Twelve definable cryptotephra layers younger than c. 8600cal. BP are reported from lacustrine core material taken from An Loch Mór, Inis Oírr, Aran Islands, western Ireland. The geochemistry of these shard layers, which represent more Holocene tephras than previously geochemically characterized from any European site outside the proximal volcanic influence of Italy or Iceland, is presented. Of these tephras, four may correlate with known Iceland-derived tephra horizons (Vo 1477, HI, Lairg A and H5); one appears to have two possible named correlatives (Hoy;‘Lairg B’ at Sluggan Bog, N Ireland); another has a plausible correlative (AD 860A); but two others represent Icelandic tephras apparently not previously reported on Iceland itself, including a tephra that has geochemistry very similar to Hl (AD 1104) but which dates to c. cal. AD 840. Four tephras that date from the period c. AD 40-1400 have a distinct geochemical signature that relates to Jan Mayen, 750km to the northeast of Iceland and some 1800km distant from An Loch Mór. The results contribute substantially to the chronology of the sediments from An Loch Mór and, at the international level, to the tephrostratigraphy of the northeast Atlantic region. The well-attested Icelandic H4 tephra (from a Hekla eruption of c. 4260cal. BP) was not recorded; it is suggested that An Loch Mór lies south of its recordable distribution in this part of the northeast Atlantic region. Taken together with work at other sites, the findings point to a wealth of potential tephra isochrons in Holocene deposits of the northeast Atlantic seaboard. It is clear also that calcareous lake sediments can be as fruitful a source of tephras as peats. Potential problems relating to dating and geochemical fingerprinting of tephra layers in individual sites are highlighted with reference to the Lairg tephras as recorded in Scotland and Northern Ireland, and to the Hoy tephra that has been described from Orkney.
Bennett, K.D. , Boreham, S. , Sharp, M.J. and Switsur, V.R.1992: Holocene history of environment, vegetation and human settlement on Catta Ness, Lunnasting, Shetland . Journal of Ecology80, 241-273 .
2.
Blackford, J.J. , Edwards, K.J. , Dugmore, A.J. , Cook, G.T. and Buckland, P.C.1992: Icelandic volcanic ash and the mid-Holocene pine (Pinus sylvestris) pollen decline in northern Scotland . The Holocene2, 260-265 .
3.
Boygle, J.E. 1994: Tephra in lake sediments: an unambiguous geochronological marker? Unpublished PhD thesis, University of Edinburgh.
4.
Boygle, J.E.1998: A little goes a long way: discovery of a new mid-Holocene tephra in Sweden . Boreas27, 195-199 .
5.
Buckley, S. and Walker, M.J.C.2002: A mid-Flandrian tephra horizon, Cambrian Mountains, West Wales . Quaternary Newsletter96, 5-11 .
6.
Caseldine, C. , Hatton, J. , Huber, U. , Chiverrell, R. and Woolley, N.1998: Assessing the impact of volcanic activity on mid-Holocene climate in Ireland: the need for replicate data . The Holocene8, 105-111 .
Dugmore, A.J.1991: Tephrochronology and UK archaeology. In Budd, P. , Chapman, B. , Jackson, C. , Jonaway, R. and Ottaway, B. , editors, Proceedings of the Archaeological Sciences Conference 1989, Oxford: Oxbow Books , 242-250.
9.
Dugmore, A.J. and Newton, A.J.1992: Thin tephra layers in peat revealed by X-radiography . Journal of Archaeological Sciences19, 163-170 .
10.
Dugmore, A.J. and Newton, A.J.1998: Holocene tephra layers in the Faroe Islands , Fróoskaparrit46, 191-204 .
11.
Dugmore, A.J. , Cook, G.T. , Shore, J.S. , Newton, A.J. , Edwards, K.J. and Larsen, G.1995a: Radiocarbon dating tephra layers in Britain and Iceland . Radiocarhon37, 379-388 .
12.
Dugmore, A.J. , Larsen, G. and Newton, A.J.1995b: Seven tephra isochrones in Scotland . The Holocene5, 257-266 .
13.
Dugmore, A.J. , Larsen, G. , Newton, A.J. and Sugden, D.E.1992: Geochemical stability of fine-grained silicic tephra layers in lceland and Scotland . Journal of Quaternarv Science7, 173-183 .
