent as the rates of relative sea-level rise decelerated. Antarctic coastal marine habitats around the continent also changed along with increasing sea-ice extent and outlet glacier advances during the mid-Holocene. In view of the diverse environmental changes that occurred around the Earth during this period, it is suggested that Antarctic coastal areas were responding to a mid-Holocene climatic shift associated with the hydrological cycle.

Emerged marine deposits also suggest that the ice-sheet retreat history along the north-south trending Victoria Land Coast involved several distinct glacial systems after the Last Glacial Maximum. Based on the marine-limit elevations from Terra Nova Bay southward to McMurdo Sound, two distinct isostatic uplift regions can be identified: (1) Evans Cove in Terra Nova Bay to Cape Ross on the northern boundary of Granite Harbor has marine limits which are higher than 30 m; and (2) Cape Roberts on the southern boundary of Granite Harbor to Explorers Cove has marine limits which are 20 m and lower. In addition, the highest macrofossil deposits in Terra Nova Bay occur more than 15 m below the marine limits whereas those in McMurdo Sound are within

 * NOTE: This presentation reflects the multi-faceted efforts of many individuals in the ANTIME Coastal Working Group who have contributed to the effective development of this international program.a few meters of the marine limits. Along with their radiocarbon ages, these macrofossil data suggest that isostatic uplift along the Victoria Land Coast began earlier and was faster north of Granite Harbor. Alternatively, these macrofossils (which thrive in low-energy systems) may have begun colonizing the coastal habitats in Terra Nova Bay relatively late compared to those in McMurdo Sound. Based on these data, it is proposed that the Macay Glacier (which emanates from the East Antarctic Ice Sheet) extended into McMurdo Sound and separated ice masses north and south of Granite Harbor, influencing their relative retreat history after the Last Glacial Maximum. This explanation is consistent with earlier interpretations about westward moving ice masses in McMurdo Sound that transported kenyte deposits from Ross Island into the Dry Valleys south of Granite Harbor.

Environmental changes in the McMurdo Sound region can be further interpreted from sediment cores that were collected during the Dry Valley Drilling Project (DVDP).

Analyses of DVDP cores 8-10, from a prograding delta in Explorers Cove at the base on Taylor Valley in West McMurdo Sound, indicate that sediment accumulation accelerated from approximately 4000 yr BP (corrected for the 1300-year marine radiocarbon reservoir) to the present. Stable isotope data from calcareous macrofossils in these cores, however, indicate that coastal environmental conditions became colder during this period as has been found from Antarctic ice cores. Resolution of these apparently divergent data may be associated with the relative extent of sea ice, which would enhance delta development in contrast to open water conditions which facilitate delta erosion. The relative impact of sea ice also is reflected by the presence of relatively large conglomerates in these stratigraphic sections around 3000 years ago when there was presumed to be open-water conditions associated with the 'penguin optimum' along the Victoria Land Coast.

 This synthesis of emerged marine deposits demonstrates the application of evaluating circum-Antarctic phenomena from the glacial-terrestrial-marine transition zone. This study also emphasizes the utility of conducting Antarctic coastal zone research in an interdisciplinary context which involves modern processes and analogs for interpreting paleoenvironmental changes around the continent during the Late Quaternary.

 Determining the paleoenvironment of the McMurdo Dry Valleys is problematic because so little is known about the nature of the modern environment. This paper reports on process-oriented studies in the dry valley lake systems aimed at Acalibrating@ the modern environment to the sediments being deposited. The research reported here focuses mainly on the behavior of stable and radioactive isotopes of carbon (e.g. d ¹³C and ¹⁴C) in the dry valley lakes.

 My work in Lake Hoare, Taylor Valley, has shown a very clear depth signal with regards to d ¹³C of modern microbial mat on the lake bottom. Mat signals become progressively heavier with depth in the lake, reflecting an increased fractionation. I have proposed three Aproductivity zones@ to account for this depth trend. The moat (seasonally open lake edge) region of the lake has very high photosynthetic rates during the 24 hours of summer sun, and therefore a diffusion-limitation is setup where carbon is utilized faster than it can be supplied to (diffused into) the mat. In the shallow under-ice regions, a similar diffusion-limitation is set up and is accentuated by an under-saturation of CO₂ in this region of the water column. Below about 11 m depth heavy mat d ¹³C signatures are encountered as the diffusion-limitation is eliminated in the light-limited, CO₂-rich water column. Hence d ¹³C of ancient mat can be use to map paleohydrology and paleoproductivity of these lakes. I am currently expanding this investigation to cover other dry valley lakes.

