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J. John Lowe - One of the best experts on this subject based on the ideXlab platform.
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Establishing tephrostratigraphic frameworks to aid the study of abrupt climatic and glacial transitions: a case study of the Last Glacial-Interglacial Transition in the British Isles (c. 16-8 ka BP)
Earth-Science Reviews, 2019Co-Authors: Rhys Timms, J. John Lowe, Ian Matthews, Adrian Palmer, Alison Macleod, Dorothy J. Weston, Simon P.e. BlockleyAbstract:Abstract Distally dispersed tephra layers have become an important tool in the investigation of palaeoenvironmental and archaeological records across the globe. They offer possibilities for the synchronisation and improved chronological control in those records to which they can be traced and hence contribute to an improved understanding of the pattern and timing of environmental and archaeological change during periods of rapid climatic adjustment. However, their use as robust isochronous markers for synchronising records is frequently compromised by uncertainties relating to stratigraphical context, precise chronology and chemical composition. Here we collate and review the tephrostratigraphical information dating to the Last Glacial-Interglacial Transition (LGIT; c. 16-8 ka BP) in the British Isles based on published and unpublished records obtained from 54 sites. Based on details of their stratigraphic position, chronology and chemical composition, we propose that 26 individual eruption events may be represented in this collective record which spans the LGIT. The great majority of these eruptives can be traced in origin to Iceland, but we also report on the recent discoveries of ultra-distal tephra from the North American Cascades range, including for the first time the Mount St Helens J Tephra at a site in southern Ireland. These particular ultra-distal discoveries have resulted from a reinterpretation of older data, demonstrating the potential importance of ‘unknown’ analyses in older tephra datasets. The outcome of this review is a comprehensive but provisional tephrostratigraphic framework for the LGIT in the British Isles, which helps to focus future research on parts of the scheme that are in need of further development or testing. The results, therefore, make an important contribution to the wider European tephrostratigraphic framework, while adding new discoveries of transcontinental isochronous tephra markers.
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Chironomid-inferred summer temperatures for the Last Glacial–Interglacial Transition from a lake sediment sequence in Muir Park Reservoir, west-central Scotland
Journal of Quaternary Science, 2016Co-Authors: Stephen J. Brooks, Ian Matthews, Kimberley L. Davies, Karen A. Mather, J. John LoweAbstract:Lake sediments spanning the Last Glacial–Interglacial Transition (LGIT: ca. 14.7 to 8 ka BP) from Muir Park Reservoir (MPR) in west-central Scotland were analysed for chironomids. The site lies just outside the southern limit of a former glacier that advanced into the Loch Lomond Basin during the Loch Lomond (Younger Dryas) Stadial. Chironomid-inferred mean July temperatures were derived using a modern Norwegian calibration dataset. Three tephra layers constrain the sequence chronologically. Inferred temperatures decline from a high value early in the Interstadial, punctuated by two cold oscillations, probably equivalent to GI-1d and GI-1b in the Greenland ice-core record, and a warm oscillation (equivalent to GI-1a) immediately before the severe cooling at the start of the Loch Lomond Stadial (GS-1), when summer temperatures fell by about 5 °C below the Interstadial average. Summer temperatures fell by about 3 °C below the Interstadial average during GI-1d, which is less severe than inferred from other chironomid records from eastern Scotland, and may reflect the influence of an oceanic–continental gradient. Cooling during GI-1b was particularly strong at MPR when minimum temperatures were about the same as those reached during GI-1d, unlike other sites investigated where GI-1d is usually between 1 and 2 °C cooler than GI-1b.
