DOCSLIB.ORG

Glacio-Lacustrine Aragonite Deposition, Meltwater Evolution And

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Glacio-Lacustrine Aragonite Deposition, Meltwater Evolution And Antarctic Science 19 (3), 365–372 (2007) & Antarctic Science Ltd 2007 Printed in the UK DOI: 10.1017/S0954102007000466 Glacio-lacustrine aragonite deposition, meltwater evolution and glacial history during isotope stage 3 at Radok Lake, Amery Oasis, northern Prince Charles Mountains, East Antarctica IAN D. GOODWIN1 and JOHN HELLSTROM2 1Environmental and Climate Change Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia 2School of Earth Sciences, University of Melbourne, Parkville, VIC 3010, Australia [email protected] Abstract: The late Quaternary glacial history of the Amery Oasis, and Prince Charles Mountains is of significant interest because about 10% of the total modern Antarctic ice outflow is discharged via the adjacent Lambert Glacier system. A glacial thrust moraine sequence deposited along the northern shoreline of Radok Lake between 20–10 ka BP, overlies a layer of thin, aragonite crusts which provide important constraints on the glacial history of the Amery Oasis. The modern Radok Lake is fed by the terminal meltwaters of the alpine Battye Glacier. The aragonite crusts were deposited in shallow water of ancestral Radok Lake 53 ka BP,during the A3 warm event in Isotope Stage 3. Oxygen isotope (d18O) analysis of the last glacial-age aragonite crusts 18 indicates that they precipitated from freshwater with a d OSMOW composition of -36%, which is 8% more depleted than the present water (-28%) in Radok Lake. A regional oxygen isotope (d18O) and elevation relationship for snow is used to determine the source of meltwater and glacial ice in Radok Lake during the A3 warm event. This relationship indicates that Radok Lake received meltwater from the confluence of both Battye Glacier ice and an expansion of grounded western Lambert Glacier ice in the Amery embayment. Received 31 July 2006, accepted 8 November 2006, first published online 29 June 2007 Key words: carbonate, glacial meltwater, lacustrine, Lambert Glacier grounding, oxygen isotope Introduction has established the pattern of glacial retreat from the Radok Lake is a large, glacial lake (20 km2 in area) in the northern shore of Radok Lake basin. Grounded ice Amery Oasis of the Northern Prince Charles Mountains retreated from a position at 125 m elevation on the slope (Bardin et al. 1990) (Figs 1 & 2). The water level in the above the northern Radok Lake shoreline at 20.0 ka Æ modern lake lies 7 m above sea level and the nearby, tidal 2.2 ka, to a position at 70 m elevation, close to the thrust Beaver Lake which is an epishelf lake formed in an moraine sequence by 10.5 Æ 1 ka. On the basis of these embayment adjacent to the Amery Ice Shelf (Adamson paired cosmogenic surface exposure ages, Fink et al. et al. 1997). The modern Radok Lake lies in an over- (2006) confirmed that the thrust moraine sequence was deepened basin that is up to 346 m deep (339 m below deposited during the Late Glacial–Holocene transition, as a modern sea level), and is surrounded by rock cliffs up to result of the shrinking of the glacial-age Battye Glacier. 400 m above the lake surface (Fig. 3). The lake is presently The fabric of the sediments in the moraine (M. Hambrey, fed by glacial meltwater from the small Battye Glacier personal communication 1999) and the pattern of surface (13 km long) which drains the local ice plateau of the exposure indicate that the moraine was deposited by ice McLeod Massif (Fig. 4). Radok Lake overflows at times of flowing from Radok Lake onto the northern slope. However, peak meltwater inflow, and drains to Pagodroma Gorge and it is unknown whether the ice in Radok Lake during the last Beaver Lake, via a shallow sill, at the eastern edge of the lake. glacial cycle originated from an alpine catchment in the Adamson et al. (1997) mapped the present and former northern Prince Charles Mountains or whether it originated shoreline geomorphology of Radok Lake and reported a from a Lambert Glacier ice stream overriding the Amery glacial thrust moraine sequence at an elevation of Oasis. The latter would require a substantial thickening and 50–80 m (after McKelvey et al. 1995, 2001) and grounding zone advance of the Amery Ice Shelf–Lambert mapped a raised shoreline at 70–80 m above the present Glacier system to at least the locality of the Amery Oasis, northern shoreline of Radok Lake. They suggested a which is 200–300 km inland from the ice shelf front in Holocene age for the thrust moraines based on their Prydz Bay. The modern Lambert Glacier Amery Ice Shelf relatively recent weathering, when compared to the grounding zone is located approximately 200 km further surrounding sediments. Subsequently, cosmogenic surface inland (Fricker et al. 2002). Adamson et al. (1997) reported dating using 10Be and 26Al