| 1. |
- Singh, B., et al.
(author)
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Study of doubly strange systems using stored antiprotons
- 2016
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In: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
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Journal article (peer-reviewed)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 2. |
- Hammarlund, Dan, et al.
(author)
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Palaeolimnological and sedimentary responses to Holocene forest retreat in the Scandes Mountains, west-central Sweden
- 2004
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In: Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 14:6, s. 862-876
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Journal article (peer-reviewed)abstract
- A suite of analyses was performed on sediments accumulated during the last 10 700 years in Lake Spaime, a small, hydrologically open water body in the modern alpine tundra zone of the Scandes Mountains, west-central Sweden. The study aimed to evaluate (1) the nature of climate changes that forced the late-Holocene lowering of altitudinal tree limit in the region, the timing of which is known from prior studies based on radiocarbon dating of subfossil wood, and (2) the impact of these vegetational changes on an aquatic ecosystem. Arboreal pollen and plant macrofossil data confirm the persistence of trees in the lake catchment at least from c. 9700 cal. BP until c. 3700 cal. BP. Although growing-season temperature is commonly believed to be the dominant factor driving boreal forest tree-limit variations in the region, a chironomid-based reconstruction of mean July air temperature suggests that local deforestation during the late Holocene was not accompanied by a significant cooling. The tree-limit retreat was more likely caused by increasing effective moisture and declining length of the growing season. The ecohydrological response of Lake Spaime to this combination of climate and vegetational changes included a decline in primary productivity, as indicated by an abrupt decrease in sediment organic matter content, while associated increases in organic delta(13)C, delta(15)N and C/N point to diminished fluxes and altered balance of catchment-derived nutrients following deforestation. The decline in aquatic productivity is also marked by a distinct change in the mineral magnetic properties, from a high magnetic concentration assemblage dominated by fine-grained magnetite of biogenic origin to one dominated by background levels of coarse-grained detrital magnetite.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Ammann, B, et al.
(author)
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The Würmian Late-glacial in lowland Switzerland
- 1994
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In: Journal of Quaternary Science. - : Wiley. - 0267-8179 .- 1099-1417. ; 9:2, s. 119-125
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Journal article (peer-reviewed)abstract
- A synthesis is provided of Late-glacial (14-9 ka BP) environmental changes in lowland Switzerland (the 'Swiss Plateau'). The chronology of deglaciation and subsequent developments in vegetation cover in the area are summarised. The sequence of climatic variations experienced in the region during the Late-glacial is then described and a curve representing the main palaeotemperature variations is presented.
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| 8. |
- Bjorck, S, et al.
(author)
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Synchronized terrestrial-atmospheric deglacial records around the North Atlantic
- 1996
-
In: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 274:5290, s. 1155-1160
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Journal article (other academic/artistic)abstract
- On the basis of synchronization of three carbon-14 (C-14)-dated lacustrine sequences from Sweden With tree ring and ice core records, the absolute age of the Younger Dryas-Preboreal climatic shift was determined to be 11,450 to 11,390 +/- 80 years before
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| 9. |
- Hammarlund, Dan, et al.
(author)
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Climate and environment during the Younger Dryas (GS-1) as reflected by composite stable isotope records of lacustrine carbonates at Torreberga, southern Sweden
- 1999
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In: Journal of Quaternary Science. - 1099-1417. ; 14:1, s. 17-28
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Journal article (peer-reviewed)abstract
- Climatic and environmental changes during the Younger Dryas stadial (GS-1) and preceding and following transitions are inferred from stable carbon and oxygen isotope records obtained from the sediments of ancient Lake Torreberga, southern Sweden. Event GS-1 is represented in the sediment sequence by 3.5 m of clay containing lacustrine carbonates of various origins. Comparison of isotopic records obtained on mollusc shells, ostracod valves, and Chara encrustations precipitated during specific seasons of the year supports estimates of relative changes in both lake water and mean annual air temperatures. Variations in soil erosion rates can also be estimated from a simple isotope-mass-balance model to separate allochthonous and autochthonous carbonate contributions to the bulk carbonate content of the sediments. The well-known, rapid climatic shifts characterising the Last Termination in the North Atlantic region are clearly reflected in the isotopic data, as well as longer-term changes within GS-1. Following maximum cooling shortly after the Allerod-Younger Dryas (GI-1-GS-1) transition, a progressive warming and a slight increase in aquatic productivity is indicated. At the Younger Dryas-Preboreal (GS-1-PB) transition mean annual air temperature rapidly increased by more than 5 degrees C and summer lake-water temperature increased by ca. 12 degrees C. The subsequent Preboreal oscillation is characterised by an increase in soil erosion and a slight decrease in mean annual air temperature. These results are in harmony with recent findings about large-scale climate dynamics during the Last Termination. Copyright (C) 1999 John Wiley & Sons, Ltd.
