WorldWideScience

Sample records for project chronology date

  1. The use of AMS radiocarbon dating for Xia-Shang-Zhou chronology

    CERN Document Server

    Guo, Z Y; LiuKeXin; Lu Xiang Yang; Ma Hong Ji; Wu Xiao Hon; Yuan Si Xun

    2000-01-01

    The possibility and problems of using radiocarbon dating to historical chronology are discussed. The current situation of ancient Chinese chronology and the project of Xia-Shang-Zhou chronology are introduced. A chronological study requires the AMS radiocarbon dating with high precision, high reliability and high efficiency. The Peking University AMS facility (PKUAMS) has been upgraded and a series of quality control steps were adopted. To reduce the error of calendar age, wiggle matching with serial samples should be used. Some preliminary results of Xia-Shang-Zhou chronology are presented.

  2. Constructing deposition chronologies for peat deposits using radiocarbon dating

    Directory of Open Access Journals (Sweden)

    N. Piotrowska

    2011-06-01

    Full Text Available Radiocarbon dating is one of the main methods used to establish peat chronologies. This article reviews the basis of the method and its application to dating of peat deposits. Important steps in the radiocarbon dating procedure are described, including selection and extraction of material (and fractions for dating, chemical and physical preparation of media suitable for measurements, measurements of 14C activity or concentration, calculations, calibration of results and age-depth modelling.

  3. Thermoluminescence dating. Application to the chronology of volcanic ashes

    International Nuclear Information System (INIS)

    Pilleyre, T.

    1991-09-01

    Thermoluminescent (TL) dating is generally used for minerals heated in the past and can be used for absolute chronology of volcanic ashes but seems limited to less than 15.000 years. The aim of the thesis is the study of thermoluminescent properties of quartz for high doses and long irradiations using the red TL peak of quartz which is situated at high temperature (about 370 deg. C) to extend the method for higher ages. A theory, based on spatial correlation between electron and hole created during the same ionization, is developed. A chapter is devoted to dosimetry because of its importance in TL dating, especially alpha scintillation counting and the influence of humidity on the determination of annual dose. Volcanic samples are dated from 10.000 to 80.000 years before present

  4. Double the dates and go for Bayes - Impacts of model choice, dating density and quality on chronologies

    Science.gov (United States)

    Blaauw, Maarten; Christen, J. Andrés; Bennett, K. D.; Reimer, Paula J.

    2018-05-01

    Reliable chronologies are essential for most Quaternary studies, but little is known about how age-depth model choice, as well as dating density and quality, affect the precision and accuracy of chronologies. A meta-analysis suggests that most existing late-Quaternary studies contain fewer than one date per millennium, and provide millennial-scale precision at best. We use existing and simulated sediment cores to estimate what dating density and quality are required to obtain accurate chronologies at a desired precision. For many sites, a doubling in dating density would significantly improve chronologies and thus their value for reconstructing and interpreting past environmental changes. Commonly used classical age-depth models stop becoming more precise after a minimum dating density is reached, but the precision of Bayesian age-depth models which take advantage of chronological ordering continues to improve with more dates. Our simulations show that classical age-depth models severely underestimate uncertainty and are inaccurate at low dating densities, and also perform poorly at high dating densities. On the other hand, Bayesian age-depth models provide more realistic precision estimates, including at low to average dating densities, and are much more robust against dating scatter and outliers. Indeed, Bayesian age-depth models outperform classical ones at all tested dating densities, qualities and time-scales. We recommend that chronologies should be produced using Bayesian age-depth models taking into account chronological ordering and based on a minimum of 2 dates per millennium.

  5. Quantity of dates trumps quality of dates for dense Bayesian radiocarbon sediment chronologies - Gas ion source 14C dating instructed by simultaneous Bayesian accumulation rate modeling

    Science.gov (United States)

    Rosenheim, B. E.; Firesinger, D.; Roberts, M. L.; Burton, J. R.; Khan, N.; Moyer, R. P.

    2016-12-01

    Radiocarbon (14C) sediment core chronologies benefit from a high density of dates, even when precision of individual dates is sacrificed. This is demonstrated by a combined approach of rapid 14C analysis of CO2 gas generated from carbonates and organic material coupled with Bayesian statistical modeling. Analysis of 14C is facilitated by the gas ion source on the Continuous Flow Accelerator Mass Spectrometry (CFAMS) system at the Woods Hole Oceanographic Institution's National Ocean Sciences Accelerator Mass Spectrometry facility. This instrument is capable of producing a 14C determination of +/- 100 14C y precision every 4-5 minutes, with limited sample handling (dissolution of carbonates and/or combustion of organic carbon in evacuated containers). Rapid analysis allows over-preparation of samples to include replicates at each depth and/or comparison of different sample types at particular depths in a sediment or peat core. Analysis priority is given to depths that have the least chronologic precision as determined by Bayesian modeling of the chronology of calibrated ages. Use of such a statistical approach to determine the order in which samples are run ensures that the chronology constantly improves so long as material is available for the analysis of chronologic weak points. Ultimately, accuracy of the chronology is determined by the material that is actually being dated, and our combined approach allows testing of different constituents of the organic carbon pool and the carbonate minerals within a core. We will present preliminary results from a deep-sea sediment core abundant in deep-sea foraminifera as well as coastal wetland peat cores to demonstrate statistical improvements in sediment- and peat-core chronologies obtained by increasing the quantity and decreasing the quality of individual dates.

  6. Rethinking About Chronology Of Chichen Itza: By Thermoluminescence Dating Of Volcanic Glass.

    Science.gov (United States)

    Chung, H.; Gonzalez, P.; Ramirez, A.; Schaaf, P.; Lee, I.

    One of the most frequently recurring questions in archaeology concerns the age of the studied objects. To date, determining the chronology of the Puuc and Chichen Slate pottery of Chchen Itza, based on the stylistic change in the pottery, has been problematic. The Thermoluminescence method of dating pottery was applied to samples of Chichen Itza, Yucatan, Mexico, which contain volcanic glass as temper. They were analyzed using the fine grain technique. The radisotopes that contribute to the accumulate annual dose in ceramic samples (40K, 238U, 232Th) were determined by means of Energy Dispersive X-ray Spectroscopy and Neutron Activation Analysis technique, while the artificial irradiation of the samples was carried out using 90Sr source beta radiation. We obtained results indicating the following dates; 875 ± 88; 1055 ± 85; 1063 ± 47, 1154 ± 76; 1110 ± 53, 1132 ± 69, 1221 ± 30, 1532 ± 26. The results demonstrate a chronological order of dates. Most results are in accordance with the established dates of Chichen Itza. However, Puuc and Chichen Slate did not show differences of 200 years as previously proposed, and there is evidence of an earlier period than those two pottery periods. This necessitates a reconsideration of the chronology of Chichen Itza.

  7. Kimberley rock art dating project

    International Nuclear Information System (INIS)

    Walsh, G.L.; Morwood, M.

    1997-01-01

    The art's additional value, unequalled by traditionally recognised artefacts, is its permanent pictorial documentation presenting a 'window' into the otherwise intangible elements of perceptions, vision and mind of pre-historic cultures. Unfortunately it's potential in establishing Kimberley archaeological 'big picture' still remains largely unrecognised. Some of findings of the Kimberley Rock Art Dating Project, using AMS and optical stimulated luminescence (OSL) dating techniques, are outlined. It is estimated that these findings will encourage involvement by a greater diversity of specialist disciplines to tie findings into levels of this art sequence as a primary reference point. The sequence represents a sound basis for selecting specific defined images for targeting detailed studies by a range of dating technique. This effectively removes the undesirable ad hoc sampling of 'apparently old paintings'; a process which must unavoidably remain the case with researchers working on most global bodies of rock art

  8. A chronology of hurricane landfalls at Little Sippewissett Marsh, Massachusetts, USA, using optical dating

    Science.gov (United States)

    Madsen, A. T.; Duller, G. A. T.; Donnelly, J. P.; Roberts, H. M.; Wintle, A. G.

    2009-08-01

    Optical dating has been applied to sediments preserved in Little Sippewissett Marsh, Massachusetts, USA, which are associated with overwashing of the beach barrier during hurricane strikes on the coast. The aims were to determine the hurricane landfall frequency, and make comparisons with independent age control and the historical record. Written sources of hurricane activity along the American east coast are only considered reliable back to the mid 19th century, but the sedimentary record is potentially much longer. Optical dating was applied to quartz grains extracted from thirteen samples within a sediment core from the salt-marsh. Variability in the luminescence characteristics between aliquots was observed and ~ 33% of the measured aliquots were discarded based upon the ratio of the fast component to the medium component. The majority of the samples gave normal dose distributions implying homogeneous resetting of the luminescence signal at the time of deposition, but three of the samples required application of the minimum age model (MAM). Ages ranging between 20 ± 2 and 594 ± 38 years were obtained and are broadly in agreement with independent chronologies, thus demonstrating the potential of optical dating in this setting. The hurricane record based upon optical dating extends approximately 300 years further back in time than the official National Oceanic Atmospheric Administration (NOAA) record. The localised nature of hurricane landfalls means that it will be necessary to collect multiple cores from a number of different sites in order to build up a complete hurricane record for this part of the coast.

  9. Radiocarbon dating and wood density chronologies of mangrove trees in arid Western Australia.

    Directory of Open Access Journals (Sweden)

    Nadia S Santini

    Full Text Available Mangrove trees tend to be larger and mangrove communities more diverse in tropical latitudes, particularly where there is high rainfall. Variation in the structure, growth and productivity of mangrove forests over climatic gradients suggests they are sensitive to variations in climate, but evidence of changes in the structure and growth of mangrove trees in response to climatic variation is scarce. Bomb-pulse radiocarbon dating provides accurate dates of recent wood formation and tree age of tropical and subtropical tree species. Here, we used radiocarbon techniques combined with X-ray densitometry to develop a wood density chronology for the mangrove Avicennia marina in the Exmouth Gulf, Western Australia (WA. We tested whether wood density chronologies of A. marina were sensitive to variation in the Pacific Decadal Oscillation Index, which reflects temperature fluctuations in the Pacific Ocean and is linked to the instrumental rainfall record in north WA. We also determined growth rates in mangrove trees from the Exmouth Gulf, WA. We found that seaward fringing A. marina trees (~10 cm diameter were 48 ± 1 to 89 ± 23 years old (mean ± 1 σ and that their growth rates ranged from 4.08 ± 2.36 to 5.30 ± 3.33 mm/yr (mean ± 1 σ. The wood density of our studied mangrove trees decreased with increases in the Pacific Decadal Oscillation Index. Future predicted drying of the region will likely lead to further reductions in wood density and their associated growth rates in mangrove forests in the region.

  10. Radiocarbon and optically stimulated luminescence dating based chronology of a polycyclic driftsand sequence at Weerterbergen (SE Netherlands)

    NARCIS (Netherlands)

    van Mourik, J.M.; Nierop, K.G.J.; Vandenberghe, D.A.G.

