Pleistocene glacial history of the NW European continental margin

Marine and Petroleum Geology 22 (2005) 1111–1129 www.elsevier.com/locate/marpetgeo

Pleistocene glacial history of the NW European continental margin Hans Petter Sejrupa,*, Berit Oline Hjelstuena, K.I. Torbjørn Dahlgrenb, Haflidi Haflidasona, Antoon Kuijpersc, Atle Nyga˚rda, Daniel Praegd, Martyn S. Stokere, Tore O. Vorrenb a Department of Earth Science, University of Bergen, Alle`gt 41, N-5007 Bergen, Norway Department of Geology, University of Tromsø, Dramsveien 201, N-9037 Tromsø, Norway c Geological Survey of Denmark and Greenland, DK-1350, Copenhagen K, Denmark d UCD School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland e British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, UK b

Received 26 May 2004; received in revised form 31 August 2004; accepted 6 September 2004

Abstract In this paper new and previously published data on the Pleistocene glacial impact on the NW European margin from Ireland to Svalbard (between c. 488N–808N) are compiled. The morphology of the glaciated part of the European margin strongly reflects repeated occurrence of fast-moving ice streams, creating numerous glacial troughs/channels that are separated by shallow bank areas. End-moraines have been identified at several locations on the shelf, suggesting shelf-edge glaciation along the major part of the margin during the Last Glacial Maximum. Deposition of stacked units of glacigenic debris flows on the continental slope form fans at a number of locations from 558N and northwards, whereas the margin to the south of this is characterised by the presence of submarine canyons. Glaciation curves, based primarily on information from the glacial fed fan systems, that depict the Pleistocene trends in extent of glaciations along the margin have been compiled. These curves suggest that extensive shelf glaciations started around Svalbard at 1.6–1.3 Ma, while repeated periods of shelf-edge glaciations on the UK margin started with MIS 12 (c. 0.45 Ma). The available evidence for MIS 2 suggest that shelf-edge glaciation for the whole margin was reached between c. 28 and 22 14C ka BP and maximum positions after this were more limited in some regions (North Sea and Lofoten). The last glacial advance on the margin has been dated to 15–13.5 14C ka BP, and by c. 13 14C ka BP the shelf areas were completely deglaciated. The Younger Dryas (Loch Lomond) advance reached the coastal areas in only a few regions. q 2005 H.P. Sejrup. Published by Elsevier Ltd. All rights reserved. Keywords: NW European margin; Pleistocene; Glaciations

1. Introduction Knowledge on the glacial history of the marine-based parts of Northern Hemisphere Pleistocene ice sheets has until recently been limited. An understanding of the number, extent and dynamics of these glacial episodes is of wide interest, considering the influence these relatively unstable parts of the ice sheets may have had upon climate, as well as their geological impact on continental margin morphology and stratigraphy. The chronology of Pleistocene glaciations has previously mainly been based on dated terrestrial sequences and records of ice-rafted detritus (IRD) in deep-sea cores (Larsen and Sejrup, 1990; Jansen and

* Corresponding author. Tel.: C47 55 58 35 05; fax: C47 55 58 36 60. E-mail address: [email protected] (H.P. Sejrup).

Sjøholm, 1991; Sejrup et al., 2000; Elliot et al., 2001). However, as acoustic methods, positioning techniques and methods for dating and analysing of marine cores steadily have improved, it has been possible to obtain new geological evidence for the Pleistocene glaciations from offshore areas. Throughout the last decade this research has also benefited greatly from increased interest in deep-water areas by the petroleum industry. The investigations of submarine fans on glaciated continental margins have contributed to our understanding of the impact of glacial stages and geological results of climatic changes. These well-defined trough mouth fans (TMFs) are characterised by convex outbuilding of the upper slope, are commonly located in connection with troughs or incisions on the shelf and are mainly composed of glacigenic debris flows (GDFs) (King et al., 1996; Vorren and Laberg, 1997). TMF development seems to be favoured

0264-8172/$ - see front matter q 2005 H.P. Sejrup. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.marpetgeo.2004.09.007

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Fig. 1. Last Glacial Maximum (LGM) in the Nordic Seas region. Pathway of Norwegian Atlantic Current is indicated by arrows (from Orvik and Niiler (2002)). Bathymetry in metres. Study area within boxes.

under conditions of a low slope gradient, a passive margin tectonic setting, and abundant and easily erodable sediments ` Cofaigh et al., 2003). For the NW on the continental shelf (O European continental margin the large Pleistocene depocentres of the TMFs on the continental slope (Fig. 2) have provided new insights into the impact and oscillation of ice sheets since c. 1.8 Ma (Stoker, 1995; King et al., 1996; Sejrup et al., 1996; Vorren and Laberg, 1997; Dahlgren et al., 2005; Nyga˚rd et al., 2005). This paper presents a compilation of offshore data relevant to the glacial history of the NW European seaboard, from the southwestern coast of Ireland to Svalbard (c. 488N–808N) (Fig. 1). We will mainly focus on geological evidence from the outer shelf areas linked to TMF development, thus the southern North Sea and the eastern part of the Barents Sea shelf are not included. First we describe the morphology and stratigraphy of the NW European continental margin before focusing on evidence for past glaciations. The glacial history will be

presented in time-distance diagrams. For the Last Glacial Maximum (LGM) maps showing the ice extent along the NW European margin have been compiled. With this as a background we will focus on the synchronicity/asynchronicity of glacier advances along the studied margin. Possible implications for our understanding of ice sheet dynamics and processes will also briefly be discussed.

2. Margin morphology 2.1. Irish margin The Irish continental margin, between 488N–568N (Fig. 2a), is characterised by an up to 400 km broad inner shelf in the Celtic Sea, narrowing to about 100 km west of Ireland, where it is joined by a W–E ‘saddle’-the Porcupine Bank—having a minimum depth of c. 150 m. The ‘saddle’ gives way, below water depths of 200–300 m, to

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Fig. 2. (a) Bathymetry (in metres) and physiography of the southern part of the studied area (Fig. 1). Location of end-moraines on the continental shelf is indicated and is based on Stoker and Holmes (1991), King et al. (1998b), Bulat and Long (2001), and Sejrup et al. (2003). Cores and seismic profiles referred to in text are shown. BBB: Bill Bailey’s Bank; BF: Barra Fan; DF: Donegal Fan; FB: Faroe Bank; FW: Foula Wedge; FR: Fugloy Ridge; FSC: Faroe-Shetland Channel; GC: Gollum Channel; HT: Hebrides Terrace Seamount; IFR: Iceland-Faroe Ridge; LB: Lousy Bank; MR: Munkagrunnur Ridge; MF: Mykines Fan; NSF: North Sea Fan; PAP: Porcupine Abbysal Plain; PB: Porcupine Bank; PSB: Porcupine Seabight; RW: Rona Wedge; RB: Rosemary Bank Seamount; RkB: Rockall Bank; SaF: Sandoy Fan; SF: Suderoy Fan; SSF: Sula Sgeir Fan; WTR: Wyllie-Thomson Ridge. (b) Detailed bathymetry (in metres) and physiography of the Norwegian-western Barents Sea-Svalbard continental margin (Fig. 1). Location of end-moraines shown is based on Vorren and Kristoffersen (1986); Elverhøi et al. (1992), and Nyga˚rd et al. (2004). Cores and seismic profiles referred to in text are shown. AF: Andfjord; AØ: Andøya; BeF: Bellsund Fan; BIF: Bear Island Fan; BM: Bremanger Moraine; BT: Bear Island Trough; BØ: Bjørnøya; IF: Isfjorden Fan; KF: Kongsfjorden Fan; LV: Lofoten-Vestera˚len; NSF: North Sea Fan; SF: Storfjorden Fan; SM: Storegga Moraine; SR: Skjoldryggen Moraine; ST: Storfjorden Trough.

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(b)

Fig. 2 (continued)

the Porcupine Seabight and the Rockall Trough, that both are over 3000 m deep and are underlain by continental crust (Shannon et al., 1993). The shelf and slope lack the glacial troughs and fans that mark the NW European continental margin to the north (Fig. 2b), although the onshore glacial record indicates that ice sheets have repeatedly extended

offshore (e.g. Bowen, 1991; Coxon, 2001). Seismic reflection profiles indicate a probable Quaternary succession that is mainly thin (!50 m), which contains evidence of glacial deposition both south and west of Ireland, and which truncates basement rocks and Mesozoic-Cenozoic strata (Bailey et al., 1974; Bailey, 1975; Evans, 1990).

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South from Ireland, across the Celtic Sea shelf, the Quaternary succession contains no obvious depositional features, other than a series of seabed ridges, locally up to 60 m thick, interpreted to be late Pleistocene tidal sand banks (Pantin and Evans, 1984; Evans, 1990) (Fig. 2a). However, vibrocores from the UK sector, in water depths of 120–180 m, proved marine sands to overlie a thin layer of glacigenic sediments, which drape the sand ridges (Pantin and Evans, 1984; Evans, 1990; Scourse et al., 1991). The vibrocores, up to 5 m long, bottomed in two glacigenic facies (Scourse et al., 1990; 1991): (1) subglacial tills and/or proximal glacimarine sediments (rich in northerly-derived clasts, including chalk) in the northern cores, and (2) distal glacimarine muds (rich in microfossils) in the southern cores. The glacimarine facies rests on subglacial facies in one of the northerly cores (49/-09/ 44; Fig. 2a). The southern glacimarine facies could be underlain by subglacial sediments not penetrated by the vibrocores, so the maximum extent of glacial deposits on the Celtic Sea shelf remains unknown. On the shelf west of Ireland, shallow seismic profiles acquired between 528N–558N show that a probable Quaternary succession, up to 50 m thick, includes a series of N–S trending, parallel to sub-parallel seabed ridges (Figs. 2a and 3). These features are up to 35–40 m high, 20 km across, and have been interpreted to represent endmoraines (King et al., 1998b). The ridges were traced to the shelf edge in the northern Porcupine Seabight and in the eastern Rockall Trough and extend across the inner part of the ‘saddle’ leading to the Porcupine Bank (Fig. 2a). It is not known whether the seaward limit of the ridges corresponds to the maximum extent of glacial deposits. On the Porcupine Bank itself, seabed grab samples indicate a linear (W–E) tract of sand and gravel (pebbles to boulders), extending from the bank crest down the slope, interpreted to be of probable Irish provenance and of glacial (ice-rafted ?) origin

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(Scoffin and Bowes, 1988). In the northern Porcupine Seabight and northeastern Rockall Trough, iceberg scours are recognised at seabed on sidescan sonar imagery from the outer shelf and upper slope, i.e. in depths of 140–500 m (Belderson et al., 1973; Pantin and Evans, 1984; Kenyon, 1987). Buried iceberg scours have also been recognised in the shallow subsurface of the northern Porcupine Basin using 3D seismic data (Games, 2001). The eastern margins of the Porcupine Seabight and the Rockall Trough are characterised by canyons of varying size (Fig. 2a), within and between which mass failures are common (Kenyon, 1987; CARTOPEP, 1998; Shannon et al., 2001; Unnithan et al., 2001). The canyons commonly extend from the shelf edge to the base of slope except in the area west of the Porcupine Bank where these features extend from the mid-slope. Only the canyons south of c. 538N continue into the deep sea, notably the Gollum Channel (Fig. 2a). The age of formation of the canyons is unknown, but they do not appear to have been active during the present interglacial, based on observations in the Gollum Channel where less than 0.1 m of post-glacial sediments have accumulated (Tudhope and Scoffin, 1995; Wheeler et al., 2003). There are no canyons north of about 55830’N, where the NE Rockall margin protrudes westward towards the Hebrides Terrace Seamount as the Barra/Donegal Fan, the only glacial fed fan on the Irish margin (Fig. 2a). 2.2. NW UK margin The UK margin is defined by the Hebrides and West Shetland margin segments (Fig. 2a), where the shelf edge is located at a water depth between 180 and 250 m. The shelf is commonly narrow, and bound by a rather uniform slope having a gradient of !18 to 38. This margin preserves

Fig. 3. Air-gun profile across moraine ridge on the continental shelf off Ireland. Modified from King et al. (1998b). Profile location in Fig. 2a.