isotopes by Fink et al. (2006) that glacial and fluvial landforms, degree of surface and 365 Downloaded from https://www.cambridge.org/core. Open University Library, on 08 May 2019 at 12:29:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0954102007000466 366 IAN D. GOODWIN & JOHN HELLSTROM Fig. 3. Topographic cross section through the Radok Lake basin from the Jetty Peninsula ice ridge in the south to the northern basin slopes. sediment weathering and the presence of surface sediments rich in Pliocene fauna indicated that the Radok Lake basin and Amery Oasis had not been overridden by Lambert Glacier ice streams since the Pliocene. On the north-eastern corner of Radok Lake, a modern melt-stream has incised into the surface sediments and has cut a number of braided channels down to the modern Radok Lake shoreline. A conspicuous feature in the main channel (Fig. 5) is an outcrop of carbonate crusts. This outcrop is located 10–20 m elevation above most of the thrust moraine sediments. These carbonate crusts were sampled in the 1988/89 summer field season for isotope geochemistry analysis, to provide an insight into their Fig. 1. Location map showing the Amery Oasis, northern Prince origin and possible evolution of meltwater in the Radok Charles Mountains, Amery Ice Shelf and Lambert Glacier Lake basin, and the associated glacial history of the Amery system. Oasis. The characteristics of the carbonates and their isotope geochemistry are discussed below, together with the glacial history of the Radok Lake catchment. Fig. 2. Topographic map showing the Radok Lake basin and the modern boundary of the Battye Glacier catchment. Downloaded from https://www.cambridge.org/core. Open University Library, on 08 May 2019 at 12:29:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0954102007000466 GLACIAL HISTORY DURING ISOTOPE STAGE 3 AT RADOK LAKE 367 Fig. 4. Aerial photograph showing the Battye Glacier trough Fig. 6. Photomicograph of an aragonite crust section. and Radok Lake basin. Carbonate sedimentology, isotopic composition, slight (28) dip towards the modern lake shoreline (Fig. 5a). depositional age and environment The discontinuous and discoid-shaped carbonate crusts, are typically 5–10 cm long, and occur as single layers or as The 5 to 10 mm thick, carbonate crusts were collected from clusters. (Figs 5b & 6). This layer forms a discontinuity the dissected channel section through the surface and is overlain by 2–3 m of sediments comprising semi- sediments. They outcrop along a defined stratum, with a stratified and massive basal diamicton, alternating with laminated silty sand. Downslope and to the west of the outcrop, Hambrey & McKelvey (2000) reported the thrust moraine sequence, comprising discontinuous slabs of stratified glacio-lacustrine or fjordal sediments, with massive silty sand and laminated clayey silts, and silty sands, with dropstones. Hambrey & McKelvey (2000) proposed that these sediments were distal turbidites, subglacial debris flows, and ice rafted deposits possibly of early Miocene to Pliocene-age Pagodroma Group that had been reworked by late Quaternary glacial events and deposited with preserved stratigraphy, in the ice marginal moraine, during ice retreat. The carbonate crusts were analysed using X-Ray Diffraction (XRD) techniques and consist entirely of aragonite. The inorganic aragonite is micritic with thin laminae and some peloids, together with some algal filaments from microbial mats. Borings, and shell castings (gastropods) were present in a few samples. Low concentrations (0 to 10%) of halite were measured by XRD on some samples of the surrounding silty sand sediments. The composition and structure of these aragonitic layers are similar to the Late Quaternary lake aragonites and algal limestones from the Taylor Valley, Transantarctic Mountains (Hendy 2000). Hence, the Radok Lake carbonate crusts are interpreted to have formed in Fig. 5a. Photograph of vertical exposure cut by gullying in the thrust association with algal mats in a shallow water environment. moraine sequence at 50 m elevation on the basin slope above Stable isotope mass spectrometry on six samples of the northern shoreline of modern Radok Lake. The exposure shows layer of aragonite crusts, outcropping beneath the aragonite (Table I) yielded a mean carbon isotopic 13 diamicton. b. Close-up photograph showing a cluster of the composition d CPDB ¼ 1.59 Æ 0.28%, and a mean oxygen 18 discoid and draped aragonite crusts, outcropping in Fig. 5a. The isotope composition d OSMOW ¼ -3.49 Æ 0.08%. The 18 stratigraphy and the whole preservation of the shallow water calculated d OSMOW value of the parent water body from crusts, indicates in situ deposition at this location. which the aragonites were precipitated under assumed Downloaded from https://www.cambridge.org/core. Open University Library, on 08 May 2019 at 12:29:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms.