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INTegration of Ice-core, MArine, and TErrestrial records (INTIMATE): refining the record of the Last Glacial–Interglacial Transition
Quaternary Science Reviews, 2008Co-Authors: Wim Z. Hoek, J. John LoweAbstract:INTegration of Ice-core, MArine and TErrestrial records (INTIMATE) is a core project of the INQUA Palaeoclimate Commission, the primary goal of which is to synchronise records of the Last Glacial–Interglacial Transition (LGIT). Through a series of international workshops, INTIMATE has encouraged direct collaboration between scientists with interests and expertise in a wide range of palaeoenvironmental approaches. The workshops have focused on the dissemination of good practice in the dating, correlation and synthesis of diverse palaeoenvironmental records that span the LGIT. This special issue of Quaternary Science Reviews presents some of the outcomes of the 8th INTIMATE International Workshop held in Iceland in September 2005, and focuses on four themes considered vital to INTIMATE's long-term strategy. (1) An event stratigraphy approach, which uses the Greenland oxygen isotope record as a stratotype sequence, lies at the core of INTIMATE's operations. A revised event stratigraphy scheme for application to North Atlantic LGIT records is presented, which is based on the new GICC05 Greenland ice-core chronology. (2) New tree-ring data from Switzerland and the application of Bayesian-based procedures in the analysis of comprehensive radiocarbon data sets provide much potential for reducing the uncertainties in radiocarbon-based age models. (3) Three of the contributions present new evidence that helps to refine the tephrostratigraphy of the LGIT in the NE Atlantic and New Zealand regions. (4) Establishing the precise order and synchroneity of events during the LGIT is vital to understand the causes and effects of abrupt climate change. Data are presented from the Baltic region and Alaska, which vary in degree of compatibility with North Atlantic records. Two final papers consider the roles of Dansgaard–Oeschger events on thermokarst during the Middle Weichselian and of solar activity variations during the mid-Holocene; both illustrate how the INTIMATE event stratigraphy approach can apply to the study of other time intervals.
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The use of magnetic separation techniques to detect basaltic microtephra in Last Glacial-Interglacial transition (LGIT; 15–10 ka cal. bp) sediment sequences in Scotland
Scottish Journal of Geology, 2002Co-Authors: Elizabeth A. V. Mackie, J. John Lowe, Chris S. M. Turney, Siwan M Davies, Kevin Dobbyn, Peter G. HillAbstract:Synopsis Basaltic tephra horizons dominate the Icelandic tephrochronological framework during the Last Glacial-Interglacial transition (LGIT; 15–10 ka cal. bp), providing excellent potential for high precision correlation of palaeoclimate data-sets as recorded in ice, marine and terrestrial sequences of the North Atlantic region. Although significant advances have been made in identifying and extending the known provenance of rhyolitic tephras (in the form of microtephra horizons), the detection of basaltic layers has proved problematic. The bimodal Vedde Ash is an important chronological marker horizon that lies firmly within the GS-1/Younger Dryas chronozone (ca. 10.3 ka 14 C bp; 12.0 ka GRIP ice-core yrs) and provides an excellent opportunity to develop methodologies for extracting both rhyolitic and basaltic ash. The recent identification of the rhyolitic component across Europe using flotation techniques has significantly extended the known provenance of this eruption event. However, there is no routine methodology for the identification of basaltic microtephra horizons and the separation of this component of the Vedde Ash has therefore been limited to visible horizons in Iceland, western Norway and the Isle of Skye. Here, we use magnetic separation techniques to identify for the first time basaltic Vedde Ash as a microtephra horizon in minerogenic sequences from two sites in western Scotland.
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Inter-regional correlation of palaeoclimatic records for the Last Glacial–Interglacial Transition: a protocol for improved precision recommended by the INTIMATE project group
Quaternary Science Reviews, 2001Co-Authors: J. John Lowe, Wim Z. HoekAbstract:The remit of the INTIMATE project of the INQUA Palaeoclimate Commission is to synthesise marine, terrestrial andice-core data for the North Atlantic region during the Last Glacial}Interglacial Transition (LGIT: ca 13}10C kyr BP; ca 15}11.5 ice-core kyr BP). A major problem, however, is the di$culty of e!ecting correlations at a temporal resolution that are adequate for de"ning &leads' and &lags' between the polar ice, terrestrial, marine, andatmospheric realms. The limitations of the d ating andcorrelation method s currently employed are summarised, and new quality assurance protocols are proposed. These include recommendations on the contextual information that should accompany radiocarbon dates, procedures for radiocarbon calibration, the use of an eventstratigraphic approach in inter-regional correlations, andthe more widespreaduse of time-parallel marker horizons (basedon tephra layers, oxygen isotope stratigraphy, palaeomagnetic stratigraphy, andradiocarbon &wiggle-matching') to underpin the geochronology and correlation of events during the LGIT. These protocols will be adopted by the INTIMATE project in future international, collaborative research and are recommended to other groups working on this important time period. 2001 Elsevier Science Ltd. All rights reserved.