    2010-01-01

    The chronology of polycyclic driftsand sequences in cultural landscapes has mainly been based on the combination of radiocarbon (14C) dating of intercalated organic horizons and pollen analysis. This approach, however, yields indirect age information for the sediment units. Also, as soils are

  11. Eneolithic pile dwellings south of the Alps precisely dated with tree-ring chronologies from the north

    OpenAIRE

    Čufar, Katarina; Tegel, Willy; Merela, Maks; Kromer, Bernd; Velušček, Anton

    2016-01-01

    We present dendrochronological dating of Eneolithic pile dwellings on Ljubljansko barje, Slovenia, from the 4th millennium BC, partly included on the UNESCO world heritage list in 2011. Samples of oak (Quercus sp.) timbers from the posts on which the dwellings were built have been collected over the past 20 years. They have been dendrochronologically cross-dated and (pre) dated by 14C wiggle-matching. We describe the construction of a 442-year chronology BAR-3330 based on 106 cross-dated tree...

  12. Fission track dating: methodology and thermo-chronological applications in alpine and continental margin contexts

    International Nuclear Information System (INIS)

    Sabil, N.

    1995-06-01

    The fission track dating method has proved to be unique in thermo-chronology by its capability to describe the final phases of the cooling history and denudation of metamorphic massifs, like the thermal history of sedimentary formations or the dating of some volcanic materials. In this work we describe this method and present a series of new analytic techniques and calibrations which we realised in the aim of further use in geology. We discuss a few examples of such applications. In the french Occidental Alps, the analysis of fission track on apatite samples from the granites of the Sept Laux (Belledonne massif), in the Eau d' Olle valley, suggests that this method could bring a contribution to the actual discussion about the origin of some alpine valleys. The fission track method suggests that the opening of this valley could be the consequence of an active faulting from the middle Miocene until the present. The characterization of fluvial deposits through their detrital apatites fission tracks record could eventually be used to study river captures related to changes tectonic regimes. Therefore we studied the apatites of a paleo-delta located in the Isere middle valley at the sub-alpine 'sillon' level, and of two valleys, those of the Arc and of the Breda, located up the delta. The distribution of the fission track ages of those mineraIs has not confirmed a previously suggested model, which proposed that the studied paleo-delta could be associated with a paleo-Arc rather than a paleo-Breda. In the Moroccan Occidental Meseta, three granitic massifs located in the Rehamna have been selected for a thermo-chronological study. The analysis of the fission track in zircons and apatites of these granites recorded the thermo-tectonic events which have affected the Meseta ever since the opening of the Central Atlantic Ocean some 200 Ma ago. We show how a numerical simulation model recently (1994) proposed for the analysis of fission track in apatites allows us to specify

  13. Radiocarbon dating, chronologic framework, and changes in accumulation rates of holocene estuarine sediments from Chesapeake Bay

    Science.gov (United States)

    Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.

    2002-01-01

    Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

  14. Aligning and synchronization of MIS5 proxy records from Lake Ohrid (FYROM) with independently dated Mediterranean archives: implications for DEEP core chronology

    Science.gov (United States)

    Zanchetta, Giovanni; Regattieri, Eleonora; Giaccio, Biagio; Wagner, Bernd; Sulpizio, Roberto; Francke, Alex; Vogel, Hendrik; Sadori, Laura; Masi, Alessia; Sinopoli, Gaia; Lacey, Jack H.; Leng, Melanie J.; Leicher, Niklas

    2016-05-01

    The DEEP site sediment sequence obtained during the ICDP SCOPSCO project at Lake Ohrid was dated using tephrostratigraphic information, cyclostratigraphy, and orbital tuning through the marine isotope stages (MIS) 15-1. Although this approach is suitable for the generation of a general chronological framework of the long succession, it is insufficient to resolve more detailed palaeoclimatological questions, such as leads and lags of climate events between marine and terrestrial records or between different regions. Here, we demonstrate how the use of different tie points can affect cyclostratigraphy and orbital tuning for the period between ca. 140 and 70 ka and how the results can be correlated with directly/indirectly radiometrically dated Mediterranean marine and continental proxy records. The alternative age model presented here shows consistent differences with that initially proposed by Francke et al. (2015) for the same interval, in particular at the level of the MIS6-5e transition. According to this new age model, different proxies from the DEEP site sediment record support an increase of temperatures between glacial to interglacial conditions, which is almost synchronous with a rapid increase in sea surface temperature observed in the western Mediterranean. The results show how a detailed study of independent chronological tie points is important to align different records and to highlight asynchronisms of climate events. Moreover, Francke et al. (2016) have incorporated the new chronology proposed for tephra OH-DP-0499 in the final DEEP age model. This has reduced substantially the chronological discrepancies between the DEEP site age model and the model proposed here for the last glacial-interglacial transition.

  15. Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean Wood Sculpture

    Science.gov (United States)

    Joanna Ostapkowicz; Christopher Bronk-Ramsey; Fiona Brock; Tom Higham; Alex C. Wiedenhoeft; Erika Ribechini; Jeannette J. Lucejko; Samuel. Wilson

    2012-01-01

    This paper establishes a chronological framework for selected pieces of Caribbean (Tafno/Lucayan) wooden sculpture, enabling previously ahistoric artefacts to fit back into the wider corpus of pre-colonial material culture. Seventy-two 14C AMS determinations from 56 artefacts held in museum collections are reported, including 32 ceremonial

  16. A reevaluation of the Pallett Creek earthquake chronology based on new AMS radiocarbon dates, San Andreas fault, California

    Science.gov (United States)

    Scharer, K.M.; Biasi, G.P.; Weldon, R.J.

    2011-01-01

    The Pallett Creek paleoseismic record occupies a keystone position in most attempts to develop rupture histories for the southern San Andreas fault. Previous estimates of earthquake ages at Pallett Creek were determined by decay counting radiocarbon methods. That method requires large samples which can lead to unaccounted sources of uncertainty in radiocarbon ages because of the heterogeneous composition of organic layers. In contrast, accelerator mass spectrometry (AMS) radiocarbon dates may be obtained from small samples that have known carbon sources and also allow for a more complete sampling of the section. We present 65 new AMS radiocarbon dates that span nine ground-rupturing earthquakes at Pallett Creek. Overall, the AMS dates are similar to and reveal no dramatic bias in the conventional dates. For many layers, however, individual charcoal samples were younger than the conventional dates, leading to earthquake ages that are overall slightly younger than previously reported. New earthquake ages are determined by Bayesian refinement of the layer ages based on stratigraphic ordering and sedimentological constraints. The new chronology is more regular than previously published records in large part due to new samples constraining the age of event R. The closed interval from event C to 1857 has a mean recurrence of 135years (?? = 83.2 years) and a quasiperiodic coefficient of variation (COV) of 0.61. We show that the new dates and resultant earthquake chronology have a stronger effect on COV than the specific membership of this long series and dating precision improvements from sedimentation rates. Copyright 2011 by the American Geophysical Union.

  17. Luminescence dating of flash flood deposits: a new approach for the chronological study of ancient irrigation perimeters in southern Yemen

    International Nuclear Information System (INIS)

    Balescu, S.; Lamothe, M.; Coque-Delhuille, B.

    1998-01-01

    This study is an attempt to assess the age of ancient irrigation silts from Southern Yemen using the optically stimulated luminescence (OSL) of the constituent K-feldspar grains. This OSL dating method is tested on the al-Haraja irrigation sequence (Wadi Bayhan) which overlies an archaeological occupation level previously dated at 2 203±123 years BP by 14 C. The OSL age estimates range between 2 097±177 years at the bottom of the sequence and 1 555±150 years at the top. This study demonstrates the potential of the luminescence dating method to provide chronological information on the deposition of ancient silts following irrigation in arid environment where 14 C datable material is rare. (authors)

  18. The quest for an absolute chronology in human prehistory: anthropologists, chemists and the fluorine dating method in palaeoanthropology.

    Science.gov (United States)

    Goodrum, Matthew R; Olson, Cora

    2009-03-01

    By the early twentieth century there was a growing need within palaeoanthropology and prehistoric archaeology to find a way of dating fossils and artefacts in order to know the age of specific specimens, but more importantly to establish an absolute chronology for human prehistory. The radiocarbon and potassium-argon dating methods revolutionized palaeoanthropology during the last half of the twentieth century. However, prior to the invention of these methods there were attempts to devise chemical means of dating fossil bone. Collaborations between Emile Rivière and Adolphe Carnot in the 1890s led to the development of the fluorine dating method, but it was not until the 1940s that this method was improved and widely implemented by Kenneth Oakley to resolve a number of problems in palaeoanthropology, including the Piltdown Man controversy. The invention of the fluorine dating method marked a significant advance in the quest for absolute dating in palaeoanthropology, but it also highlights interesting problems and issues relating to the ability of palaeoanthropologists and chemists to bring together different skills and bodies of knowledge in order successfully to develop and apply the fluorine dating method.

  19. Radiocarbon dating for tree rings of dendro-chronologically dated Japan cedars buried in the paddy field at Fukui

    International Nuclear Information System (INIS)

    Shibata, S.; Kawano, E.; Kimura, K.; Mine, T.; Harada, M.

    1999-01-01

    14 C dating of 6 Japan cedars having the relative growing ages were made. On the basis of correlation analysis of our data to a 14 C age data set, INTCAL of CALIB (Stuiver), the growing ages of these Japan cedars were estimated (BC 1090-2375). The atmospheric 14 C concentration (Δ 14 C) at their growing ages were obtained from the 14 C age data. The variation of Δ 14 C shows basically the same pattern with that of Europe or America (r=0.783). (author)

  20. Violet stimulated luminescence dating of quartz from Luochuan (Chinese loess plateau): Agreement with independent chronology up to ∼600 ka

    DEFF Research Database (Denmark)

    Ankjærgaard, C.; Guralnik, B.; Buylaert, Jan-Pieter

    2016-01-01

    Luminescence dating at the Luochuan loess type (China) section is at present limited to ∼0.1 Ma using quartz blue light stimulated luminescence (BLSL), but can be extended back in time to ∼0.5 Ma by resorting to the more developmental post-infrared infrared stimulated luminescence (post-IR IRSL...... demonstrate that the Multi-Aliquot Additive-Dose (MAAD) protocol produces a VSL chronology at Luochuan which is in agreement with independent ages up to ∼0.6 Ma. For a more representative environmental dose rate of ∼2 Gy/ka (∼35% lower than at Luochuan), the documented range of MAAD-VSL sensitivity (200...

  1. A chronology of hurricane landfalls at Little Sippewissett Marsh, Massachusetts, USA, using optical dating

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Duller, G.A.T.; Donnelly, J.P.

    2009-01-01

    Optical dating has been applied to sediments preserved in Little Sippewissett Marsh, Massachusetts, USA, which are associated with overwashing of the beach barrier during hurricane strikes on the coast. The aims were to determine the hurricane landfall frequency, and make comparisons with indepen...