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a glacial succession, where the seismic architecture varies from the outer shelf to the slope. The outer shelf is characterised by regionally extensive, sheet-like, depositional sequences commonly preserved as an aggrading succession of diamicton-dominated deposits (Stewart and Stoker, 1990; Stoker et al., 1994; Stoker, 1995). The most prominent geomorphic expressions of former glaciations are the submarine ridges representing terminal moraines (Fig. 2a). These ridges are !5 m to 50 m high, 1 to 8 km wide, and can individually be traced laterally for up to 70 km (Selby, 1989; Stoker and Holmes, 1991; Stoker, 1997; Bulat and Long, 2001). At the shelf edge, the end-moraine deposits interdigitate with the slope apron, implying that an ice-marginal environment existed at the edge of the Hebrides and West Shetland shelves during times of maximum shelf glaciation (Stoker, 1997). Four major glacial fed fans are preserved off NW Britain (Fig. 2a); the Barra/Donegal (w400 m thick glacial section: middle-upper Pleistocene) and Sula Sgeir (200 m thick) fans on the Hebrides-Malin margin, and the Rona and Foula (!200 m thick) wedges on the West Shetland margin. The glacial fed fans display a prograding architecture built up of several distinct, acoustically structureless to chaotic, massflow packages that may be several tens of metres thick, separated by thinner (!10 m) slope-wide clinoforms (Fig. 4a) (Stoker, 1990, 1995). Each mass-flow package consists of an amalgamated sequence of smaller lensoid bodies, several metres thick and with a lateral extent in the kilometres scale. Such individual lobes have been depicted on seabed images of the Rona and Foula wedges (Bulat and Long, 2001). Boreholes and short cores that have sampled these packages, which most likely were accumulated during peak glaciations, have shown debris-flow diamictons interbedded with thin turbidite sands and muds (Stoker, 1990; Davison and Stoker, 2002). The thinner clinoform units consist of hemipelagites, glacimarine and marine contourites, and thin-bedded sandy turbidite deposits (Stoker et al., 1991; Davison and Stoker, 2002), deposited predominantly during glacial stages. This is confirmed by a high-resolution study of a 30 m long piston core (MD95-2005) from the distal part of the Barra Fan, which proved that the heterogeneous nature of the upper Pleistocene-Holocene succession reflects changes in bottom-current-flow strength, and fluctuations in glacimarine discharge and downslope sedimentation from the adjacent southern Hebrides shelf since 45 ka BP (Kroon et al., 2000; Knutz et al., 2001, 2002; Wilson et al., 2002). In particular, increased clay input and expanded sediment sections characterise the sedimentation during cold periods, such as marine isotope stage (MIS) 2, whereas stronger current activity during warmer intervals, such as the Holocene, has resulted in winnowing and erosion. In areas between the glacial fed fans, the slope apron has accumulated less mass-flow material and the preserved succession is generally thinner. On the upper slope between the Barra and Sula Sgeir fans (Fig. 2a), the glacial

succession is about 70 m thick, and consists predominantly of hemipelagic glacimarine sediments deposited under the influence of along-slope currents (Leslie, 1993). The meltwater plume feeding the Barra/Donegal Fan may have been an important source of sediment for the slope apron; the plume material being deflected to the north by the bottom currents (Leslie, 1993). 2.3. Faroe margin The Faroe Islands are surrounded by a rather broad continental shelf, where the shelf edge is located at water depths between 300 and 500 m. The glacial Sandoy, Suderoy and Mykines fans are located at the mouths of transverse troughs or depressions on the continental shelf (Fig. 2a). The most pronounced expression at the seabed is provided by the Sandoy Fan, which shows well-defined fan lobes and a meandering channel (most likely eroded by turbidity currents) on top of the fan (Kuijpers et al., 2001). While the Sandoy Fan is located below the high-energy current of south flowing Norwegian Sea Overflow Water, the Suderoy and Mykines fans are situated close to, or within, the high-energy core of Atlantic water where bottom current velocities are around 1 m/s or more (Kuijpers et al., 2002). Thus, the seabed expressions of the latter two fan systems have been strongly modified by postglacial current activity. For all three fan systems it can be concluded that mass-flow activity was highest during LGM and early deglaciation. In addition, the mass-flow deposits of the three fan systems are generally fine-grained, i.e. mainly containing sediments in the clay-silt size fraction. The most recent, but minor mass-flow activity occurred in the early Holocene (Lassen et al., 2002). The Suderoy Fan displays evidence for mass-flow activity prior to the LGM, i.e. during MIS 3. However, this information is based on evidence from a number of sediment cores that have a limited length and thus most likely record only part of the glacial mass-flow history of the fans involved. 2.4. Norwegian margin With the exception of the areas off Lofoten and Møre, the Norwegian continental margin is characterised by a broad continental shelf (Fig. 2b). The seafloor morphology of the shelf strongly reflects the influence of glacial erosional and depositional processes. Numerous glacially eroded troughs, separated by relatively shallow banks cut across the shelf, the largest being the Norwegian Channel (Ottesen et al., 2001). Smaller-scale glacial morphological features, such as moraine ridges, glacial lineations, drumlins and iceberg scours, have also been identified on the shelf (e.g. Holtedahl, 1972, 1989; Vorren et al., 1989; Ottesen 2001, 2002; Sejrup et al., 2003). Based on bathymetric mapping, shallow seismic profiling and sampling, numerous marginal moraines have been identified on the Norwegian continental shelf. In the outer

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Fig. 4. (a) Seismic profile and line drawing across the Sula Sgeir Fan showing its regional setting, internal acoustic character and relation to end-moraines on the Hebrides shelf. Profile location in Fig. 2a. C10, RPa, RPb, RPc, C30: identified sequence boundaries. (b) Geoseismic section across the North Sea Fan. Profile location in Fig. 2b. GDFs: glacigenic debris flows; MIS: marine isotope stage; P1-P10: identified seismic sequences. Modified from Nyga˚rd et al. (2005). (c) Geoseismic section across the Bear Island Fan. Profile location in Fig. 2b. Modified from Fiedler and Faleide (1996).

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part of the Norwegian Channel two well-defined ridges (Fig. 2), interpreted as terminal moraines, are found (Sejrup et al., 2003). The Bremanger Moraine (Fig. 2b) represents a prominent landform on the Møre continental margin (Nyga˚rd et al., 2004). This feature is roughly defined by the 180 m contour, is up to 55–60 m high, 10–15 km wide and was probably deposited during a glacial advance between c. 15 and 13.3 14C ka BP. The Bremanger Moraine is likely contemporaneous with the Storegga and Skjoldryggen end moraines (Andersen, 1979) to the north (Fig. 2b). On the Mid-Norwegian shelf King et al. (1987) identified a number of so-called lift-off moraines which they interpreted to have been formed beneath a retreating, partly floating, ice margin. However, based on detailed bathymetry, Ottesen et al. (2001, 2002) suggested that the moraine ridges in this region are of a different and more complex genetic origin. To the southwest of Lofoten, sets of sub-parallel ridges, interpreted to represent closely spaced marginal moraines, have been identified from 3D seismic data (Hammer, 2003). Off northern Norway, north of the Lofoten islands (Fig. 2b), terminal moraines have been identified at the shelf edge (Egga Moraine), as well as within the fjords (Vorren and Plassen, 2002). Off the Norwegian Channel the large North Sea Fan has been identified (Figs. 2b and 4b). The fan complex can be divided into a proximal and a distal part with a total sediment volume of at least 32,000 km3 (Nyga˚rd et al., 2005). A major part (ca 80%) of the sediment volume is a result of deposition of elongated, tens of km wide, and up to 60 m thick GDF bodies (King et al., 1998a; Nyga˚rd et al., 2005). These bodies are found as far as 400–500 km from the shelf edge and have been deposited during maximum glaciations, when the ice sheet extended to the shelf edge. Within the stacked sequences of debris flows, well-defined headwalls, on the upper slope, representing large slide events, have been observed (Fig. 4b). The slide debrites corresponding to these slides constitute a large part of the sedimentary sequence in the distal part of the fan. The sedimentary units recorded in the North Sea Fan have been chronologically constrained based on tie to cores in the Norwegian Channel and on the south Vøring Plateau (Nyga˚rd et al., 2005). Further northwards, on the Vøring Plateau (Fig. 2b), the late Plio-Pleistocene is characterised by the deposition of a major prograding wedge (e.g. Dahlgren et al., 2005). This wedge reaches a thickness of up to 1500 m (Hjelstuen et al., 1999; STRATAGEM partners, 2002), and comprises units of till/diamicton that interdigitate with hemipelagic/glacimarine sediments (STRATAGEM partners, 2003; Hjelstuen et al., 2004). The Lofoten continental slope is much steeper and represents a sediment starved margin (Fig. 2b), dissected by canyons. On the North-Norwegian margin (north of Lofoten) several bathymetric protrusions in the continental