Load more

Recommended publications
  • Annual Report
    annual report 2006-07 Antarctic Climate & Ecosystems COOPERATIVE RESEARCH CENTRE Established and supported under the Australian Government’s Cooperative Research Centre Programme Antarctic Climate & Ecosystems COOPERATIVE RESEARCH CENTRE annual report 2006-07 table of contents executive summary 1 context and major developments during the year 1 national research priorities 3 national research priority goals 3 table 1: national research priorities and CRC research 3 governance & management 4 table 2: speciied personnel 5 research programs 8 climate variability & change 9 ocean control of carbon dioxide 12 antarctic marine ecosystems 15 sea-level rise 17 policy 20 table 3: research outputs and milestones 23 research collaboration 31 commercialisation & utilisation 36 commercialisation & utilisation strategies and activities 36 intellectual property management 37 table 4: commercialisation milestones 37 communication strategy 38 end-user involvement and CRC impact on end-users 39 education & training 42 table 6: education & training outputs and/or milestones 43 third year review 44 performance measures 45 table 7: progress on performance measures 45 glossary of terms 49 executive summary The Antarctic Climate & Ecosystems Cooperative past climate captured in the Antarctic ice sheet. We Research Centre (ACE CRC) was funded to lead Australian have strengthened the previous evidence of signals research on the roles of Antarctica and the Southern in ice cores of winter sea ice cover around eastern Ocean in the global climate system and climate change. Antarctica, allowing hind-casting of sea ice dynamics We also have a brief to investigate likely impacts of that will enable us to properly interpret recent events climate change on Southern Ocean marine ecosystems possibly related to climate change.
    [Show full text]
  • Boeckella Poppei and Gladioferens Antarcticus I.A.E
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Tasmania Open Access Repository Antarctic Science 15 (4): 439–448 (2003) © Antarctic Science Ltd Printed in the UK DOI: 10.1017/S0954102003001548 Taxonomy, ecology and zoogeography of two East Antarctic freshwater calanoid copepod species: Boeckella poppei and Gladioferens antarcticus I.A.E. BAYLY1,2, J.A.E. GIBSON3,4*, B. WAGNER5 and K.M. SWADLING4 1School of Biological Sciences, Monash University, VIC 3800, Australia 2501 Killiecrankie Rd, Flinders Island, TAS 7255, Australia 3Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Private Bag 77, Hobart, TAS 7001, Australia 4School of Zoology, University of Tasmania, Private Bag 5, Hobart, TAS 7001, Australia 5Institute for Geophysics and Geology, Faculty for Physics and Geoscience, University Leipzig, Talstrasse 35, D-04103 Leipzig, Germany *corresponding author: [email protected] Abstract: New populations of the two species of calanoid copepods known to inhabit freshwater lakes in East Antarctica, Boeckella poppei (Mrázek, 1901) and Gladioferens antarcticus Bayly, 1994, have recently been discovered. The morphology of the populations of B. poppei showed significant differences, notably a reduction in the armature of the male fifth leg, when compared with typical specimens from the Antarctic Peninsula and South America. Gladioferens antarcticus had previously been recorded from a single lake in the Bunger Hills, but has now been recorded from three further lakes in this region. A recent review of Antarctic terrestrial and limnetic zooplankton suggested that neither of these species can be considered an East Antarctic endemic, with B.