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| 10. |
- Wohlfarth, B, et al.
(author)
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An 800-year long, radiocarbon-dated varve chronology from south-eastern Sweden
- 1998
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In: BOREAS. - : SCANDINAVIAN UNIVERSITY PRESS. - 0300-9483. ; 27:4, s. 243-257
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Journal article (other academic/artistic)abstract
- More than 50 varve-thickness diagrams, which were established from glacial varved clays in south-eastern Sweden were correlated with each other to form an 800-year long floating varve chronology. AMS C-14 measurements on terrestrial macrofossils from the
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| 11. |
- Wohlfarth, B, et al.
(author)
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Pitfalls in the AMS radiocarbon-dating of terrestrial macrofossils
- 1998
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In: JOURNAL OF QUATERNARY SCIENCE. - : JOHN WILEY & SONS LTD. - 0267-8179. ; 13:2, s. 137-145
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Journal article (other academic/artistic)abstract
- The AMS C-14 technique has the advantage that small samples of Late Quaternary age can be dated with high accuracy, and that errors due to reservoir effects can be avoided if specifically determined terrestrial micro- and macrofossils are measured. Howeve
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| 12. |
- Wohlfarth, C., et al.
(author)
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miR-16 and miR-103 impact 5-HT4 receptor signalling and correlate with symptom profile in irritable bowel syndrome
- 2017
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Journal article (peer-reviewed)abstract
- Irritable bowel syndrome (IBS) is a gut-brain disorder involving alterations in intestinal sensitivity and motility. Serotonin 5-HT4 receptors are promising candidates in IBS pathophysiology since they regulate gut motor function and stool consistency, and targeted 5-HT4R selective drug intervention has been proven beneficial in subgroups of patients. We identified a single nucleotide polymorphism (SNP) (rs201253747) c.*61 T > C within the 5-HT4 receptor gene HTR4 to be predominantly present in diarrhoea-IBS patients (IBS-D). It affects a binding site for the miR-16 family and miR-103/miR-107 within the isoforms HTR4b/i and putatively impairs HTR4 expression. Subsequent miRNA-profiling revealed downregulation of miR-16 and miR-103 in the jejunum of IBS-D patients correlating with symptoms. In vitro assays confirmed expression regulation via three 3'UTR binding sites. The novel isoform HTR4b_2 lacking two of the three miRNA binding sites escapes miR-16/103/107 regulation in SNP carriers. We provide the first evidence that HTR4 expression is fine-tuned by miRNAs, and that this regulation is impaired either by the SNP c.*61 T > C or by diminished levels of miR-16 and miR-103 suggesting that HTR4 might be involved in the development of IBS-D.
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| 13. |
- Andersson, Maria, et al.