A strong carbon reservoir effect in the terrestrial antarctic carbon pathway has long been cited as making carbon dating problematic, yet very little research has been carried out on the nature and extent of the effect. My research has shown that stream microbial mat and some surface lake water dissolved inorganic carbon (DIC) date modern, while other surface lake waters carry a relict signal. The controlling factor seems to be the mode of stream input. Direct input from glaciers introduces old carbon, but if water travels through streams, it is allowed to equilibrate with modern carbon dioxide before entering the lake.

Once the radiocarbon is in the lake, strong stratification can create DIC bottom water ages in excess of 10,000 yr B.P. Due to these phenomena, radiocarbon dating is a viable technique for lake edge deposits, and lake bottom deposits where a correction to the sediment surface age is possible. Paleolake deposits can not be reliably dated using radiocarbon dating alone because the age of the reservoir correction (i.e. accounting for the initial carbon reservoir, plus the age of the bottom water) can not be determined.

 A suite of alternative and complimentary dating techniques have been tested on modern and ancient lacustrine deposits. These include paleomagnetism, lead-210, cesium-137, and thermoluminescence (TL). Of these techniques, TL holds the most promise for correcting lake sediment radiocarbon ages.

 In order to clarify the possibility of carbon-14 dating, carbon-14 activities of fresh water algae collected from some coastal lakes Antarctica are analyzed. Samples used were collected from Lake Richardson, Riiser-Larsen, near the Napir Peninsula, Enderby Land, the First Crater, McMurdo Station, Ross Island, and Lake Canopus, Bull Lake at Wright Valley, Victoria Land, Antarctica.

 The modern algae of the Dry Valley area and McMurdo station represent similar carbon-14 activities to the modern carbon-14 level. On the other hand the result of modern algae from the Lake Richardson which is inflowed by the terminal Glacier, shows less activity rather than the modern one. The carbon in algae from the Lake Richardson was used old carbon derived from the melt water of the Glacier.

Ecological and palaeoecological studies were carried out in marine-derived saline lakes and adjacent fresh water systems in the Vestfold Hills (60^o38'S, 78^o06'E), East Antarctica. Based on geomorphological and chemical factors (salinity, temperature and dissolved oxygen) of these lakes and catchments, three types of hydrological habitats were identified: stable, unstable and extremely variable. These habitat types also had distinct biological assemblages. In the stable lakes, biological communities were simple and faunal species were generally absent. In the unstable lakes, however, marine faunal species have been recorded with biological succession occurring in recent years due to stronger tidal flow and water exchange with the sea. Marine macrofossils collected from terraces surrounding these lakes have radiocarbon ages from the Late Pleistocene 32,000-24,000 ¹⁴C-yr BP and Holocene 8,000-2,500 ¹⁴C-yr BP. These data suggest that chemical and biological characteristics of the marine derived lakes in the Vestfold Hills reflect localized glacial impacts as well as global sea-level and climate impacts.

 Three glaciers entering McMurdo Sound, Antarctica have different glacial regimes and behaved differently during the Holocene. Mackay and Ferrar Glaciers, outlet glaciers of the East Antarctic Ice Sheet flow fast and end as floating glacier tongues at 77^oS. Blue Glacier is a thin valley glacier ending as a grounded tidewater terminus at about 78^oS; fed from local mountains, it flows slowly, and is probably frozen to its bed.

Mackay Glacier Tongue (MGT) was advanced beyond its present terminus by 7 km, about 100 years ago. By 1965 MGT had lost about 2 km and by 1975 it had lost another 4 km. Through the 1980s and 1990s the terminus oscillated but had experienced a further net loss of 1 km through to the 1990s.