  2. A Chronology of Late-Glacial and Holocene Advances of Quelccaya Ice Cap, Peru, Based on 10Be and Radiocarbon Dating

    Science.gov (United States)

    Kelly, M. A.; Lowell, T. V.; Schaefer, J. M.

    2007-12-01

    The Quelccaya Ice Cap region in the southeastern Peruvian Andes (~13-14°S latitude) is a key location for the development of late-glacial and Holocene terrestrial paleoclimate records in the tropics. We present a chronology of past extents of Quelccaya Ice Cap based on ~thirty internally consistent 10Be dates of boulders on moraines and bedrock as well as twenty radiocarbon dates of organic material associated with moraines. Based on results from both dating methods, we suggest that significant advances of Quelccaya Ice Cap occurred during late-glacial time, at ~12,700-11,400 yr BP, and during Late Holocene time ~400-300 yr BP. Radiocarbon dating of organic material associated with moraines provides maximum and minimum ages for ice advances and recessions, respectively, thus providing an independent check on 10Be dates of boulders on moraines. The opportunity to use both 10Be and radiocarbon dating makes the Quelccaya Ice Cap region a potentially important low-latitude calibration site for production rates of cosmogenic nuclides. Our radiocarbon chronology provides a tighter constraint on maximum ages of late-glacial and Late Holocene ice advances. Upcoming field research will obtain organic material for radiocarbon dating to improve minimum age constrains for late-glacial and Late Holocene ice recessions.

  3. A new luminescence dating chronology for the Rhafas cave site (NE Morocco): Insights into Palaeolithic human cultural change under varying palaeoenvironmental conditions in the Maghreb

    Science.gov (United States)

    Dörschner, Nina; Fitzsimmons, Kathryn E.; Ditchfield, Peter; McLaren, Sue J.; Steele, Teresa E.; Zielhofer, Christoph; McPherron, Shannon P.; Bouzouggar, Abdeljalil; Hublin, Jean-Jacques

    2016-04-01

    Archaeological sites in northern Africa provide a rich record that is of increasing importance for current debates relating to the origins of modern human behaviour and to Out of Africa human dispersal events. Particular interest is placed on the cultural transition between the North African Middle Stone Age (MSA) and Late Stone Age (LSA), and the need for accurately defined chronologies, however the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb) and potential correlation with environmental conditions remain poorly understood. The inland cave site of Rhafas (Morocco) preserves a long stratified sequence providing valuable chronological information about cultural changes in the Maghreb spanning the North African MSA through to the Neolithic. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz grains to the cave deposits of Rhafas as well as to a section on the terrace in front of the cave entrance. Single grain OSL dating reliably constrains the timing of technocomplexes beyond the limits of radiocarbon by directly dating sediment associated with archaeological traces. We combine OSL dating with multi-proxy geological investigations (XRF, grain size analyses, stable isotopes, thin sections) to investigate site formation processes and reconstruct palaeoenvironmental conditions during human occupation phases at Rhafas. Our results indicate that the occupation of the site started at least in MIS 6 during a phase of relatively arid environmental conditions. Climatic amelioration after c.140 ka is associated with a change in sediment geochemistry at the site, most likely linked to a change in sediment source due to shifting wind directions. Tanged pieces - typical for the classical Aterian technocomplex - start to occur in the archaeological sequence in MIS 5, consistent with previously published chronological data from the Maghreb. From 55 ka, climatic conditions were

  4. Chronology of fluid paleo-circulations in mesozoic formations on the site of Bure by U/Pb dating of secondary calcites

    International Nuclear Information System (INIS)

    Pisapia, C.; Deschamps, P.; Hamelin, B.; Pisapia, C.; Buschaert, S.

    2009-01-01

    The French national agency for the management of radioactive wastes (ANDRA, Agence nationale pour la gestion des dechets radioactifs) has developed an underground research laboratory in mesozoic formations of the eastern Parisian Basin in order to test the design of radioactive waste storage site in sedimentary formations. The authors report an investigation which aims at understanding the site paleo-hydrology. This investigation is based on the disintegration chain of uranium and on U/Th and U/Pb dating methods, and aims at giving a precise chronology of the different phases of precipitation of centimetric and millimetric secondary calcites sampled on this site

  5. High-resolution OSL chronology of a sediment core from Lake Nam Co on the southern Tibetan Plateau: Comparison with radiocarbon dating

    Science.gov (United States)

    Long, Hao; Shen, Ji; Haberzettl, Torsten; Fuchs, Markus; Frechen, Manfred; Wang, Junbo

    2013-04-01

    Numerous studies on lake sediment cores from the Tibetan Plateau aimed to reconstruct spatial and temporal changes of the late Glacial and Holocene monsoon variations, which are characterized by fluctuations in precipitation and expansion of monsoonal air masses across the Plateau. Accurate and reliable dating of lacustrine deposits is of crucial importance in both the reconstruction of palaeolake and palaeoclimate evolution and the understanding of the mechanisms for climate changes, especially abrupt changes of regional-hemispheric hydrological circulation. Radiocarbon dating is the most commonly used method for establishing chronologies of lake sediments. However, 14C dating of such sediments could be problematic due to the lack of organic matter or a reservoir effect, which appears common in radiocarbon dating of lacustrine sediments from the Tibetan Plateau. In this study, ca. 10.5 m long core (NC core) was retrieved from the water depth of 93 m at Nam Co Lake, which is the second largest saline lake in China, located on the southern Tibetan Plateau. For this core, high-resolution samples (23 samples) were obtained for optically stimulated luminescence (OSL) dating. Quartz of fine-grain (4-11 μm) fraction were extracted from this samples for OSL dating, which is compared with the 14C chronology of NC core based on accelerator mass spectrometry (AMS) dating of bulk organic matter of 22 samples. The sample from the top of NC core was dated to approximate zero age, indicating the sediments bleached well before deposition. Luminescence behaviors of the study samples further confirmed the robustness of OSL ages. Comparison between OSL and 14C ages suggested that: (1) two kinds of ages are in agreement within error from top to 1.8 m, (2) from 1.8 m to the base of NC core, the 14C ages show a general trend to ca. 4 ka higher ages than the OSL ages. Although 14C dating overestimate the ages from 1.8 m to base, they still show the general trend in sedimentation rate

  6. The luminescence dating chronology of a deep core from Bosten Lake (NW China) in arid central Asia reveals lake evolution over the last 220 ka

    DEFF Research Database (Denmark)

    Li, Guoqiang; Duan, Yanwu; Huang, Xiaozhong

    2016-01-01

    The lacustrine deposits of lakes in arid central Asia (ACA) potentially record palaeoclimatic changes on orbital and suborbital time scales, but such changes are still poorly understood due to the lack of reliable chronologies. Bosten Lake, the largest freshwater inland lake in China, is located...... in the southern Tianshan Mountains in central ACA. A 51.6-m-deep lacustrine succession was retrieved from the lake and 30 samples from the succession were used for luminescence dating to establish a chronology based on multi-grain quartz OSL and K-feldspar post-IR IRSL (pIRIR290) dating. Quartz OSL ages were only....... A stable deep lake occurred at c. 220, 210–180, c. 165, 70–60, 40–30 and 20–5 ka, while shallow levels occurred at c. 215, 180–165, 100–70, 60–40 and 30–20 ka. Bosten Lake levels decreased by at least ~29 m and possibly the lake even dried up between c. 160 and c. 100 ka. We suggest that the water...

  7. Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago

    Science.gov (United States)

    Meltzer, David J.; Holliday, Vance T.; Cannon, Michael D.; Miller, D. Shane

    2014-05-01

    According to the Younger Dryas Impact Hypothesis (YDIH), ∼12,800 calendar years before present, North America experienced an extraterrestrial impact that triggered the Younger Dryas and devastated human populations and biotic communities on this continent and elsewhere. This supposed event is reportedly marked by multiple impact indicators, but critics have challenged this evidence, and considerable controversy now surrounds the YDIH. Proponents of the YDIH state that a key test of the hypothesis is whether those indicators are isochronous and securely dated to the Younger Dryas onset. They are not. We have examined the age basis of the supposed Younger Dryas boundary layer at the 29 sites and regions in North and South America, Europe, and the Middle East in which proponents report its occurrence. Several of the sites lack any age control, others have radiometric ages that are chronologically irrelevant, nearly a dozen have ages inferred by statistically and chronologically flawed age-depth interpolations, and in several the ages directly on the supposed impact layer are older or younger than ∼12,800 calendar years ago. Only 3 of the 29 sites fall within the temporal window of the YD onset as defined by YDIH proponents. The YDIH fails the critical chronological test of an isochronous event at the YD onset, which, coupled with the many published concerns about the extraterrestrial origin of the purported impact markers, renders the YDIH unsupported. There is no reason or compelling evidence to accept the claim that a cosmic impact occurred ∼12,800 y ago and caused the Younger Dryas.

  8. A chronology of the PY608E–PC sediment core (Lake Pumoyum Co, southern Tibetan Plateau) based on radiocarbon dating of total organic carbon

    International Nuclear Information System (INIS)

    Watanabe, Takahiro; Nakamura, Toshio; Matsunaka, Tetsuya; Nara, Fumiko Watanabe; Zhu Liping; Wang Junbo; Kakegawa, Takeshi; Nishimura, Mitsugu

    2013-01-01

    Paleoclimatic records from the Tibetan Plateau provide important clues for understanding the Asian monsoon and Asian climate systems. To reconstruct climatic and environmental changes in the southern Tibetan Plateau, a 3.77-m-long sediment core (PY608E–PC) was taken from the southeastern part of Lake Pumoyum Co in August 2006. Because terrestrial plant residues are extremely rare in this core, we performed radiocarbon dating on the total organic carbon fraction. We also estimated the old carbon effect and radiocarbon reservoir age of the total organic carbon fraction. Using these estimates, we propose a new radiocarbon chronology for past climatic changes from ca. 12,500 to 700 cal BP. The linear sedimentation rate of the core was founded to be constant at 32.0 cm/kyr, indicating stable sedimentation conditions in Lake Pumoyum Co from the period of the Younger Dryas to the Holocene.

