Glacier-Influenced Sedimentation on High-Latitude Continental Margins (Geological Society Special Publication)

Contents......Page 6
Glacier-influenced sedimentation on high-latitude continental margins: introduction and overview......Page 10
Large-scale morphology of Arctic continental slopes: the influence of sediment delivery on slope form......Page 20
Fig. 1. Conceptual model showing the change in the style of slope .........Page 21
Fig. 2. International Bathymetric Chart of the Arctic Ocean (IBCAO) digital bathymetric .........Page 22
Fig. 3. Definition of the continental slope in terms of bathymetric curvature, .........Page 23
Fig. 4. Results of spatial algorithms on masked slope bathymetry. (a) Slope angle .........Page 24
Fig. 5. (a) Arbitrary polygons used in the analysis. Numbers correspond to those .........Page 25
Fig. 6. Six shaded images of continental margins from the IBCAO. In .........Page 27
Fig. 7. Slope angle of the sea floor as a function of .........Page 28
Fig. 8. Histograms and statistics of polygon slope angle and roughness for .........Page 31
Fig. 9. Histograms of slope angle and roughness for polygons adjacent to .........Page 32
Fig. 10. Scatter plots of approximate shelf width v. mean polygon slope angle. .........Page 33
Fig. 11. Sediment discharge data for several glacial margins and trough-mouth fans .........Page 34
Fig. 12. The relationship between slope angle of trough-mouth fans and the .........Page 35
Table 1. Qualitative description of six representative Arctic continental slopes (see Figs 2, 6 & 7)......Page 29
On the architecture of high-latitude continental margins: the influence of ice-sheet and sea-ice processes in the Polar North Atlantic......Page 42
Fig. 1. Idealized high-latitude continental margin, with the locations of interglacial and .........Page 43
Fig. 2. Iceberg scours on East Greenland continental shelf. (a) 12 kHz swath .........Page 44
Fig. 3. (a) Location map of the Norwegian–Greenland Sea with the 500m and .........Page 45
Fig. 4. GLORIA 6.5 kHz side-scan sonar image mosaics of (a) the North sea .........Page 47
Fig. 5. GLORIA 6.5 kHz side-scan sonar mosaic of the Traenadjupet Slide (outlined .........Page 49
Fig. 6. Acoustic imagery of the blocky nature of the more distal .........Page 50
Fig. 7. GLORIA 6.5 kHz side-scan sonar mosaic of the Greenland Basin (Meinert .........Page 51
Fig. 8. EM120 12 kHz swath-bathymetric mosaic of part of the Greenland Basin. .........Page 52
Fig. 9. Acoustic imagery and sub-bottom profile from the channel systems of .........Page 53
Fig. 10. Sediment waves in the Greenland Basin. (a) 30 kHz TOBI side-scan sonar .........Page 54
Fig. 11. Other features on the continental margins of the Norwegian–Greenland Sea .........Page 55
Fig. 12. EM120 swath bathymetric image from a traverse across the mid-ocean .........Page 56
Fig. 13. Conceptual diagram of sedimentary architecture on ice-influenced continental margins in .........Page 57
Late Quaternary architecture of trough–mouth fans: debris flows and suspended sediments on the Norwegian margin......Page 64
Fig. 1. The North Sea and Bear Island fans (black outlines) are .........Page 65
Fig. 2. (a) The distribution of GDFs on the North Sea Fan mapped .........Page 67
Fig. 3. (a) GLORIA mosaic of GDFs on the Bear Island Fan. (b) Flows .........Page 68
Fig. 4. The relationship between fan morphology and GDF location is shown .........Page 69
Fig. 5. 3.5 kHz sections from Bear Island Fan, showing the transition from .........Page 70
Fig. 6. Outside of the area of the Bear Island Fan most .........Page 73
Fig. 7. Lithostratigraphy of JR51 GC07 (located in Fig. 6b) interpreted in the .........Page 75
Fig. 8. The relationship between numerically modelled ice-sheet velocity and GDF deposition .........Page 77
Submarine mass-wasting on glacially-influenced continental slopes: processes and dynamics......Page 82
Fig. 1. Runout distances of submarine mass movements plotted against mobilized sediment .........Page 83