 Within 300 m of the present grounding line, ROV data show recently exposed subglacial till draped by soft glacimarine sediment. Grounding line retreat was also within the last 100 years based on: (a) thickness of glacimarine sediment and its known sedimentation rate, and (b) epibenthic community structure. Mass balance calculations derived from net accumulation, sublimation, subglacial melting, submarine melting and iceberg calving flux is nearly in steady state depending on the main variable, iceberg calving flux. Increased creep thinning of the floating terminus associated with increased iceberg calving may have forced associated grounding line retreat, but the control on iceberg calving speed is unknown. Increased surface melting may have induced increased calving but that should not produce oscillations in terminus position. Glacier tongue flexure may force calving too but if the glacier is near steady state the terminus must remain in about the same position given time to recover after calving, but MGT terminus has retreated. Global sea level rise may have affected retreat, but measurements of sediment accumulation rates near the Mackay grounding line indicate that those are faster than sea level rise and could counteract the destabilizing sea level effect.

The floating tongue of Ferrar Glacier also was farther advanced by 0.9 to 2.8 km in 1911-12 than it is today and is likely to have been influenced by the same forcing as the MGT. Blue Glacier terminus was slightly retreated in 1901-04 and 1907 compared with its current position and it may have advanced slightly by 1910-13. Comparatively, today the northern section of the terminus has retreated relative to that 1911-12 position and the southern section has advanced. The glacier has very little debris within it but a morainal bank is at the grounding line. The bank is several meters high and is composed of pushed glacimarine sediment originally deposited on the flat sea floor. The pushed sediment appears to substantiate that the terminus has advanced recently.

The recent retreat from earlier advanced positions of Mackay and Ferrar Glaciers may be from global warming at these high latitudes. But the critical factor appears to be determining what forces iceberg calving and may not be directly related to sea level rise. The response time of the less dynamic Blue Glacier may be a factor in the offset timing of it from the other two or it may be a factor of the different ice sources of local nèvè versus the ice sheet. Very low calving speed at the tidewater cliff of Blue Glacier probably means that calving is not a major factor in forcing its terminus position.

 Techniques of accelerator mass spectrometry (AMS), developed since 1977, based mainly on a tandem accelerator and associated apparatus used to analyze charge state, energy, mass number, and atomic number of accelerated ions, enabled us to measure extremely-low-abundance radioisotopes such as ¹⁰Be, ¹⁴C, ²⁶Al, ³⁶Cl, ⁴¹Ca, ⁵³Mn, ¹²⁹I, etc., in natural samples. One of the main AMS application is ¹⁴C measurement, and in particular, ¹⁴C dating.

 A Tandetron AMS system, an apparatus dedicated to ¹⁴C measurements with high sensitivity, manufactured by General Ionex Corporation, USA, has been used since 1983, to measure ¹⁴C concentrations of environmental samples as well as ¹⁴C dates of geological and archeological materials, at the Dating and Materials Research Center, Nagoya University. Routinely, about 700-800 samples have been measured a year, and totally 7,300 samples in various research fields have been measured since the installation of the machine.

 Recently, we have introduced a second Tandetron AMS system which was manufactured by High Voltage Engineering Europe (HVEE), BV, the Netherlands. Two sets of the similar HVEE AMS system have previously been installed successfully at University of Groningen, the Netherlands, and at University of Christian-Albrechts, Kiel, Germany. They have already proved excellent performances in carbon-isotope-ratio measurements for graphite targets prepared by themselves from natural samples. The highest performances in the ¹⁴C measurements with the new Tandetron AMS system are of highly potential use to the Antarctic samples, in particular, to older samples of more than 20,000 yr BP.

Mollusc samples with ages older than 20,000 yr BP may have suffered from contamination from modern carbon, by exchange of carbon dissolved in the sea water during CaCO₃ re-crystallization on the surface of the molluscs. A evidence of modern carbon contamination on the surface of coral fossil has been reported by Burr et al. (1995). To investigate such modern carbon contamination to Antarctic molluscs, we started a joint experimental program with the AMS facility of the University of Arizona. At the first step of the experiment, we try to date several CO₂ samples produced from the outer part to the inner part of a mollusc fragment, by H₃PO₄ treatment. We could find possibly different apparent ¹⁴C ages of them, if the contamination is really existing. We also planning to conduct a research on the carbon reservoir effect of several Antarctic materials, which tend to show a low ¹⁴C-concentration effect (Berkman & Forman, 1996; Stuiver & Braziunas, 1993).

 References:

 Burr, G.S., et al.(1992). Radiocarbon, 34(3) 611-618.

Berkman, P.A. and Forman, S.L. (1996) G.R.L., 23(4)363-366.

Stuiver, M. and Braziunas, T.F. (1993) Radiocarbon, 35(1) 137-189.

