Antarctic Science

Earth Sciences

Lithofacies distribution in relation to the geomorphic provinces of Prydz Bay, East Antarctica

P.T. Harris a1a2c1, F. Taylor a1, Z. Pushina a3, G. Leitchenkov a3, P.E. O'Brien a1a2 and V. Smirnov a4
a1 Antarctic CRC, GPO Box 252-80, Hobart, TAS 7001, Australia
a2 Australian Geological Survey Organisation, GPO Box 378, Canberra, ACT 2601, Australia
a3 VNIIOkeangeologia, 1 Angliysky Ave, 190 121 St Petersburg, Russia
a4 Polar Marine Geological Research Expedition (PMGRE), 24 Pobeda Street, 189 510 Lomonosov, Russia

Article author query
harris p   [PubMed][Google Scholar] 
taylor f   [PubMed][Google Scholar] 
pushina z   [PubMed][Google Scholar] 
leitchenkov g   [PubMed][Google Scholar] 
o'brien p   [PubMed][Google Scholar] 
smirnov v   [PubMed][Google Scholar] 


Over the past 15 years, Japanese, Australian and Russian expeditions to Prydz Bay have collected about 30 000 km of bathymetric data, 6000 km of sidescan sonar data and more than 250 sediment grab and core samples. These data were used in the present study to compile surficial sediment, bathymetric, and geomorphological maps of the Prydz Bay region. Lithofacies distribution was determined by surficial sediment data analysis using sample matrix (Q-mode) and cluster analysis techniques based on data from 206 sites. Data included percentage biogenic silica (opal), calcium carbonate, gravel, mud, and relative abundance of two diatom species (Fragilariopsis curta and F. kerguelensis). Five lithofacies are identified from the available data: (1) slightly gravelly sandy mud (g)sM lithofacies, (2) siliceous mud and diatom ooze (SMO) lithofacies, (3) F. kerguelensis pelagic ooze lithofacies, (4) F. curta gravelly muddy sand gmS lithofacies and (5) calcareous gravel lithofacies. In many areas the lithofacies correlate to geomorphological provinces as defined by previous investigators using 3.5 kHz and sidescan sonar data. In some cases, Holocene SMO sediments are seen to drape over iceberg plough marks, implying that these are relict features. These five lithofacies are likely to dominate most of the East Antarctic shelf region and may be helpful in defining sedimentary successions resulting from ice-sheet advance and retreat over glacial-interglacial cycles.

(Received December 16 1997)
(Accepted May 29 1998)

Key Words: Amery Ice Shelf; diatoms; facies; geomorphology; Prydz Bay; sediments.

c1 corresponding author, Antarctic CRC, GPO Box 252-80, Hobart, Tasmania 7001, Australia