Stratified glacimarine basin-fills in West Greenland fjords

Abstract

Acoustically stratified sediments that infill glacially eroded bedrock basins are common in fjords (Seramur et al. 1997; Gilbert et al. 1998; Hogan et al. 2012; Dowdeswell & Vasquez 2013). Internally, such stratified sediments are often characterized by relatively smooth reflections that parallel the seafloor. Sills between basins usually comprise bedrock, sometimes covered by a thin veneer of glacimarine sediment and/or till. Fjords in West Greenland, including Rink Fjord and Vaigat, contain bedrock basins infilled by acoustically stratified sediment (Fig. 1). The basin fills are a product of rain-out from turbid meltwater plumes, probably supplemented by iceberg-rafting and downslope resedimentation. Fig. 1. Multibeam bathymetry and acoustic sub-bottom profiles of submarine basins close to the coast of West Greenland. ( a ) Multibeam bathymetry from Rink Fjord, West Greenland, with water depths >1000 m. ( b ) 3.5 kHz sub-bottom profile from Rink Fjord showing stratified, conformable basin fill (Facies 2) between basement pinnacles (Facies 1). VE×96. ( c , d ) Multibeam bathymetry in Vaigat strait and a coastal basin, West Greenland, respectively; arrows indicate ice-flow directions during the last glacial based on the orientation of sculpted …