 Mollusc shell fossils are a common constituent of Antarctic beach sediments. These fossils have been a significant source of dating material over nearly 4 decades of study of Antarctic beaches. A substantial number of these fossils have yielded ages greater than 33 ka BP from carbon-14 analysis, results that suggest this is a minimum age for these shells. Amino acid analysis of mollusc fossils offers a dating method which spans a greater depth of time than radiocarbon dating. Amino acid analysis of fossil shells from several Antarctic "raised" beach deposits indicate that shells ranging between 4000 and 3,300,000 years in age are present in beach sediments. Fossil shells from beach locations on James Ross Island, Lutzow-Holm Bay region, the Vestfold Hills and the McMurdo Sound region have been analyzed with this method. The spread of amino acid ratios from these diverse localities suggest that coastal regions of Antarctica may have experienced multiple episodes of marine transgressions/ice margin retreat since the middle Pliocene.

 Analyses of both faunal and oxygen isotopic compositions of fossil foraminifera recovered from raised beach deposits of bimodal AMS radiocarbon age groups (33-43 ka, 2-8 ka) was carried out for the purpose of estimating paleoceanographic changes and their contribution to peripheral retreat of ice sheet around the eastern coast of Lutzow-Holm Bay. The results suggest contribution of inflow of the Circumpolar Deep Water toward the coast to the deglaciation and more severe deglaciation during 33-43 ka than that during 2-8 ka. As a future strategy, further detailed analyses of microfauna and their stable isotopes would be necessary. These methods should be conducted by collecting marine deposits on nearshore sea floor whose age spans at least up to beyond 43 ka.

 The deglaciation history of Bunger Hills is being reassessed by a detailed study using Optically Stimulated Luminescence (OSL), cosmogenic isotope and radiocarbon dating. Results from an initial suite of samples demonstrate consistency between the techniques, leading to a high degree of confidence that the data are accurate. The dates are interpreted to show that parts of western Bunger Hills were ice free by 30 ka BP, and that much of the oasis was free of the ice sheet at the Last Glacial Maximum. The types of sediments suitable for OSL dating, and the reasons for the strong disparity between our data and the radiocarbon ages obtained from lake and fjord cores nearby, will be discussed.

 Circumpolar coastal sites of Antarctic preserve an abundant population of skeletal carbonates in raised beach sequences and shallow coastal cores that provide the temporal framework for examining variation in surface water temperature, salinity and productively at both the seasonal to millennium time scales. Our studies have concentrated on the marine scallop, Adamussium colbecki for which an abundant and well dated record is available. Carbon-14 dated specimens encompassing the mid- to late Holocene are available from raised beach sequences around the circumference of Antarctica. Given the well-developed accretionary growth structure of this bivalve, its calcite mineralogy, and its shallow marine habitat, Adamussium offers the potential of providing geochemical proxies of climatic throughout the Holocene.

 The geochemical approach for resolving temperature and salinity variations is focussed on a combined isotopic, elemental, and crystal chemistry analysis of the shell carbonate. Preliminary studies of the elemental contents, d ¹⁸O and unit cell volume of calcite in living specimens suggests a relation to both temperature and meltwater inputs. In addition, new microanalytical techniques examining variations in minor element contents (notably Sr/Ca and Mg/Ca) may offer the potential of providing independent measures of surface water temperature and salinities (d ¹⁸O seawater). While still in the preliminary stages of development, if such proxies can be validated for living specimens, application of this approach to fossil populations may provide seasonal scale records of variation of the meltwater input and surface water temperature during the Holocene.

 Changes in surface water productivity can also be extracted from these carbonate shell materials. For example, high resolution sampling of growth banding in living specimens of Adamussium, shows a cyclic variation in d ¹³C which likely records changes in surface water productivity. Although the degree of metabolic or vital influence on this record is not yet well understood, examination of specimens spanning the mid to late Holocene should allow evaluation of long term changes in surface water productivity of the circumpolar coastal waters of Antarctica.

 Future studies must concentrate on integrating multiple measures of the shell carbonate chemistry. Primary changes in elemental and isotopic composition, in combination with systematic changes in calcite crystal chemistry have the potential of providing a multi-proxy approach for reconstructing intra- to inter-annual changes in surface water conditions throughout the Holocene.