Chris S. M. Turney - One of the best experts on this subject based on the ideXlab platform.
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north european Last glacial interglacial transition lgit 15 9 ka tephrochronology extended limits and new events
Journal of Quaternary Science, 2006Co-Authors: Chris S. M. Turney, Stefan Wastegard, K Van Den Burg, Siwan M Davies, Nicki J Whitehouse, J R Pilcher, C CallaghanAbstract:High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the Last glacial–interglacial transition (LGIT; 15–9 ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgard Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously. Copyright © 2006 John Wiley & Sons, Ltd.
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North European Last glacial–interglacial transition (LGIT; 15–9 ka) tephrochronology: extended limits and new events
Journal of Quaternary Science, 2006Co-Authors: Chris S. M. Turney, Stefan Wastegard, Siwan M Davies, Nicki J Whitehouse, J R Pilcher, K. Van Den Burg, C CallaghanAbstract:High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the Last glacial–interglacial transition (LGIT; 15–9 ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgard Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously. Copyright © 2006 John Wiley & Sons, Ltd.
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The use of magnetic separation techniques to detect basaltic microtephra in Last Glacial-Interglacial transition (LGIT; 15–10 ka cal. bp) sediment sequences in Scotland
Scottish Journal of Geology, 2002Co-Authors: Elizabeth A. V. Mackie, J. John Lowe, Chris S. M. Turney, Siwan M Davies, Kevin Dobbyn, Peter G. HillAbstract:Synopsis Basaltic tephra horizons dominate the Icelandic tephrochronological framework during the Last Glacial-Interglacial transition (LGIT; 15–10 ka cal. bp), providing excellent potential for high precision correlation of palaeoclimate data-sets as recorded in ice, marine and terrestrial sequences of the North Atlantic region. Although significant advances have been made in identifying and extending the known provenance of rhyolitic tephras (in the form of microtephra horizons), the detection of basaltic layers has proved problematic. The bimodal Vedde Ash is an important chronological marker horizon that lies firmly within the GS-1/Younger Dryas chronozone (ca. 10.3 ka 14 C bp; 12.0 ka GRIP ice-core yrs) and provides an excellent opportunity to develop methodologies for extracting both rhyolitic and basaltic ash. The recent identification of the rhyolitic component across Europe using flotation techniques has significantly extended the known provenance of this eruption event. However, there is no routine methodology for the identification of basaltic microtephra horizons and the separation of this component of the Vedde Ash has therefore been limited to visible horizons in Iceland, western Norway and the Isle of Skye. Here, we use magnetic separation techniques to identify for the first time basaltic Vedde Ash as a microtephra horizon in minerogenic sequences from two sites in western Scotland.
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Carbon isotope variations and chronology of the Last Glacial-Interglacial transition (14-9 ka BP).
Radiocarbon, 1997Co-Authors: Chris S. M. Turney, Doug Harkness, J. John LoweAbstract:We present δ13C data from both bulk organic sediment samples and terrestrial plant macrofossils from five high-resolution sedimentary sequences from the United Kingdom from which extensive multiproxy data sets have been obtained. These span the Last Glacial-Interglacial transition. Chronological control has been provided by radiocarbon dating and/or tephrochronology. The results demonstrate that significant shifts in bulk organic δ13C can be identified at key climatic transitions in most of the sites. The data are affected by site-specific influences that restrict their use as chronological markers. However, terrestrial plant macrofossil records are more consistent and reveal shifts that appear to be synchronous and which therefore offer a basis for interregional correlation as well as significant paleoenvironmental information.