    [Show full text]
  • New Zircon U∓Pb and Hf∓Nd Isotopic Constraints on the Timing of Magmatism, Sedimentation and Metamorphism in the N
    Precambrian Research 299 (2017) 15–33 Contents lists available at ScienceDirect Precambrian Research journal homepage: www.elsevier.com/locate/precamres New zircon U–Pb and Hf–Nd isotopic constraints on the timing of magmatism, sedimentation and metamorphism in the northern Prince Charles Mountains, East Antarctica ⇑ Xiaochun Liu a, , Yue Zhao a, Hong Chen a, Biao Song b a Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China b Beijing SHRIMP Centre, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China article info abstract Article history: The northern Prince Charles Mountains (PCM) in East Antarctica represent the largest continuously Received 17 April 2017 exposed section of the Rayner Complex and may provide important insights into the tectonic evolution Revised 10 July 2017 of the Rayner orogen. We present new U–Pb and Hf isotopic data for zircons from felsic orthogneisses, Accepted 13 July 2017 mafic granulites, paragneisses and charnockites and additional Nd isotopic data for the former two rock Available online 15 July 2017 types from the Beaver Lake area in the northern PCM. Zircons from the felsic orthogneisses document protolith ages of ca. 1170–1070 Ma, with Hf and Nd model ages of 1.99–1.74 Ga, suggesting the genera- Keywords: tion of the felsic magmas by partial melting of crustal rocks that were extracted from the mantle during Zircon the Paleoproterozoic. Detrital zircons from one paragneiss sample yield a major age population at ca. Magmatic age Depositional age 1480–1140 Ma and three subordinate populations at ca. 2130–1850, 1780–1620 and 1010–860 Ma, Metamorphic age whereas those from another paragneiss sample produce a major age population at ca.
    [Show full text]
  • Boeckella Poppei and Gladioferens Antarcticus I.A.E
    Antarctic Science 15 (4): 439–448 (2003) © Antarctic Science Ltd Printed in the UK DOI: 10.1017/S0954102003001548 Taxonomy, ecology and zoogeography of two East Antarctic freshwater calanoid copepod species: Boeckella poppei and Gladioferens antarcticus I.A.E. BAYLY1,2, J.A.E. GIBSON3,4*, B. WAGNER5 and K.M. SWADLING4 1School of Biological Sciences, Monash University, VIC 3800, Australia 2501 Killiecrankie Rd, Flinders Island, TAS 7255, Australia 3Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Private Bag 77, Hobart, TAS 7001, Australia 4School of Zoology, University of Tasmania, Private Bag 5, Hobart, TAS 7001, Australia 5Institute for Geophysics and Geology, Faculty for Physics and Geoscience, University Leipzig, Talstrasse 35, D-04103 Leipzig, Germany *corresponding author: [email protected] Abstract: New populations of the two species of calanoid copepods known to inhabit freshwater lakes in East Antarctica, Boeckella poppei (Mrázek, 1901) and Gladioferens antarcticus Bayly, 1994, have recently been discovered. The morphology of the populations of B. poppei showed significant differences, notably a reduction in the armature of the male fifth leg, when compared with typical specimens from the Antarctic Peninsula and South America. Gladioferens antarcticus had previously been recorded from a single lake in the Bunger Hills, but has now been recorded from three further lakes in this region. A recent review of Antarctic terrestrial and limnetic zooplankton suggested that neither of these species can be considered an East Antarctic endemic, with B. poppei being listed as a recent anthropogenic introduction and G. antarcticus a ‘marine interloper’. We conclude differently: B. poppei has been present in isolated populations in East Antarctica for significant lengths of time, possibly predating the current interglacial, while G.