  9. A chronology of the PY608E-PC sediment core (Lake Pumoyum Co, southern Tibetan Plateau) based on radiocarbon dating of total organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Takahiro, E-mail: twatanabe@geo.kankyo.tohoku.ac.jp [Graduate School of Environmental Studies, Tohoku University, 6-6-20 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579 (Japan); Graduate School of Science, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601 (Japan); Matsunaka, Tetsuya [School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu, Shizuoka 424-0902 (Japan); Nara, Fumiko Watanabe [Graduate School of Science, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578 (Japan); Zhu Liping; Wang Junbo [Institute of Tibetan Plateau Research, Chinese Academy of Science, No. 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Kakegawa, Takeshi [Graduate School of Science, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578 (Japan); Nishimura, Mitsugu [School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu, Shizuoka 424-0902 (Japan)

    2013-01-15

    Paleoclimatic records from the Tibetan Plateau provide important clues for understanding the Asian monsoon and Asian climate systems. To reconstruct climatic and environmental changes in the southern Tibetan Plateau, a 3.77-m-long sediment core (PY608E-PC) was taken from the southeastern part of Lake Pumoyum Co in August 2006. Because terrestrial plant residues are extremely rare in this core, we performed radiocarbon dating on the total organic carbon fraction. We also estimated the old carbon effect and radiocarbon reservoir age of the total organic carbon fraction. Using these estimates, we propose a new radiocarbon chronology for past climatic changes from ca. 12,500 to 700 cal BP. The linear sedimentation rate of the core was founded to be constant at 32.0 cm/kyr, indicating stable sedimentation conditions in Lake Pumoyum Co from the period of the Younger Dryas to the Holocene.

  10. An international research project on Armenian archaeological sites: fission-track dating of obsidians

    Energy Technology Data Exchange (ETDEWEB)

    Badalian, R.; Bigazzi, G. E-mail: g.bigazzi@iggi.pi.cnr.it; Cauvin, M.-C.; Chataigner, C.; Jrbashyan, R.; Karapetyan, S.G.; Oddone, M.; Poidevin, J.-L

    2001-06-01

    In the Mediterranean and adjacent regions, the Caucasus is one of the less studied areas in relation to provenance studies of prehistoric obsidian artefacts. In the frame of an international INTAS research project, an extensive surveying and sampling campaign was carried out in the numerous obsidian bearing volcanic complexes of Armenia. 33 obsidian samples were analysed using the fission-track dating method in order to characterise the potential sources of the numerous artefacts found in prehistoric sites. Ages cluster into five groups--Upper Neopleistocene Q{sub III}, Middle Neopleistocene Q{sub II}, Lower Neopleistocene Q{sub I}, Lower Eopleistocene Q{sub EI} and Lower Pliocene N{sub 3}{sup 1} groups. This research represents a significant contribution to a better knowledge of chronology of Armenian volcanism for which only few data were available. The resulting data-set appears to be a solid base for future provenance studies.

  11. K/Ar dating of Neogene volcanic activity in Hungary: Experimental technique, experiences and methods of chronological studies

    International Nuclear Information System (INIS)

    Balogh, Kadosa

    1985-01-01

    Construction and essential parameters of an argon extraction line and magnetic mass spectrometer for K/Ar dating are descibed. Experiences of chronoligical studies on Miocene intermediate and acid lavas and tuffs as well as on Pliocene basalts are summarized. Great attention is paid to the ascertainment of the geological reliability of radiometric ages. Experiences concerning the frequency, character and reason of geological errors for the different rock types are reviewed and methods of sample selection used for the recognition of unreliable ages are outlined. The isochron methods are used mostly for dating Pliocene basalts. The limitations of the pure mathematical treatment of the experimental data are pointed out and geological interpretation of the isochron ages is discussed. The uncertainty of error estimation of isotopic ratio and potassium concentration measurements is emphasized. (author)

  12. The radiocarbon dating project at Aboriginal Affairs, Victoria

    International Nuclear Information System (INIS)

    Godfrey, M.C.S.

    1997-01-01

    The purpose of this project has been to publish a complete list of the age estimates relating to the archaeological sites in the State of Victoria from 1951 to 1995, and to assess the value and the limitations of this information for interpreting the prehistory of this region. This project has recorded 476 dates coming from 14 laboratories, and ranging in age from the time of European settlement to the limit of the technique at around 40,000 years BP. However, the available evidence indicates that large discrepancies may exist in these results, and this has lead to the recommendation that this data should not be used in research projects requiring dating accuracies of less than a few hundred years

  13. Chronology of magmatism and mineralization in the Kassandra mining area, Greece: The potentials and limitations of dating hydrothermal illites

    Science.gov (United States)

    Gilg, H. Albert; Frei, Robert

    1994-05-01

    . The Rb/Sr dating of hydrothermal clays is sensitive to contamination by adsorbed strontium, which may not be cogenetic with the clay, as well as feldspars, which may not have been homogenized isotopically by the illitization process.

  14. Helium-4 characteristics of groundwaters from Central Australia: Comparative chronology with chlorine-36 and carbon-14 dating techniques

    Science.gov (United States)

    Kulongoski, Justin T.; Hilton, David R.; Cresswell, Richard G.; Hostetler, Stephen; Jacobson, Gerry

    2008-01-01

    SummaryHelium isotope and concentration characteristics were determined for a suite of groundwater samples from the Amadeus Basin in Central Australia. Two study areas include a wellfield south of Alice Springs, and the Dune Plains and Mututjulu aquifers near Uluru. Measurements of 36Cl/Cl and 14C on the same sample suite enable us to assess the relative applicability of the three groundwater chronometers over a range of anticipated groundwater residence times (ages), and to investigate possible causes of discordant 'ages' derived from the different groundwater dating techniques. Results from the analyses of 39 groundwater samples reveal helium-4 ( 4He) concentrations that range from 0.80 to 98.8 (×10 -7 cm 3 STP g -1 H 2O) in the Alice Springs samples, and from 0.47 to 65.6 (×10 -7 cm 3 STP g -1 H 2O) in the Uluru samples. 4He concentrations yield uncorrected groundwater residence times (i.e. time since recharge) of between modern to >2500 ka (near Alice Springs) and modern to 1600 ka (near Uluru) assuming an effective porosity of 20%, and uranium and thorium contents of 1.7 and 6.1 ppm, respectively. 36Cl/Cl ratios on the same samples range from 93 to 158 (×10 -15) (near Alice Springs) and from 80 to 335 (×10 -15) (near Uluru) representing groundwater residence times near Alice Springs from modern to >200 ka, and from modern to >300 ka near Uluru. Percent modern carbon (pmc) on the same samples ranged from 64.9 to 12.5 pmc near Alice Springs, and from 93.5 to 30 ka. For the Amadeus Basin groundwater samples, the 4He method (uncorrected) over-estimates groundwater residence time compared to 36Cl and 14C techniques. This implies the presence of an extraneous He component or basal flux of He ( J0). To reconcile groundwater 4He and 14C residence times, it is necessary to adopt J0 values between 0 and 30 (×10 -8) cm 3 STP He cm -2 a -1 which supplements in situ produced He within the aquifer. Adoption of J0 values over this range lowers 4He residence times

  15. Sedimentation rate and chronology of As and Zn in sediment of a recent former tin mining lake estimated using Pb-210 dating technique

    International Nuclear Information System (INIS)

    Zaharidah Abu Bakar; Ahmad Saat; Zaini Hamzah; Abdul Khalik Wood; Zaharudin Ahmad

    2011-01-01

    Sedimentation in lake occurred through run-off from the land surface and settles on the bottom lake. Past mining activities might enhance sedimentation process in the former tin mining lakes either through natural or human activities. Former tin mining lakes were suspected to have high sedimentation rate due undisturbed environment for almost 50 years. To estimate sedimentation rate and metals contamination in this lake, Pb-210 dating technique was used. Two sediments cores were sampled using gravity corer from a former tin mining lake then analyzed using alpha-spectrometry and Neutron Activation Analysis (NAA). From this study, the results showed the sedimentation rate for sediment cores S1 and S2 are 0.26 cm y -1 and 0.23 cmy -1 respectively. According to sediment chronological sequences, high concentrations of As and Zn in the upper layer indicated that human activities contributed to these metals contamination in the lake sediment. Sedimentation rate and metals contamination possibly due to recent anthropogenic activities around the lake such as human settlement, farming and agricultures activities since the ceased of mining activities a few decades ago. (author)

  16. Chronology. Classroom Focus.

    Science.gov (United States)

    McGoldrick, Neale

    1995-01-01

    Presents a chronology of important dates and events in the struggle for women's rights and women's suffrage. Begins in 1648 with the first call for women's suffrage in Maryland and concludes in 1920 with the passage of the 19th Amendment by Tennessee. (CFR)

  17. 40Ar/ 39Ar, K-Ar and 230Th- 238U dating of the Laschamp excursion: A radioisotopic tie-point for ice core and climate chronologies

    Science.gov (United States)

    Singer, Brad S.; Guillou, Hervé; Jicha, Brian R.; Laj, Carlo; Kissel, Catherine; Beard, Brian L.; Johnson, Clark M.

    2009-08-01

    A brief period of enhanced 10Be flux that straddles the interstadial warm period known as Dansgaard-Oeschger event 10 in Greenland and its counterpart in Antarctica, the Antarctic Isotope Maximum 10 is but one consequence of the weakening of Earth's magnetic field associated with the Laschamp excursion. This 10Be peak measured in the GRIP ice core is dated at 41,250 y b2k (= before year 2000 AD) in the most recent GICC05 age model obtained from the NorthGRIP core via multi-parameter counting of annual layers. Uncertainty in the age of the 10Be peak is, however, no better than ± 1630 y at the 95% confidence level, reflecting accumulated error in identifying annual layers. The age of the Laschamp excursion [Guillou, H., Singer, B.S., Laj, C., Kissel, C., Scaillet, S., Jicha, B., 2004. On the age of the Laschamp geomagnetic excursion. Earth Planet. Sci. Lett. 227, 331-343.] is revised on the basis of new 40Ar/ 39Ar, unspiked K-Ar and 238U- 230Th data from three lava flows in the Massif Central, France, together with the 40Ar/ 39Ar age of a transitionally magnetized lava flow at Auckland, New Zealand. Combined, these data yield an age of 40,700 ± 950 y b2k, where the uncertainty includes both analytical and systematic ( 40K and 230Th decay constant) errors. Taking the radioisotopic age as a calibration tie point suggests that the layer-counting chronologies for the NorthGRIP and GISP2 ice cores are more accurate and precise than previously thought at depths corresponding to the Laschamp excursion.

  18. Internet dating as a project: the commodification and rationalisation of online dating

    Directory of Open Access Journals (Sweden)

    Tjaša Žakelj

    2015-04-01

    Full Text Available Based on qualitative empirical data from two studies on Internet dating in Slovenia, this paper discusses the social contexts of the Internet dating of heterosexual men and women and homosexual men. Special attention is given to different aspects of the commodification and rationalisation of dating in the process of forming potential (romantic partnerships. First, we discuss our respondents’ reasons for using the Internet to get in touch with potential (romantic partners. Second, we focus on the demands and strategies of targeted market- ing in personal profile writing and, finally, on the process of selecting potential partners. Our study shows that the primary understanding of Internet dating among people who engage in it is its economic nature. Together with targeted marketing and the predeter- mined criteria for choosing interesting others, Internet dating can thus be understood as a market that encourages rationalisation and commodification in the process of forming intimate relationships.

  19. Second interlaboratory-comparison project on ESR dating

    International Nuclear Information System (INIS)

    Barabas, M.; Walther, R.; Radtke, U.