 Relative emergence or depression of Antarctic coastal regions with respect to sea-level is controlled by the interplay between the isostatic response of the earth's crust to changing ice loads, and to the fluctuations in eustatic and steric sea-levels, principally controlled by climate. During the last glacial cycle, the coastal regions of the Antarctic ice sheet were thicker and geographically more extensive in many localities than the present ice margin. There remains great debate on the specific details of such an expansion, although it is known that sea-level is the principal control on ice sheet extent. Conversely, analysis of gas bubbles in deep ice cores at Vostok on the central east Antarctic plateau, indicates that ice sheet elevations over this vast region were lower than present by 100-150 m as a result of significantly lower precipitation rates over the ice sheet, during the last glacial cycle. These changes to the distribution of ice over the Antarctic continent have a profound effect on the amount and geographic distribution of isostatic depression, particularly in the coastal regions and on the continental shelf, near the ice sheet margins. Fluctuations in sea-level of 100-130 m over the last glacial cycle have also influenced the hydro-isostasy of the Antarctic continental shelf. In general, these changes are small in areas where the continental shelf is deep (>500 m), and of more significance, in areas dominated by shallow banks <200 m deep.

 There is widespread evidence of emergence of coastal regions during the mid to late Holocene. The general cause of this emergence is understood to be due to isostatic uplift of the crust, accompanying the thinning and melting of the greater than present glacial ice volume over the coastal and shelf regions. This isostatic uplift or recovery of the crust to the reduction in ice load was synchronous in part, to the increase in ocean mass and rise in eustatic sea-level during the post-glacial Stage 2 and the early to mid Holocene. The isostatic uplift continued throughout the Holocene, culminating in the occurrence of raised marine shorelines and now isolated former marine embayments in the circum-Antarctic. However, there is great variation in the amount and rate of coastal emergence along the regional coasts. The paper describes the regional variation in coastal emergence, and discusses the implications for the interpretation of former ice loads, and Holocene sea-level fluctuations.

Three issues on the Quaternary environmental variability will be discussed; They are the so called Terra Nova Drift, Holocene raised beaches and Holocene local glacier fluctuation. It is undoubtedly said that the last or penultimate interglacial raised beach had occurred on the Terra Nova Drift in the Northern Foothills. On the basis of this geomorphological fact and the severe weathering degree of tills imply that the Terra Nova Drift was not originated during the Last Glacial Maximum. A set of upper and lower delta landforms and their deposits are well developed along the coastal area where the relatively large stream pours into the sea. They provide the most reliable evidence that two relatively stable sea levels during the Holocene had occurred. Concerning the Holocene local glacier fluctuation, Hells Gate glacier in Terra Nova Bay region had once advanced and interrupted the successive development of raised beaches.

 Geomorphological evidence of sea-level change combined with numerical modelling of isostatic rebound provides useful constraints on eustatic sea-level change and regional histories of deglaciation. In Antarctica, sea-level records are sparse, making the task of ice sheet reconstruction difficult, and generally restricted to the last 6000 years, the time during which global sea-level have been relatively stable. This means that ice reconstructions using these data are sensitive to the small eustatic changes which have occurred during this time. Including constraints from satellite geodesy and tide-gauge records will allow more accurate reconstructions with better spatial coverage of the continent.

 The Vestfold Hills form the second largest deglaciated oasis area in East Antarctica. The last time that the oasis was submerged by the East Antarctic ice sheet as it extended onto the continental shelf has been termed the "Vestfold Glaciation" (Adamson &Pickard 1986). To date the Vestfold Glaciation has been assumed to correlate with the late Wisconsin Glaciation on the basis of Holocene radiocarbon dates obtained from marine deposits in the inlets and from derived sediments ice-proximal to the margin of the Sorsdal Glacier (Adamson & Pickard 1986; Fitzsimons & Domack 1993). Since radiocarbon dates on Holocene marine shells can only be minimum ages for the Vestfold Glaciation other approaches to dating are required. Fabel et al. (1997) have obtained exposure age dates on erratics within 5km of the present ice edge and conclude that the ice margin retreated around 9-12k yr BP. Gore and Colhoun (1997) suggested from observations on weathering features that it could be possible the oasis was not ice covered during the late Wisconsin. Gore et al (1994) also show from the widespread presence of derived shell fragments and iron-rich granules of a former weathering surface in the regionally distributed Vestfold till that the ice of the Vestfold Glaciation was not highly erosive and may have been of limited thickness.