Fig. 2. The various stages of sediment mass behaviour along the flow .........Page 86
Fig. 3. Simplified model for the effect of sea-floor undulations found, for .........Page 87
Fig. 4. (a) Simulation of non-hydroplaning debris flow using BING. Final geometry of .........Page 91
Fig. 5. Plot showing the run-out distances with and without hydroplaning as .........Page 92
Fig. 6. Mobility of submarine mass flows, expressed as H/L ratio plotted .........Page 93
Table 1. Characteristics of selected submarine slides including some data on subaerial slides......Page 84
Experimental constraints on shear mixing rates and processes: implications for the dilution of submarine debris flows......Page 98
Fig. 1. Gravity cores from the Bear Island and Scoresby Sund trough .........Page 99
Fig. 2. (A) Schematic summary of the three main mixing processes for submarine .........Page 101
Fig. 3. Experimental data showing controls on critical shear stress (τ[sub(s)]) for .........Page 103
Fig. 4. (A) Experimental set-up used to investigate shear mixing in annular flumes, .........Page 105
Fig. 5. Experimental data from subaqueous density flows (from Van Kessel & Kranenburg .........Page 107
Fig. 6. Experimental data from subaqueous density flows (from Van Kessel & Kranenburg .........Page 109
Fig. 7. Plot showing entrainment rate (in m min[sup(–1)]) for a debris .........Page 110
Late Oligocene and early Miocene glacimarine sedimentation in the SW Ross Sea, Antarctica: the record from offshore drilling......Page 114
Fig. 1. Tectonic setting of drill sites in the western Ross Sea .........Page 116
Fig. 2. Location of drill sites in the McMurdo Sound region.......Page 117
Fig. 3. Summary of core data, plotted against time, for drill sites .........Page 119
Fig. 4. Summary logs of the upper parts of drill-cores CIROS-1 and .........Page 122
Fig. 5. Representative lithofacies from CRP-1 and CRP-2/2A drill cores: (a) well-sorted sandstone, .........Page 123
Fig. 6. Lithological log through an inferred morainal bank succession in the .........Page 126
Fig. 7. Lithological log through an inferred grounding-line fan succession, underlain by .........Page 128
Fig. 8. Fades model for the development of typical glacimarine successions in .........Page 129
Fig. 9. Generalized three-dimensional perspective of palaeoenvironmental setting for sedimentation along the .........Page 132
Table 1. Drill holes of the Ross continental shelf and coastal Victoria .........Page 115
Table 2. Upper Oligocene and Lower Miocene lithofacies and their interpretation in .........Page 124
Late Pleistocene glacially-influenced deep-marine sedimentation off NW Britain: implications for the rock record......Page 138
Fig. 1. (a) Location of borehole 99/3. (b) Location of the studied section of .........Page 140
Fig. 2. Schematic section across the West Shetland Margin.......Page 141
Fig. 3. Sea-bed image derived from 3-D seismic surveys of the lower .........Page 142
Fig. 4. Seismic (sparker) reflection profiles from the area of borehole 99/3 .........Page 143
Fig. 5. Enlarged section of seismic reflection profile A, showing the location .........Page 144
Fig. 6. Summary log of the Quaternary section of borehole 99/3.......Page 147
Fig. 6. Key to figure.......Page 148
Fig. 7. Hypothetical model for a glacially-influenced base of slope area, incorporating .........Page 152
Fig. 8. Detailed log of the Macduff sequence, simplified from Stoker et al. (1999).......Page 154
Table 1. Summary of interpreted seismic units and corresponding lithofacies.......Page 145
Table 2. Summary of lithological characteristics and interpretation.......Page 146
Late Quaternary sedimentation in Kejser Franz Joseph Fjord and the continental margin of East Greenland......Page 158
Fig. 1. (a) Location map of East Greenland. The inset box outlines the .........Page 160
Fig. 2. (a) Sedimentation and (b) accumulation rates for cores PS2631, PS2641, PS2630, PS2629 .........Page 164