    1993-01-01

    An intercomparison project on ESR dating in which 14 ESR groups participated was initiated. Each group was provided with two samples of a coral powder, one of which (Sample A) was a fossil coral with a mass spectrometric determined U/Th age. Sample B was a recent coral, irradiated with a definite γ-dose (checked by alanine dosimetry). In both cases the accumulated dose (AD) had to be determined (for sample A the U-content and age as well). Additionally, the chance of a calibration of γ-sources by alanine dosimeters was offered. The results show that the γ-source calibration is better then ± 5%, the mean value of the AD from sample A seems to agree with the expected AD but the mean AD value from sample B is overestimated, systematic errors occur due to the fitting procedure: the AD estimate depends on the maximum γ-dose used for the irradiation curve, the AD determination including the smallest systematic error gives correct values for sample B but too low values for sample A which may be caused by fading of the signal g = 2.0006. (author)

  20. Last Glacial Maximum and Lateglacial in the Polish High Tatra Mountains - Revised deglaciation chronology based on the 10Be exposure age dating

    Science.gov (United States)

    Makos, Michał; Rinterknecht, Vincent; Braucher, Régis; Tołoczko-Pasek, Anna; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Keddadouche, Karim; Aster Team

    2018-05-01

    Deglaciation chronology of the Polish High Tatra Mountains has been reconstructed based on 10Be exposure age dating. Fifty-seven rock samples were collected from boulders located on the terminal and lateral moraines that limit the horizontal extent of the LGM and the Lateglacial glaciers in the Biała Woda and Sucha Woda catchments. The uncertainty-weighted mean age of 21.5 ± 2.5 ka obtained for the maximum terminal moraine in the Sucha Woda Valley indicates that the oldest preserved moraines were formed during the global LGM. The age population ranges between 15.1 ± 1.0 and 28.3 ± 2.0 ka, and suggests that glaciers reached their maximum position (LGM I) as early as 28-25 ka and the final stabilization of the form occurred much later possibly after melting of buried dead ice. The younger glacial oscillation (LGM II) occurred no later than 20.5 ka and is represented by well-preserved termino-lateral moraine systems in the Pańszczyca Valley. The first Lateglacial stage (LG1) in the study area is documented in the Rybi Potok Valley at the RP1 moraine (1300 m a.s.l.), which was stable at around 16.6 ± 0.3 ka. The younger LG2 stage has no defined absolute age, however, it is constrained between 16.5 and 15.5 ka by the timing of the LG3 stage. This cold event is represented by well-formed moraines in the Roztoka/Pięć Stawów Polskich, Rybi Potok and Pańszczyca valleys of which exposure age indicates their deposition between 15.0 ± 0.5 and 15.6 ± 0.1 ka. The LG1, LG2 and LG3 stages likely occurred during the Oldest Dryas cold stage (Greenland Stadial 2.1a) related to the North Atlantic cooling Heinrich Event 1. The youngest glacial oscillation is evidenced by moraines in the Pusta and Pańszczyca valleys. These moraines are composed of very large granitic blocks of which exposure ages often exhibit isotope inheritance. This is reflected by the youngest P3 moraine in the Pańszczyca Valley with a mean age of deposition close to the LGM. The R4 moraine system in

  1. RELATIVE AND ABSOLUTE CHRONOLOGY OF YAMNAYA AND CATACOMB MONUMENTS THE ISSUE OF CO-EXISTENCE

    OpenAIRE

    Telegin, Dmitriy Y.; Pustovalov, Sergey Z.; Kovalyukh, Nikolay N.

    2003-01-01

    This volume of the Baltic-Pontic Studies is a record of investigations carried out under the research project begun earlier in vol. 7 ("The Foundations of radiocarbon chronology of cultures between the Vistula and Dnieper: 3150-1850 BC", Poznań 1999). Here, the approach is broader in terms of chronology and culture. Our purpose has been to fill taxonomic gaps hitherto present in the discussion (supplementing the dating of cultures, groups or phases) or reanalyze the grounds for findings consi...

  2. The Antarctic ice core chronology (AICC2012): an optimized multi-parameter and multi-site dating approach for the last 120 thousand years

    Science.gov (United States)

    Veres, D.; Bazin, L.; Landais, A.; Toyé Mahamadou Kele, H.; Lemieux-Dudon, B.; Parrenin, F.; Martinerie, P.; Blayo, E.; Blunier, T.; Capron, E.; Chappellaz, J.; Rasmussen, S. O.; Severi, M.; Svensson, A.; Vinther, B.; Wolff, E. W.

    2013-08-01

    The deep polar ice cores provide reference records commonly employed in global correlation of past climate events. However, temporal divergences reaching up to several thousand years (ka) exist between ice cores over the last climatic cycle. In this context, we are hereby introducing the Antarctic Ice Core Chronology 2012 (AICC2012), a new and coherent timescale developed for four Antarctic ice cores, namely Vostok, EPICA Dome C (EDC), EPICA Dronning Maud Land (EDML) and Talos Dome (TALDICE), alongside the Greenlandic NGRIP record. The AICC2012 timescale has been constructed using the Bayesian tool Datice (Lemieux-Dudon et al., 2010) that combines glaciological inputs and data constraints, including a wide range of relative and absolute gas and ice stratigraphic markers. We focus here on the last 120 ka, whereas the companion paper by Bazin et al. (2013) focuses on the interval 120-800 ka. Compared to previous timescales, AICC2012 presents an improved timing for the last glacial inception, respecting the glaciological constraints of all analyzed records. Moreover, with the addition of numerous new stratigraphic markers and improved calculation of the lock-in depth (LID) based on δ15N data employed as the Datice background scenario, the AICC2012 presents a slightly improved timing for the bipolar sequence of events over Marine Isotope Stage 3 associated with the seesaw mechanism, with maximum differences of about 600 yr with respect to the previous Datice-derived chronology of Lemieux-Dudon et al. (2010), hereafter denoted LD2010. Our improved scenario confirms the regional differences for the millennial scale variability over the last glacial period: while the EDC isotopic record (events of triangular shape) displays peaks roughly at the same time as the NGRIP abrupt isotopic increases, the EDML isotopic record (events characterized by broader peaks or even extended periods of high isotope values) reached the isotopic maximum several centuries before. It is

  3. The Antarctic ice core chronology (AICC2012: an optimized multi-parameter and multi-site dating approach for the last 120 thousand years

    Directory of Open Access Journals (Sweden)

    D. Veres

    2013-08-01

    Full Text Available The deep polar ice cores provide reference records commonly employed in global correlation of past climate events. However, temporal divergences reaching up to several thousand years (ka exist between ice cores over the last climatic cycle. In this context, we are hereby introducing the Antarctic Ice Core Chronology 2012 (AICC2012, a new and coherent timescale developed for four Antarctic ice cores, namely Vostok, EPICA Dome C (EDC, EPICA Dronning Maud Land (EDML and Talos Dome (TALDICE, alongside the Greenlandic NGRIP record. The AICC2012 timescale has been constructed using the Bayesian tool Datice (Lemieux-Dudon et al., 2010 that combines glaciological inputs and data constraints, including a wide range of relative and absolute gas and ice stratigraphic markers. We focus here on the last 120 ka, whereas the companion paper by Bazin et al. (2013 focuses on the interval 120–800 ka. Compared to previous timescales, AICC2012 presents an improved timing for the last glacial inception, respecting the glaciological constraints of all analyzed records. Moreover, with the addition of numerous new stratigraphic markers and improved calculation of the lock-in depth (LID based on δ15N data employed as the Datice background scenario, the AICC2012 presents a slightly improved timing for the bipolar sequence of events over Marine Isotope Stage 3 associated with the seesaw mechanism, with maximum differences of about 600 yr with respect to the previous Datice-derived chronology of Lemieux-Dudon et al. (2010, hereafter denoted LD2010. Our improved scenario confirms the regional differences for the millennial scale variability over the last glacial period: while the EDC isotopic record (events of triangular shape displays peaks roughly at the same time as the NGRIP abrupt isotopic increases, the EDML isotopic record (events characterized by broader peaks or even extended periods of high isotope values reached the isotopic maximum several centuries before

  4. C-14 dates from a profile of Arroyo Tapalque, Buenos Aires Province, Argentina. Contribution to the chronology of faunal and environmental events

    International Nuclear Information System (INIS)

    Figini, Anibal; Huarte, Roberto; Carbonari, Jorge; Tonni, Eduardo P.

    1998-01-01

    Eleven radiocarbon dates were obtained from different materials in a stratigraphic section spanning the last 30,000 years. These new dates allow to calibrate different faunal and environmental events occurring in the area. (author)

  5. Pile Structure Program, Projected Start Date : January 1, 2010 (Implementation).

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Chris; Corbett, Catherine [Lower Columbia River Estuary Partnership; Ebberts, Blaine [U.S. Army Corps of Engineers

    2009-07-27

    The 2008 Federal Columbia River Power System Biological Opinion includes Reasonable and Prudent Alternative 38-Piling and Piling Dike Removal Program. This RPA directs the Action Agencies to work with the Estuary Partnership to develop and implement a piling and pile dike removal program. The program has since evolved to include modifying pile structures to enhance their habitat value and complexity by adding large woody debris. The geographic extent of the Pile Structure Program (PSP) includes all tidally-influenced portions of the lower Columbia River below Bonneville Dam; however, it will focus on the mainstem. The overarching goal of the PSP is to enhance and restore ecosystem structure and function for the recovery of federally listed salmonids through the active management of pile structures. To attain this goal, the program team developed the following objectives: (1) Develop a plan to remove or modify pile structures that have lower value to navigation channel maintenance, and in which removal or modification will present low-risk to adjacent land use, is cost-effective, and would result in increased ecosystem function. (2) Determine program benefits for juvenile salmonids and the ecosystem through a series of intensively monitored pilot projects. (3) Incorporate best available science and pilot project results into an adaptive management framework that will guide future management by prioritizing projects with the highest benefits. The PSP's hypotheses, which form the basis of the pilot project experiments, are organized into five categories: Sediment and Habitat-forming Processes, Habitat Conditions and Food Web, Piscivorous Fish, Piscivorous Birds, and Toxic Contaminant Reduction. These hypotheses are based on the effects listed in the Estuary Module (NOAA Fisheries in press) and others that emerged during literature reviews, discussions with scientists, and field visits. Using pilot project findings, future implementation will be adaptively managed

  6. WIMS library up-date project: first stage results

    International Nuclear Information System (INIS)

    Prati, A.; Claro, L.H.