slope indicate the presence of trough-mouth fans seaward of shelf troughs and fjords. 2.5. Western Barents Sea-Svalbard margin Similar to the Norwegian margin, the western Barents Sea margin is characterised by shallow banks and glacially eroded troughs. The Bjørnøya and Storfjorden troughs represent prominent morphological features of the western Barents Sea shelf (Fig. 2b). Troughs also intersect the relatively narrow continental shelf along the western Svalbard margin, where they form the continuation of the fjords of west Spitsbergen (Fig. 2b). A set of 20–50 m high sediment ridges are found at 300 m water depth on the northern flank of the Bjørnøya Trough and on the shelf west of Bjørnøya. These ridges have been interpreted as marginal moraines (Elverhøi and Solheim, 1983). On the southwestern Barents Sea shelf, Vorren and Kristoffersen (1986) identified several ridges (Fig. 2b), commonly 10–40 m high and 1–3 km broad, which they related to the Late Weichselian glaciation. The glacigenic sequence on the western Barents Sea margin is dominated by two depocentres, the Bear Island and Storfjorden fans (Vorren et al., 1989; Faleide et al., 1996; Fiedler and Faleide, 1996; Hjelstuen et al., 1996; Laberg and Vorren, 1996a,b; Vorren and Laberg, 1997) (Figs. 2b and 4c). The oldest sediments, which arguably reflect direct sediment delivery from an ice sheet reaching the shelf edge of the western Barents Sea have been estimated to be c. 1.6 Ma old based on seismic correlation to ODP Site 986 (Fig. 2b) (Forsberg et al., 1999; Butt et al., 2000). The glacigenic units on the fans display thickness maxima along the shelf edge, and are composed of sets of stacked/shingled GDFs (Vorren et al., 1989; Laberg and Vorren, 1996a,b; Vorren and Laberg, 1997) interbedded with hemipelagic sediments, which to various extents have been modified by bottom currents (Yoon et al., 1991). Large-scale slope failures have also affected the glacigenic deposits along the western Barents Sea margin (Laberg and Vorren, 1993; Kuvaas and Kristoffersen, 1996).

3. Pleistocene glaciation history 3.1. Irish margin There is limited evidence as to the number, or extent, of glacial advances onto the Atlantic continental margin south or west of Ireland (Fig. 5). The first appearance of IRD in DSDP Site 548 on the Goban Spur is just 4.5 m below the base of the Pleistocene, placed at 101.1 m at the base of the Matuyama magnetic chron dated at 1.72 Ma (de Graciansky and Poag, 1985). Glaciations of the Scottish and Welsh uplands are reflected in fluvial deposits dating back to the early Matuyama chron, i.e. late Pliocene to early Pleistocene, but ice sheets are inferred to have formed over Ireland

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Fig. 5. Glaciation curves for the Ireland-Svalbard margin segment. Based on Laberg and Vorren (1996a), Stoker (1990); Sejrup et al. (2000); Dahlgren et al. (2002), Nyga˚rd et al. (2005) and Hjelstuen et al. (2005). GDF: glacigenic debris flow; MIS: marine isotope stage; NC: Norwegian Channel; NSF: North Sea Fan.

and Britain only during the last ca. 0.5 Ma (Bowen, 1989; Bowen, 1991). The onshore glacial record of Ireland contains evidence of at least one glaciation prior to the last, but there is no control on its absolute age (Coxon, 2001) (Fig. 5). The southern limits of glaciation in Britain (Fig. 6a) could indicate that Ireland was completely covered by the Anglian (Elsterian) ice sheet, correlated to MIS 12 (ca. 0.45 Ma) (Bowen, 1989; Bowen, 1991). In the NE Celtic Sea between Ireland and Britain (Fig. 2a), seismic profiles reveal stacked glacigenic sequences, each including glacifluvial drainage features (tunnel-valleys), that imply up to four glacial phases (Wingfield, 1990; Wingfield and Tappin, 1991). The last (Midlandian) ice sheet was once thought to have reached a limit in the southern parts of Ireland (Charlesworth, 1928, 1973), but it is now accepted that it extended both south and west of the present coastline (Warren, 1992; ` Cofaigh, 1996; Warren and Ashley, 1994; McCabe and O ` Cofaigh and Evans, 2001; Bowen et al., 2002) (Fig. 6a). O The vibrocore samples of glacial sediments from the shelf in the UK sector of the Celtic Sea, have been linked to a lateglacial readvance of ice from the Irish Sea and across the NW Isles of Scilly soon after c. 21.5 14C ka BP (Scourse et al., 1991; Scourse, 1991). The interpretation of a glacial readvance is supported by two cores, OMEX 2K and OMEX 4K, from the continental

slope of the Goban Spur (Fig. 2a), which contain IRD layers correlative to Heinrich layers H2 and H1, dated to c. 20–22 14 C ka BP and c. 14 14C ka BP, respectively (Hall and McCave, 1998). In core OMEX 2K, the IRD bracketing the H2 layer contains a distinctive ’chalk fingerprint’ consistent with derivation from an Irish-British ice sheet, while the lack of such a signature for H1 implies that by c. 14 14C ka BP ice had receded and was no longer supplying sediment directly to the slope (Scourse et al., 2000; Scourse and Furze, 2001). The ice margin in the Celtic Sea, as shown on Fig. 6a, corresponds to the southerly extent of the subglacial facies of Scourse et al. (1990, 1991), suggested to represent the grounding line at c. 20–22 14C ka BP (Scourse and Furze, 2001). It does not necessarily represent the maximum extent of glacial ice, as the southern glacimarine facies of Scourse et al. (1990, 1991) could be underlain by subglacial sediments not penetrated by the vibrocores. Thus, the southwesternmost extent of the last glaciation of the NW European margin, as with the extent of earlier glaciations (Fig. 6a), remains unknown. It has long been assumed that at least one glaciation extended to the shelf edge southwest and west of Ireland (Kilroe, 1888; Wright, 1914; Charlesworth, 1931; Graham and Straw, 1992). This is supported by the series of N–S trending moraine ridges (Figs. 2a and 3) recognised across

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the shelf west of Ireland by King et al. (1998b) who inferred them to have formed during the withdrawal of the last ice sheet margin. The seaward extent of the ridges, along 200 km of the shelf, implies that the last glaciation reached the shelf edge of both the northern Porcupine Seabight

and eastern Rockall Trough and extended least part way across the saddle leading to the Porcupine Bank. This distribution supports suggestions that the canyons dissecting the eastern slopes of the Porcupine Seabight and the Rockall Trough, which extend upslope to breach the shelf edge, may

Fig. 6. (a) Ice extent for the Last Glacial Maximum (LGM) and Younger Dryas (Loch Lomond) within the southern part of the study area. Fan complexes are outlined and bathymetry is in metres. (b) Ice extent for the Last Glacial Maximum (LGM) and Younger Dryas within the Norway-Svalbard region. AØ: Andøya; BØ: Bjørnøya; BT; Bear Island Trough; SF; Storfjorden Trough. Fan complexes are outlined. Bathymetry is in metres.

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Fig. 6 (continued)

have received coarse-gained sediment supplied by glacial meltwater (Tudhope and Scoffin, 1995; Unnithan et al., 2001; Weaver et al., 2000; Wheeler et al., 2003). The significance of glacial meltwater on the Irish margin is attested by the abundance of glacifluvial drainage features

(eskers) of the last glaciation in Ireland (Warren and Ashley, 1994), as well as by the presence of buried drainage features (tunnel-valleys) in the Irish Sea (Eyles and McCabe, 1989) and at multiple stratigraphic levels in the NE Celtic Sea (Wingfield, 1990; Wingfield and Tappin, 1991).

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3.2. NW UK margin BGS borehole 88/7,7A (Fig. 2a), drilled on the upper Hebrides slope, remains the most important record of glacial sedimentation recovered from the margin off NW Britain, as it penetrated the entire, preserved, Plio-Pleistocene succession (Stoker et al., 1994). The borehole demonstrated that although the record of ice-rafting offshore NW Britain dates from the late Pliocene (w2.5 Ma), consistent with DSDP data from the Rockall Plateau (Shackleton et al., 1984), the expansive glaciation of the continental shelf did not occur until about 0.44 Ma (MIS 12). Prior to MIS 12, ice sheets probably did not expand beyond the coastline or inner shelf; thus on the outer shelf, the glacial influence remained predominantly distal in character. However, in the early mid-Pleistocene, there was a major expansion of the British Ice Sheet (BIS) onto the Hebrides and West-Shetland shelves. A glacial unconformity is the seismic stratigraphic expression of this expansion (Fig. 4a). Seismic sequences, mapped across the edge of these shelves suggest that ice-marginal and proglacial processes have both contributed to the development of the adjacent Hebrides and West Shetland slope aprons (Stoker et al., 1994; Stoker, 1995; Davison and Stoker, 2002; Stoker, 2002; Holmes et al., 2003). A glaciation curve has been constructed for the BIS on the NW UK margin covering the last 0.5 Ma (Fig. 5). Collectively, the available data—mostly from the Hebridean slope apron (BGS borehole 88/7,7A; Stoker et al., 1994)—suggest that there may have been significant expansion of the BIS during each of the main glacial stages, i.e. MIS 2, 4, 6, 8, 10 and 12. However, it is difficult to map these individual advances on a regional basis away from the Hebrides slope. Moreover, the resolution of the borehole data precludes unambiguous delineation between MIS 12–8 and MIS 4–2. The expansion of the BIS during MIS 6 is based solely on long-range correlation with the North Sea succession (Holmes, 1997), thus, the validity of this curve (Fig. 5) remains to be thoroughly tested. The limit of the last BIS (LGM, MIS 2) on the NW UK margin remains poorly defined. The most comprehensive attempts of ice sheet reconstruction on the shelf, based on stratigraphy and geomorphology, are those of Stoker et al. (1994) and Hall et al. (2003). These reconstructions incorporate the best morphological indicators, end moraines, preserved on the continental shelf (Selby, 1989; Stoker and Holmes, 1991), and suggest that the LGM represented an expansive glaciation, reaching the edge of the continental shelf except, perhaps, on the northern Hebrides shelf (Fig. 6a). Expansive glaciation on the southern Hebrides shelf is supported by the recorded increase in sedimentation on the Barra Fan, described above (Kroon, et al., 2000; Knutz et al., 2001; Knutz et al., 2002; Wilson et al., 2002), which is envisaged to be associated with LGM shelf-edge glaciation in this region. Other published reconstructions and models (Bowen et al.,