14.
Dwyer, R.B. and Mitchell, F.J.G.1997: Investigation of the environmental impact of remote volcanic activity on north Mayo, Ireland, during the mid-Holocene . The Holocene7, 113-118 .
15.
Edwards, K.J. , Buckland, P.C. , Blackford, J.J. , Dugmore, A.J. and Sadler, J.P.1994: The impact of tephra: proximal and distal studies of Icelandic eruptions . Munchener Geographische AbhandlungenB12, 79-99 .
16.
Eiriksson, J. , Knudsen, K.L. , Haflidason, H. and Henriksen, P.2000: Late-glacial and Holocene palaeoceanography of the North Icelandic shelf . Journal of Quaternary Science15, 23-42 .
17.
Grönvold, K. , Óskarsson, N. , Johnsen, S.J. , Clausen, H.B. , Hammer, C.U. , Bond, G. and Bard, E.1995: Ash layers from Iceland in the Greenland GRIP ice core correlated with oceanic and land sediments . Earth and Planetary Science Letters135, 149-155 .
18.
Haflidason, H. , Eiriksson, J. and Kreveld, S.2000: The tephrochronology of Iceland and the North Atlantic region during the Middle and Late Quaternary: a review . Journal of Quaternary Science15, 3-22 .
19.
Haffidason, H. , Larsen, G. and Olafsson, G.1992: The recent sedimentation history of Thingvallavatn, Iceland . Oikos64, 80-95 .
20.
Hall, V.A.2000: The documentary and pollen analytical records of the vegetational history of the Irish landscape AD 200-1650 . Peritia14, 342-371 .
21.
Hall, V.A.2003: Assessing the impact of Icelandic volcanism on vegetation systems in the north of Ireland in the fifth and sixth millennia BC . The Holocene13, 131-138 .
22.
Hall, V.A. and Bunting, M.J.2001: Tephra-dated pollen studies of Medieval landscapes in the north of Ireland. In Duffy, P.J. , Edwards, D. and FitzPatrick, E. , editors, Gaelic Ireland c.1250-c.1650. Land, lordship and settlement, Dublin: Four Courts Press , 207-222.
23.
Hall, V.A. and Pilcher, J.R.2002: Late Quaternary Icelandic tephras in Ireland and Great Britain: detection, characterization and usefulness . The Holocene12, 223-230 .
24.
Hall, V.A. , Pilcher, J.R. and McCormac, F.G.1993: Tephra dated low-land landscape history of the north of Ireland, AD 750-1150 . New Phytologist125, 193-202 .
25.
Hunt, J.B. 1997: Quaternary tephrology and tephrochronology of the North Atlantic region. Unpublished PhD thesis, University of Edinburgh.
26.
Hunt, J.B.2004: Tephrostratigraphical evidence for timing of Quaternary explosive volcanism at Jan Mayen, Norwegian-Greenland Sea. Quaternaire, in press.
27.
Hunt, J.B. , and Hill, P.G.1993: Tephra geochemistry: a discussion of some persistent analytical problems . The Holocene3, 271-278 .
28.
Hunt, J.B. , and Hill, P.G.1996: An inter-laboratory comparison of the electron probe microanalysis of glass geochemistry. Quaternary International34-36, 229-241.
29.
Hunt, J.B. , and Hill, P.G.2001: Tephrological implications of beam size - sample-size effects in electron microprobe analysis of glass shards . Journal of Quaternary Science16, 105-117 .
30.
Hunt, J.B. , Clift, P.D. , Lacasse, C. , Vallier, T.L. and Werner, R.1998: Standardisation of electron probe microanalysis of glass geochemistry . In Saunders, A.D., Larsen, H.C. and Wise, S.W. Jr, editors, Proceedings of the Ocean Drilling Program, Scientific Results152, 85-91 .
31.
Hunt, J.B. , Fannin, N.G.T. , Hill, P.G. and Peacock, J.D.1995: The tephrochronology and radiocarbon dating of North Atlantic, Late-Quaternary sediments: an example from the St Kilda Basin. In Scruttom, R.A. , Stoker, M.S. , Shimmield, G.B. and Tudhope, A.W. , editors, The tectonics, sedimentation and palaeoceanography of the North Atlantic region, London: Geological Society Special Publication 90 , 227-248.