    1990-01-01

    The following benchmarks: TRX1, TRX2, BAPL-UO sub(2)-1, BAPL-UO sub (2)-2, BAPL-UO sub(2)-3 have been calculated with the WIMSD/4 code, as a contribution of CTA/IEAv, to the first stage of the WIMS Library Update Project, coordinated by the International Atomic Energy Agency. The card image input for each benchmark has been attached and the major input options/parameters are commented. The version of the WIMSD/4 code and its multigroup cross section library used to run the benchmarks are specified. Results from the major integral parameters are presented and discussed. (author)

  7. Absolute chronology and stratigraphy of Lepenski Vir

    Directory of Open Access Journals (Sweden)

    Borić Dušan

    2007-01-01

    Full Text Available In the last decade, a number of specialist analyses were made on the material from old excavations of Mesolithic-Neolithic sites in the Danube Gorges. These new results altered significantly our understanding of the Lepenski Vir culture. The question of chronology of this regional phenomenon has been acute since the discovery of Lepenski Vir in the 1960s, and it remains of key importance for understanding the character of Mesolithic-Neolithic transformations in this and the neighbouring regions. The most heated debate was fuelled by the initial stratigraphic and chronological attribution of the type-site itself. There remained the question about the adequate dating of the most prominent phase at this site characterized by buildings with trapezoidal bases covered with limestone floors and with rectangular stone-lined hearths placed in the centre of these features. There have been suggestions that these features also contain Early Neolithic Starčevo type pottery and other similar items of material culture and should thus be dated to the Early Neolithic historical context. Moreover, the first series of conventional radiocarbon determinations (21 dates also suggested that the absolute chronology of these features should be confined to the period from around 6400-5500 cal BC (Fig. 1. Due to the importance of defining more precisely the chronology for the start of construction of these particular features at Lepenski Vir and for establishing the life-span of these buildings and their associated material culture, we have AMS (Accelerator Mass Spectrometry dated a number of contexts from this site. The results are presented in this paper. The project was made possible through the Oxford Radiocarbon Accelerate Dating Service (ORADS programme funded by the Arts and Humanities Research Council (AHRC and the Natural Environment Research Council (NERC of the Great Britain. Apart from those dates presented in this paper, there are 29 previously published

  8. Settlement duration and materiality: formal chronological models for the development of Barnhouse, a Grooved Ware settlement in Orkney

    OpenAIRE

    Richards, Colin; Jones, Andrew Meirion; MacSween, Ann; Sheridan, Alison; Dunbar, Elaine; Reimer, Paula; Bayliss, Alex; Griffiths, Seren; Whittle, Alasdair

    2016-01-01

    Radiocarbon dating and Bayesian chronological modelling, undertaken as part of the investigation by the Times of Their Lives project into the development of Late Neolithic settlement and pottery in Orkney, has provided precise new dating for the Grooved Ware settlement of Barnhouse, excavated in 1985–91. Previous understandings of the site and its pottery are presented. A Bayesian model based on 70 measurements on 62 samples (of which 50 samples are thought to date accurately the deposits fro...

  9. The EASTNET Project: Extending the Network of Climate-Sensitive Tree-Ring Chronologies From the Eastern United States for Reconstructing the Spatio-Temporal Characteristics of Climate and Drought Over the Past Millennium

    Science.gov (United States)

    Buckley, B. M.; Cook, E. R.

    2002-12-01

    Recently, a network of gridded PDSI reconstructions for the contiguous United States was produced, based on the available network of drought-sensitive tree-ring chronologies (Cook et al. 1999). Analyses were constrained to the common period of 1700 - 1979 due to the limitations of the available tree-ring data. While several chronologies from the western U.S. span 1,000 years or more, very few chronologies from the eastern U.S. covered even the past 500 years. The objective of this project, funded by the National Science Foundation's ESH program, is to extend the tree-ring chronology network from the eastern U.S. with chronologies spanning the past 500-1,000 years. This aim is being achieved by sampling in areas that have escaped the effects of development, logging and major disturbance such as fire. The two main target species are Thuja occidentalis (eastern white cedar) and Juniperus virginiana (eastern red cedar). The primary terrain types are on cliffs, rocky outcrops, and other areas that have been difficult to access. We have already developed chronologies from Wisconsin, New Hampshire, Pennsylvania, West Virginia, and Virginia that span from 500 to 1500 years. The temporal depth of these chronologies is being extended through the exploitation of "sub-fossil" wood found at these sites, in the form of standing-dead stems and downed and buried logs. We are also currently pursuing leads in Maine, Vermont, Massachusetts, Connecticut, New York, New Jersey Pennsylvania, Kentucky and North Carolina where old cedar trees have either been reported or where terrain types match criteria developed for this project. In this paper we discuss the current status of the network, and explore the spatio-temporal characteristics of climate and drought across the eastern US for the past 500 years and more. We use our preliminary network to explore the regional expression of climate anomalies such as drought. Our analyses so far demonstrates multicentennial variability suggestive

  10. Radiocarbon dating

    International Nuclear Information System (INIS)

    Lazos R, L.

    2005-01-01

    The application of the radiocarbon dating in archaeology has not served only to solve problems related with the establishment of chronologies, but also in the development of archaeological methods of excavation and interpretation. This has been possible because the dating method by radiocarbon provides a common temporary scale that transcends the cultural and regional frontiers. It is even spoken of the revolution that has meant the fact that the application of this method has allowed to the archaeologist to pass from the construction of chronologies until the evaluation and dynamic interpretation of the archaeological data to build theories. This work explains and compares methods for the detection of 14 C, as the gas counting, the liquid scintillation counting and the mass spectrometry with accelerators. (Author)

  11. Project Date SMART: a Dating Violence (DV) and Sexual Risk Prevention Program for Adolescent Girls with Prior DV Exposure.

    Science.gov (United States)

    Rizzo, Christie J; Joppa, Meredith; Barker, David; Collibee, Charlene; Zlotnick, Caron; Brown, Larry K

    2018-05-01

    This study assessed the initial feasibility, acceptability, and efficacy of an intervention aimed at reducing dating violence and sexual risk behavior in a sample of adolescent girls (ages 14-17) with prior exposure to physical dating violence (DV). One hundred and nine girls were randomly assigned to Date SMART (Skills to Manage Aggression in Relationships for Teens) or a Knowledge-only (KO) comparison group. Both intervention arms consisted of six, weekly 2-h sessions and one "booster" session 6 weeks later. Based on principles of cognitive behavioral therapy, the Date SMART intervention was designed to target common underlying skills deficits linked to both DV and sexual risk behavior in adolescent females: depression, self-regulation deficits, and interpersonal skills deficits. Assessments were administered at four time points (baseline, 3, 6, and 9 months). The Date SMART group was effective as reducing sexual DV involvement across the 9-month follow-up period. Both groups evidenced clinically meaningful reductions in physical, emotional, and digital DV involvement, total time in dating relationships, as well as reductions in depression. Findings indicate that delivering a DV and sexual risk prevention intervention to DV-affected adolescent girls is feasible and well-received. Furthermore, a skills-based approach that addresses the co-occurrence of DV and sexual risk behavior may be particularly useful for promoting reductions of sexual DV among high-risk adolescent girls. A future, large-scale trial with an inactive comparison condition is needed to evaluate the efficacy of Date SMART further. Clinical Trials, NCT01326195, and http://www.clinicaltrials.gov.

  12. Comparing records with related chronologies

    Science.gov (United States)

    Bronk Ramsey, Christopher; Albert, Paul; Kearney, Rebecca; Staff, Richard A.

    2016-04-01

    In order to integrate ice, terrestrial and marine records, it is necessary to deal with records on different timescales. These timescales can be grouped into those that use a common fundamental chronometer (such as Uranium-Thorium dating or Radiocarbon) and can also be related to one another where we have chronological tie points such as tephra horizons. More generally we can, through a number of different methodologies, derive relationships between different timescales. A good example of this is the use of cosmogenic isotope production, specifically 10Be and 14C to relate the calibrated radiocarbon timescale to that of the Greenland ice cores. The relationships between different timescales can be mathematically expressed in terms of time-transfer functions. This formalism allows any related record to be considered against any linked timescale with an appropriate associated uncertainty. The prototype INTIMATE chronological database allows records to be viewed and compared in this way and this is now being further developed, both to include a wider range of records and also to provide better connectivity to other databases and chronological tools. These developments will also include new ways to use tephra tie-points to constrain the relationship between timescales directly, without needing to remodel each associated timescale. The database as it stands allows data for particular timeframes to be recalled and plotted against any timescale, or exported in spreadsheet format. New functionality will be added to allow users to work with their own data in a private space and then to publish it when it has been through the peer-review publication process. In order to make the data easier to use for other further analysis and plotting, and with data from other sources, the database will also act as a server to deliver data in a JSON format. The aim of this work is to make the comparison of integrated data much easier for researchers and to ensure that good practice in

  13. The Great Bear Flare Pit Project : review of work to date

    International Nuclear Information System (INIS)

    Ridal, J.; Lean, D.; Findlay, S.C.

    1998-01-01

    Published information regarding potential toxic agents associated with flare emissions and a study to determine the risk posed to Treaty 8 First Nations (T8FN) peoples and wildlife was reviewed as part of the Great Bear Flare Pit Project (GBFPP). The project is concerned with the study of water and soil contamination in the immediate vicinity of flare pits in the Del Rio, Doig basin, Blueberry River, and Halfway River regions of T8FN lands in Alberta. The GBFPP has established good baseline data on metal contamination, and other contaminants such as benzene, toluene, ethylbenzene, xylenes (BTEX) and polycyclic aromatic hydrocarbons (PAHs) in the immediate vicinity of selected flare pits. Based on a critical assessment of reports published to date a series of prioritized recommendations for further research are made. 18 refs., 2 tabs

  14. Glacial evolution in King George and Livingston Islands (Antarctica) since the Last Glacial Maximum based on cosmogenic nuclide dating and glacier surface reconstruction - CRONOANTAR project

    Science.gov (United States)

    Ruiz Fernández, Jesús; Oliva, Marc; Fernández Menéndez, Susana del Carmen; García Hernández, Cristina; Menéndez Duarte, Rosa Ana; Pellitero Ondicol, Ramón; Pérez Alberti, Augusto; Schimmelpfennig, Irene

    2017-04-01

    CRONOANTAR brings together researchers from Spain, Portugal, France and United Kingdom with the objective of spatially and temporally reconstruct the deglaciation process at the two largest islands in the South Shetlands Archipelago (Maritime Antarctica), since the Global Last Glacial Maximum. Glacier retreat in polar areas has major implications at a local, regional and even planetary scale. Global average sea level rise is the most obvious and socio-economically relevant, but there are others such as the arrival of new fauna to deglaciated areas, plant colonisation or permafrost formation and degradation. This project will study the ice-free areas in Byers and Hurd peninsulas (Livingston Island) and Fildes and Potter peninsulas (King George Island). Ice-cap glacier retreat chronology will be revealed by the use of cosmogenic isotopes (mainly 36Cl) on glacially originated sedimentary and erosive records. Cosmogenic dating will be complemented by other dating methods (C14 and OSL), which will permit the validation of these methods in regions with cold-based glaciers. Given the geomorphological evidences and the obtained ages, a deglaciation calendar will be proposed and we will use a GIS methodology to reconstruct the glacier extent and the ice thickness. The results emerging from this project will allow to assess whether the high glacier retreat rates observed during the last decades were registered in the past, or if they are conversely the consequence (and evidence) of the Global Change in Antarctica. Acknowledgements This work has been funded by the Spanish Ministry of Economy, Industry and Competitiveness (Reference: CTM2016-77878-P).

