Sedimentology and Stratigraphy of the AND-1B Core, ANDRILL McMurdo Ice Shelf Project, Antarctica

Authors

L. Krissek, Ohio State University
G. Browne, GNS Science
L. Carter, Victoria University of WellingtonFollow
E. A. Cowan, Appalachian State UniversityFollow
G. Dunbar, Victoria University of Wellington
R. McKay, Victoria University of Wellington
T. Naish, GNS Science
R. D. Powell, Northern Illinois UniversityFollow
J. Reed, Iowa State University
T. Wilch, Albion College
ANDRILL-MIS Science Team

Date of this Version

2007

Comments

Published in Terra Antartica, 2007, 14(3), 185-222. © Terra Antartica Publication 2007

Abstract

During the 2006–2007 austral season, the ANDRILL McMurdo Ice Shelf Project recovered a core 1285 m-long (AND-1B) from Windless Bight in the McMurdo Sound region. This core contains a range of lithologies, including both siliciclastic and volcanic diamictites, sandstones and mudstones; diatomites; and volcanic ash/tuff and one phonolitic lava flow. The succession has been subdivided into eight lithostratigraphic units and 25 subunits, based on lithological abundances. Eleven lithofacies have been recognized, ranging from open marine diatomites and mudstones to turbidites to ice-proximal massive and stratified diamictites. More than 60 glacimarine sequences have been recognised, bounded by glacial surfaces of erosion. Three distinct facies stacking patterns are present, showing evidence of glacial advance/retreat/advance with varying degrees of preservation. Carbonate and pyrite are the dominant secondary phases in the core. The pyrite overprint is especially notable in volcanic sediments below ~400 metres below seafloor (mbsf), where it often obscures stratification and sediment texture.