Abstract Plio-Pleistocene records of ice-rafted detritus suggest NW European ice sheets regularly reached coastlines. However, these records provide limited insight on the frequency, extent and dynamics of ice sheets delivering the detritus. Three-dimensional reflection seismic data of the NW European glaciated margin have previously documented buried landforms that inform us on these uncertainties. This paper reviews and combines these existing records with new seismic geomorphological observations to catalogue landform occurrence along the European glaciated margin and considers how they relate to ice sheet history. The compilation shows Early Pleistocene ice sheets regularly advanced across the continental shelves. Early Pleistocene sea-level reconstructions demonstrate lower magnitude fluctuations compared to the Middle–Late Pleistocene, and more extensive/frequent Early Pleistocene glaciation provides a possible mismatch with sea-level reconstructions. This evidence is discussed with global records of glaciation to consider possible impacts on our wider understanding of Plio-Pleistocene climate changes, in particular how well Early Pleistocene sea-level records capture ice sheet volume changes. Resolving such issues relies on how well landforms are dated, whether they can be correlated with other proxy datasets, and how accurately these proxies reconstruct the magnitudes of past climatic changes. Many questions about Pleistocene glaciation in Europe and elsewhere remain.

Abstract About 3 million years ago, major ice sheets developed over Scandinavia and began to deliver large volumes of sediment to the mid-Norwegian shelf. The shelf was built out in a prograding pattern towards the west, and more than 1000 m of sediments was deposited over large areas on the middle/outer shelf. The dominating large-scale depositional pattern is a series of prograding wedges and flat-lying, sheet-like units mainly of glacial origin. On top of these units are flat-lying till units deposited during the last few glaciations, commonly separated from the underlying units by one or several erosional unconformities. The lithology of these layers is generally fine-grained, mainly clay and silt, but with sporadic clasts up to boulder size. Based on regional and detailed bathymetry, the ice-flow pattern from the last glaciation has been reconstructed on the shelf. This involved a very dynamic ice sheet with fast-flowing ice streams in the transverse, cross-shelf troughs, separated by more passive ice domes on the intermediate shallow banks. The ice streams appear to follow the cross-shelf troughs from glaciation to glaciation, but occasionally they switched to new flow paths. The thick Quaternary sediments on the outer part of the mid-Norwegian shelf represent a challenge for hydrocarbon exploration. Several large slides have occurred from the shelf break and down the continental slope. During the last few years there has been an increased focus on investigating the Quaternary succession in order to search for hydrocarbon prospects. The potential for finding reservoirs in these sediments is discussed, and a few examples of gas discoveries are shown. The Peon gas field ( c . 250 km 2 ) is located in the glacially eroded Norwegian Channel above the Upper Regional Unconformity (URU) separating flat-lying glaciogenic sediments from dipping sedimentary units. The reservoir is developed in glaciofluvial sands a few hundred thousand years old, and sealed by flat-lying glaciomarine sediments and till units.

Abstract The papers in this volume are the outcome of a Geological Society (London) meeting concerning glacier-influenced sedimentation on high-latitude continental margins, held at the University of Bristol, UK, in 2001. Since the publication of the Geological Society Special Publication Glacimarine Environments: Processes and Sediments (Dowdeswell & Scourse 1990), the intervening 11 years have seen a significant increase in research into the processes and patterns of glacimarine sedimentation, and the relationship between ice dynamics and the sediments and landforms preserved in the glacimarine environment. In this introduction, we outline the papers that make up the volume and we highlight the main findings and significance of each. First, however, we highlight three areas relating to sedimentation in glacimarine environments where we believe significant progress has been made in the last 11 years. These are: (1) glacially-influenced continental slope sedimentation; (2) iceberg-rafting processes and events; and (3) reconstructing the dynamics of former marineterminating ice sheets from glacial geomorphological evidence on continental shelves. Each of these areas is represented by papers in this volume.

Abstract Geological evidence indicates that sediment reworking is common around the continental margins and abyssal depths of the Norwegian–Greenland Sea, a high-latitude setting with glacier-influenced margins. Detailed analysis of 22 cores up to 5 m long, placed in context by accompanying geophysical data including high resolution sub-bottom profiles, swath bathymetry and backscatter maps, indicates that reworking is variable and ranges from debris flows and turbidity currents, to bottom-current activity, as well as iceberg scouring. Reworking by debris flows appears to be restricted mainly to the main trough-mouth fans and sediment slides. Elsewhere, turbidity-current activity frequently dominates, although iceberg ploughing down to 600 m depth and current winnowing assume increasing significance on continental shelves. Reworking in the Norwegian–Greenland Sea reflects variations in ice-sheet dynamics that, in turn, influence the rate of sediment delivery and location of depocentres. Spatial variations in the style of reworking may also reflect the influence of continental slope gradient and bedrock geology on continental shelves. The widespread nature of sediment reworking has important implications for palaeoceanographic investigations in the region, as reworking can result in erosion and disturbance of the sediment column. It is estimated that less than 7% of material delivered to the Norwegian–Greenland Sea since the Late Weichselian is derived from hemipelagic and pelagic sedimentation. This problem is significant where continuous, high-resolution records of hemipelagic and pelagic sedimentation are required, and attempts are made to correlate with other high-resolution proxy records, such as ice cores, at sub-millennial scales. Bioturbation results in the smoothing of high-resolution records and imposes a maximum resolution for sediment-core time-slices of generally 400 years or more. In the Norwegian–Greenland Sea, areas of high sedimentation such as trough-mouth fans or contourite drifts are commonly associated with extensive reworking. Identification of reworking is particularly important where attempts are made to link records of iceberg-rafted debris to past ice-sheet dynamics, as bottom-current winnowing and mass-flow processes can increase the concentration of coarse-grained iceberg-rafted debris. Such localized accentuation of the iceberg-rafted debris signal may lead to erroneous palaeo-environmental interpretations. It is therefore critical that palaeoceanographic interpretations are firmly underpinned by an explicit sedimentological assessment of reworking.