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Josep Vallverdu Poch - One of the best experts on this subject based on the ideXlab platform.
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soil Stratigraphy in the cave entrance deposits of middle pleistocene age at the trinchera del ferrocarril sites sierra de atapuerca spain
Quaternary International, 2017Co-Authors: Josep Vallverdu PochAbstract:Abstract This research focuses on the description of the sedimentary infills of the Trinchera del Ferrocarril caves (Sierra de Atapuerca) in order to identify buried soils (paleosols). Sediments, soils, and sediments derived from soils form a continuity that is difficult to analyze in the field or at microscopic scales of observation. The sediments of the cave entrances of Trinchera del Ferrocarril contain weakly to strongly developed soil properties. The results presented in this paper describe three different styles of soil Stratigraphy during the Middle Pleistocene. These soil-stratigraphic styles are classified based on the maturity of the soils (by development) and the degree of incision (entrenchment), similarly to pedostratigrahic models of alluvial fans. Soil Stratigraphy contributes to our understanding of the different implications in the sedimentary record of environmental changes at a local and regional scale. The absolute dates of the soil Stratigraphy in the Trinchera del Ferrocarril caves indicate that the environmental changes have the same temporal scale as the orbital climatic cycles (interglacial/glacial, stadial/interstadial). The different soil properties, horizon types and time intervals of soil formation indicate a specific mode of environmental change for each style of soil Stratigraphy identified.
Svante Björck - One of the best experts on this subject based on the ideXlab platform.
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a new high resolution holocene tephra Stratigraphy in eastern iceland improving the icelandic and north atlantic tephrochronology
Quaternary Science Reviews, 2016Co-Authors: Esther Ruth Gudmundsdottir, Svante Björck, Gudrun Larsen, Olafur Ingolfsson, Johan StribergerAbstract:A new and improved Holocene tephra Stratigraphy and tephrochronological framework for eastern and northern Iceland is presented. Investigations of a sediment sequence from Lake Logurinn have revealed a comprehensive tephra record spanning the last 10.200 years. A total of 157 tephra layers have been identified, whereof 149 tephra layers have been correlated to its source volcanic system using geochemistry, Stratigraphy and age. Fifteen layers have chemical composition of two affinities that possibly represent two very closely spaced eruptions. Thus, these 157 tephra layers are believed to represent 172 explosive eruptions. Nineteen tephra marker layers have been identified in the Lake Logurinn record (G1922, A1875, V1477, V1410, H1636, K1625, O1362, G1354, K1262, V874, Hrafnkatla, Sn-1, Grakolla, HY, H3, H4, HO, LL1755 and Reitsvik-8 tephra markers). New potential tephra markers are the silicic Askja L (∼9400 cal BP), the low titanium basalt layers, LL 1774 (∼10.150 cal BP) and LL 1755 (∼9990 cal BP), assigned to Veidivotn-Bardarbunga and the tephra layers, LL 1527.8 (∼7850 cal BP), LL 911.2 (∼2370 cal BP), LL 908.4 (∼2350 cal BP), LL 781.9 (∼1930 cal BP), LL 644.4 (∼1480 cal BP), not yet correlated to a source volcanic system. A silicic tephra marker layer, Reitsvik 8, correlated to the Fosen tephra in Norway has been identified in Lake Logurinn. The Lake Logurinn tephra record has been connected and integrated with the Icelandic terrestrial tephrochronology and Stratigraphy through 102 tephra layers, the marine tephra Stratigraphy through 39 layers and overseas through 9 tephra layers. This record is the first high-resolution tephra stratigraphical and chronological framework for the Holocene in eastern Iceland as well as the most detailed and continuous record, and has considerable potential to serve as a key section or a stratotype for the Holocene in eastern Iceland and the North Atlantic.
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formal subdivision of the holocene series epoch
1st International Congress on Stratigraphy (STRATI), 2014Co-Authors: Michael Walker, Svante Björck, Les C. Cwynar, P L Gibbard, Max Berkelhammer, David A Fisher, Antony J Long, J J Lowe, Rewi M Newnham, Sune Olander RasmussenAbstract:This proposal, by a Working Group of Integration of ice-core, marine, and terrestrial records (INTIMATE) and the Subcommission on Quaternary Stratigraphy (SQS) of the International Commission on Stratigraphy (ICS), is for a formal subdivision of the Holocene Series/Epoch. Although previous attempts to subdivide the Holocene have proved inconclusive, recent developments in Quaternary Stratigraphy, notably the definition of the Pleistocene–Holocene boundary and the emergence of formal subdivisions of the Pleistocene Series/Epoch, mean that it may be timely to revisit this matter. The Quaternary literature reveals a widespread but variable informal usage of a tripartite division of the Holocene (“early”, “middle” or “mid-”, and “late”), and we propose that this de facto subdivision should now be formalised to ensure consistency in stratigraphic terminology. We advocate a formal Early–Middle Holocene boundary at 8200 a BP and a formal Middle–Late Holocene boundary at 4200 a BP, each of which is linked to a Global Stratotype Section and Point (GSSP).
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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
Journal of Quaternary Science, 1998Co-Authors: Svante Björck, Mike Walker, Les C. Cwynar, Sigfus J Johnsen, Karen Luise Knudsen, J. John Lowe, Barbara WohlfarthAbstract: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 14 C 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. © 1998 John Wiley & Sons, Ltd.