(author)
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Metabolic profiling of new synthetic cannabinoids AMB and 5F-AMB by human hepatocyte and liver microsome incubations and high-resolution mass spectrometry
- 2016
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In: Rapid Communications in Mass Spectrometry. - : WILEY-BLACKWELL. - 0951-4198 .- 1097-0231. ; 30:8, s. 1067-1078
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Journal article (peer-reviewed)abstract
- RationaleAMB (methyl (1-pentyl-1H-indazole-3-carbonyl)-L-valinate)) and its fluoro analog 5F-AMB (methyl (1-(5-fluoropentyl)-1H-indazole-3-carbonyl)-L-valinate) are two new synthetic cannabinoids that are structural analogs of AB-PINACA and 5F-AB-PINACA, respectively. 5F-AMB is scheduled as an illicit drug in China, Germany, Singapore and Japan, and no metabolism data are currently available for either drug. The aim of the present work was to investigate the metabolism of AMB and 5F-AMB and propose appropriate markers to identify their intake in clinical or forensic cases. MethodsAMB and 5F-AMB were incubated in human hepatocytes (10 mol/L) to generate phase I and II metabolites, which were identified with a TripleTOF 5600(+) high-resolution mass spectrometer. AMB and 5F-AMB metabolic stability studies also were performed with human liver microsomes (HLM) to evaluate metabolic clearances, and to adequately design the human hepatocyte experiment. ResultsAMB and 5F-AMB were quickly metabolized in HLM with a 1.1 0.1 and 1.0 +/- 0.2min T-1/2, respectively. The predominant metabolic pathway for AMB and 5F-AMB in hepatocytes was ester hydrolysis, and further oxidation and/or glucuronidation. In total, 19 metabolites were identified for AMB and 17 for 5F-AMB. We describe metabolites to differentiate AMB from 5F-AMB, and metabolites that are common to both analytes due to oxidative defluorination of 5F-AMB. ConclusionsFor the first time, AMB and 5F-AMB metabolism profiles were characterized, providing valuable data for identifying these two novel psychoactive substances. The difficulties of differentiating AMB and 5F-AMB from AB-PINACA/5F-AB-PINACA metabolites also were examined. These data improve the interpretation of urinary markers after AMB and 5F-AMB intake. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA
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| 14. |
- Bergman, Jonas, et al.
(author)
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Deglacial vegetation succession and Holocene tree-limit dynamics in the Scandes Mountains, west-central Sweden: stratigraphic data compared to megafossil evidence
- 2005
-
In: Review of Palaeobotany and Palynology. - : Elsevier BV. - 0034-6667. ; 134:3-4, s. 129-151
-
Research review (peer-reviewed)abstract
- High-resolution records of plant macrofossils, magnetic susceptibility, and total carbon content, complemented by pollen data, were obtained from a postglacial lake sediment sequence at alpine Lake Stentjarn (987 m a.s.l.), in west-central Sweden. Holocene vegetational and environmental changes were reconstructed from the data, with particular emphasis on the deglacial establishment of terrestrial vegetation and subsequent tree-limit dynamics. A short-lived pioneer flora with Geum rivale, Dryas octopetala, Empetrum nigrum, Ledum palustre, Saxifraga sp., Salix spp., and Oxyria digyna established locally following deglaciation at c. 10,500 cat year BP. The pioneer flora was out-competed by establishing Betula pubescens and grasses at c. 10,300 cat year BP. Subsequent local expansions of B. pubescens at c. 9800 cat year BP and Pinus sylvestris at c. 9200 cal year BP were followed by a temporary retraction of the birch tree-limit and a permanent retreat of pine between 8500 and 8000 cat year BP, accompanied by declining aquatic productivity and increasing catchment erosion. A gradual decrease in forest density initiated at c. 6000 cat year BP led to a retreat of the birch tree-limit from the lake catchment at c. 3500 cat year BP, followed by persistence of scattered trees until c. 2000 cat year BP. A mosaic heath vegetation dominated by Empetrum nigrum and Betula nana developed at c, 3500 cat year BP. Comparison of the stratigraphic data from Lake Stenljiirn with records of radiocarbon-dated subfossil wood remains (megafossils) obtained from adjacent areas during recent decades revealed a high level of consistency of the inferred tree-limit variations for P. sylvestris, B. pubescens, and Alnus incana. Chronological control was established by radiocarbon dating of terrestrial macrofossils and geochemical identification of a tephra horizon originating from the Icelandic Askja- 1875 eruption.
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| 15. |
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| 16. |
- BJORCK, S, et al.
