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Debris flow deposits within the Palaeogene lava fields of NW Scotland: evidence for mass wasting of the volcanic landscape during emplacement of the Ardnamurchan Central Complex


Coarse fragmental rocks, previously interpreted as primary pyroclastic accumulations infilling flared vents (Richey JE 1938) “The rhythmic eruptions of Ben Hiant, Ardnamurchan, a tertiary volcano. Bull Volcanol” 2(3):1–21), are re-interpreted as predominantly debris flow deposits, with minor hyperconcentrated and stream-flow deposits, temporally and spatially associated with the Palaeogene Ardnamurchan Central Complex (ACC), NW Scotland. These volcaniclastic rocks are conglomerates and breccias, interbedded with siltstones and sandstones, which formed by surface processes on a dissected landscape, developed in response to shallow emplacement of the ACC. Clast-matrix and photo-statistical analyses allow the palaeo-topography and drainage system to be reconstructed and the development of a palaeo-geographic model for the volcanic landscape. Slabs of basalt, dolerite and sandstone were transported as megablocks during catastrophic, gravity-driven events. Lower energy intervals during volcanic hiatuses are marked by lacustrine-fluvial volcaniclastic siltstones and sandstones preserving palynomorph assemblages. We suggest that shallow intrusion is a plausible initiation mechanism for mass wasting in other large igneous provinces. Historically, deposits of the type described here may have been misidentified as vent facies pyroclastic materials.

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  1. Bailey EB, Clough CT, Wright WB, Richey JE, Wilson GV (1924) Tertiary and post-tertiary geology of Mull, Loch Aline and Oban. Memoirs of the Geological Survey, Scotland

  2. Bell BR, Williamson IT (2002) Tertiary igneous activity. In: Trewin NH (ed) The Geology of Scotland (4th edn). The Geological Society, London, pp 371–407

  3. Bertran P, Hetu B, Texier JP, Van Steijn H (1997) Fabric characteristics of sub-aerial slope deposits. Sedimentology 44:1–16

  4. Blair TC, McPherson JG (1998) Recent debris flow processes and resultant form and facies of the dolomite alluvial fan, Owens Valley, California. J Sed Res 68:800–818

  5. British Geological Survey (1969) Tobermory. Scotland Sheet 52. Solid. 1:50 000. British Geological Survey, Keyworth, Nottingham

  6. British Geological Survey (1976) Caliach Point. Scotland Sheet 51(E). Solid. 1:50 000. British Geological Survey, Keyworth, Nottingham

  7. Browne GH, Naish TR (2003) Facies development and sequence architecture of a late Quaternary fluvial-marine transition, Canterbury Plains and shelf, New Zealand: implications for forced regressive deposits. Sed Geol 158:57–86

  8. Butler RWH, Hutton DHW (1994) Basin structure and Tertiary magmatism on Skye, NW Scotland. J Geol Soc Lond 151:931–944

  9. Cappaccioni B, Sarrochi D (1996) Computer-assisted image analysis on clast shape fabric from the Orvieto-Bagnoreggio ignimbrite (Vulsini district, central Italy): implications on the emplacement mechanisms. J Volcanol Geotherm Res 70:75–90

  10. Cas RAF, Wright JV (1987) Volcanic successions: modern and ancient. Allen, London

  11. Chambers LM, Pringle MS, Parrish RR (2005) Rapid formation of the Small Isles Tertiary Centre constrained by precise 40Ar/39Ar and U-Pb ages. Lithos 79:367–384

  12. Collinson JD (1996) Alluvial sediments. In: Reading HG (ed) Sedimentary environments: processes, facies and stratigraphy (3rd edn). Blackwell, Oxford, pp 37–82

  13. Davies IC, Walker RG (1974) Transport and deposition of resedimented conglomerates, the cap enrage formation, Cambro-Ordovician, Gaspe, Quebec. J Sed Pet 44:1200–1216

  14. Emeleus CH (1983) Tertiary igneous activity. In: Craig GY (ed) Geology of Scotland (2nd edn). The Geological Society, London, pp 357–397

  15. Emeleus CH (1985) The tertiary lavas and sediments of northwest Rhum, Inner Hebrides. Geol Mag 122:419–437

  16. Fisher RV (1960) Classification of volcanic breccias. Geol Soc Am Bull 72:973–982

  17. Fisher RV (1983) Flow transformations in sediment gravity flows. Geology 11:273–274

  18. Geikie A (1897) The ancient volcanoes of Great Britain. McMillan, London

  19. Glicken H (1991) Sedimentary architecture of large volcanic-debris avalanches. In: Fisher RV, Smith GA (eds) Sedimentation in volcanic settings. SEPM Spec Publ 45:99–106