1986; Lambeck, 1993, 1995; Ballantyne et al., 1998a,b; Stone et al., 1998; Bowen et al., 2002), may be too conservative. In the central and northern North Sea region Sejrup et al. (1994, 2000) have proposed that the British and Scandinavian ice sheets were confluent from 28–22 14C ka BP, and separated after this time (Fig. 6a). 3.3. Faroe margin Few details are known from the glacial history of the Faroe Islands (Fig. 2a). Nevertheless, pioneering work by Helland (1879) demonstrated that the Faroes once were glaciated. During the Weichselian glaciation the ice cap covered the islands up to at least 700 m above sea level, and extended onto the shelf well beyond the present coastline (Jørgensen and Rasmussen, 1986). The latter authors also concluded that during the Quaternary the Faroe Islands were repeatedly covered by a local ice cap. No foreign erratics have been found, and glacial striations show a radiating pattern from the larger islands. Radiocarbon dating and pollen stratigraphy indicate that glaciers may have been present in the larger valleys until the beginning of the Holocene (Jo´hansen, 1975; Jo´hansen, 1985). Marine geological studies suggest offshore grounding of the Faroe Islands ice cap down to present water depths of at least 400 m (Waagstein and Rasmussen, 1975). Around the Faroe-Islands evidence of glacial reworking of seabed sediments has been found down to water depths of around 750 m (Kuijpers et al., 1998), whereas seismic sections from the northern slope of the Faroe Platform display evidence of glacial reworking of sediments in water depths of up to 900 m (Nielsen and van Weering, 1998). In addition, on the Iceland-Faroe Ridge (Fig. 2a) isolated iceberg ploughmarks are observed down to 960 m water depth (Kuijpers et al., 1998). 3.4. Norwegian margin The glacial influence on the Mid-Norwegian continental shelf (Naust Formation) ranges from the last glacial back to the late Pliocene (Eidvin et al., 1998; Eidvin et al., 2000). The age of the earliest glacial deposits is not well constrained. However, it is often assumed that they are contemporaneous with the inferred onset of the major Northern Hemisphere glaciations at c. 2.75 Ma (Eidvin et al., 2000). This has been deduced from a marked increase in the accumulation of IRD in deep-sea sediments in the Norwegian Sea (Jansen et al., 1988). We note, however, that based on the presence of small amounts of IRD in sediments on the Vøring Plateau as old as 12.6 Ma, Fronval and Jansen (1996) suggested that glaciers and small ice caps large enough to calve into the sea have existed on land areas boarding the Nordic Seas during cold phases since middle Miocene times. More detailed stratigraphic information of the glacial deposits on the shelf are available both for the northern North Sea area (Stoker et al., 1983; Stoker

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and Bent, 1985; Sejrup et al., 1987, 1991, 1994; Eidvin and Rundberg, 2001) and from the Mid-Norwegian shelf (Haflidason et al., 1991; Eidvin et al., 1998; Dahlgren et al., 2002; Hjelstuen et al., 2004). The glacial advances are recorded by deposition of tills and glacimarine diamicton and/or subglacially developed unconformities on the shelf (Sejrup et al., 1996). A glaciation curve for the southwestern part of Fennoscandia was published by Sejrup et al. (2000). This curve was based on stratigraphic evidence from the west coast of Norway and from the northern North Sea. A geotechnical boring from the Norwegian Channel (8903 in Fig. 2a) was especially important in terms of dating marine sediments interlayered with till units. The Fedje Till recorded in this borehole is the oldest (1.1 Ma) identified till in Scandinavia (Sejrup et al., 1995). After this glaciation, ice expanded from western Norway onto the shelf during two glacial stages, before extensive glaciations started around MIS 12. Subsequently, ice sheets have advanced to the shelf edge during each glacial maxima (Fig. 5). Also on the MidNorwegian shelf both the surface morphology (Holtedahl, 1972; Ottesen et al., 2001) and the thick Quaternary sequence (King et al., 1991; Rokoengen et al., 1995; Dahlgren et al., 2002; Hjelstuen et al., 2004) reflect multiple periods of glaciations. As for the North Sea the oldest till sampled on the Mid-Norwegian shelf is dated to c. 1.1 Ma (Haflidason et al., 1991). Over the last five years a number of papers dealing with the glacial development of the outer shelf and continental slope along the Norwegian margin have appeared. From these investigations, inferences of the glacial history on the shelf have been made from three lines of evidence: (1) GDFs, that are linked with shelf-edge glaciation following the arguments by Vorren and Laberg (1997) and King et al. (1998a) (2) identification of till units, and (3) pulses of meltwater plume sedimentation along the upper slope (Sejrup et al., 2003; Hjelstuen et al., 2004). The youngest plume sediments have been dated directly and debris flows and tills are chronologically constrained by the enclosing sediments. In Fig. 5 the glaciation curve from SW Fennoscandia is presented together with a glaciation curve for the Mid-Norwegian margin. These curves are compilations of previously published curves from the region (Sejrup et al., 2000; Dahlgren et al., 2002; Dahlgren and Vorren, 2003; Nyga˚rd et al., 2005; Hjelstuen et al., 2005). In addition to the chronological information from IMAGES cores and shallow drillings from the slope (Hjelstuen et al., 2004; Nyga˚rd et al., 2005) the slope sequences have also been correlated to ODP Site 644 on the Vøring Plateau (Fig. 2b) (e.g. Dahlgren et al., 2002) and geotechnical boring 8903 in the Norwegian Channel (Fig. 2a) (Sejrup et al., 1995) by high-quality shallow seismic data. Generally, the two curves from the Norwegian margin show the same picture. However, there are some discrepancies. For the Mid-Norwegian margin there is evidence, in the form of GDFs, for shelf-edge glaciation

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during MIS 14 (Dahlgren et al., 2002). Similar evidence is not found in the area to the south. This may be related to more extensive glaciation in the north during this glacial stage. This pattern of ice extent is also found during parts of the last deglaciation of the region (Nyga˚rd et al., 2004). There is good evidence for the expansion of glaciers in the coastal region of western Norway during the mid and early Weichselian (Larsen and Sejrup, 1990; Larsen et al., 2000; Sejrup et al., 2000). However, little information exists from the coastal region to the north for this period. Instead we have to rely on evidence from the continental shelf and slope which suggest that these early and mid-Weichselian ice advances did not reach the shelf edge (Dahlgren and Vorren, 2003; Sejrup et al., 2003). For the Andfjord area (Fig. 2b), northern Norway, as well as for the North Sea region, there is evidence for a shelf-edge glaciation between c. 29 14C ka and c. 23 14C ka BP ˚ lesund interstadial) (Sejrup et al., 1994; (following the A Vorren and Plassen, 2002). After this ice advance the ice front in southern Norway receded beyond the coastal areas (Valen et al., 1996) and the central North Sea was deglaciated. The glaciers then advanced again, both in the south and north, after c. 19 14C ka BP. Between c. 19 and c. 15 14 C ka BP the ice was at the shelf edge along the entire Norwegian continental margin, with the exception of the central North Sea (Fig. 6a). Based on radiocarbon dates from core 77/2 (Fig. 2a) it has been shown that the central North Sea has remained ice free since c. 22 14C ka BP (Sejrup et al., 1994). However, the Norwegian Channel Ice Stream was reactivated at c. 19 14C ka BP and was active until c. 15 14C ka BP when it rapidly disintegrated (Sejrup et al., 2000). After c. 15 14C ka BP the ice front was rapidly withdrawing from the shelf edge along parts of the Mid-Norwegian margin, with the exceptions of the shallow banks off Møre. Both within this region, and in northern Norway, a short glacial advance between c. 15 and 13.5 14C ka BP has been recorded (Nyga˚rd et al., 2004; Vorren and Plassen, 2002). The coastal areas in the south became ice free at c. 12.7 14C ka BP. However, in the Vestera˚len area parts of the outer islands have been ice free throughout the last c. 22 14C ka (Vorren et al., 1988; Alm, 1993; Vorren and Plassen, 2002). 3.5. Barents Sea-Svalbard margin Analyses of samples from ODP Site 986 (Fig. 2b) indicated that the long-range glacial history of the Svalbard margin was characterised by three distinct phases (Butt et al., 2000): (i) initial growth between 2.3 and 1.6 Ma, during which period the glaciers were most likely restricted to Svalbard, (ii) further glacial expansion between 1.6 and 1.3 Ma, when ice sheets reached the shelf and possibly even the shelf edge, and (iii) since 1.3 Ma there have been several episodes of glacial advances and retreats across the shelf. Solheim et al. (1998) inferred that the SW Barents Sea margin most likely was glacially influenced in the period after 2.6 Ma. However, glacial expansion to the shelf edge

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did not occur before the early Pleistocene, i.e. around 1.5 Ma. Since this time, ice sheets have repeatedly reached the shelf edge in this region. The chronological constraints for the glacigenic deposits older than the last glacial maximum are sparse. Consequently, Laberg and Vorren (1996a, 1996b) used a ‘count from the top’ approach to estimate the age of the youngest glacigenic units deposited on the Bear Island and Storfjorden Fans (Fig. 2b), all of which reflect glaciations reaching the shelf edge (Fig. 5). Their correlation of middle Pleistocene GDF units to the deep-sea oxygen isotope stratigraphy suggested that an ice sheet extended to the shelf edge of the western Barents Sea at MIS 6, 8, 10, 12 and 14. Landvik et al. (1998) inferred three major ice advances, possibly reaching the shelf edge off Svalbard during MIS 2, 4 and 5d. In the Storfjorden Trough region it has been inferred that an ice sheet reached the shelf edge twice during Weichselian, at MIS 2 and 4; whereas on the SW Barents Sea shelf the ice sheet reached the shelf edge only during MIS 2 (Laberg and Vorren, 1996a). Landvik et al. (1998) stated that during the LGM (Fig. 6b) the ice sheet reached the shelf edge between c. 19 14C ka BP and the onset of the deglaciation at c. 15 14C ka BP. The Barents Sea shelf was largely deglaciated at 12 14C ka BP.