(author)
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C-14 AMS MEASUREMENTS FROM THE LATE WEICHSELIAN PART OF THE SWEDISH TIME-SCALE
- 1995
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In: QUATERNARY INTERNATIONAL. - : PERGAMON-ELSEVIER SCIENCE LTD. ; 27, s. 11-18
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Journal article (other academic/artistic)abstract
- Accelerator mass spectrometry measurements on plant macrofossils from the older part of the Swedish Time Scale, a chronology spanning over the past 13,000 calendar years, indicate a good agreement between varve years and calibrated ages (tree-rings, U-Th)
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| 17. |
- Björck, S., et al.
(author)
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An event stratigraphy for the Last Termination in the North Atlantic region based on the Greenland Ice-core record: a proposal by the INTIMATE group.
- 1998
-
In: Journal of Quaternary Science. - 0267-8179 .- 1099-1417. ; 13:4, s. 283-292
-
Journal article (peer-reviewed)abstract
- It is suggested that the GRIP Greenland ice-core should constitute the stratotype for the Last Termination. Based on the oxygen isotope signal in that core, a new event stratigraphy spanning the time interval from ca. 22.0 to 11.5 k GRIP yr BP (ca. 19.0-10.0 k C-14 yr BP) is proposed for the North Atlantic region. This covers the period from the Last Glacial Maximum, through Termination 1 of the deep-ocean record, to the Pleistocene-Holocene boundary, and encompasses the Last Glacial Late-glacial of the traditional northwest European stratigraphy. The isotopic record for this period is divided into two stadial episodes, Greenland Stadials 1 (GS-1) and 2 (GS-2), and two interstadial events, Greenland Interstadials 1 (GI-1) and 2 (GI-2). In addition, GI-1 and GS-2 are further subdivided into shorter episodes. The event stratigraphy is equally applicable to ice-core, marine and terrestrial records and is considered to be a more appropriate classificatory scheme than the terrestrially based radiocarbon-dated chronostratigraphy that has been used hitherto.
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| 18. |
- Björck, S., et al.
(author)
-
Synchronized terrestrial-atmospheric deglacial records around the North Atlantic.
- 1996
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 274:5290, s. 1155-1160
-
Journal article (peer-reviewed)abstract
- On the basis of synchronization of three carbon-14 (C-14)-dated lacustrine sequences from Sweden With tree ring and ice core records, the absolute age of the Younger Dryas-Preboreal climatic shift was determined to be 11,450 to 11,390 +/- 80 years before the present. A 150-year-long cooling in the early Preboreal, associated with rising Delta(14)C values, is evident in all records and indicates an ocean ventilation change. This cooling is similar to earlier deglacial coolings, and box-model calculations suggest that they all may have been the result of increased freshwater forcing that inhibited the strength of the North Atlantic heat conveyor, although the Younger Dryas may have begun as an anomalous meltwater event.
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| 19. |
- Blaauw, M., et al.
(author)
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Bayesian testing for synchrony of events in glacial proxy archives
- 2007
-
In: European Geosciences Union, 2007. ; , s. 00301-
-
Conference paper (other academic/artistic)abstract
- Often chronological uncertainties are ignored in multi-site comparisons, resulting inpotentially wrong assumptions concerning (a)synchrony of events between archives.We explore this problem in a Bayesian framework, constructing millions of plausiblewiggle-match age-models in order to quantify the chronological uncertainties withinand between proxy archives. Using these data we can now calculate the statisticalprobability that events indeed coincided. The method is applied to a high-resolution14C and OSL dated lake core from south-eastern France which largely predates theIntCal04 14C calibration curve. Depending on the applied comparison curve, eventsin this core appear synchronous or asynchronous with events in the NGRIP ice core.
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| 20. |
- Castaneto, Marisol S., et al.