    [Show full text]
  • Early Neoproterozoic Granulite Facies Metamorphism of Mafic Dykes From
    J. metamorphic Geol., 2014, 32, 1041–1062 doi:10.1111/jmg.12106 Early Neoproterozoic granulite facies metamorphism of mafic dykes from the Vestfold Block, east Antarctica X. C. LIU,1 W.-(R. Z.)WANG,1 Y. ZHAO,1 J. LIU1 AND B. SONG2 1Key Laboratory of Paleomagnetism and Tectonic Reconstruction of Ministry of Land and Resources, Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China ([email protected]) 2Beijing SHRIMP Centre, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China ABSTRACT Proterozoic mafic dykes from the southwestern Vestfold Block experienced heterogeneous granulite facies metamorphism, characterized by spotted or fractured garnet-bearing aggregates in garnet- absent groundmass. The garnet-absent groundmass typically preserves an ophitic texture composed of lathy plagioclase, intergranular clinopyroxene and Fe–Ti oxides. Garnet-bearing domains consist mainly of a metamorphic assemblage of garnet, clinopyroxene, orthopyroxene, hornblende, biotite, plagioclase, K-feldspar, quartz and Fe–Ti oxides. Chemical compositions and textural relationships suggest that these metamorphic minerals reached local equilibrium in the centre of the garnet-bearing domains. Pseudosection calculations in the model system NCFMASHTO (Na2O–CaO–FeO–MgO– Al2O3–SiO2–H2O–TiO2–Fe2O3) yield P–T estimates of 820–870 °C and 8.4–9.7 kbar. Ion microprobe U–Pb zircon dating reveals that the NW- and N-trending mafic dykes were emplaced at 1764 Æ 25 and 1232 Æ 12 Ma, respectively, whereas their metamorphic ages cluster between 957 Æ 7 and 938 Æ 9 Ma. The identification of granulite facies mineral inclusions in metamorphic zircon domains is also consistent with early Neoproterozoic metamorphism.
    [Show full text]
  • Glaciomarine Sedimentation at the Continental Margin of Prydz Bay, East Antarctica: Implications on Palaeoenvironmental Changes During the Quaternary
    Alfred-Wegener-Institut für Polar- und Meeresforschung Universität Potsdam, Institut für Erd- und Umweltwissenschaften Glaciomarine sedimentation at the continental margin of Prydz Bay, East Antarctica: implications on palaeoenvironmental changes during the Quaternary Dissertation zur Erlangung des akademischen Grades Doktor der Naturwissenschaften (Dr. rer. nat.) in der Wissenschaftsdisziplin “Geowissenschaften” eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam von Andreas Borchers Potsdam, 30. November 2010 Das Höchste, wozu der Mensch gelangen kann, ist das Erstaunen. J. W. von Goethe Acknowledgements This dissertation would not have been possible without the support and help of numerous people to whom I would like to express my gratitude. First, I am highly indebted to PD Dr. Bernhard Diekmann for the possibility to conduct this work under his supervision and for his constant support, whenever discussion or advice was needed. I appreciated his vast expertise and knowledge of marine geology, sedimentology and Quaternary Science that he so enthusiastically shared with me, adding considerably to my experience. Besides being a full-hearted geologist, he is also a great guitarist, which I enjoyed during the past years, especially during the expeditions I had the chance to participate. I would also like to thank Prof. Dr. Hans-Wolfgang Hubberten for his general support and understanding, giving me the opportunity to broaden my knowledge of marine geology in the field. Using the infrastructure of the institute in Potsdam, Bremerhaven and on the world’s oceans has made a major contribution realizing this work. I am deeply grateful to Prof. Dr. Ulrike Herzschuh and Dr. Gerhard Kuhn who provided a large part of assistance by discussions, constructive advices and moral support.
    [Show full text]
  • Paleoceanography
    PUBLICATIONS Paleoceanography RESEARCH ARTICLE Sea surface temperature control on the distribution 10.1002/2014PA002625 of far-traveled Southern Ocean ice-rafted Key Points: detritus during the Pliocene • New Pliocene East Antarctic IRD record and iceberg trajectory-melting model C. P. Cook1,2,3, D. J. Hill4,5, Tina van de Flierdt3, T. Williams6, S. R. Hemming6,7, A. M. Dolan4, • Increase in remotely sourced IRD 8 9 10 11 9 between ~3.27 and ~2.65 Ma due E. L. Pierce , C. Escutia , D. Harwood , G. Cortese , and J. J. Gonzales to cooling SSTs 1 2 • Evidence for ice sheet retreat in the Grantham Institute for Climate Change, Imperial College London, London, UK, Now at Department of Geological Sciences, Aurora Basin during interglacials University of Florida, Gainesville, Florida, USA, 3Department of Earth Sciences and Engineering, Imperial College London, London, UK, 4School of Earth and Environment, University of Leeds, Leeds, UK, 5British Geological Survey, Nottingham, UK, 6Lamont-Doherty Earth Observatory, Palisades, New York, USA, 7Department of Earth and Environmental Sciences, Columbia Supporting Information: 8 • Readme University, Lamont-Doherty Earth Observatory, Palisades, New York, USA, Department of Geosciences, Wellesley College, • Text S1 and Tables S1–S3 Wellesley, Massachusetts, USA, 9Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR, Armilla, Spain, 10Department of Geology, University of Nebraska–Lincoln, Lincoln, Nebraska, USA, 11Department of Paleontology, GNS Science, Lower Hutt, New Zealand Correspondence to: C. P. Cook, c.cook@ufl.edu Abstract The flux and provenance of ice-rafted detritus (IRD) deposited in the Southern Ocean can reveal information about the past instability of Antarctica’s ice sheets during different climatic conditions.