  15. Chronology of early lunar crust

    International Nuclear Information System (INIS)

    Dasch, E.J.; Nyquist, L.E.; Ryder, G.

    1988-01-01

    The chronology of lunar rocks is summarized. The oldest pristine (i.e., lacking meteoritic contamination of admixed components) lunar rock, recently dated with Sm-Nd by Lugmair, is a ferroan anorthosite, with an age of 4.44 + 0.02 Ga. Ages of Mg-suite rocks (4.1 to 4.5 Ga) have large uncertainties, so that age differences between lunar plutonic rock suites cannot yet be resolved. Most mare basalts crystallized between 3.1 and 3.9 Ga. The vast bulk of the lunar crust, therefore, formed before the oldest preserved terrestrial rocks. If the Moon accreted at 4.56 Ga, then 120 Ma may have elapsed before lunar crust was formed

  16. Separating the wheat from the chaff: Dating charred plant remains extracted from Daub (with reference to the 14C chronology of the Epi-Lengyel culture in Upper Silesia)

    Czech Academy of Sciences Publication Activity Database

    Chmielewski, T. J.; Sady, A.; Goslar, T.; Furmanek, M.; Juchelka, Jiří

    2017-01-01

    Roč. 59, č. 1 (2017), s. 251-268 ISSN 0033-8222 Institutional support: RVO:68081758 Keywords : food residue * dates * pottery * bones * ams * radiocarbon AMS dating * chaff temper dating * Eneolithic * epi-Lengyel * Upper Silesia Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology Impact factor: 1.280, year: 2016

  17. The contribution of 14C AMS dating to the Greater Angkor archaeological project

    International Nuclear Information System (INIS)

    Zoppi, U.; Barbetti, M.; Fletcher, R.; Hua, Q.; Chhem, R.K.; Pottier, C.; Watanasak, M.

    2004-01-01

    For well over five centuries, the Khmer kingdom ruled over a vast territory, including most of what is now known as Cambodia, Thailand, Vietnam and Laos. Between the 9th and 14th century AD, the Khmer Kings developed the Angkor area into a remarkable administrative and religious centre for their society. According to new estimates by the Greater Angkor Project, the entire urban complex of the capital city covered about 1000 square km making it probably the largest archaeological site in the world. Great stone temples and some other monumental structures and earthworks are the only visible remains of this fascinating civilisation. Thankfully, there is a substantial on-going multinational effort to preserve and restore what is left and in 1992 UNESCO (United Nations Educational Scientific and Cultural Organisation) declared Angkor a World Heritage Site. This paper presents two particular aspects of the Greater Angkor Project where radiocarbon dating by AMS specifically added to our knowledge of the history of this ancient capital city

  18. Nuclear cosmo-chronology

    International Nuclear Information System (INIS)

    Berkes, I.

    2002-01-01

    Nuclear cosmo-chronology is based on the age determination method by using pairs of isotopes or elements: 235 U / 238 U, 187 Re / 187 Os and Th / U or Th / Eu. In this article we examine the age of the galaxy that has been deduced from the analysis of meteorites or from the absorption spectra of the solar light and the age of old stars. Since the solar system is far younger than the galaxy, the evaluation based on the abundances of nuclei in the solar system (absorption spectra of the sun, abundance ratio on meteorites) should take into account a model of the chemistry evolution of the galaxy. The age of the galaxy appears to be somewhere between 12 and 15 Gy with an absolute error of 3 Gy. As for very old stars, they appear to be just a bit older than the galaxy so the evaluation of their age is independent from the chemical evolution of the galaxy. The formation of galaxies began 1 to 2 Gy after the big-bang, the nuclear cosmo-chronology gives the same age for the galaxy as cosmological considerations on the age of the universe do. (A.C.)

  19. Ancient Egyptian chronology and the astronomical orientation of pyramids

    Science.gov (United States)

    Spence, Kate

    2000-11-01

    The ancient Egyptian pyramids at Giza have never been accurately dated, although we know that they were built approximately around the middle of the third millennium BC. The chronologies of this period have been reconstructed from surviving lists of kings and the lengths of their reigns, but the lists are rare, seldom complete and contain known inconsistencies and errors. As a result, the existing chronologies for that period (the Old Kingdom) can be considered accurate only to about +/-100 years, a figure that radiocarbon dating cannot at present improve. Here I use trends in the orientation of Old Kingdom pyramids to demonstrate that the Egyptians aligned them to north by using the simultaneous transit of two circumpolar stars. Modelling the precession of these stars yields a date for the start of construction of the Great Pyramid that is accurate to +/-5 yr, thereby providing an anchor for the Old Kingdom chronologies.

  20. The project of decontamination of Tominari primary school in date city, Fukushima prefecture

    International Nuclear Information System (INIS)

    Katsumi, Satsuki

    2013-01-01

    The previous principal reports his concerned decontamination process of the school, localizing at 60 km distance from Fukushima Nuclear Power Plant, after its Accident (Mar. 2011). The school was defined as one of 11 with >3.8 mc-Sv/h ambient dose necessary for decontamination by Japanese Ministry of Education, Culture, Sports, Science an Technology (MEXT). Measurements of the dose by Date City and MEXT started from April, which revealed that it was 3.3-5.5 mc-Sv/h at 1 m height of the schoolyard. Decontamination was done by weeding, then removal of the ground soil at 3 ) and spreading a new soil, resulting in the reduction of the dose to 0.75 mc-Sv/h at 50 cm height. Unexpectedly, the removed soil was buried for tentative storage by wrapping with Volclay tarpaulin in a 140 cm deep hole at the corner of the yard, which was a result of residents' disagreement with the scheduled estate. Decontamination of school circumstances was conducted in July by experts, PTA voluntary parents and applied volunteers with their repeated meetings involving the radiological explanation of even radiation units. The classroom ambient dose at 50 cm height was declined from 0.11 to 0.06 mc-Sv, pavements from 2-3 to 0.7-1.0, plantings from 3.7 to 0.7, and the bank between the yard and schoolhouse from 4-5 to 1-1.5. The swimming pool water was first purified with zeolite, which made its radiocesium level below the standard limit <50 Bq/L, then was released out, and the pool was filled with fresh city water (<7 Bq/L). The ambient dose 6-8 mc-Sv/h around the pool at 50 cm height was reduced to 0.7-0.8 after decontamination. The project finished within July. Now the decontamination is still under progress for the forest and resident's houses; pupils are enjoying lessons, swimming and sports; and the author looks back the successful importance of experts' easy explanation about radiology. (T.T)

  1. The Colorado Front Range Ecosystem Management Research Project: Accomplishments to date

    Science.gov (United States)

    Brian Kent; Wayne D. Shepperd; Deborah J. Shields

    2000-01-01

    This article briefly describes the goals and objectives for the Colorado Front Range Ecosystem Management Project (FREM). Research under this project has addressed both biophysical and human dimensions problems relating to ecosystem management in the Colorado Front Range. Results of completed work are described, and the status of the ongoing demonstration project at...

  2. Projected Crop Production under Regional Climate Change Using Scenario Data and Modeling: Sensitivity to Chosen Sowing Date and Cultivar

    Directory of Open Access Journals (Sweden)

    Sulin Tao

    2016-02-01

    Full Text Available A sensitivity analysis of the responses of crops to the chosen production adaptation options under regional climate change was conducted in this study. Projections of winter wheat production for different sowing dates and cultivars were estimated for a major economic and agricultural province of China from 2021 to 2080 using the World Food Study model (WOFOST under representative concentration pathways (RCPs scenarios. A modeling chain was established and a correction method was proposed to reduce the bias of the resulting model-simulated climate data. The results indicated that adjusting the sowing dates and cultivars could mitigate the influences of climate change on winter wheat production in Jinagsu. The yield gains were projected from the chosen sowing date and cultivar. The following actions are recommended to ensure high and stable yields under future climate changes: (i advance the latest sowing date in some areas of northern Jiangsu; and (ii use heat-tolerant or heat-tolerant and drought-resistant varieties in most areas of Jiangsu rather than the currently used cultivar. Fewer of the common negative effects of using a single climate model occurred when using the sensitivity analysis because our bias correction method was effective for scenario data and because the WOFOST performed well for Jiangsu after calibration.

  3. Application of the 210Pb-dating technique to establish a chronological framework of trace element and heavy metal contamination resulting from the impact of European settlement in estuarine systems of the Sydney Basin, Australia

    International Nuclear Information System (INIS)

    Jenkinson, A.V.; Chisari, R.; Farrar, Y.J.; Heijnis, H.; McOrist, G.D.; Tinker, R.A.; Smith, J.D.; Napoli, M.; Hughes, M.; James, J.M.

    1997-01-01

    The estuaries of Georges River and Hacking River, partly located in suburban Sydney, are at significant risk of contamination by heavy metal and trace element pollutants associated with urban/industrial development. The object of the current work is to correlate changes in land use resulting from European settlement with chemical changes observed in soil sediments. At each location core samples were taken and selected slices analysed for 226 Ra and 210 Po using alpha spectrometry. The 226 Ra activity equates to the supported 210 Pb activity and the 210 Po activity equates to the total 210 Pb activity. The difference between the total and the supported 210 Pb is the excess 210 Pb activity. Once the excess 210 Pb has been layed down in the sediment its activity at depth (assuming the core to be undisturbed) is solely a function of its half-life and the initial amount present; a circumstance which readily affords the calculation of a sedimentation rate. Owing to its relatively short half-life (22.26 year) the 20P b dating technique can be used to date sediments as far back as about 120 years. In Australia this time frame would cover most of the period of European settlement

  4. Application of the {sup 210}Pb-dating technique to establish a chronological framework of trace element and heavy metal contamination resulting from the impact of European settlement in estuarine systems of the Sydney Basin, Australia.

    Energy Technology Data Exchange (ETDEWEB)

    Jenkinson, A.V.; Chisari, R.; Farrar, Y.J.; Heijnis, H.; McOrist, G.D. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia); Tinker, R.A.; Smith, J.D. [Melbourne University Parkville, VIC (Australia). School of Chemistry; Napoli, M.; Hughes, M. [Sydney Univ., NSW (Australia). Dept. of Geology and Geophysics; James, J.M. [Sydney Univ., NSW (Australia). School of Chemistry

    1997-12-31

    The estuaries of Georges River and Hacking River, partly located in suburban Sydney, are at significant risk of contamination by heavy metal and trace element pollutants associated with urban/industrial development. The object of the current work is to correlate changes in land use resulting from European settlement with chemical changes observed in soil sediments. At each location core samples were taken and selected slices analysed for {sup 226}Ra and {sup 210}Po using alpha spectrometry. The {sup 226}Ra activity equates to the supported {sup 210}Pb activity and the {sup 210}Po activity equates to the total {sup 210}Pb activity. The difference between the total and the supported {sup 210}Pb is the excess {sup 210}Pb activity. Once the excess {sup 210}Pb has been layed down in the sediment its activity at depth (assuming the core to be undisturbed) is solely a function of its half-life and the initial amount present; a circumstance which readily affords the calculation of a sedimentation rate. Owing to its relatively short half-life (22.26 year) the {sup 20P}b dating technique can be used to date sediments as far back as about 120 years. In Australia this time frame would cover most of the period of European settlement. Paper no. 42; Extended abstract. 1 fig.