(author)
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Identification of AB-FUBINACA metabolites in human hepatocytes and urine using high-resolution mass spectrometry
- 2015
-
In: Forensic Toxicology. - : Springer Verlag (Germany). - 1860-8965 .- 1860-8973. ; 33:2, s. 295-310
-
Journal article (peer-reviewed)abstract
- AB-FUBINACA, N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide, is an indazole synthetic cannabinoid identified in drug seizures around the world. Few metabolism data are available, despite the need for human urinary markers to detect AB-FUBINACA intake. Our main objective was to identify suitable analytical targets by analyzing human hepatocyte incubation samples with high-resolution mass spectrometry (HRMS) and to confirm the results in authentic urine specimens. We also determined AB-FUBINACAs metabolic stability in human liver microsomes (HLMs) and compared hepatocyte and urine results with in silico predictions. The metabolic stability of AB-FUBINACA was determined in pooled HLMs (1 A mu mol/l, up to 1 h). The metabolite profile of human hepatocytes (10 A mu mol/l, 1 and 3 h) and urine samples from two subjects were determined by HRMS using information-dependent tandem-mass spectrometry (MS-MS) acquisition. Data were analyzed with MetabolitePilot (TM) software utilizing different processing algorithms, including generic peak finding, mass defect filtering, neutral loss, and product ion filtering. In silico metabolite prediction was performed with MetaSite (TM) software. AB-FUBINACAs half-life in HLMs was 62.6 +/- A 4.0 min. AB-FUBINACA produced 11 metabolites (2 glucuronides) in human hepatocytes and 10 were identified in authentic human urine. Major metabolic pathways were terminal amide hydrolysis, acyl glucuronidation and hydroxylation at the aminooxobutane moiety. Epoxidation followed by hydrolysis, hydroxylation at the indazole moiety and dehydrogenation were minor pathways. Defluorination did not occur. Seventeen first-generation metabolites were predicted in silico, of which seven were observed in vitro and eight in vivo. We recommend AB-FUBINACA carboxylic acid, hydroxy AB-FUBINACA carboxylic acid, dihydrodiol AB-FUBINACA and dihydrodiol AB-FUBINACA carboxylic acid as suitable urinary markers.
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| 21. |
- Cirtwill, Alyssa R., et al.
(author)
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Related plants tend to share pollinators and herbivores, but strength of phylogenetic signal varies among plant families
- 2020
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In: New Phytologist. - : WILEY. - 0028-646X .- 1469-8137. ; 226:3, s. 909-920
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Journal article (peer-reviewed)abstract
- Related plants are often hypothesized to interact with similar sets of pollinators and herbivores, but this idea has only mixed empirical support. This may be because plant families vary in their tendency to share interaction partners. We quantify overlap of interaction partners for all pairs of plants in 59 pollination and 11 herbivory networks based on the numbers of shared and unshared interaction partners (thereby capturing both proportional and absolute overlap). We test for relationships between phylogenetic distance and partner overlap within each network; whether these relationships varied with the composition of the plant community; and whether well-represented plant families showed different relationships. Across all networks, more closely related plants tended to have greater overlap. The strength of this relationship within a network was unrelated to the composition of the networks plant component, but, when considered separately, different plant families showed different relationships between phylogenetic distance and overlap of interaction partners. The variety of relationships between phylogenetic distance and partner overlap in different plant families probably reflects a comparable variety of ecological and evolutionary processes. Considering factors affecting particular species-rich groups within a community could be the key to understanding the distribution of interactions at the network level.
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| 22. |
- Clague, JJ, et al.