4. Discussion and conclusions The evidence for Pleistocene extension of the NW European ice sheets, onto the eastern North Atlantic-Nordic Seas continental margins is summarized in Fig. 5. The oldest direct evidence for glaciation along the NW European seaboard, which suggests glaciation onto the shelf, is around 2.5 Ma (Henrich and Baumann, 1994; Eidvin et al., 1998; Eidvin and Rundberg, 2001). This probably corresponds to the first major pulse of IRD in the North Atlantic dated to 2.4 Ma (Shackleton et al., 1984) and to the increased level of IRD found on the Vøring Plateau at c. 2.5 Ma (Jansen and Sjøholm, 1991). These ages, were later revised to 2.74 Ma by Jansen et al. (2000). Off Svalbard, glacial influence is evidenced from 2.3 Ma. The first glaciation of the Spitsbergen shelf has been dated to between 1.6 and 1.3 Ma, after which glacial advances repeatedly reached the shelf edge. Somewhat later, the first shelf-edge glaciation along the Norwegian margin occurred (1.1 Ma) which has been correlated with the first distal evidence of Fennoscandian glaciation recorded in the Netherlands (De Jong and Maarleveld, 1983; Sejrup et al., 2000). However, this glaciation was followed by a period of more restricted ice sheets, which ended by the onset of larger glaciations at MIS 14 on the Mid-Norwegian margin and MIS 12 on the southwestern Norwegian margin. For the Hebrides margin (Fig. 2a), the first period with shelf-edge glaciation is also dated to MIS 12. This corresponds to the oldest tills in Britain representing the Anglian glaciation

(Bowen, 1991). However, a less extensive upland glaciation of the British Isles has been suggested for the early Bruhnes chron, and also for the North Sea region during the early Matuyama chron (Bowen et al., 1986; Bowen, 1991). Thus, the overall picture is of a longer period of glaciation of the northern (Svalbard and North Norway) shelf areas, including shelf-edge glaciations, whilst only in glacial episodes during the last 0.5 Ma did ice sheets reach the shelf edge along the whole NW European margin. The observed latitudinal differences in the glacial history most likely reflect an interplay between oceanic and atmospheric processes forced by orbitally induced variability in insolation. In addition, the interplay between stability of marine-based ice sheets, ocean circulation, climate and sea level adds further complexity. A numerical ice sheet model, forced by sea level and temperature, generated an ice sheet configuration for the European seaboard very similar to that observed for the maximum glaciations starting at MIS 12, by reducing the temperature by 10 8C for the region (Siegert et al., 2001). Reducing the temperature by only 5 8C, Siegert et al. (2001) obtained a more restricted glaciation in the south, while glaciers reached the shelf edge in the north. This suggests that the observed change in timing and extent of glaciation may reflect different temperature conditions, which in this region are strongly controlled by the strength of the Norwegian Current. Terrestrial sites from Svalbard to Ireland provide extensive evidence for a large variability in the extent of glaciation through the Weichselian which are relevant for the glacial history of the NW European seaboard (Vorren et al., 1981; Caseldine and Edwards, 1982; Jardine et al., 1988; Landvik et al., 1995; Olsen, 1997; Larsen et al., 2000; Sejrup et al., 2000). However, our knowledge of Weichselian glaciation of the outer shelf areas prior to MIS 2 is limited. On Fig. 6 a possible ice sheet configuration for the margin between c. 28 and c. 15 14 C ka BP is outlined. Both the data from the North Sea and Andøya suggest a less extensive ice cover after c. 22 14 C ka BP. In contrast, off Mid-Norway maximum glacial advances are inferred between c. 22 and 16.5 14C ka BP (Dahlgren and Vorren, 2003). The northeastern part of the Fennoscandian ice sheet has been shown to attain its maximum as late as 17 14C ka BP (Larsen et al., 1999). These data demonstrate that the glacial maximum during MIS 2 was not contemporaneous, and may suggest that pulses of warm water into the southern Norwegian Sea (Weinelt et al., 2003) could have contributed to melting (heat flux) in the west and to increased ice growth in the northeast (precipitation). For the UK and southern Norwegian margin a regional glacial advance dated to between c. 15 and c. 13.3 14C ka BP has been interpreted as a response to a cooling related to H1 (McCabe and Clark, 1998; Nyga˚rd et al., 2004). The latitudinal variations in the gross morphology (Fig. 2) and stratigraphy of the NW European margin may in part reflect the longer duration of glaciation to the north

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(Fig. 5), but also changes in the nature of the sediment supplied by the ice sheets, in particular an increasing importance of glacifluvial (meltwater) processes at southerly latitudes. The observed transition from trough mouth fans to slopes dissected by canyons west of Ireland (Fig. 2) has been suggested to record a greater influence in the north of direct sediment supply from ice sheets grounded on the outer shelf (e.g. Weaver et al., 2000). However, the transition from fans to canyons takes place along the margin west of NW Britain and Ireland, which has experienced shelf-edge glaciation over the same period, i.e. the last 0.5 Ma (e.g. Bowen, 1991). A southerly increase in the abundance of canyons and channels is also observed on the eastern Canadian shelf and slope, where it has been inferred to reflect a greater influence of meltwater processes at lower latitudes (Piper, 1988; Piper et al., 1990). The importance of meltwater along the southern margins of the former European ice sheets is reflected in the abundance of glacifluvial deposits and drainage features left by successive glaciations over the last 500 ka (e.g. Ehlers et al., 1984; Ehlers and Wingfield, 1991; Huuse and Lykke-Andersen, 2000), including in Ireland and the NE Celtic Sea (Wingfield, 1990; Warren and Ashley, 1994). In contrast, along most of the NW European margin, at times of maximum extent, ice streams supplied poorly-sorted sediments (diamicts) to feed the growth of slope fans composed of aggrading successions of GDFs. The lack of sorted sediments is consistent with a more limited role of subglacial meltwater at high latitudes on tidewater ice sheet margins, where ablation may have taken place entirely through iceberg calving (Arnold and Sharp, 1992). In the south, the same subglacial drainage networks that left eskers and tunnel-valleys across Ireland and in the Irish-Celtic Sea (Wingfield, 1990; Warren and Ashley, 1994) may have supplied sorted sediment directly to the shelf edge south of the Donegal Fan, to be received by slope canyons, which have been inactive since the end of the last glaciation (Tudhope and Scoffin, 1995; Unnithan et al., 2001; Weaver et al., 2000; Wheeler et al., 2003).

Acknowledgements This work was part of the EC-supported STRATAGEM (Contract Number EVK3-CT-199-00011) and EUROSTRATAFORM (Contract Number EVK3-CT-200200079) projects, funded through the 5th Framework Programme, and NORPAST II funded by the Research Council of Norway. Financial support from Norsk Hydro ASA to B.O.H is acknowledged, whereas K.I.T.D. thanks STATOIL for PhD and Post Doc. Scholarships. We acknowledge our discussions with the STRATAGEM participants. Comments and suggestions from two anonymous reviewers are greatly appreciated.

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References Alm, T., 1993. Øvre Ara˚svatn—palynostratigraphy of a 22,000 to 10,000 lacustrine record Andøya, Northern Norway. Boreas 22, 171–188. Andersen, B.G., 1979. The deglaciation of Norway 15,000-10,000 B.P. Boreas 8, 79–87. Arnold, N., Sharp, M., 1992. Influence of glacier hydrology on the dynamics of a large Quaternary ice sheet. Journal of Quaternary Science 7 (2), 109–124. Bailey, R.J., 1975. geology of the Irish continental margin and some comparisons with offshore eastern Canada. In: Yorath, C.J., Parker, E. R., Glass, D.J. (Eds.), Canada’s Continental Margins and Offshore Petroleum Exploration. Canadian Society of Petroleum Geologists, Calgary; Memoir 4, pp. 313–340. Bailey, R.J., Grzywacz, J.M., Buckley, J.S., 1974. Seismic reflection profiles of the continental margin bordering the Rockall Trough. Journal of the Geological Society, London 130 (1), 55–69. Ballantyne, C.K., McCarrol, D., Nesje, A., Dahl, S.O., Stone, J.O., 1998a. The last ice sheet in north-west Scotland: Reconstruction and implications. Quaternary Science Reviews 17, 1149–1184. Ballantyne, C.K., McCarroll, D., Nesje, A., Dahl, S.O., Stone, J.O., Fifield, L.K., 1998b. High-resolution reconstruction of the last ice sheet in NW Scotland. Terra Nova 10 (1), 63–67. Belderson, R.H., Kenyon, N.H., Wilson, J.B., 1973. Iceberg plough marks in the northeast Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology 13, 215–224. Bowen, D.Q., 1989. The last interglacial-glacial cycle in the British Isles. Quaternary International 3/4, 41–47. Bowen, D.Q., 1991. Time and space in the glacial sediment systems of the British Isles. In: Ehlers, J., Gibbard, P.L., Rose, J. (Eds.), A Glacial Deposits in Great Britain and Ireland. Balkema, Rotterdam, pp. 3–13. Bowen, D.Q., Phillips, F.M., McCabe, A.M., Knutz, A.M., Sykes, G.A., 2002. New data for the last Glacial Maximum in Great Britain and Ireland. Quaternary Science Reviews 21, 89–101. Bowen, D.Q., Rose, J., McCabe, A.M., Sunderland, D.G., 1986. Correlation of Quaternary glaciations in England, Ireland, Scotland and Wales. Quaternary Science Reviews 5, 229–340. Bulat, J., Long, D., 2001. Images of the seabed in the Faroe-Shetland channel from commercial 3D seismic data. Marine Geophysical Researches 22, 345–367. Butt, F.A., Elverhøi, A., Solheim, A., Forsberg, C.F., 2000. Deciphering Late Cenozoic development of the western Svalbard Margin from ODP Site 986 results. Marine Geology 169, 373–390. CARTOPEP, 1998. Cartographic des Fonds de Peˆche Profonde de l’Atlantique du nord-est. Plouzane´ (Bretagne) IFREMER. Caseldine, C.J., Edwards, K.J., 1982. Interstadial and last interglacial deposits covered by till in Scotland: comments and new evidence. Boreas 11, 119–122. Charlesworth, J.K., 1928. The glacial retreat from central and southern Ireland. Quarterly Journal of the Geological Society of London 84, 293–342. Charlesworth, J.K., 1931. A tentative reconstruction of the successive margins of the Quaternary ice-sheets in the region of the North Sea. Proceedings of the Royal Irish Academic 40B (4), 67–83. Charlesworth, J.K., 1973. Stages in the dissolution of the last ice-sheet in Ireland and the Irish Sea region. Proceedings of the Royal Irish Academic 73B, 79–86. Coxon, P., 2001. Cenozoic: Tertiary and Quaternary (until 10,000 years before present). In: Holland, C.H. (Ed.), The Geology of Ireland. Dunedin Academic Press, Edinburgh. Dahlgren, K.I.T., Vorren, T.O., 2003. Sedimentary environment and glacial history during the last 40 ka of the Vøring continental margin, midNorway. Marine Geology 193, 93–127.