32.
Imsland, P.1978: The geology of the volcanic island Jan Mayen, Arctic Ocean. Nordic Volcanological Institute Research Report 7813. University of Iceland: Reykjavik , 74-74 pp.
33.
Imsland, P.1984: Petrology and evolution of the Jan Mayen magma system . Visindafelag Islendinga Rit 43, 1-332 .
34.
Imsland, P.1986: The volcanic eruption of Jan Mayen, January 1985: interaction between a volcanic island and a fracture zone . Journal of Volcanology and Geothermal Research28, 45-53 .
35.
Jakobsson, S.P.1972: Chemistry and distribution of recent basaltic rocks in Iceland . Lithos5, 365-386 .
36.
Jakobsson, S.P.1979a: Petrology of recent basalts of the Eastern Volcanic Zone, Iceland . Acta Naturalia Islandica26, 1-103 .
37.
Jakobsson, S.P.1979b: Outline of the petrology of Iceland . Jókull29, 57-73 .
38.
Jeličić, L. and O'Connell, M.1992: History of vegetation and land use from 3200 BP to the present in the north-west Burren, a karstic region of western Ireland . Vegetation History and Archaeobotany1, 119-140 .
39.
Kvamme, T. , Mangerud, J. , Furnes, H. and Ruddiman, W.F.1989: Geochemistry of Pleistocene ash zones in cores from the North Atlantic . Norsk Geologisk Tiddskrift69, 251-272 .
40.
Lacasse, C. and Garbe-Schonberg, C.D.2001: Explosive silicic volcanism in Iceland and the Jan Mayen area during the last 6 Ma: sources and timing of major eruptions . Journal of Volcanology and Geothermal Research107, 113-147 .
41.
Lacasse, C. , Paterne, M. , Werner, R. , Wallrabe-Adams, H.-J. , Sigurdsson, H. , Carey, S. and Pinte, G.1996: Geochemistry and origin of Pliocene and Pleistocene ash layers from the Iceland Plateau, Site 907. In Thiede, J. , Myhre, A.M. , Firth, J.V. , Johnson, G.L. and Ruddiman, W.F. , editors, Proceedings of the Ocean Drilling Program, Scientific Results, vol. 151, College Station, TX: Ocean Drilling Program , 309-331.
42.
Langdon, P. and Barber, K.E.2002: The‘AD860’ tephra in Scotland: new data from Langlands Moss, East Kilbride, Strathclyde . Quaternary Newsletter97, 11-18 .
43.
Larsen, G.1982: Gjoskutimatel Jokuldals og nagrennis. In Thórarinsdóttir, H. , Óskarrson, Ó.H. , Steinthórsson, S. and Einarsson, Th. , editors, Eldur er i Norori, Reykjavik: Sögufelag , 51-65.
44.
Larsen, G.1984: Recent volcanic history of the Veiéivötn fissure swarm, southern Iceland-an approach to volcanic risk assessment . Journal of Volcanology and Geothermal Research22, 33-58 .
45.
Larsen, G. and Thórarinsson, S.1977: H4 and other acid Hekla tephra layers . Jökull27, 28-45 .
46.
Larsen, G. , Dugmore, A. and Newton, A.1999: Geochemistry of historical-age silicic tephras in Iceland . The Holocene9, 463-471 .
47.
Larsen G. , Gudmundsson, M.T. and Bjornsson, H.1998: Eight centuries of periodic volcanism at the center of the Iceland hotspot revealed by glacier tephrostratigraphy . Geology26, 943-946 .
48.
Lowe, D.J. and Hunt, J.B.2001: A summary of terminology used in tephra-related studies . In Juvigne, E.T. and Raynal, J.-P., editors, Tephras: chronology, archaeology, CDERAD editeur, Goudet, Les Dossiers de l'Archeo-Logis1, 17-22 .
49.
MacDonald, R. , McGarvie, D.W. , Pinkerton, H. , Smith, R.L. and Palacz, Z.A.1990: Petrogenetic evolution of the Torfajökull volcanic complex, Iceland I. Relationship between magma types . Journal of Petrology31, 429-459 .
