Holocene glaciomarine sediment in Maxwell Bay of the South Shetland Islands, Antarctica: its paleoceanographic implication

Abstract

The glaciomarine sediment record of Maxwell Bay, South Shetland Islands, is composed of cyclic deposits. Each glaciomarine couplet forms alternating clast-rich massive diamicton deposited in cold climate conditions by iceberg rafting detached from coastal fast ice in which algal plants as well as sand and/or gravel were entrained and, in warmer climate conditions, meltwater deposits of weakly laminated mud with clast-poor stratified diamicton deposited by iceberg rafting coming from the tidewater glaciers depleted in sand and algal components. Although iceberg rafting occurs throughout the deposition of the whole cores, organic matter is deposited in high concentration and forms organic-rich massive diamicton only during cold conditions because of minimal dilution of siliciclastic particles by meltwater influx in Maxwell Bay.