1126

H.P. Sejrup et al. / Marine and Petroleum Geology 22 (2005) 1111–1129

Dahlgren, K.I.T., Vorren, T.O., Laberg, J.S., 2002. Late Quaternary glacial development of the mid-Norwegian margin K658K688N. Marine and Petroleum Geology 19, 1089–1113. Dahlgren, K.I.T., Vorren, T.O., Stoker, M.S., Nielsen, T., Nyga˚rd, A., Sejrup, H.P., De Santis, L., 2005. Late Cenozoic prograding wedges on the NW European continental margin: their formation and relationship to tectonics and climate. Marine and Petroleum Geology this issue, doi: 10:1016/j.warpetgeo.2004.12.008. Davison, S., Stoker, M.S., 2002. Late Pleistocene glacially-influenced deep-marine sedimentation off NW Britain: implications for the rock ´ Cofaigh, C. (Eds.), Glacier-influenced record. In: Dowdeswell, J.A., O Sedimentation in High-Latitude Continental Margins. Geological Society, London, Special Publication, vol. 203, pp. 129–147. de Graciansky, P.C., Poag, C.W., 1985. Geologic history of Goban Spur, Northwest Europe continental margin. In: de Graciansky, P.C., Poag, C. W. et al. (Eds.), Initial Reports of the Deep Sea Drilling Project. Ocean Drilling Program, College Station, Texas, USA, vol. 80, pp. 1187–1216 (Part 2). De Jong, J., Maarleveld, G.C., 1983. The glacial history of the Netherlands. In: Ehlers (Ed.), Glacial Deposits of Northwestern Europe. Balkema, Rotterdam, pp. 353–356. Eidvin, T., Brekke, H., Riis, F., Renshaw, D.K., 1998. Cenozoic stratigraphy of the Norwegian Sea continental shelf 648N–688N. Norsk Geologisk Tidsskrift., 78125–78152. Eidvin, T., Jansen, E., Rundberg, Y., Brekke, H., Grogan, P., 2000. The upper Cainozoic of the Norwegian continental shelf correlated with the deep sea record of the Norwegian Sea and the North Atlantic. Marine and Petroleum Geology 17, 579–600. Eidvin, T., Rundberg, Y., 2001. Late Cainozoic stratigraphy of the Tampen area (Snorre and Visund fields) in the northern North Sea, with emphasis on the chronology of early Neogene sands. Norsk Geologisk Tidsskrift 81, 119–160. Ehlers, J., Meyer, K.-D., Stephan, H.-J., 1984. The pre-Weichselian glaciations of north-west Europe. Quaternary Science Reviews 3 (1), 1–40. Ehlers, J., Wingfield, R.T.R., 1991. The extension of the Late Weichselian\Late Devensian ice sheets in the North Sea Basin. Journal of Quaternary Science 6 (4), 313–326. Elliot, M., Labeyrie, L., Dokken, T., Manthe, S., 2001. Coherent patterns of ice-rafted debris deposits in the Nordic regions during the last glacial (10–60 ka). Earth and Planetary Science Letters 194, 151–163. Elverhøi, A., Solheim, A., 1983. The Barents Sea ice-sheet—a sedimentological discussion. Polar Research 1, 23–42. Elverhøi, A., Solheim, A., Nyland-Berg, M., Russwurm, L., 1992. Last Interglacial-glacial cycle, Western Barents Sea. LUNDQUA report 35, 17–24. Evans, C.D.R. 1990. The Geology of the Western English Channel and its Western Approaches. United Kingdom Offshore Regional Report, British Geological Survey; HMSO, London (93 pp) Eyles, N., McCabe, A.M., 1989. Glaciomarine facies within subglacial tunnel-valleys: the sedimentary record of glacio-isostatic downwarping in the Irish Sea Basin. Sedimentology 36, 431–448. Faleide, J.I., Solheim, A., Fiedler, A., Hjelstuen, B.O., Andersen, E.S., Vanneste, K., 1996. Late Cenozoic evolution of the western Barents SeaSvalbard continental margin. Global and Planetary Change 12, 53–74. Fiedler, A., Faleide, J.I., 1996. Cenozoic sedimentation along the southwestem Barents Sea margin in relation to uplift and erosion of the shelf. Global and Planetary Change 12, 75–93. Forsberg, C.F., Solheim, A., Elverhøi, A., Jansen, E., Channell, J.E.T., Andersen, E.S., 1999. The depositional environment of the Western Svalbard Margin during the Late Pliocene and the Pleistocene: Sedimentary facies changes at Site 986. Proceedings of the Ocean Drilling Program, Scientific Results 162, 233–246. Fronval, T., Jansen, E., 1996. Late Neogene Paleoclimates and Paleoceanography in the Iceland-Norwegian Sea: Evidence from the Iceland and Vøring Plateaus. Proceedings of the Ocean Drilling Program, Scientific Results 151, 455–468.

Games, K.P., 2001. Evidence of shallow gas above the Connemara oil accumulation, Block 26/28, Porcupine Basin. In: Shannon, P.M., Haughton, W., Corcoran, D.V. (Eds.), The Petroleum exploration of Ireland’s Offshore Basin. Geological Society, London, Special Publication, vol. 188, pp. 361–373. Graham, C.C., Straw, A., 1992. Quaternary. In: Cape, J.C.W., Ingham, J.K., Rawson, P.F. (Eds.), Atlas of Palaeography and Lithofacies London, Geological Society Memoir, vol. 13, pp. 149–153. Haflidason, H., Aarseth, I., Haugen, J.-E., Sejrup, H.P., Løvlie, R., Reither, E., 1991. Quaternary stratigraphy of the Draugen area, Mid-Norwegian Shelf. Marine Geology 101, 125–146. Hall, I.R., McCave, I.N., 1998. Late Glacial to Recent accumulation fluxes of sediments at the shelf edge and slope of NW Europe, 48–508N. In: Stoker, M., Evans, D., Cramp, A. (Eds.), Geological Processes on Continental Margins: Sedimentation, Mass-Wasting and Stability Geological Society of London Special Publication, pp. 339–350. Hall, A.M., Peacock, J.D., Connell, E.R., et al., 2003. New data for the last glacial maximum in Great Britain and Ireland: a Scottish perspective on the paper by Bowen et al. Quaternary Science Reviews 22, 1551–1554. Hammer, E. (2003). A 3D-seismic study of the Late Pliocene to Pleistocene prograding wedge off Lofoten. Unpublished thesis, Department of Geology and Mineral Resources Engineering. Trondheim, Norwegian University of Science and Technology. ¨ ber die Vergletscherung der Fa¨ro¨er, sowie der Helland, A., 1879. U Shetland- und Orkney-Inseln. Zeitschrift Deutsche Geologischer Gesellschaft XXXI, 149–755. Henrich, R., Baumann, K.-H., 1994. Evolution of the Norwegian current and the Scandinavian ice sheets during the past 2.6 my: evidence from ODP Leg 104 biogenic carbonate and terrigenous records. Palaeogeography, Palaeoclimatology, Palaeoecology 108, 75–94. Hjelstuen, B.O., Eldholm, O., Skogseid, J., 1999. Cenozoic evolution of the northern Vøring margin. Geological Society of America Bulletin 111 (12), 1792–1807. Hjelstuen, B.O., Elverhøi, A., Faleide, J.I., 1996. Cenozoic erosion and sediment yield in the drainage area of the Storfjorden Fan. Global and Planetary Change 12, 95–117. Hjelstuen, B.O., Sejrup, H.P., Haflidason, H., Nyga˚rd, A., Berstad, I.M., Knorr, G., 2004. Late Quaternary seismic stratigraphy and geological development of the south Vøring margin, Norwegian Sea. Quaternary Science Reviews 23, 1847–1865. Hjelstuen, B.O., Sejrup, H.P., Haflidason, H., Nyga˚rd, A., Ceramicola, S., Bryn, P., 2005. Late Cenozoic glacial history and evolution of the Storegga Slide area and adjacent slide flank regions, Norwegian continental margin. Marine and Petroleum Geology 22, 57–69. Holmes, R., 1997. Quaternary stratigraphy: the offshore record. In: Gordon, J.E. (Ed.), Reflections on the ice age in Scotland: an update on Quaternary studies. The Scottish Association of Geography Teachers and Scottish Natural Heritage, Glasgow, pp. 72–94. Holmes, R., Bulat, J., Hamilton, I., Long, D., 2003. Morphology of an icesheet limit and constructional glacially-fed slope front, Faeroe-Shetland Channel. In: Mienert, J., Weaver, P. (Eds.), European Margin Sediment Dynamics: Side-Scan Sonar and Seismic Images. Springer-Verlag, Berlin, pp. 149–151. Holtedahl, H., 1972. Notes on the influence of glaciation on the Norwegian continental shelf bordering the Norwegian Sea. Ambio Special Report 2, 31–38. Holtedahl, H., 1989. Submarine end moraines and associated deposits off the south coast of Norway. Marine Geology 88, 23–48. Huuse, M., Lykke-Andersen, H., 2000. Overdeepened Quaternary valleys in the eastern Danish North Sea: morphology and origin. Quaternary Science Reviews 19, 1233–1253. Jansen, E., Bleil, U., Henrich, R., Kringstad, L., Slettemark, B., 1988. Paleoenvironmental changes in the Norwegian sea and the northeast Atlantic during the last 2.8 my: deep sea drilling project/ocean drilling program sites 610, 642, 643 and 644. Paleoceanography 3, 563–581.

H.P. Sejrup et al. / Marine and Petroleum Geology 22 (2005) 1111–1129 Jansen, E., Fronval, T., Rack, F., Channell, J.E.T., 2000. PliocenePleistocene ice rafting history and cyclicity in the Nordic Seas during the last 3.5 Myr. Paleoceanography 15, 709–721. Jansen, E., Sjøholm, J., 1991. Reconstruction of glaciation over the past 6 Myr from ice-borne deposits in the Norwegian Sea. Nature 349, 600–603. Jardine, W.G., Dickson, J.H., Haughton, P.D.W., Harkness, D.D., Bowen, D.Q., Sykes, G.A., 1988. A late middle Devensian interstadial site at Sourlie, near Irvine, Strathclyde. Scottish Journal of Geology 24, 288–295. Jo´hansen, J., 1975. Pollen-diagrams from the Shetland and Faroe Islands. New Phytologist 75, 369–387. Jo´hansen, J., 1985. Studies in the vegetational history of the Faroe and Shetland Islands, Annales Societas Scientiarum Foeroensis Supplementum XI. Jørgensen, G., Rasmussen, J., 1986. Glacial striae, roches moutonne´es and ice movements in the Faroe Islands. Geological Survey of Denmark; DGU Series. Kenyon, N.H., 1987. Mass-wasting features on the continental slope of northwest Europe. Marine Geology 74, 57–77. Kilroe, J.R., 1888. Directions of ice-flow in the north of Ireland, as determined by the observations of the Geological Survey. Quarterly Journal of the Geological Society of London 44 (4), 827–833. King, E.L., Haflidason, H., Sejrup, H.P., Løvlie, R., 1998a. Glacigenic debris flows on the North Sea Trough Mouth Fan during ice stream maxima. Marine Geology 152, 217–246. King, E.L., Haflidason, H., Sejrup, H.P., Shipboard Scientific Party: Austin, W., Duffy, M., Klitgaard-Kristensen, D., Scource J., 1998b. End moraines on the northwest Irish continental shelf. Abstract 3rd ENAM II Workshop, Scotland, 1998. King, E.L., Sejrup, H.P., Haflidason, H., Elverhøi, A., Aarseth, I., 1996. Quaternary seismic stratigraphy of the North Sea Fan: glacially fed gravity flow aprons, hemipelagic sediments, and large submarine slides. Marine Geology 130, 293–315. King, L.H., Rokoengen, K., Fader, G.B.J., Gunleiksrud, T., 1991. Tilltongue stratigraphy. Geological Society of America Bulletin 103, 637–659. King, L.H., Rokoengen, K., Gunleiksrud, T., 1987. Quaternary seismostratigraphy of the Mid Norwegian Shelf, 658–67830’N—a till tongue stratigraphy. IKU Publication 114, 58. Knutz, P.C., Austin, W.E.N., Jones, E.J.W., 2001. Millennial-scale depositional cycles related to British Ice Sheet variability and North Atlantic paleocirculation since 45 kyr B.P., Barra Fan, UK margin. Paleoceanography 16, 53–64. Knutz, P.C., Jones, E.J.W., Austin, W.E.N., van Weering, T.C.E., 2002. Glacimarine slope sedimentation, contourite drifts and bottom current pathways on the Barra Fan, UK North Atlantic margin. Marine Geology 188, 129–146. Kroon, D., Shimmield, G., Austin, W.E.N., Derrick, S., Knutz, P., Shimmield, T., 2000. Century- to millennial-scale sedimentologicalgeochemical records of glacial—Holocene sediment variations from the Barra Fan (NE Atlantic). Journal of the Geological Society, London 157, 643–653. Kuijpers, A., Andersen, M.S., Kenyon, N.H., Kunzendorf, H., van Weering, T.C.E., 1998. Quaternary sedimentation and Norwegian Sea overflow pathways around Bill Bailey Bank, northeastern Atlantic. Marine Geology 152, 101–127. Kuijpers, A., Hansen, B., Hu¨hnerbach, V., Larsen, B., Nielsen, T., Werner, F., 2002. Norwegian Sea overflow through the Faroe-Shetland gateway as documented by its bedforms. Marine Geology 188, 147–164. Kuijpers, A., Nielsen, T., Akhmetzhanov, A., de Haas, H., Kenyon, N.H., van Weering, T.C.E., 2001. Late Quaternary slope instability on the Faeroe margin: mass flow features and timing of events. Geo-Marine Letters 20, 149–159. Kuvaas, B., Kristoffersen, Y., 1996. Mass movements in glaciomarine sediments on the Barents Sea continental slope. Global and Planetary Change 12, 287–307.