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Stable carbon isotope variations in northwest Europe during the Last glacial–interglacial transition
Journal of Quaternary Science, 1997Co-Authors: Chris S. M. Turney, J. John Lowe, David J. Beerling, D. D. Harkness, E. Marian ScottAbstract:Stable carbon isotope data that span part of the Last glacial–interglacial transition (ca. 14-9 ka 14C BP; ca. 15–11 ka cal. BP), and which derive from organ-specific plant macrofossils recovered from two lake sediment profiles in the UK and one in Norway, are compared. The recorded temporal variations show similar trends, which, over a millennial time-scale appear to parallel the main drift in δ18O as determined for the GRIP ice-core. It is postulated that some smaller scale variations in the δ13C profiles may reflect the shorter term oscillations in δ18O values evident in the GRIP record, although this is less certain. Overall, however, the results suggest that stable carbon isotope measurements based on organ-specific terrestrial plant macrofossils may provide (i) a means for establishing correlations between terrestrial successions and (ii) additional paleoenvironmental information, as the apparent ‘shadowing’ of the GRIP record indicates a common forcing mechanism for both Greenland δ18O and northwest European δ13C variations. From the evidence available we suggest that the recorded δ13C variations reflect fluctuations in air temperature and/or changes in water vapour pressure in the atmosphere. © 1997 John Wiley & Sons, Ltd.
Stefan Wastegard - One of the best experts on this subject based on the ideXlab platform.
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north european Last glacial interglacial transition lgit 15 9 ka tephrochronology extended limits and new events
Journal of Quaternary Science, 2006Co-Authors: Chris S. M. Turney, Stefan Wastegard, K Van Den Burg, Siwan M Davies, Nicki J Whitehouse, J R Pilcher, C CallaghanAbstract:High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the Last glacial–interglacial transition (LGIT; 15–9 ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgard Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously. Copyright © 2006 John Wiley & Sons, Ltd.
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North European Last glacial–interglacial transition (LGIT; 15–9 ka) tephrochronology: extended limits and new events
Journal of Quaternary Science, 2006Co-Authors: Chris S. M. Turney, Stefan Wastegard, Siwan M Davies, Nicki J Whitehouse, J R Pilcher, K. Van Den Burg, C CallaghanAbstract:High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the Last glacial–interglacial transition (LGIT; 15–9 ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgard Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously. Copyright © 2006 John Wiley & Sons, Ltd.
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climate oscillations and tephrochronology in eastern middle sweden during the Last glacial interglacial transition
Journal of Quaternary Science, 1999Co-Authors: Jonas Bjorck, Stefan WastegardAbstract:ABSTRACT: Two sequences spanning the Last glacial–interglacial transition in southern O¨ stergo¨t-land, eastern middle Sweden have been investigated for high-resolution vegetation change andtephrochronology. Organic carbon and pollen analysis indicates that the Younger Dryas–Pre-boreal climatic transition was characterised by at least one well-defined oscillation or possiblytwo shorter climatic oscillations. The Vedde Ash (ca. 12000 GRIP yr BP or ca. 10300 14 CyrBP) has been identified at both sites, significantly increasing the known distribution of thismarker horizon. In addition, a previously unrecorded rhyolitic tephra of Icelandic origin hasbeen identified at ca. 9000 14 C yr BP. The expansion of Corylus into southern O¨ stergo¨tland isestimated to be ca. 9400 14 C yr BP. Copyright 1999 John Wiley & Sons, Ltd. KEYWORDS: Preboreal oscillation; lacustrine records; Vedde Ash; Last glacial–interglacial transition; expan-sion of Corylus . Introduction The Last glacial–interglacial transition (15–10 k cal. yr BP)was a period characterised by a succession of rapid, extremeclimatic oscillations throughout the North Atlantic. The eventstratigraphy recently proposed by Bjo¨rck
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Climate oscillations and tephrochronology in eastern middle Sweden during the Last glacial–interglacial transition
Journal of Quaternary Science, 1999Co-Authors: Jonas Bjorck, Stefan WastegardAbstract:ABSTRACT: Two sequences spanning the Last glacial–interglacial transition in southern O¨ stergo¨t-land, eastern middle Sweden have been investigated for high-resolution vegetation change andtephrochronology. Organic carbon and pollen analysis indicates that the Younger Dryas–Pre-boreal climatic transition was characterised by at least one well-defined oscillation or possiblytwo shorter climatic oscillations. The Vedde Ash (ca. 12000 GRIP yr BP or ca. 10300 14 CyrBP) has been identified at both sites, significantly increasing the known distribution of thismarker horizon. In addition, a previously unrecorded rhyolitic tephra of Icelandic origin hasbeen identified at ca. 9000 14 C yr BP. The expansion of Corylus into southern O¨ stergo¨tland isestimated to be ca. 9400 14 C yr BP. Copyright 1999 John Wiley & Sons, Ltd. KEYWORDS: Preboreal oscillation; lacustrine records; Vedde Ash; Last glacial–interglacial transition; expan-sion of Corylus . Introduction The Last glacial–interglacial transition (15–10 k cal. yr BP)was a period characterised by a succession of rapid, extremeclimatic oscillations throughout the North Atlantic. The eventstratigraphy recently proposed by Bjo¨rck
Mike Walker - One of the best experts on this subject based on the ideXlab platform.
