Holocene tephra horizons at Klocka Bog, west‐central Sweden: aspects of reproducibility in subarctic peat deposits

Abstract

This paper presents one of the most extensive Holocene tephra records found to date in Scandinavia. Microtephra horizons originating from Icelandic eruptions were recorded in two ca. 2 m thick peat profiles at Klocka Bog in west-central Sweden. Five of the microtephra horizons were geochemically correlated to the Askja-1875, Hekla-3, Kebister, Hekla-4 and Lairg A tephras respectively. Radiocarbon-based dating of these tephras broadly agree with previously published ages from Iceland, Sweden, Germany and the British Isles. The identification of the Lairg A tephra demonstrates a more widespread distribution than previously thought, extending the usefulness of Icelandic Holocene tephrochronology further north into west-central Scandinavia. Long-lasting snow cover and seasonal wind distribution in the lower stratosphere are suggested as factors that may be responsible for fragmentary tephra deposition patterns in peat deposits of subarctic Scandinavia.

The chronology of abrupt climate change and Late Upper Palaeolithic human adaptation in Europe

“…Sites plotted are not exhaustive, but illustrate the extent of, ash plume fallout for the various volcanic centres. Icelandic data from: Bergman et al, 2004;Bjö rck and Wastegard, 1999;Boygle, 1994;Caseldine et al, 1998;Chambers et al, 2004;Dugmore and Newton, 1997;Dugmore et al, 1995;Dugmore et al, 1992;Eiriksson et al, 2000;Haflidason et al, 2000;Hall and Pilcher, 2002;Hunt, 2004;Langdon et al, 2003;Langdon and Barber, 2001;Litt et al, 2001;Mortensen et al, 2005;Pilcher et al, 1995;Plunckett et al, 2004;Turney et al, 1997;van den Bogaard and Schmincke, 2002;Wastegard et al, 2000Wastegard et al, , 2001. Eifel data from: Litt et al, 2001;Moscariello and Costa, 1997;van den Bogaard and Schmincke, 1985;Vanniere et al, 2004.…”

An overview of distal tephrochronology in northern Europe during the last 1000 years

“…In particular, sitespecific processes may have contributed to the patchy distribution and low shard concentrations of some of the tephras identified in Table 1. For instance, in Scandinavia a large part of the precipitation occurs as snow during the winter months and post-depositional processes associated with fallout on the snow cover, such as redeposition by wind and meltwater, may result in patches of tephra in hollows on the peat surface (Bergman et al, 2004). Thus it is quite possible that some tephras may be missed in studies that tend to focus on one recovered core or monolith.…”

“…Ireland is probably the most studied area with regard to distal tephrochronology in Europe, but recent investigations show the potential for similar studies also in Scandinavia (e.g. Bergman et al, 2004;Boygle, 2004;Pilcher et al, 2005;Davies et al, 2007;Vorren et al, 2007;Borgmark and Wastegård, 2008). For instance, historically dated distal tephras from the last millennium have been used to constrain age-depth models and for validation of other dating methods, e.g.…”

“…The grey field in (b) shows the distribution of FeO tot versus TiO 2 in SILK tephra layers from Iceland and the Faroe Islands (Larsen et al, 2001;Wastegård, 2002;Ó ladó ttir et al, 2008). Data points are from the following sources: MOR-T4 (Chambers et al, 2004); Hekla-1 (Pilcher et al, 1995(Pilcher et al, , 1996(Pilcher et al, , 2005Hall and Pilcher, 2002;Chambers et al, 2004;Vorren et al, 2007); BGMT-1 (Langdon and Barber, 2001); Hekla-1158 (Hall and Pilcher, 2002;Pilcher et al, 2005); GB4-50 (Hall and Pilcher, 2002); Ö raefajö kull-1362 (Pilcher et al, 1995(Pilcher et al, , 2005Hall and Pilcher, 2002); MOR-T2 (Chambers et al, 2004); Veiðivö tn-1477 (Chambers et al, 2004;Davies et al, 2007); Hekla-1510 (Dugmore et al, 1995;Pilcher et al, 1996;Swindles, 2006); Loch Portain B (Dugmore et al, 1995); SLU-5 (Hall and Pilcher, 2002); QUB-384 (Pilcher et al, 2005); PMG-5 (Hall and Pilcher, 2002); Hekla-1845 (Wastegård, 2002); Askja-1875 (Oldfield et al, 1997;Boygle, 2004;Bergman et al, 2004;Davies et al, 2007;Borgmark and Wastegård, 2008); Hekla-1947 (Hall andPilcher, 2002;Swindles, 2006) Icelandic eruption during the early Medieval period. MOR-T4 and GB4-50 have similar geochemical signatures, but GB4-50 is considerably higher in FeO tot …”

A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits: Case Studies from the Netherlands

“…The Hekla-3 tephra, which dates to around 3000 cal BP, has been reported from its source area in Iceland (Boygle 1999), the North Atlantic Ocean Haflidason et al 2000), Ireland (Plunkett 2006), Sweden (Zillén et al 2002;Bergman et al 2004;Boygle 2004;Wastegård 2005), and northern Germany (van den Bogaard et al 2002), and has been 14 C dated to approximately 3100-2800 cal BP. Core Eng-XV from a raised bog peat deposit in the province of Overijssel (Netherlands) spans the mid to late Holocene and has been 14 C dated at very high resolution (57 dates on thoroughly cleaned aboveground macrofossils; Blaauw et al 2004).…”