1127

Laberg, J.S., Vorren, T.O., 1993. A Late Pleistocene submarine slide on the Bear Island Trough Mouth Fan. Geo-Marine Letters 13, 227–234. Laberg, J.S., Vorren, T.O., 1996a. The glacier-fed fan at the mouth of Storfjorden trough, western Barents Sea: a comparative study. Geologische Rundschau 85, 338–349. Laberg, J.S., Vorren, T.O., 1996b. The Middle and Late Pleistocene evolution of the Bear Island Trough Mouth Fan. Global and Planetary Change 12, 309–330. Lambeck, K., 1993. Glacial rebound of the British Isles: 2. A highresolution, high precision model. Geophysical Journal International 15, 960–990. Lambeck, K., 1995. Late Devensian and Holocene shorelines of the British Isles and North Sea from models of glacio-hydro-isostatic rebound. Journal of the Geological Society, London 152, 437–448. Landvik, J.Y., Bondevik, S., Elverhøi, A., Fjeldskaar, W., Mangerud, J., Salvigsen, O., Siegert, M.J., Svendsen, J.O., Vorren, T.O., 1998. The last glacial maximum of Svalbard and the Barents Sea area: Ice sheet extent and configuration. Quaternary Science Reviews 17, 43–75. Landvik, J.Y., Hjort, C., Mangerud, J., Møller, P., Salvigsen, O., 1995. The Quaternary record of eastern Svalbard—an overview. Polar Research 14 (2), 95–103. Larsen, E., Lysa˚, A., Demidov, I., Funder, S., Houmark-Nielsen, M., Kjær, K.H., Murray, A.S., 1999. Age and extent of the Scandinavian ice sheet in northwest Russia. Boreas 28, 115–132. Larsen, E., Sejrup, H.P., 1990. Weichselian land-sea interaction; western Norway—Norwegian Sea. Quaternary Science Reviews 9, 85–97. Larsen, E., Sejrup, H.P., Janocko, J., Landvik, J.Y., Stalsberg, K., Steinslund, P.I., 2000. Recurrent interaction between the Norwegian Channel Ice Stream and terrestrial-based ice across southwest Norway. Boreas 29, 185–203. Lassen, S., Kuijpers, A., Nielsen, T., 2002. Intermediate water signal leads surface water response during Northeast Atlantic deglaciation. Global and Planetary Change 32 (2–3), 111–125. Leslie, A.B., 1993. Shallow Plio-Pleistocene contourites on the Hebrides Slope, northern Rockall Trough region. Sedimentary Geology 82, 61–78. McCabe, A.M., Clark, P.U., 1998. Ice-sheet variability around the North Atlantic Ocean during the last deglaciation. Nature 392, 373–377. ´ Cofaigh, C., 1996. Upper pleistocene facies sequences McCabe, A.M., O and relative sea-level trends along the south coast of Ireland. Journal of Sedimentary Research 66 (2), 376–390. Nielsen, T., van Weering, T.C.E., 1998. Seismic stratigraphy and sedimentary processes at the Norwegian Sea margin northeast of the Faeroe Islands. Marine Geology 152, 141–157. Nyga˚rd, A., Sejrup, H.P., Haflidason, H., Bryn, P., 2005. The glacial North Sea fan, southern Norwegian Margin: architecture and evolution from the continental slope to the deepsea basin. Marine and Petroleum Geology 22, 71–84. Nyga˚rd, A., Sejrup, H.P., Haflidason, H., Cecchi, M., Ottesen, D., 2004. Deglaciation history of the southwestern Fennoscandian Ice Sheet between 15 and 13 14C ka BP. Boreas 33, 1–17. ` O Cofaigh, C., Evans, D.J.A., 2001. Sedimentary evidence for bed conditions associated with a grounded Irish Sea glacier, southern Ireland. Journal of Quaternary Science 16, 435–454. ` Cofaigh, C., Taylor, J., Dowdeswell, J.A., Pudsey, C.J., 2003. Paleo-ice O streams, through mouth fans and high-latitude continental slope sedimentation. Boreas 32, 37–55. Olsen, L., 1997. Rapid shifts in glacial extension characterise a new conceptual model for glacial variations during the Mid and Late Weichselian in Norway. NGU Bulletin 433, 54–55. Orvik, K.A., Niiler, P., 2002. Major pathways of Atlantic water in the northern North Atlantic and Nordic Seas toward Arctic. Geophysical Research Letters 29, X1–X4. Ottesen, D., Dowdeswell, J.A., Rise, L., Rokoengen, K., Henriksen, S., 2002. Large-scale morphological evidence for past ice-stream flow on the mid-Norwegian continental margin. In: Dowdeswell, J.A.,

1128

H.P. Sejrup et al. / Marine and Petroleum Geology 22 (2005) 1111–1129

` Cofaigh, C. (Eds.), Glacier-Influenced Sedimentation on HighO Latitude Continental Margins. Geological Society London, Special Publications, vol. 203, pp. 245–258. Ottesen, D., Rise, L., Rokoengen, K., Sættem, J., 2001. Glacial processes and large-scale morphology on the mid-Norwegian continental shelf. In: Martinsen, O.J., Dreyer, T. (Eds.), Sedimentary Environments Offshore Norway-Palaozoic to Recent. Norwegian Petroleum Society, Special Publication, vol. 10, pp. 441–449. Pantin, H.M., Evans, C.D.R., 1984. The Quaternary history of the central and southwestern Celtic Sea. Marine Geology 57, 259–293. Piper, D.J.W., 1988. Glaciomarine sedimentation on the continental slope off eastern Canada. Geoscience Canada 15 (1), 23–28. Piper, D.J.W., Mudie, P.J., Fader, G.B., Josenhans, H.W., MacLean, B., Vilks, G., 1990. Quaternary geology. In: Keen, M.J., Williams, G.L. (Eds.), Geology of the Continental Margin of Eastern Canada. Geology of Canada no. 2, Geological Survey of Canada (also Geological Society of America, the Geology of North America, v. I-1), pp. 475–607 (chapter 10). Rokoengen, K., Rise, L., Bryn, P., Frengstad, B., Gustavsen, B., Nygaard, E., Sættem, J., 1995. Upper Cenozoic stratigraphy on the MidNorwegian continental shelf. Norsk Geologisk Tidsskrift 71, 88–104. Scoffin, T.P., Bowes, G.E., 1988. The facies distribution of carbonate sediments on Porcupine Bank, northeast Atlantic. Sedimentary Geology 60, 125–134. Scourse, J., Hall, I.R., McCave, I.N., Young, J.R., Sugden, C., 2000. The origin of Heinrich layers: evidence from H2 for European precursor events. Earth and Planetary Science Letters 182, 187–195. Scourse, J., Robinson, J.E., Evans, C.D.R., 1991. Glaciation of the central and southwestern Celtic Sea. In: Ehlers, J., Gibbard, P., Rose, J. (Eds.), Glacial deposits in Great Britain and Ireland. Balkema, Rotterdam, pp. 301–310. Scourse, J.D., 1991. Late Pleistocene stratigraphy and palaeobotany of the Isles of Scilly. Philosophical Transactions. The Royal Society of London, B 334, 405–448. Scourse, J.D., Austin, W.E.N., Bateman, R.M., Catt, J.A., Evans, C.D. R., Robinson, J.E., &Young, J.R., 1990. Sedimentology and micropaleontology glacimarine sediments from the Central and Southwestern Celtic Sea. Geological Society, London, Special Publication 53, 329–347. Scourse, J.D., Furze, M.F.A., 2001. A critical review of the glaciomarine model for Irish Sea deglaciation: evidence from southern Britain, the Celtic shelf rand adjacent continental slope. Journal of Quaternary Science 16 (5), 414–419. Sejrup, H.P., Aarseth, I., Ellingsen, K.L., Løvlie, R., Reither, E., Bent, A., Brigham-Grette, J., Jansen, E., Larsen, E., Stoker, M., 1987. Quaternary stratigraphy of the Fladen area, central North Sea: a multidisciplinary study. Journal of Quaternary Science 2 (1), 35–58. Sejrup, H.P., Aarseth, I., Haflidason, H., 1991. The Quaternary succession in the northern North Sea. Marine Geology 101, 103–111. ˚ ., Tjøstheim, Sejrup, H.P., Aarseth, I., Haflidason, H., Løvlie, R., Bratten, A G., Forsberg, C.F., Ellingsen, K.I., 1995. Quaternary of the Norwegian Channel: glaciation history and palaeoceanography. Norsk Geologisk Tidsskrift 75, 65–87. Sejrup, H.P., Haflidason, H., Aarseth, I., Forsberg, C.F., King, E., Long, D., Rokoengen, K., 1994. Late Weichselian glaciation history of the northern North Sea. Boreas 23, 1–13. Sejrup, H.P., King, E., Aarseth, I., Haflidason, H., Elverhøi, A., 1996. Quaternary erosion and depositional processes: western Norwegian fjords, Norwegian Channel and North Sea Fan. Geological Society of London 117, 187–202. Sejrup, H.P., Larsen, E., Haflidason, H., Berstad, I., Hjelstuen, B.O., Jonsdottir, H., King, E.L., Landvik, J., Longva, O., Nyga˚rd, A., Ottesen, O., Raunholm, S., Rise, L., Stalsberg, K., 2003. Configuration, history and impact of the Norwegian Channel Ice Stream. Boreas 32, 18–36.

