Geophysical surveys of the sediments of Loch Ness, Scotland: implications for the deglaciation of the Moray Firth Ice Stream, British–Irish Ice Sheet

We present results from three geophysical campaigns using high‐resolution sub‐bottom profiling to image sediments deposited in Loch Ness, Scotland. Sonar profiles show distinct packages of sediment, providing insight into the loch's deglacial history. A recessional moraine complex in the north of the loch indicates initial punctuated retreat. Subsequent retreat was rapid before stabilisation at Foyers Rise formed a large stillstand moraine. Here, the calving margin produced significant volumes of laminated sediments in a proglacial fjord‐like environment. Subsequent to this, ice retreated rapidly to the southern end of the loch, where it again deposited a sequence of proglacial laminated sediments. Sediment sequences were then disturbed by the deposition of a thick gravel layer and a large turbidite deposit as a result of a jökulhlaup from the Spean/Roy ice‐dammed lake. These sediments are overlain by a Holocene sheet drape. Data indicate: (i) a former tributary of the Moray Firth Ice Stream migrated back into Loch Ness as a major outlet glacier with a calving margin in a fjord‐like setting; (ii) there was significant sediment supply to the terminus of this outlet glacier in Loch Ness; and (iii) that jökulhlaups are important for sediment supply into proglacial fjord/lake environments and may compose >20% of proglacial sedimentary sequences. Copyright © 2011 John Wiley & Sons, Ltd.

[1]  C. Ó. Cofaigh,et al.  Marine geophysical evidence for Late Pleistocene ice sheet extent and recession off northwest Ireland , 2012 .

[2]  C. Clark,et al.  What controls the location of ice streams , 2010 .

[3]  R. Quinn,et al.  Marine geophysical evidence for ice sheet extension and recession on the Malin Shelf: New evidence for the western limits of the British Irish Ice Sheet , 2010 .

[4]  John W. Davis,et al.  3D seismic imaging of buried Younger Dryas mass movement flows: Lake Windermere, UK. , 2010 .

[5]  R. Chiverrell,et al.  Extent and timing of the Last Glacial Maximum (LGM) in Britain and Ireland: a review , 2010 .

[6]  N. Waldmann,et al.  Geophysical evidence of multiple glacier advances in Lago Fagnano (54°S), southernmost Patagonia , 2010 .

[7]  C. Ó. Cofaigh,et al.  Glacial and glacially-related features on the continental margin of northwest Ireland mapped from marine geophysical data , 2010 .

[8]  Martyn S. Stoker,et al.  Lateglacial ice-cap dynamics in NW Scotland: evidence from the fjords of the Summer Isles region , 2009 .

[9]  F. Anselmetti,et al.  Environmental history of southern Patagonia unravelled by the seismic stratigraphy of Laguna Potrok Aike , 2009 .

[10]  D. Sugden,et al.  Dynamic cycles, ice streams and their impact on the extent, chronology and deglaciation of the British-Irish ice sheet , 2009 .

[11]  P. Wadhams,et al.  Marine geophysical evidence for former expansion and flow of the Greenland Ice Sheet across the north‐east Greenland continental shelf , 2009 .

[12]  A. Graham,et al.  Seafloor glacial features reveal the extent and decay of the last British Ice Sheet, east of Scotland , 2009 .

[13]  Alan G. Stevenson,et al.  The northern sector of the last British Ice Sheet: Maximum extent and demise , 2008 .

[14]  A. Hubbard,et al.  High-resolution numerical simulation of Younger Dryas glaciation in Scotland , 2008 .

[15]  M. Batist,et al.  Reconstruction of the Holocene seismotectonic activity of the Southern Andes from seismites recorded in Lago Icalma, Chile, 39°S , 2008 .

[16]  C. Firth.  Late Devensian raised shorelines and ice limits in the inner Moray Firth area, northern Scotland , 2008 .

[17]  T. Bradwell,et al.  Morphology and Significance of Transverse Ridges (De Geer Moraines) Adjacent to the Moray Firth, NE Scotland , 2007 .

[18]  D. Fabel,et al.  First cosmogenic 10Be age constraint on the timing of Younger Dryas glaciation and ice cap thickness, western Scottish Highlands , 2007 .

[19]  C. Ballantyne,et al.  Age and significance of former low-altitude corrie glaciers on Hoy, Orkney Islands , 2007, Scottish Journal of Geology.

[20]  N. Eyles,et al.  Late Quaternary contourites and glaciomarine sedimentation in the Fram Strait , 2007 .

[21]  T. Bradwell,et al.  Geomorphological signature and flow dynamics of The Minch palaeo‐ice stream, northwest Scotland , 2007 .

[22]  Brian J. Todd,et al.  Glacial landforms on German Bank, Scotian Shelf: evidence for Late Wisconsinan ice‐sheet dynamics and implications for the formation of De Geer moraines , 2007 .

[23]  A. Graham,et al.  Evidence for Late Pleistocene ice stream activity in the Witch Ground Basin, central North Sea, from 3D seismic reflection data , 2007 .

[24]  Roberto Urrutia,et al.  Giant earthquakes in South-Central Chile revealed by Holocene mass-wasting events in Lake Puyehue , 2007 .

[25]  G. Boulton,et al.  Glaciology of the British Isles Ice Sheet during the last glacial cycle: form, flow, streams and lobes , 2006 .

[26]  R. Herbert,et al.  High‐resolution shallow seismic identification of gas escape features in the sediments of Loch Tay, Scotland: tectonic and microbiological associations , 2006 .

[27]  Rory Quinn,et al.  A side-scan sonar and high-resolution Chirp sub-bottom profile study of the natural and anthropogenic sedimentary record of Lower Lough Erne, northwestern Ireland , 2006 .