Fig. 3. Stable oxygen isotope records and corresponding lithological log of cores .........Page 165
Fig. 4. Detailed map of the study area showing the distribution of .........Page 166
Fig. 5. Parasound records of acoustic facies within middle–outer Kejser Franz Joseph .........Page 167
Fig. 6. Sedimentological logs of cores PS2633, PS2632, PS2631 and PS2641, middle–outer .........Page 168
Fig. 7. Coarse-particle counts (particles >0.2 cm/10 cm[sup(3)]) from cores PS2633, PS2632, PS2631 and PS2641. .........Page 169
Fig. 8. Down-core grain size distribution, mean grain size, sorting and particles .........Page 170
Fig. 9. Core X-radiographs of representative lithofacies in this study. (a) Bioturbated mud .........Page 172
Fig. 10. Parasound records of acoustic facies from the inner continental shelf. .........Page 174
Fig. 11. Parasound record of the moraine and acoustic facies on the .........Page 175
Fig. 12. Sedimentological logs and coarse-particle counts (particles >0.2 cm/10 cm[sup(3)]) of (a) PS2630, (b) PS2629, .........Page 176
Fig. 13. Parasound records of acoustic facies from the continental slope. (a) Acoustically .........Page 178
Fig. 14. Summary time–distance diagram of the Late Weichselian and Holocene glacial .........Page 181
Table 1. Acoustic facies identified from Parasound records from Kejser Franz Joseph .........Page 161
Table 3. Lithofacies in cores from middle–outer Kejser Franz Joseph Fjord and .........Page 162
Table 4. Radiocarbon dates for cores PS2631, PS2641, PS2630, PS2629, PS2628 and .........Page 163
Contrasting glacial sedimentation processes and sea-level changes in two adjacent basins on the Pacific margin of Canada......Page 190
Fig. 1. The regional and tectonic setting of Georgia Basin, including the .........Page 191
Fig. 2. The Queen Charlotte Basin showing the extent and flow direction .........Page 192
Fig. 3. Distribution of sediment cores collected in the central and northern .........Page 193
Fig. 4. Huntec DTS sub-bottom profile and sediment core (TUL00A06) from central .........Page 194
Table 1. Radiocarbon dates obtained from cores recovered in central and northern .........Page 195
Fig. 6a. Huntec DTS sub-bottom profile and sediment cores (END88B35 and END88B36) .........Page 197
Fig. 6b.......Page 198
Fig. 7. Huntec DTS sub-bottom profile of the heavily iceberg-scoured surface of .........Page 199
Fig. 8b.......Page 200
Developing high-resolution chronologies in glacimarine sediments: examples from southeastern Alaska......Page 204
Fig. 1. Excess [sup(234)]Th, porosity and percent clay (for core 223 BC) .........Page 207
Fig. 2. Map of Icy Bay, Alaska. Locations of box cores are .........Page 210
Fig. 3. X-ray radiograph positives from box cores collected in Icy Bay. .........Page 211
Fig. 4. Transmissometer beam attenuation coefficients and water-column [sup(238)]U total activity profiles .........Page 212
Fig. 5. Application of the constant rate of supply (CRS) method to .........Page 213
Fig. 6. Grey-scale pixel intensity values from core 223 BC X-ray radiograph .........Page 214
Fig. 7. Time-series analysis techniques applied to 223 BC pixel intensity data .........Page 216
Fig. 8. The wavelet power spectra of 223BC X-ray radiograph pixel intensity, .........Page 218
A glacial sequence stratigraphic model for temperate, glaciated continental shelves......Page 224
Fig. 1. End-member processes that contribute to forming grounding-line systems in the .........Page 226
Fig. 2. An hypothetical glacial advance, retreat and readvance sequence that depicts .........Page 227
Fig. 3. A three-dimensional conceptual model of three sequences on a temperate .........Page 229
Fig. 4. Location map in the area of Bering Trough on the .........Page 230
Fig. 5. Interpreted seismic reflection profiles, in mainly dip orientation, from the .........Page 231
Fig. 6. Selected individual facies motifs from different locations on the 3-D .........Page 241
Fig. 6. Legend.......Page 246