Sejrup, H.P., Larsen, E., Landvik, J., King, E.L., Haflidason, H., Nesje, A., 2000. Quaternary glaciations in southern Fennoscandia: evidence from southwestern Norway and the northern North Sea region. Quaternary Science Reviews 19, 667–685. Selby, I. 1989. Quaternary Geology of the Hebridean Continental Margin. Unpublished PhD Thesis, University of Nottingham, UK. Shackleton, N.J., Backman, J., Zimmerman, H.B., Kent, D.V., Hall, M. A., Roberts, D.G., Schnitker, D., Baldauf, J.G., Despraires, A., Homrighausen, R., Huddlestun, P., Keene, J.B., Kaltenback, A.J., Krumsick, K.O., Morton, A.C., Murray, J.W., Westberg-Smith, J., 1984. Oxygen isotope calibration of the onset of ice-rafting and history of glaciation in the North Atlantic region. Nature 307, 620–623. Shannon, P.M., Moore, J.G., Jacob, A.W.B., Makris, J., 1993. Cretaceous and Tertiary basin development west of Ireland. In: Parker, J.R. (Ed.), Petroleum Geology of Northwest Europe: Proceedings of the Fourth Conference. The Geological Society, London, pp. 1057–1066. Shannon, P.M., O’Reilly, B.M., Readman, P.W., Jacob, A.W.B., Kenyon, N., 2001. Slope failure features on the margin of the Rockall Trough. In: Shannon, P.M., Haughton, P.D.W., Corcoran, D. (Eds.), The Petroleum Exploration of Ireland’s Offshore Basins. Geological Society, London, Special Publication, vol. 188, pp. 455–464. Siegert, M.J., Dowdeswell, J.A., Hald, M., Svendsen, J.O., 2001. Modelling the Eurasian Ice Sheet through a full (Weichselian) glacial cycle. Global and Planetary Change 31, 367–385. Solheim, A., Faleide, J.I., Andersen, E.S., Elverhøi, A., Forsberg, C.F., Vanneste, K., Uenzelmann-Neben, G., 1998. Late Cenozoic seismic stratigraphy and glacial geological development of the east Greenland and Svalbard-Barents Sea Continental Margin. Quaternary Science Reviews 17, 155–185. Stewart, F.S., Stoker, M.S., 1990. Problem associated with seismic facies analysis of diamicton-dominated, shelf glacigenic sequences. GeoMarine Letters 10, 151–156. Stoker, M.S., 1990. Glacially-influenced sedimentation on the Hebridean Slope, northwestern United Kingdom continental margin. In: Dowdeswell, J.A., Scourse, J.D. (Eds.), Glacimarine Environments: Processes and Sediments. Geological Society, London, Special Publications, vol. 53, pp. 349–362. Stoker, M.S., 1995. The influence of glacigenic sedimentation on slopeapron development on the continental margin off Northwest Britain. In: Scrutton, R.A., Stoker, M.S., Shimmield, G.B., Tudhope, A.W. (Eds.), The Tectonics, Sedimentation and Palaeoceanography of the North Atlantic Region. Geological Society, London. Special Publications, vol. 90, pp. 159–177. Stoker, M.S., 1997. Seismic-stratigraphic record of glaciation on the Hebridean margin, North-west Britain. In: Davies, T.A., Bell, T., Cooperet, A.E. (Eds.), Glaciated Continental Margins. An Atlas of Acoustic Images. Chapman and Hall, London, pp. 264–267. Stoker, M.S., 2002. Late Neogene development of the UK Atlantic margin. In: Dore´, A.G., Cartwright, J.A., Stoker, M.S., Turner, J.P., Mite, N. (Eds.), Exhumation of the North Atlantic Margin: Timing, Mechanisms and Implications for Petroleum Exploration. Geological Society, London, Special Publications, vol. 196, pp. 411–438. Stoker, M.S., Bent, A., 1985. Middle Pleistocene glacial and glaciomarine sedimentation in the west central North Sea. Boreas 14, 325–332. Stoker, M.S., Harland, R., Morton, A.C., Graham, D.K., 1991. Glacially influenced basin plain sedimentation in the southern Faeroe-Shetland Channel, northwest United Kingdom continental margin. Marine Geology 100, 185–199. Stoker, M.S., Holmes, R., 1991. Submarine end-moraines as indicators of Pleistocene ice-limits off northwest Britain. Journal of the Geological Society, London 148, 431–434. Stoker, M.S., Leslie, A.B., Scott, W.D., Briden, J.C., Hine, N.M., Harland, R., Wilkinson, I.P., Evans, D., Ardus, D.A., 1994. A record of Late

H.P. Sejrup et al. / Marine and Petroleum Geology 22 (2005) 1111–1129 Cenozoic stratigraphy, sedimentation and climate change from the Hebrides slope, NE Atlantic Ocean. Journal of the Geological Society, London 151, 235–249. Stoker, M.S., Skinner, A.C., Fyfe, J.A., Long, D., 1983. Palaeomagnetic evidence for early Pleistocene in the central and northern North Sea. Nature 304, 332–334. Stone, J.O., Ballantyne, C.K., Fifielt, L.K., 1998. Exposure dating and validation of periglacial weathering-limits, northwest Scotland. Geology 26 (7), 590–597. STRATAGEM Partners, 2002. Stoker, M.S. (Compiler). The Neogene stratigraphy of the glaciated European margin from Lofoten to Porcupine. A product of the EC-supported STRATAGEM Project. Contract No. EVK3-CT-1999-00011. Atlas, 65 pp. STRATAGEM Partners, 2003. Stoker, M.S. (Compiler). Neogene evolution of the glaciated European margin. A product of the ECsupported STRATAGEM Project. Contact No. EVK3-CT-l999-00011. Report, 165 pp. Tudhope, A.W., Scoffin, T.P., 1995. Processes of sedimentation in Gollum Channel, Porcupine Seabight; submersible observations and sediment analyses. Transaction of the Royal Society of Edinburgh, Earth Sciences 86, 49–55. Unnithan, V., Shannon, P.M., McGrane, K., Readman, P.W., Jacob, A.W. B., Keary, R., Kenyon, N.H., 2001. Slope instability and sediment redistribution in the Rockall Trough: constraints from GLORIA. In: Shannon, P.M., Haughton, P.D.W., Corcoran, D. (Eds.), The Petroleum Exploration of Ireland’s Offshore Basins. Geological Society, London, Special Publication, vol. 188, pp. 439–454. Valen, V., Mangerud, J., Larsen, E., Hufthammer, A.K., 1996. Sedimentology and stratigraphy in the cave Hamnsundhelleren, western Norway. Journal of Quaternary Science 11, 185–201. Vorren, T.O., Corner, G.D., Nagy, J., 1981. Weichselian sediments containing redeposited interstadial/interglacial fossils at Slettaelva, North Norway. Boreas 10, 477–484. Vorren, T.O., Kristoffersen, Y., 1986. Late Quaternary glaciation in the south-western Barents Sea. Boreas 15, 51–59. Vorren, T.O., Laberg, J.S., 1997. Trough Mouth Fans — Palaeoclimate and ice-sheet Monitors. Quaternary Science Reviews 16 (8), 865–882.

1129

Vorren, T.O., Lebesbye, E., Andreassen, K., Larsen, K.-B., 1989. Glacigenic sediments on a passive continental margin as exemplified by the Barents Sea. Marine Geology 85, 251–271. Vorren, T.O., Plassen, L., 2002. Deglaciation and Paleoclimate of Andfjord-Va˚gsfjord area North Norway. Boreas 31, 97–125. Vorren, T.O., Vorren, K.D., Alm, T., Gulliksen, S., Løvlie, R., 1988. The last deglaciation (20,000 to 11,000 B.P.) on Andøya, northern Norway. Boreas 17, 41–77. Waagstein, R., Rasmussen, J., 1975. Glacial erratics from the seafloor southeast of the Faeroe Islands and the limit of glaciation. Annal Society Faeroenis (Fiydskaparrit) 23, 101–119. Warren, W.P., 1992. Drumlin orientation and the pattern of glaciation in Ireland. Sveriges Geologiska Underso¨kning 81, 359–366. Warren, W.P., Ashley, G.M., 1994. Origins of the ice-contact stratified ridges (eskers) of Ireland. Journal of Sedimentary Research A64 (3), 433–449. Weaver, P.P.E., Wynn, R.B., Kenyon, N.H., Evans, J., 2000. Continental margin sedimentation, with special reference to the north-east Atlantic margin. Sedimentology 47, 239–256. Weinelt, M.E., Vogelsang, E., Kucera, M., Pflaumann, U., Sarnthein, M., Voelker, A., Erlenkeuser, H., Malmgren, B.A., 2003. Variability of North Atlantic heat transfer during MIS 2. Paleoceanography 18 (3) doi: 1071.10.1029/2002PA000772. Wheeler, A.J., Kenyon, N.H., Ivanov, M.K., Beyer, A., Cronin, B.T., WcDonnell, A., Schenke, H.W., Akhmetzhanov, A.M., Satur, N., Zaragosi, S., 2003. Canyon heads and channel architecture of the Gollum Channel, Porcupine Seabight. In: Mienert, J., Weaver, P. (Eds.), European Margin Sediment, Dynamics—Sidescan Sonar and Seismic Images. Springer, Berlin, pp. 183–186. Wilson, L.J., Austin, W.E.N., Jansen, E., 2002. The last British Ice Sheet: growth, maximum-extent and deglaciation. Polar Research 21, 243–250. Wingfield, R., 1990. The origin of major incisions within the Pleistocene deposits of the North Sea. Marine Geology 91, 31–52. Wingfield, R.T.R., Tappin, D.R., 1991. North Celtic Sea, Geology. British Geological Survey and Geological Survey of Ireland. Wright, W.B., 1914. The Quaternary Ice Age. Macmillan, London. Yoon, S.H., Chough, S.K., Thiede, J., Werner, F., 1991. Late Pleistocene sedimentation the Norwegian continental slope between 678 and 718 N. Marine Geology 99, 187–207.