[28]  R. Holmes,et al.  The Last Glacial Maximum in the North Sea Basin: micromorphological evidence of extensive glaciation , 2006 .

[29]  T. Vorren,et al.  Pleistocene glacial history of the NW European continental margin , 2005 .

[30]  T. Bradwell,et al.  Subglacial landforms of the tweed palaeo‐ice stream , 2005 .

[31]  Stuart Marsh,et al.  Map and GIS database of glacial landforms and features related to the last British Ice Sheet , 2004 .

[32]  J. Dowdeswell,et al.  Late Quaternary submarine bedforms and ice‐sheet flow in Gerlache Strait and on the adjacent continental shelf, Antarctic Peninsula , 2004 .

[33]  Ian M. Howat,et al.  Reconstructions of western Ross Sea palaeo‐ice‐stream grounding zones from high‐resolution acoustic stratigraphy , 2003 .

[34]  R. Gilbert,et al.  Glacimarine sedimentation in Kangerdluk (Disko Fjord), West Greenland, in response to a surging glacier , 2002 .

[35]  M. Vanneste,et al.  Sublacustrine mud volcanoes and methane seeps caused by dissociation of gas hydrates in Lake Baikal , 2002 .

[36]  Tracy M Shimmield,et al.  Post-glacial depositional environments in a mid-high latitude glacially-overdeepened sea loch, inner Loch Etive, western Scotland , 2002 .

[37]  R. Powell,et al.  Modern glaciomarine environments , 2002 .

[38]  J. Dix,et al.  A high-resolution seismic stratigraphy from a Scottish sea loch and its implications for Loch Lomond stadial deglaciation , 2000 .

[39]  M. Stewart,et al.  Deformation processes and weakening mechanisms within the frictional–viscous transition zone of major crustal-scale faults: insights from the Great Glen Fault Zone, Scotland , 2000 .

[40]  J. Halfman,et al.  Seismic stratigraphy of Waterton Lake, a sediment-starved glaciated basin in the Rocky Mountains of Alberta, Canada and Montana, USA , 2000 .

[41]  M. Batist,et al.  High-resolution seismic stratigraphy of glacial to interglacial fill of a deep glacigenic lake: Lake Le Bourget, Northwestern Alps, France , 1999 .

[42]  L. D. Santis,et al.  Ice shelf grounding zone features of western Prydz Bay, Antarctica: sedimentary processes from seismic and sidescan images , 1999, Antarctic Science.

[43]  A. Russell,et al.  A Younger Dryas (Loch Lomond Stadial) jökulhlaup deposit, Fort Augustus, Scotland , 1998 .

[44]  P. O'sullivan,et al.  The laminated sediments of Loch Ness, Scotland: Preliminary report on the construction of a chronology of sedimentation and its potential use in assessing Holocene climatic variability , 1998 .

[45]  M. Batist,et al.  High-resolution seismic stratigraphy of late quaternary fill of Lake Annecy (northwestern Alps): evolution from glacial to interglacial sedimentary processes , 1998 .

[46]  N. Eyles,et al.  Seismic-stratigraphy of Shuswap Lake, British Columbia, Canada , 1997 .

[47]  John B. Anderson,et al.  Grounding Zone Wedges on the Antarctic Continental Shelf, Antarctic Peninsula , 1997 .

[48]  John B. Anderson,et al.  Lineations on the Ross Sea Continental Shelf, Antarctica , 1997 .

[49]  R. Powell,et al.  Facies architecture and grounding-line fan processes of morainal banks during the deglaciation of Coastal Maine , 1996 .

[50]  C. Auton,et al.  Ice-proximal glaciomarine sedimentation and sea-level change in the inverness area, Scotland: A review of the deglaciation of a major ice stream of the British Late Devensian ice sheet , 1995 .

[51]  David J. Evans,et al.  A record of late Cenozoic stratigraphy, sedimentation and climate change from the Hebrides Slope, NE Atlantic Ocean , 1994, Journal of the Geological Society.

[52]  J. Whittow.  Geology and Scenery in Britain , 1992 .

[53]  A. Hine,et al.  The seismic stratigraphy of Okanagan Lake, British Columbia; a record of rapid deglaciation in a deep ‘fiord-lake’ basin , 1991 .

[54]  R. Holmes,et al.  Submarine end-moraines as indicators of Pleistocene ice-limits off northwest Britain , 1991, Journal of the Geological Society.

[55]  G. Boulton.  Push-moraines and glacier-contact fans in marine and terrestrial environments , 1986 .

[56]  A. Mccabe,et al.  Correlation of Quaternary glaciations in England, Ireland, Scotland and Wales , 1986 .

[57]  J. B. Sissons.  Lateglacial marine erosion and a jökulhlaup deposit in the Beauly Firth , 1981, Scottish Journal of Geology.

[58]  J. B. Sissons.  The Loch Lomond Stadial in the British Isles , 1979, Nature.

[59]  J. B. Sissons.  The limit of the Loch Lomond Advance in Glen Roy and vicinity , 1979, Scottish Journal of Geology.

[60]  J. B. Sissons.  Catastrophic lake drainage in Glen Spean and the Great Glen, Scotland , 1979, Journal of the Geological Society.

[61]  R. H. Campbell,et al.  Debris flows originating from soil slips during rainstorms in Southern California* , 1974, Quarterly Journal of Engineering Geology.

[62]  A. R. Hunt.  The Parallel Roads of Glen Roy , 1896, Geological Magazine.

[63]  J. Nicol.  On the Parallel Roads of Glen Roy , 1869, Quarterly Journal of the Geological Society of London.