50.
Mangerud, J. , Furnes, H. and Johansen, J.1986: A 9000-year old ash bed on the Faroe Islands . Quaternary Research26, 262-265 .
51.
Mangerud, J. , Lie, S.E. , Furnes, H. , Kristiansen, I.L. and Loemo, L.1984: A Younger Dryas ash bed in western Norway and its possible correlations with tephra in cores from the Norwegian Sea and the North Atlantic . Quaternary Research21, 85-104 .
52.
McGarvie, D.W.1984: Torfajökull: a volcano dominated by magma mixing . Geology12, 685-688 .
53.
McGarvie, D.W. , Macdonald, R. , Pinkerton, H. and Smith, R.L.1990: Petrogenetic evolution of the Torfajökull volcanic complex, Iceland II. The role of magma mixing . Journal of Petrology31, 461-481 .
54.
Merkt, J. , Müller, H. , Knabe, W. , Müller, P. and Weiser, T.1993: The early Holocene Saksunarvatn tephra found in lake sediments in NW Germany . Boreas22, 93-100 .
55.
Molloy, K. and O'Connell, M.1993: Early land use and vegetation history at Derryinver Hill, Renvyle Peninsula, Co. Galway, Ireland. In Chambers, F.M. , editor, Climate change and human impact on the landscape, London: Chapman and Hall , 185-199.
56.
Molloy, K. and O'Connell, M.2004: Holocene vegetation and land-use dynamics in the karstic environment of Inis Oirr, Aran Islands, western Ireland: pollen analytical evidence evaluated in light of the archaeological record . Quaternary International113, 41-64 .
57.
O'Connell, M. , Molloy, K. and Bowler, M.1988: Post-glacial landscape evolution in Connemara, western Ireland with particular reference to woodland history. In Birks, H.H. , Birks, H.J.B. , Kaland, P.E. and Moe, D. , editors, Thle cultural landscape - past, present, future, Cambridge: Cambridge University Press , 487-514.
58.
O'Connell, M. , Molloy, K. , Holmes, J.A. , Jones, R. , Saarinen, T. , Roberts, M. , McDermott, F. , Hawkesworth, C.J. , Barton, K. , Leuenberger, M. , Eicher, U. , Chambers, F.M. , Hunt, J.B. , van der Plicht, J. , van Geel, B. , Schettler, G. , Dalton, C. , Battarbee, R.W. , Dörfler, W. , Usinger, H. and Haas, J.N.1999: Timing and mechanisms of Holocene climate change in NW Europe (TIMECHS): multidisciplinary investigations of calcareous, lake sediments from Inis Oírr, Aran Islands, W. Ireland. In Proceedings of European Climate Science Conference, Vienna (19-23 October 1998), Brussels: European Union Commission .
59.
O'Connell, M. , Molloy, K. , Saarinen, T. , Schettler, G. , McDermott, F. , Hawkesworth, C.J. , Huang, Y. , Holmes, J.A. , Jones, R. , Leuenberger, M. , Chambers, F.M. , Hunt, J.B. , Daniell, J. , van der Plicht, J. , Heijnis, H. , van Geel, B. , Barton, K. , Haas, J.N. and Dalton, C.2000: Human impact and climate change at the western fringe of Europe: multidisciplinary studies of calcareous sediments from An Loch Mór, Aran Islands, W. Ireland . Terra Nostra2000, 77-81 .
60.
Persson, C.1971: Tephrochronological investigations of peat deposits in Scandinavia and on the Faroe Islands . Sveriges Geologiska Under-sökning65, 3-34 .
61.
Pilcher, J.R. and Hall, V.A.1992: Towards a tephrochronology for the Holocene of the north of Ireland . The Holocene2, 255-259 .
62.
Pilcher, J.R. and Hall, V.A.1996: Tephrochronological studies in northern England . The Holocene6, 100-105 .
63.
Pilcher, J.R. , Hall, V.A. and McCormac, F.G.1995: Dates of Holocene Icelandic volcanic eruptions from tephra layers in Irish peats . The Holocene5, 103-110 .
64.