J M Mcarthur - One of the best experts on this subject based on the ideXlab platform.
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strontium isotope Stratigraphy
In: A Geologic Time Scale 2004. (pp. 96-105). (2005), 2012Co-Authors: J M Mcarthur, Richard J HowarthAbstract:© F. M. Gradstein, J. G. Ogg, and A. G. Smith 2004. The 87Sr/86Sr value of Sr dissolved in the world's oceans has varied though time, which allows one to date and correlate sediments. This variation and its stratigraphic resolution is discussed and graphically displayed. INTRODUCTION The ability to date and correlate sediments using Sr isotopes relies on the fact that the 87Sr/86Sr value of Sr dissolved in the world's oceans has varied though time. In Fig. 7.1, we show this variation, plotted according to the time scale presented in this volume. More detail is given in Fig. 7.2, on which we plot both the curve of 87Sr/86Sr through time and the data used to derive it. Comparison of the measured 87Sr/86Sr of Sr in a marine mineral with a detailed curve of 87Sr/86Sr through time can yield a numerical age for the mineral. Alternatively, 87Sr/86Sr can be used to correlate between stratigraphic sections and sequences by comparison of the 87Sr/86Sr values in minerals from each (Fig. 7.3). Such correlation does not require a detailed knowledge of the trend through time of 87Sr/86Sr, but it is useful to know the general trend in order to avoid possible confusion in correlation near turning points on the Sr curve. Strontium isotope Stratigraphy (SIS) can be used to estimate the duration of stratigraphic gaps (Miller et al., 1988), estimate the duration of biozones (McArthur et al., 1993, 2000, 2004) and stages (Weedon and Jenkyns, 1999), and to distinguish marine from non-marine environments (Schmitz et al., 1991; Poyato-Ariza et al., 1998).
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strontium isotope Stratigraphy
In: Gradstein FM and Ogg JG and Schmitz MD and Ogg GM (eds.) The Geologic Time Scale 2012. (pp. 127-144). Elsevier: Amsterdam Netherlands. (2012), 2012Co-Authors: J M Mcarthur, Richard J Howarth, Graham A ShieldsAbstract:The 87Sr/86Sr value of Sr dissolved in the world’s oceans varied though time in a known way, facts that allow 87Sr/86Sr to be used to date and to correlate marine sedimentary rocks worldwide. In this work, the variation in 87Sr/86Sr is displayed graphically and the theory and practice of the methodology is discussed.
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recent trends in strontium isotope Stratigraphy
Terra Nova, 1994Co-Authors: J M McarthurAbstract:An introduction to Sr-isotope Stratigraphy can be obtained from several recent reviews (Elderfield, 1986; Veizer, 1989; McArthur, 1991, 1992a). The purpose of this article is not to repeat these reviews but to give to those not expert in the field, but who may be prospective users, a summary of aspects of the method not covered elsewhere, and some examples of recent applications of the technique and the problems that affect it. Highlighting problems inevitably means highlighting the publications in which they occur; I hope the authors will forgive me for spotlighting their work. Neither is this article intended to be a review of all that has been written on the use of Sr isotopes in low-temperature geochemistry; it concentrates on their use in Stratigraphy and dating, rather than how they may be used to elucidate geochemical processes. Many excellent papers are thereby excluded from consideration. Implicit in this article is the view that the successful application of strontium isotope Stratigraphy requires an application of good methodology in both geochemistry and Stratigraphy.
Kristian Schoning - One of the best experts on this subject based on the ideXlab platform.
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an event Stratigraphy for the last glacial holocene transition in eastern middle sweden results from investigations of varved clay and terrestrial sequences
Quaternary Science Reviews, 2002Co-Authors: Jonas Björck, Thomas Andrén, Stefan Wastegård, Göran Possnert, Kristian SchoningAbstract:This paper presents an event Stratigraphy for the Last Glacial-Holocene transition in eastern middle Sweden. The event Stratigraphy for eastern middle Sweden comprises ten events and covers the tim ...
Henrik Nohrhansen - One of the best experts on this subject based on the ideXlab platform.
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dinoflagellate cyst Stratigraphy of the palaeogene strata from the hellefisk 1 ikermiut 1 kangâmiut 1 nukik 1 nukik 2 and qulleq 1 wells offshore west greenland
Marine and Petroleum Geology, 2003Co-Authors: Henrik NohrhansenAbstract:Abstract A new Palaeogene dinoflagellate cyst Stratigraphy from offshore West Greenland has been described based on the strata from the Hellefisk-1, Ikermiut-1, Kangâmiut-1, Nukik-1, Nukik-2 and Qulleq-1 wells. Twenty-one palynological intervals are defined from the Late Eocene to the late Early Paleocene. This Stratigraphy has been correlated with a new microfossil zonation and previous established North Sea zonations. The Stratigraphy and well correlation are based on last appearance datum events and abundances of stratigraphically important species from 355 samples, 148 of which are sidewall core samples. A major middle Eocene hiatus spanning the early Lutetian and a major Early Paleocene hiatus spanning the Late Santonian, Late Cretaceous to the early Danian have been recognised from the offshore deposits.