 Radiocarbon dating of shell fragments from Vestfold till deposits distributed throughout the southern and seaward parts of the oasis have given ages of from 31.1 to 43.7 kyr BP. The dates indicate unequivocally that the Vestfold Glaciation post-dates 31 kyr BP and shows that the East Antarctic ice sheet margin advanced onto the continental shelf during the equivalent of late Wisconsin time. The range of dates of the shell fragments derived into the till also shows that the fjord inlets of Vestfold Hills were occupied by the sea during at least the late part of middle Wisconsin time, presumably when the continental margin was already isostatically depressed by an ice load.

References:

Adamson D.A. & Pickard. 1986. Cainozoic History of the Vestfold Hills. Pp. 63-98 in Pickard, J. (ed). Antarctic Oasis. Academic Press.

Fabel, D., Stone. J., Fifield. L.K. & Cresswell. R.G. 1997. Deglaciation of the Vestfold Hills: Preliminary Evidence from Exposure Dating of Three Subglacial Erratics. Pp. 829-834 in Ricci, C.A. (ed) The Antarctic Region: Geological Evolution and Processes.

Fitzsimons, S.J. & Domack, E. W. 1993. Evidence for Early Holocene deglaciation of the Vestfold Hills, Antarctica. Polar Record 29:237-240.

Gore, D.B. & Colhoun, E.A. 1997 Regional Contrasts in Weathering and Glacial Sediments Suggests Long Term Subaerial Exposure of Vestfold Hills, East Antarctica. Pp. 835-840 in Ricci, C.A. (ed). The Antarctic Region: Geological Evolution and Processes.

Gore, D.B., Colhoun, E.A. & Bell, K. 1994. Derived constituents in the glacial sediments of the Vestfold Hills, East Antarctica. Quaternary Science Reviews 13: 301-307.

The role of Antarctic glacial ice as a meltwater source for global sea-level rise since the Last Glacial Maximum (LGM) is controversial. Estimates range from as little as 0.5-2.5 m to #37 m of the total estimated global sea level rise of 120-130 m since LGM. Our reconstruction indicates that the Antarctic contribution to global sea level lagged behind the northern hemisphere contribution, and that deglaciation in Antarctica contributed a significant portion of the c. 17 m global sea level rise between 8000-5000 BP.

 Salinity has a clear relationship with changing precipitation and evaporation in polar lake environments. Therefore, changes in lakewater salinity allow inferences to be made about the changes in a lake basins local climate. By determining the relationship between diatom assemblages and salinity in Antarctic lakes, fossil diatom assemblages enable palaeo-lake salinities in these lake ecosystems to be quantified. Diatom stratigraphies from both saline and freshwater lakes in the Vestfold Hills reveal detailed salinity histories for these coastal Antarctic lakes. Such histories offer a means of determining past climatic influences on these sensitive ecosystems.

The recent climatic history of closed-basin lakes in Taylor Valley, Southern Victoria Land is complex in that the waxing and waning of the West Antarctic Ice Sheet (WAIS) have greatly influenced lake level variations as well as the geochemistries of these lakes. Recent cosmogenic isotopic measurements from Lakes Bonney, Fryxell and Hoare in Taylor Valley indicate that the hypolimnia of these lakes are not the same age. Chloride isotope data (both stable isotopes and ³⁶Cl) demonstrate that salt in the bottom waters of Lake Bonney may represent that left from a previous marine transgression. Recent ¹⁴C dates yield dates of between ~7 Kyr and 10.2 Kyr for the deep waters of Lake Bonney (Doran et al. in press). When combined, these new data suggest that the possibility exists that during the LGM the WAIS "pushed" seawater into Taylor Valley. This idea does not, however, fit with all the previous geochemical information collected from the lakes. In this paper, all available information will be synthesized and a conceptual model presented in order to reconcile all the data collected over the past 35 years.

The use of raised beach uplift rates to model ice thickness is dependent on the accurate assessment of the timing of raised beach development. In the Bunger Hills, ¹⁴C has been the sole arbiter of the timing of raised beach formation although it suffers from a range of problems. In an attempt to assess the veracity of the ¹⁴C ages already obtained from Bunger Hills beaches, luminescence dating was undertaken on raised marine sediments from a number of sites where independent ¹⁴C ages were available. Aspects of raised beach development, and some implications of the new ages for Holocene coastal uplift in the Bunger Hills region will be discussed.