(author)
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Late Holocene environmental change at treeline in the Northern Coast Mountains, British Columbia, Canada
- 2004
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In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 23:23-24, s. 2413-2431
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Journal article (peer-reviewed)abstract
- An integrated stratigraphic, paleoecological, and geochronological study of lake and fen sediments just beyond the terminus of Berendon Glacier provides insights into late Holocene climate, vegetation, and glacier change in the northern Coast Mountains of British Columbia. Cores collected from two small lakes in the foreland of Berendon Glacier and pits dug in a nearby fen record Little lee Age and older glacier advances. The first Little Ice Age advance in this area began more than 500 years ago and peaked in the early 17th century. An earlier Neoglacial advance began about 2800-3000 cal yr ago and may have lasted for hundreds of years. There is also evidence for an intervening advance of even smaller magnitude around 1200-1300 cal yr ago. The advances are broadly synchronous with those in other parts of western North America, indicating that they were caused by regional, possibly global, changes in climate. Plant communities within the study area did not change dramatically during the late Holocene. The ranges of some plants, however, likely retracted or extended near treeline in response to changes in mean temperatures of perhaps 1-2degreesC, as A well as changes in summer snow cover. The greatest changes in vegetation occurred within and just beyond the forefields of Berendon, Frank Mackie, and other nearby glaciers. The largest climate shifts of the last 3000 years took place during the late Little Ice Age and the last century. Climate warmed about 1-2degreesC during the 20th century, accompanied by a rise in treeline, an increase in coniferous tree cover in the subalpine zone, and an increase in the temperature and biological productivity of ponds. These trends are likely to continue if climate, as expected, continues to warm. (C) 2004 Elsevier Ltd. All rights reserved.
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| 23. |
- Cortese, S., et al.
(author)
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The future of child and adolescent clinical psychopharmacology: A systematic review of phase 2, 3, or 4 randomized controlled trials of pharmacologic agents without regulatory approval or for unapproved indications
- 2023
-
In: Neuroscience and Biobehavioral Reviews. - : Elsevier BV. - 0149-7634. ; 149
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Journal article (peer-reviewed)abstract
- We aimed to identify promising novel medications for child and adolescent mental health problems. We systematically searched https://clinicaltrials.gov/ and https://www.clinicaltrialsregister.eu/ (from 01/01/ 2010-08/23/2022) for phase 2 or 3 randomized controlled trials (RCTs) of medications without regulatory approval in the US, Europe or Asia, including also RCTs of dietary interventions/probiotics. Additionally, we searched phase 4 RCTs of agents targeting unlicensed indications for children/adolescents with mental health disorders. We retrieved 234 ongoing or completed RCTs, including 26 (11%) with positive findings on & GE; 1 primary outcome, 43 (18%) with negative/unavailable results on every primary outcome, and 165 (70%) without publicly available statistical results. The only two compounds with evidence of significant effects that
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| 24. |
- Davies, SM, et al.
(author)
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Cryptotephra sedimentation processes within two lacustrine sequences from west central Sweden
- 2007
-
In: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 17:3, s. 319-330
-
Journal article (peer-reviewed)abstract
- Distal tephra horizons, particularly within lacustrine sequences, are increasingly being used as time-synchronous marker horizons within palaeoclimatic and palaeoenvironmental investigations. As sedimentary features marking the presence of these so-called cryptotephras are absent to the naked eye, it is of some importance that the stratigraphic position representing primary airfall, and likewise the timing Of the volcanic event, is accurately and consistently recorded amongst these deposits. Often tephra shards from a cryptotephra deposit can be found spanning several centimetres of sediments within lacustrine and peat sequences. Very few studies, however, have looked in detail at the sedimentation and vertical distribution of cryptotephra deposits within such sequences and, more importantly, the criteria for defining the correct stratigraphic position of the volcanic event. Two sediment cores from Lake Spaime and Lake Getvaltjarnen, west central Sweden are employed to investigate in detail the vertical distribution of the tephra shards derived from the AD 1875 eruption of the Askja volcano in Iceland. Detailed geochemical analysis of shards from both records indicate that products of the Askja eruption are present for at least 120 years and thus emphasize the importance of carefully identifying the correct horizon that marks the timing of the volcanic event rather than shards resulting from a period of reworking or downward migration. Both sites yield contrasting shard concentration profiles and thus raise a number of questions regarding the influence of site-specific processes on cryptotephra sedimentation, particularly the role of snow-beds acting as tephra traps, the possibility of reworking, and downward migration of shards in soft sediment. A second tephra is also identified at Lake Getvaltjarnen and is believed to originate from the AD 1477 Veidivotn eruption and represents the first occurrence of this tephra outside of Iceland.
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| 25. |
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