    [Show full text]
  • Early Diagenetic Siderite in the Panorama Point Beds (Radok Conglomerate, Early to Middle Permian), Prince Charles Mountains, East Antarctica
    vol. 31, no. 2, pp. 169–194, 2010 doi: 10.4202/ppres.2010.10 Early diagenetic siderite in the Panorama Point Beds (Radok Conglomerate, Early to Middle Permian), Prince Charles Mountains, East Antarctica Krzysztof P. KRAJEWSKI 1,3*, Nikolai A. GONZHUROV 2, Anatoly A. LAIBA2 and Andrzej TATUR3 1 Instytut Nauk Geologicznych PAN, Twarda 51/55, 00−818 Warszawa, Poland <[email protected]> *corresponding author 2 Polar Marine Geological Research Expedition, Pobedy 24, 198412 St. Petersburg, Russia 3 Zakład Biologii Antarktyki PAN, Ustrzycka 10/12, 02−141 Warszawa, Poland Abstract: The Panorama Point Beds represent a subfacies of the Early to Middle Permian Radok Conglomerate, which is the oldest known sedimentary unit in the Prince Charles Mountains, MacRobertson Land, East Antarctica. This unit records clastic sedimentation in fresh−water depositional system during the early stages of development of the Lambert Graben, a major structural valley surrounded by crystalline highlands in the southern part of Gondwana. It contains common siderite precipitated through early diagenetic processes in the swamp, stagnant water, and stream−flow environments. There are two types of siderite in the Panorama Point Beds: (1) disseminated cement that occurs throughout the sedimentary suc− cession; and (2) concretions that occur at recurrent horizons in fine−grained sediments. The cement is composed of Fe−depleted siderite (less than 90 mol % FeCO3) with an elevated con− d13 tent of magnesium, and trace and rare earth elements. It has negative CVPDB values (−4.5 to −1.5‰). The concretions are dominated by Fe−rich siderite (more than 90 mol % FeCO3), with d13 positive CVPDB values (+1 to +8‰).
    [Show full text]
  • Glacio-Lacustrine Aragonite Deposition, Meltwater Evolution And
    Antarctic Science 19 (3), 365–372 (2007) & Antarctic Science Ltd 2007 Printed in the UK DOI: 10.1017/S0954102007000466 Glacio-lacustrine aragonite deposition, meltwater evolution and glacial history during isotope stage 3 at Radok Lake, Amery Oasis, northern Prince Charles Mountains, East Antarctica IAN D. GOODWIN1 and JOHN HELLSTROM2 1Environmental and Climate Change Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia 2School of Earth Sciences, University of Melbourne, Parkville, VIC 3010, Australia [email protected] Abstract: The late Quaternary glacial history of the Amery Oasis, and Prince Charles Mountains is of significant interest because about 10% of the total modern Antarctic ice outflow is discharged via the adjacent Lambert Glacier system. A glacial thrust moraine sequence deposited along the northern shoreline of Radok Lake between 20–10 ka BP, overlies a layer of thin, aragonite crusts which provide important constraints on the glacial history of the Amery Oasis. The modern Radok Lake is fed by the terminal meltwaters of the alpine Battye Glacier. The aragonite crusts were deposited in shallow water of ancestral Radok Lake 53 ka BP,during the A3 warm event in Isotope Stage 3. Oxygen isotope (d18O) analysis of the last glacial-age aragonite crusts 18 indicates that they precipitated from freshwater with a d OSMOW composition of -36%, which is 8% more depleted than the present water (-28%) in Radok Lake. A regional oxygen isotope (d18O) and elevation relationship for snow is used to determine the source of meltwater and glacial ice in Radok Lake during the A3 warm event.