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Radiocarbon Dating the Last Glacial-Interglacial Transition (Ca. 14–9 14C Ka Bp) in Terrestrial and Marine Records: The Need for New Quality Assurance Protocols
Radiocarbon, 2000Co-Authors: J. John Lowe, Mike WalkerAbstract:The publication during the 1990s of Greenland ice-core records spanning the transition from the Last Cold Stage to the present interglacial (ca. 14-9 (super 14) C ka BP) presented new challenges to scientists working on marine and terrestrial sequences from this important time interval. In particular, there is now an overriding imperative to increase the levels of precision by which events during this period can be dated and correlated. We review some of the problems commonly encountered when using radiocarbon dating for these purposes, and consider some of the new approaches that will be required if this dating method is to provide a basis for a high precision chronology for the Last Glacial-Interglacial transition.
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Climatic changes in areas adjacent to the North Atlantic during the Last Glacial-Interglacial transition (14-9 ka BP): a contribution to IGCP-253
Journal of Quaternary Science, 1994Co-Authors: J. John Lowe, Brigitta Ammann, Hilary H. Birks, Svante Björck, G.r. Coope, Les C. Cwynar, J.-l. De Beaulieu, R. J. Mott, Dorothy M. Peteet, Mike WalkerAbstract:This paper presents a summary of the evidence for climatic changes during the Last Glacial-Interglacial transition (14-9 ka BP) in land areas adjacent to the North Atlantic. It is a synthesis of the results of the 12 regional summaries compiled by contributors to the North Atlantic Seaboard Programme of IGCP-253 that are published separately in this issue of journal of Quaternary Science. Eighteen palaeotemperature curves are compared and arranged in three transects, one from southern Europe to Spitsbergen, a second from Ireland to Poland, and the third from southern New England to the Labrador-Baffin Shelf area. Ten maps are presented that summarise the synoptic climatic conditions of the region in 500-year time periods. The purpose of the exercise is to examine the extent to which any emerging patterns support the Ruddiman and Mclntyre model of large-scale shifts in the position of the oceanic Polar Front during the Last Glacial-Interglacial transition. Some broad agreement emerges, although the influence of oceanic changes is diminished in areas that lay in close proximity to the Laurentide and Fennoscandian ice sheets. Attention is drawn to limitations in the compilations and to the potential for improved models in the future.
C Callaghan - One of the best experts on this subject based on the ideXlab platform.
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north european Last glacial interglacial transition lgit 15 9 ka tephrochronology extended limits and new events
Journal of Quaternary Science, 2006Co-Authors: Chris S. M. Turney, Stefan Wastegard, K Van Den Burg, Siwan M Davies, Nicki J Whitehouse, J R Pilcher, C CallaghanAbstract:High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the Last glacial–interglacial transition (LGIT; 15–9 ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgard Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously. Copyright © 2006 John Wiley & Sons, Ltd.
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North European Last glacial–interglacial transition (LGIT; 15–9 ka) tephrochronology: extended limits and new events
Journal of Quaternary Science, 2006Co-Authors: Chris S. M. Turney, Stefan Wastegard, Siwan M Davies, Nicki J Whitehouse, J R Pilcher, K. Van Den Burg, C CallaghanAbstract:High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the Last glacial–interglacial transition (LGIT; 15–9 ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgard Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously. Copyright © 2006 John Wiley & Sons, Ltd.