Table 1. Lithofacies and depositional systems from Alaskan fjords......Page 225
Table 2. Lithofacies of the onshore exposures of Yakataga Formation (after Eyles & Lagoe 1990)......Page 233
Table 3. Summary of facies characteristics and their interpretations, Cape Roberts cores .........Page 235
Table 4. Seismic facies characteristics and their interpretations as lithofacies......Page 240
Table 5. Characteristics of temperate glaciated continental margins compared with polar and .........Page 249
Large-scale morphological evidence for past ice-stream flow on the mid-Norwegian continental margin......Page 254
Fig. 1. Satellite synthetic aperture radar (SAR) interferogram of the Vestfonna ice .........Page 255
Fig. 2. Location map of the mid-Norwegian continental shelf between 63° and .........Page 256
Fig. 3. Composite seismic profile showing the Upper Cenozoic stratigraphy across the .........Page 257
Fig. 4. Bathymetry of the mid-Norwegian shelf illustrated as a shaded relief .........Page 258
Fig. 5. Shaded relief image of the sea bottom of the inner .........Page 259
Fig. 6. Bathymetry of Sklinnadjupet and Trænadjupet cross-shelf troughs together with Trænabanken .........Page 260
Fig. 7. Large-scale streamlined sedimentary features on the floor of Trænadjupet (emphasized .........Page 261
Fig. 8. Swath bathymetric image of the Sula Reef area in the .........Page 262
Fig. 9. Inferred ice-stream flow lines and ridges during the Late Weichselian .........Page 263
Fig. 10. Numerical-model reconstructions of part of the Late Weichselian Eurasian Ice .........Page 264
Geomorphology of buried glacigenic horizons in the Barents Sea from three-dimensional seismic data......Page 268
Fig. 1. (a) Location and bathymetry of the southwestern Barents Sea. The areas .........Page 269
Fig. 2. Effect of 2-D and 3-D migration on Fresnel zone size .........Page 271
Fig. 3. (a) Seismic profile showing a cross-section of an asymmetrical curved furrow .........Page 272
Fig. 4. (a) Seismic profile showing irregularities on horizon bC in SG9804. The .........Page 273
Fig. 5. Seismo-stratigraphic units and horizons from the 3-D seismic surveys correlated .........Page 274
Fig. 6. (a) Stratigraphy from the 3-D survey SG9804. (b) Horizon bC from SG9804 .........Page 275
Table 2. Size and predominant orientation of subglacial lineations from the four .........Page 276
Fig. 8. Rose diagram showing the 13 dominant orientations of subglacial lineations .........Page 277
Fig. 9. (a) Seismic profile showing buried type I depressions in the northwestern .........Page 279
Fig. 10. (a) Extent of ice sheet during advance 5 (LGM II; Vorren & Laberg 1996). .........Page 282
Table 1. Relationship between the present seismo-stratigraphic units defined from 3-D data .........Page 270
Retreat signature of a polar ice stream: sub-glacial geomorphic features and sediments from the Ross Sea, Antarctica......Page 286
Fig. 1. The geological and geophysical data, bathymetry and geography of the .........Page 287
Fig. 2. Lithologies of the cores used in this investigation grouped by .........Page 289
Fig. 3. Side-scan and chirp-sonar data displaying the lineations in Zone 1. .........Page 291
Fig. 4. (a) Side-scan sonar data displaying the wedge geometry and surface features .........Page 292
Fig. 5. Swath bathymetry data across zone of ridges in Zone 3; .........Page 296
Fig. 6. (a) Side-scan and chirp-sonar data across the straight-crested ridges in Zone 4. .........Page 297
Fig. 7. (a) Swath bathymetry data across the grounding-zone wedge in Zone 5 .........Page 299
Fig. 8. (a) Swath bathymetry data recording mega-scale glacial lineations in Zone 6. .........Page 301
Fig. 9. Summary of the distribution of features in the study region .........Page 309
Table 1. Total sediment volume and sediment per unit area for each zone shown in Figure 9......Page 308
Grain-size characteristics and provenance of ice-proximal glacial marine sediments......Page 314