Pilcher, J.R. , Hall, V.A. and McCormac, F.G.1996: An outline tephrochronology for the Holocene of the north of Ireland . Journal of Quaternary Science11, 485-494 .
65.
Rose, N.L. , Golding, P.N.E. and Battarbee, R.W.1996: Selective concentration and enumeration of tephra shards from lake sediment cores . The Holocene6, 243-246 .
66.
Sigurdsson, H.1982: Útbreidsla íslenska gjóskulaga á botni Atlanshafs. In Thórarinsdóttir, H. , Óskarsson, Ó.H. , Steinthórsson, S. and Einarsson, Th. , editors, Elduŕ er iNorori, Reykjavik: Sögufelag Reykjaviku , 119-127.
67.
Sigvaldason, G.1974: The petrology of Hekla and the origin of silicic rocks in Iceland. The eruption of Hekla 1947-48V. Reykjavik: Societas Scientiarum Islandica , 1-44.
68.
Sweatman, T.R. and Long, J.V.P.1969: Quantitative electron-probe microanalysis of rock-forming minerals . Journal of Petrology10, 332-379 .
Thórarinsson, S.1944: Tefrokronologiska studier på Island (Tephrochronological studies in Iceland). Geografiska Annaler26, 1-217 .
71.
Thórarinsson, S.1967: The eruption of Hekla in historical times. In Einarsson, Th. , Kjartansson, G. and Thorarinsson, S. , editors, The eruption of Hekla 1947-1948 1, Reykjavik: Societas Scientiarum Islandica , 1-183.
72.
Thórarinsson, S.1981: Greetings from Iceland-ash-falls and volcanic aerosols in Scandinavia . Geografiska Annaler Series A63, 109-110 .
73.
TIMECHS Members , 2001: TIMECHS: Timing and mechanisms of Holocene climate change in NW Europe. EU 4th Framework Programne (phase 2), Climate and Environment. Contract no. ENV4-CT107-0557. Final Report to European Commission, Brussels. Galway: NUIG .
74.
Turney, C.S.M.1998: Extraction of rhyolitic component of Vedde microtephra from minerogenic lake sediments . Journal of Paleolimnology19, 199-206 .
75.
van den Bogaard, C. and Schmincke, H.-U.2002: Linking the North Atlantic to central Europe: a high-resolution Holocene tephrochronological record from northern Germany . Journal of Quaternary Science17, 3-20 .
76.
van den Bogaard, C. , Dörfler, W. , Sandgren, P. and Schmincke, H.-U.1994: Correlating the Holocene records: Icelandic tephra found in Schleswig-Holstein (northern Germany). Naturwissenschaften81, 554-556 .
77.
Wastegård, S. , Björck, S. , Grauert, M. and Hannon, G.E.2001: The Mjáuvøtn tephra and other Holocene tephra horizons from the Faroe Islands: a link between the Icelandic source region, the Nordic Seas, and the European continent . The Holocene11, 101-109 .
78.
Wastegård, S. , Björck, S. , Possnert, G. and Wohlfarth, B.1998: Evidence of the occurrence of Vedde ash in Sweden: radiocarbon age estimates . Journal of Quaternary Science13, 271-274 .
79.
Weir, D.A.1995: A palynological study of landscape development in County Louth from the second millennium BC to the first millennium AD. In Discovery Programnme Reports: 1. Project Restults 1993, Dublin: Royal Irish Academy/Discovery Programme , 77-126.
80.
Wells, C. , Huckerby, E. and Hall, V.1997: Mid-and late-Holocene vegetation history and tephra studies at Fenton Cottage, Lancashire , UK. Vegetation History and Archaeobotany6, 153-166 .
81.
Zielinski, G.A. , Mayewski, P.A. , Meeker, L.D. , Grönvold, K. , Germani, M.S. , Whitlow, S.I. , Twickler, M.S. and Taylor, K.C.1997: Volcanic aerosol records and tephrochronology of the Summit, Greenland, ice cores . Journal of Geophysical Research102, 26625-26640 .
82.
Zillen, L.M. , Wastegård, S. and Snowball, I.F.2002: Calendar year ages of three mid-Holocene tephra layers identified in varved lake sediments in west central Sweden . Quaternary Science Reviews21, 1583-1591 .