  20. Hall A (1996) Igneous petrology (2nd edn). Addison-Wesley, New York

  21. Hamilton MA, Pearson DG, Thompson RN, Kelley SP, Emeleus CH (1998) Rapid eruption of Skye lavas inferred from precise U-Pb and Ar-Ar dating of the Rum and Cuillin plutonic complexes. Nature 294:260–263

  22. Harker A (1904) The tertiary igneous rocks of Skye. Memoirs of the Geological Survey, Scotland

  23. Holness MB (1999) Contact metamorphism and anatexis of Torridonian arkose by minor intrusions of the Rum Igneous Complex, Inner Hebrides, Scotland. Geol Mag 136:527–542

  24. Innes JL (1983) Debris flows. Prog Phys Geog 7:469–501

  25. Johnson AM (1984) Debris flow. In: Brunsden D, Prior DB (eds) Slope instability. Wiley, New York, pp 257–361

  26. Jolley DW (1996) The earliest Eocene sediments of eastern England; an ultra-high resolution palynological correlation. In: Knox RWO’B, Corfield R, Dunay RE (eds) Correlation of the Early Palaeogene in Northwest Europe. Geol Soc Lond Spec Publ 101:219–254

  27. Jolley DW (1997) Palaeosurface palynofloras of the Skye lava field and the age of the British tertiary volcanic province. In: Widdowson M (ed) Palaeosurfaces: recognition, reconstruction and palaeoenvironmental interpretation. Geol Soc Lond Spec Publ 120:67–94

  28. Judd JW (1889) The tertiary volcanoes of the Western Isles of Scotland. Q J Geol Soc Lond 46:341–385

  29. Karatson D, Sztano O, Telbisz T (2002) Preferred clast orientation in volcaniclastic mass-flow deposits: application of a new photo-statistical method. J Sed Res 72:823–835

  30. Le Bas MJ (1971) Cone-sheets as a mechanism of uplift. Geol Mag 108:373–376

  31. Lipman PW, Normark WR, Moore JG, Wilson JB, Gutmacher CE (1988) The giant Alika debris slide, Mauna Loa, Hawaii. J Geophys Res 93:4279–4299

  32. Lirer L, Vinci A, Alberico I, Gifuni T, Bellucci F, Petrosino P, Tinterri R (2001) Occurrence of inter-eruption debris flow and hyperconcentrated flood-flow deposits on Vesuvio volcano, Italy. Sed Geol 139:151–167

  33. Major JJ, Voight B (1986) Sedimentology and clast orientations of the 18th May 1980 Southwest-Flank Lahars, Mt. St. Helens, Washington. J Sed Petrol 56:691–705

  34. Masson DG, Watts AB, Gee MJR, Urgeles R, Mitchell NC, Le Bas TP, Canals M (2002) Slope failures on the flanks of the western Canary Islands. Earth-Sci Rev 57:1–35

  35. O’Driscoll B, Troll VR, Reavy RJ, Turner P (2006) The Great Eucrite intrusion of Ardnamurchan, Scotland: reevaluating the ring-dike concept. Geology 34:189–192

  36. Orton GJ (1996) Volcanic environments. In: Reading HG (ed) Sedimentary environments: processes, facies and stratigraphy (3rd edn). Blackwell, Oxford, pp 485–567

  37. Pierson TC, Costa JE (1987) A rheologic classification of subaerial sediment water flows. In: Costa JE, Wieczorek GF (eds) Debris flows/avalanches: process, recognition and mitigation. Rev Eng Geol 7:1–12

  38. Reubi O, Hernandez J (2000) Volcanic debris avalanche deposits of the upper Maronne valley (Cantal Volcano, France): evidence for contrasted formation and transport mechanisms. J Volcanol Geotherm Res 102:271–286

  39. Reubi O, Ross P-S, White JDL (2006) Debris avalanche deposits associated with large igneous province volcanism: an example from the Mawson formation, central Allan Hills, Antarctica. Geol Soc Am Bull 117:1615–1628

  40. Richey JE (1932) Tertiary ring structures in Britain. Trans Royal Soc Glasgow 19:42–140

  41. Richey JE (1938) The rhythmic eruptions of Ben Hiant, Ardnamurchan, a tertiary volcano. Bull Volcanol 2:1–21

  42. Richey JE, Thomas HH (1930) The geology of Ardnamurchan, north–west Mull and Coll. Memoirs of the Geological Survey, Scotland