    [Show full text]
  • Prydz Bay Region, East Antarctica J.M
    Antarctic Science 18 (1), 83–99 (2006) © Antarctic Science Ltd Printed in the UK DOI: 10.1017/S0954102006000083 A review of the Cenozoic stratigraphy and glacial history of the Lambert Graben–Prydz Bay region, East Antarctica J.M. WHITEHEAD1*, P.G. QUILTY2, B.C. MCKELVEY3 and P.E. O’BRIEN4 1Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Private Bag 77, Hobart, TAS 7001, Australia 2School of Earth Sciences University of Tasmania, Private Bag 79, Hobart, TAS 7001, Australia 3Division of Earth Sciences, University of New England, Armidale, NSW 2351, Australia 4Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia *[email protected] Abstract: The Cenozoic glacial history of East Antarctica is recorded in part by the stratigraphy of the Prydz Bay–Lambert Graben region. The glacigene strata and associated erosion surfaces record at least 10 intervals of glacial advance (with accompanying erosion and sediment compaction), and more than 17 intervals of glacial retreat (enabling open marine deposition in Prydz Bay and the Lambert Graben). The number of glacial advances and retreats is considerably less than would be expected from Milankovitch frequencies due to the incomplete stratigraphic record. Large advances of the Lambert Glacier caused progradation of the continental shelf edge. At times of extreme glacial retreat, marine conditions reached > 450 km inland from the modern ice shelf edge. This review presents a partial reconstruction of Cenozoic glacial extent within Prydz Bay and the Lambert Graben that can be compared to eustatic sea-level records from the southern Australian continental margin. Received 1 December 2004, accepted 15 July 2005 Key words: glaciation, ice sheet, Milankovitch, Prince Charles Mountains Introduction Study area In recent years there has been considerable investigation of This paper reviews the Cenozoic stratigraphy of the the Cenozoic geology of the Lambert Graben and Prydz Antarctic continent and margin from 60°E to 80°E.
    [Show full text]
  • Investigation of Glacial Dynamics in Lambert Glacial Basin
    INVESTIGATION OF GLACIAL DYNAMICS IN LAMBERT GLACIAL BASIN USING SATELLITE REMOTE SENSING TECHNIQUES A Dissertation by JAEHYUNG YU Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2005 Major Subject: Geography INVESTIGATION OF GLACIAL DYNAMICS IN LAMBERT GLACIAL BASIN USING SATELLITE REMOTE SENSING TECHNIQUES A Dissertation by JAEHYUNG YU Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Hongxing Liu Committee Members, Andrew G. Klein Vatche P. Tchakerian Mahlon Kennicutt Head of Department, Douglas Sherman December 2005 Major Subject: Geography iii ABSTRACT Investigation of Glacial Dynamics in Lambert Glacial Basin Using Satellite Remote Sensing Techniques. Jaehyung Yu, B.S., Chungnam National University; M.S., Chungnam National University Chair of Advisory Committee: Dr. Hongxing Liu The Antarctic ice sheet mass budget is a very important factor for global sea level. An understanding of the glacial dynamics of the Antarctic ice sheet are essential for mass budget estimation. Utilizing a surface velocity field derived from Radarsat three-pass SAR interferometry, this study has investigated the strain rate, grounding line, balance velocity, and the mass balance of the entire Lambert Glacier – Amery Ice Shelf system, East Antarctica. The surface velocity increases abruptly from 350 m/year to 800 m/year at the main grounding line. It decreases as the main ice stream is floating, and increases to 1200 to 1500 m/year in the ice shelf front.
    [Show full text]
  • Coastal Change and Glaciological Map of The
    Prepared in cooperation with the Scott Polar Research Institute, University of Cambridge, United Kingdom Coastal-Change and Glaciological Map of the Amery Ice Shelf Area, Antarctica: 1961–2004 By Kevin M. Foley, Jane G. Ferrigno, Charles Swithinbank, Richard S. Williams, Jr., and Audrey L. Orndorff Pamphlet to accompany Geologic Investigations Series Map I–2600–Q 2013 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2013 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Foley, K.M., Ferrigno, J.G., Swithinbank, Charles, Williams, R.S., Jr., and Orndorff, A.L., 2013, Coastal-change and glaciological map of the Amery Ice Shelf area, Antarctica: 1961–2004: U.S. Geological Survey Geologic Investigations Series Map I–2600–Q, 1 map sheet, 8-p.
    [Show full text]