| Title | Late Pleistocene to Holocene strata from soft-sediment coring at the AND-1B Site, ANDRILL McMurdo Ice Shelf Project, Antarctica |
| Author | Dunbar, G.; Niessen, F.; Vogel, S.; Tulaczyk, S.; Mandernack, K.; Krissek, L.; Carter, L.; Cowan, E.; Wilch, T.; Peng, C.; Strong, C.P.; Scherer, R.; Sjunneskog, C.; Winter, D.; McKay, R.; Talarico, F.; Pompilio, M.; ANtarctic geological DRILLing- McMurdo Ice Shelf (ANDRILL-MIS) Science Team |
| Author Affil | Dunbar, G., Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand. Other: Northern Illinois University; University of Nebraska- Lincoln; Alfred Wegener Institute for Polar and Marine Research, Federal Republic of Germany; Northern Illinois University; University of California, Santa Cruz; Colorado School of Mines; Ohio State University; Appalachian State University; Albion College; Texas A&M University; Geological and Nuclear Science, New Zealand; Louisiana State University; University of Nebraska-Lincoln; Universita di Siena, Italy; Istituto Nazionale di Geofisica e Vulcanologia, Italy |
| Source | Studies from the ANDRILL, McMurdo Ice Shelf Project, Antarctica; initial science report on AND-1B, edited by T.R. Naish, R. Powell and R. Levy. Terra Antartica, 14(3), p.141-154, . Publisher: Universita degli Studi di Siena, Sezione Scienze della Terra, Siena, Italy. ISSN: 1122- 8628 |
| Publication Date | 2007 |
| Notes | In English. 17 refs. GeoRef Acc. No: 284752. CRREL Acc. No: 62005075 |
| Index Terms | algae; boreholes; density (mass/volume); drilling; elastic waves; isotopes; magnetic properties; marine deposits; oxygen; physical properties; Pleistocene; porosity; Quaternary deposits; sediments; cohesion; velocity; seismic velocity; Antarctica--McMurdo Ice Shelf; Southern Ocean--McMurdo Sound; Southern Ocean- -Victoria Land Basin; alkalinity; AND-1B Core; Antarctica; biostratigraphy; body waves; Cenozoic; clastic sediments; clasts; cores; density; diatoms; electrical conductivity; Foraminifera; Holocene; Invertebrata; isotope ratios; lithofacies; lithostratigraphy; magnetic susceptibility; marine sediments; McMurdo Ice Shelf; McMurdo Sound; microfossils; O-18/O-16; P-waves; paleoenvironment; paleomagnetism; paleotemperature; palynomorphs; Plantae; pore water; Protista; Quaternary; Ross Ice Shelf; Ross Sea; seismic waves; shear strength; Southern Ocean; spatial variations; stable isotopes; upper Pleistocene; Victoria Land Basin; well logs |
| Abstract | Prior to rotary coring, a range of soft-sediment coring tools were deployed to recover the sediment-water interface and the upper few meters of strata, whose integrity was threatened by embedment of the sea riser for drilling of the ANDRILL (AND)-1A/1B holes. These coring options included (1)a sediment gravity corer deployed through the ice-shelf hole, and (2) a push corer deployed through the sea riser suspended a few meters above the seabed. Within the AND-1A hole (during an attempt at sea-riser embedment) an extended-nose corer was advanced in front of the sea riser with limited success. The hydraulic piston corer was not deployed as a consequence of the firmness of the Last Glacial maximum (LGM) diamicton and the occurrence of outsized clasts that could damage the drill string and compromise the deeper coring options. Successive attempts at gravity and push coring recovered 12 cores up to a maximum of 1.56 meters below sea-floor (mbsf). The longest core was dedicated to sampling for microbial life and pore-water geochemical studies which were expected to show the greatest gradients in the upper few meters of the sediment column. All cores sampled Holocene sub-ice-shelf sediments above the LGM diamicton, and displayed a similar stratigraphy to a previously obtained site survey core, 250 m to the southeast (McKay et al., in press), with an unconsolidated diamicton passing upwards into muddy sub-ice-shelf facies. The sediment cores record the retreat of the grounding line through the region about 10,000 years ago and a transition from grounding line proximal, through sub-ice-shelf to calving- line proximal environments. |
| Publication Type | journal article |
| Record ID | 84149 |