  43. Ross S-P, Ukstins Peate I, McClintock MK, Xu YG, Skilling IP, White JDL, Houghton BF (2005) Mafic volcaniclastic deposits in flood basalt provinces: a review. J Volcanol Geotherm Res 145:285–314

  44. Schneider JL, Fisher RV (1998) Transport and emplacement mechanisms of large volcanic debris avalanches: evidence from the northwest sector of Cantal Volcano (France). J Volcanol Geotherm Res 83:141–165

  45. Smith GA (1986) Coarse-grained non-marine volcaniclastic sediment: terminology and depositional process. Geol Soc Am Bull 97:1–10

  46. Smith GA, Lowe DR (1991) Lahars: volcano-hydrologic events and deposition in the debris flow—hyperconcentrated flow continuum. In: Fisher RV, Smith GA (eds) Sedimentation in volcanic settings. SEPM Spec Publ 45:99–106

  47. Sohn YK, Choe MY, Jo HR (2002) Transition from debris flow to hyperconcentrated flow in a submarine channel (the Cretaceous Cerro Toro Formation, southern Chile). Terra Nova 14:405–415

  48. Takahashi T (1978) Mechanical characteristics of debris flow. J Hydraul Div, Am Soc Civ Eng 104:1153–1169

  49. Takahashi T (1980) Debris flow on prismatic open channel. J Hydraul Div, Am Soc Civ Eng 106:381–396

  50. Takahashi T (1981) Debris flow. Ann Rev Fluid Mech 13:57–77

  51. Thompson RN, Gibson SA (1991) Subcontinental mantle plumes, hotspots and pre-existing thinspots. J Geol Soc Lond 148:973–977

  52. Thouret J-C (1999) Volcanic geomorphology—an overview. Earth-Sci Rev 47:95–131

  53. Walker GPL (1971) Distribution of amygdale minerals in the Mull and Morvern (Western Scotland). In: Murty TVVGRK, Rao SS (eds) Studies in earth sciences, west commemoration volume. Today & Tomorrow’s Printers & Publishers, Faridabad, India, pp 181–194

  54. Walker GPL (1975) A new concept of the evolution of the British Tertiary intrusive centres. J Geol Soc Lond 131:121–141

  55. Walker GPL (1993a) Basaltic-volcano systems. In: Prichard HM, Alabaster T, Harris NBW, Neary CR (eds) Magmatic processes and plate tectonics. Geol Soc Lond Spec Publ 76:3–38

  56. Walker GPL (1993b) Re-evaluation of inclined intrusive sheets and dykes in the Cuillins volcano, Isle of Skye. In: Prichard HM, Alabaster T, Harris NBW, Neary CR (eds) Magmatic processes and plate tectonics. Geol Soc Lond Spec Publ 76:589–597

  57. Williams H, McBirney AR (1979) Volcanology. Freeman Cooper, San Francisco

  58. Williamson IT, Bell BR (1994) The Palaeocene lava field of west-central Skye, Scotland: stratigraphy, palaeogeography and structure. Trans Roy Soc Edinburgh, Earth Sci 85:39–75

  59. Yarnold JC (1993) Rock-avalanche characteristics in dry climates and the effect of flow into lakes: insights from mid-Tertiary sedimentary breccias near Artillery Peak, Arizona. Geol Soc Am Bull 105:345–360

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We thank David Jolley for his palynological analysis and Henry Emeleus for his assistance in the field and insightful discussion. The fieldwork would have been impossible without the time and skill of Graham McLeod. Colin Braithwaite, Brian Bluck and Jeff Harris are thanked for their valuable input to the project. We thank the staff of the Sonachan Hotel for their continued support. We gratefully acknowledge Pierre-Simon Ross and two anonymous reviewers for their comments and James White for his editorial support and thorough, helpful reviews.

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Correspondence to David J. Brown.

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Brown, D.J., Bell, B.R. Debris flow deposits within the Palaeogene lava fields of NW Scotland: evidence for mass wasting of the volcanic landscape during emplacement of the Ardnamurchan Central Complex. Bull Volcanol 69, 847 (2007). https://doi.org/10.1007/s00445-007-0114-9

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  • Mass wasting
  • Debris flows
  • Conglomerates
  • Volcaniclastic
  • Palaeogene flood basalts
  • Ardnamurchan Central Complex
  • Palaeo-geography