Fig. 1. (Upper) Location of HU75-056 in the Labrador Sea. (Lower) Bathymetry .........Page 315
Fig. 2. Outline of the distribution of clasts over 2 mm from X-radiographs .........Page 317
Fig. 3. Histograms of the diameters of clasts larger than 2 mm in .........Page 318
Fig. 4. Counts of visible clasts on X-radiographs of split cores (Fig. 1A & B for location). .........Page 319
Fig. 5. (A) Down-core plot of different sand fractions from K14, East Greenland .........Page 320
Fig. 6. (A) Down core plot of the sediment composition over 105 μm .........Page 321
Fig. 7. (A) Principal component scores with and without the below 1 μm fraction .........Page 322
Fig. 8. (A) Sedigraph data for surface samples less than 2 mm from East .........Page 323
Fig. 9. (A) Plot of grain size data from present-day ice-proximal settings in .........Page 325
Fig. 10. (A) Plot of principal component scores from grain-size data (centred and .........Page 327
Fig. 11. (A) Cumulative percentage X-ray diffraction data on the fraction below 4 μm .........Page 329
Table 1. Principal component analysis: Ross & EG grain size......Page 324
Sediment reworking on high-latitude continental margins and its implications for palaeoceanographic studies: insights from the Norwegian–Greenland Sea......Page 334
Fig. 1. Map of Norwegian–Greenland Sea showing main sediment slides, trough-mouth fans, .........Page 335
Fig. 2. (A) GLORIA 6.5 kHz side-scan sonar mosaic showing a large submarine channel .........Page 337
Fig. 3. Sediment cores from the Greenland Basin and abyssal plain of .........Page 339
Fig. 4. Geological and geophysical evidence of contrasting styles of sediment reworking .........Page 342
Fig. 6. Sediment cores from the Icelandic and Norwegian continental margins of .........Page 343
Fig. 7. Debris flows on the Bear Island Fan. (A) GLORIA 6.5 kHz side-san .........Page 345
Fig. 8. Sediment cores from the Bear Island Fan, Norwegian margin. Core .........Page 346
Fig. 9. (A) Linear sedimentation rates (cm ka[sup(–1)]) based on radiocarbon-dated sediment core .........Page 347
Fig. 10. Geophysical and geological evidence of iceberg reworking on the East .........Page 348
Fig. 11. Examples of cores recovered from areas of acoustically stratified sediment, .........Page 350
Table 1. Site information on sediment cores from the Norwegian–Greenland Sea. Locations .........Page 336
Millennial and sub-millennial-scale variability in sediment colour from the Barra Fan, NW Scotland: implications for British ice sheet dynamics......Page 358
Fig. 1. Location map of core MD95-2006 (57°01.82 N, 10°03.48 W, water depth 2120 m), .........Page 359
Fig. 2. Lithological summary of core MD95-2006. General log modified after Kroon et al. .........Page 361
Fig. 3. Age:depth models of core MD95-2006. Dated levels shown are calibrated .........Page 363
Fig. 4. Stratigraphic summary of sediment reflectance (400–700 nm) and lightness (L*) of core .........Page 365
Fig. 5. Summary plots of sediment reflectance and lightness against calcium carbonate .........Page 366
Fig. 6. Summary figures illustrating power spectra of various sedimentological proxies from .........Page 367
Fig. 7. Summary plot showing clay (volume %) against calcium carbonate (weight %) from .........Page 368
Fig. 8. Stratigraphic summary of core MD95-2006 and Greenland Ice Sheet Project .........Page 369
Table 1. Radiocarbon ages of Barra Fan cores VE 56/-10/36, VE 57/-11/59, and MD95-2006......Page 362
Table 2. Age estimates of Heinrich events 1 to 5. The GISP 2 data are derived from Grootes & Stuiver (1997)......Page 370
Observations of surge periodicity in East Greenland using molybdenum records from marine sediment cores......Page 376
Fig. 1. Map showing the location of Noret Inlet and Mesters Vig .........Page 377
Fig. 2. Molybdenum (Mo) record from a sediment core extracted from the .........Page 379
Fig. 4. Oblique photograph taken in 1998 showing the snout of Östre .........Page 380
G......Page 384
M......Page 385
S......Page 386
Y......Page 387