  5. Titanite chronology, thermometry, and speedometry of ultrahigh-temperature (UHT) calc-silicates from south Madagascar: U-Pb dates, Zr temperatures, and lengthscales of trace-element diffusion

    Science.gov (United States)

    Holder, R. M.; Hacker, B. R.

    2017-12-01

    Calc-silicate rocks are often overlooked as sources of pressure-temperature-time data in granulite-UHT metamorphic terranes due to the strong dependence of calc-silicate mineral assemblages on complex fluid compositions and a lack of thermodynamic data on common high-temperature calc-silicate minerals such as scapolite. In the Ediacaran-Cambrian UHT rocks of southern Madagascar, clinopyroxene-scapolite-feldspar-quartz-zircon-titanite calc-silicate rocks are wide-spread. U-Pb dates of 540-520 Ma from unaltered portions of titanite correspond to cooling of the rocks through upper-amphibolite facies and indicate UHT metamorphism occurred before 540 Ma. Zr concentrations in these domains preserve growth temperatures of 900-950 °C, consistent with peak temperatures calculated by pseudosection modeling of nearby osumilite-bearing gneisses. Younger U-Pb dates (510-490 Ma) correspond to fluid-mediated Pb loss from titanite grains, which occurred below their diffusive Pb-closure temperature, along fractures. The extent of fluid alteration is seen clearly in back-scattered electron images and Zr-, Al-, Fe-, Ce-, and Nb-concentration maps. Laser-ablation depth profiling of idioblastic titanite grains shows preserved Pb diffusion profiles at grain rims, but there is no evidence for Zr diffusion, indicating that it was effectively immobile even at UHT.

  6. Thermoluminescence dating of Indian archaeological sites

    International Nuclear Information System (INIS)

    Singhvi, A.K.; Sharma, Y.P.; Agrawal, D.P.

    1983-01-01

    In an attempt to provide a chronology for Indian archaeological sites, an extensive pottery dating programme was initiated during 1978-1979. So far we have provided a chronology for seven important Indian archaeological sites. The dated cultures include: 1) the Ochre Colour Ware culture, 2) the Pre-Harappan culture, 3) the megalithic culture and 4) the Painted Grey Ware culture. A complete survey of recently measured TL dates are presented in a model format similar to that used in Radiocarbon. (author)

  7. Meeting up-to-date safety requirements in the Russian NPP projects

    International Nuclear Information System (INIS)

    Tepkyan, G. O.; Yashkin, A. V.

    2014-01-01

    Safety features in Russian NPP designs are implemented by the combination of active and passive safety systems • Russian NPP designs are in compliance with up-to-date international and European safety requirements and refer to Generation III+ • Russian state-of-the-art designs have already implemented some design solutions, which take into account “post-Fukushima” requirements. Russian NPP design principles have been approved during the European discussions in spring 2012, including the IAEA extraordinary session addressed to Fukushima NPP accident

  8. The Cosmetics Europe strategy for animal-free genotoxicity testing: project status up-date.

    Science.gov (United States)

    Pfuhler, S; Fautz, R; Ouedraogo, G; Latil, A; Kenny, J; Moore, C; Diembeck, W; Hewitt, N J; Reisinger, K; Barroso, J

    2014-02-01

    The Cosmetics Europe (formerly COLIPA) Genotoxicity Task Force has driven and funded three projects to help address the high rate of misleading positives in in vitro genotoxicity tests: The completed "False Positives" project optimized current mammalian cell assays and showed that the predictive capacity of the in vitro micronucleus assay was improved dramatically by selecting more relevant cells and more sensitive toxicity measures. The on-going "3D skin model" project has been developed and is now validating the use of human reconstructed skin (RS) models in combination with the micronucleus (MN) and Comet assays. These models better reflect the in use conditions of dermally applied products, such as cosmetics. Both assays have demonstrated good inter- and intra-laboratory reproducibility and are entering validation stages. The completed "Metabolism" project investigated enzyme capacities of human skin and RS models. The RS models were shown to have comparable metabolic capacity to native human skin, confirming their usefulness for testing of compounds with dermal exposure. The program has already helped to improve the initial test battery predictivity and the RS projects have provided sound support for their use as a follow-up test in the assessment of the genotoxic hazard of cosmetic ingredients in the absence of in vivo data. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Resource Constrained Project Scheduling Subject to Due Dates: Preemption Permitted with Penalty

    Directory of Open Access Journals (Sweden)

    Behrouz Afshar-Nadjafi

    2014-01-01

    Full Text Available Extensive research works have been carried out in resource constrained project scheduling problem. However, scarce researches have studied the problems in which a setup cost must be incurred if activities are preempted. In this research, we investigate the resource constrained project scheduling problem to minimize the total project cost, considering earliness-tardiness and preemption penalties. A mixed integer programming formulation is proposed for the problem. The resulting problem is NP-hard. So, we try to obtain a satisfying solution using simulated annealing (SA algorithm. The efficiency of the proposed algorithm is tested based on 150 randomly produced examples. Statistical comparison in terms of the computational times and objective function indicates that the proposed algorithm is efficient and effective.

  10. Development of a wind farm noise propagation prediction model - project progress to date

    International Nuclear Information System (INIS)

    Robinson, P.; Bullmore, A.; Bass, J.; Sloth, E.

    1998-01-01

    This paper describes a twelve month measurement campaign which is part of a European project (CEC Project JOR3-CT95-0051) with the aim to substantially reduce the uncertainties involved in predicting environmentally radiated noise levels from wind farms (1). This will be achieved by comparing noise levels measure at varying distances from single and multiple sources over differing complexities of terrain with those predicted using a number of currently adopted sound propagation models. Specific objectives within the project are to: establish the important parameters controlling the propagation of wind farm noise to the far field; develop a planning tool for predicting wind farm noise emission levels under practically encountered conditions; place confidence limits on the upper and lower bounds of the noise levels predicted, thus enabling developers to quantify the risk whether noise emission from wind farms will cause nuisance to nearby residents. (Author)

  11. Absolute dating and palaeoenvironmental evolution in Palaeolithic Mani, SW Peloponnesus

    Science.gov (United States)

    Christodoulakis, John; Bassiakos, Yannis; Athanassas, Constantin

    2013-04-01

    Data derived from palaeoenvironmental indicators are considered the most reliable in back casting former environmental contexts and also, where possible, in forecasting future trends in the environment. The peninsula of Mani, southern Peloponnesus, southwestern Greece, is a challenging area for studying past environmental changes of the Upper Quaternary, because of its nodal position between three continents, its long and multifarious coastal zone, as well as its active local tectonic regime. A great deal of sea level oscillations and palaeoclimatic and palaeoanthropological evidence have been well-documented in the terrestrial and coastal sedimentery deposits of the peninsula, particularly for the later part of the Quaternary (Kelletat und Gassert, 1975, Imperatori, 1966). That evidence mostly comes from paleoenvironmental indicators such as raised marine notches and marine terraces, as well as from other,indicators, and is frequently associated with sites of paleoanthropological significance An important parameter of those sedimentary deposits is their chronology. To date, the chronological framework of those processes is only loosely constrained. A first effort to produce chronological data for this area was made about twenty years ago by applying electron spin resonance (ESR) dating to speleothems from the local subsurface caverns system and other karst formations. Here, by engaging luminescence dating, we aimed to further control former ESR chronology as well as to extend numeric dating on sedimentary formations previously non-datable through ESR alone (i.e. fluvial/deltaic sediments occurring in the area as well as anthropogenic composite deposits usually including burnt bones and fragments of stone tools). Specifically, optically stimulated luminescence (OSL) dating, combined with the single-aliquot regenerative dose (SAR) protocol, produced a number of ages that are in fair agreement with the previous ESR chronology. Current data allowed us to comprehend

  12. Detailed chronology of a giant Pleistocene rock-avalanche sequence in the hyperarid southern Peru revealed by jointly applied 10Be and 3He cosmic ray exposure dating : The Study case of the Cerro Caquilluco landslide complex.

    Science.gov (United States)

    Swann, Zerathe; Laurence, Audin; Carlos, Benavente; Régis, Braucher; Pierre-Henri, Blard; Didier, Bourlès; Julien, Carcaillet; Fabrizio, Delgado; Pascal, Lacroix; Valderrama Patricio, Murillo; Aster Team

    2015-04-01

    Giant landslides are recognized to be remarkably abundant on the Western Andean front of southern Peru and northern Chile, especially in the Arica Bend region (e.g. Crosta et al., 2014a). This area is characterized by strong topographic gradients and subsequent incision of deep canyons, due to the evolution of the Andean range that provide suitable conditions for the development of such instabilities. The climate is hyper-arid (Atacama Desert), although rare but highly impulsive wet events have been evidenced since the Pleistocene. In parallel, this region is submitted to strong (Mw 8-9) and recurrent (~100 yrs) subduction earthquakes. Previous studies suggest that large landslides represent the main agent of erosion of the Western Cordillera, providing soft material for subsequent fluvial remobilization. However the lack of time constrains on the numerous fossil landslides identified away from major canyons still hamper to assess a real mass balance of sliding material versus the known fluvial erosion and tectonic uplift rates. Finally the role of landslides in the long-term erosion rates of the Andean range on its arid flank remains quantitatively unknown. Recently, two studies gave divergent opinions about the main factor supposed to control the slope failures in that region. Based on cosmogenic nuclides derived erosion rates, McPhillips et al. (2014) argue that the last Holocene climate variation did not have had any effect on the rate of landsliding, suggesting that here landslides are mainly triggered by earthquake. On the other hand, Margirier et al. (2014) have showed a temporal correlation between a failure episode of the giant Chuquibamba landslide and the Ouki wet climatic event identified on the Altiplano ~100 ka ago. In this study we focus on dating the Cerro Caquilluco rock avalanche complex described by Crosta et al. (2014). With a total volume of about 15 km3, a length of 43 km and an internal structure characterized by various depositional lobes

  13. Appearance and chronology of Textile ceramics in the Middle and Upper Volga region: critical comparison of conventional 14C-, AMS- and typological chronologies

    Directory of Open Access Journals (Sweden)

    Lavento Mika T.

    2015-06-01

    Full Text Available The article offers a comparison of three different methods of chronology construction – conventional 14C (radiocarbon dating, AMS (accelerator mass-spectrometry dating and the so called typological chronology – to date the textile ceramics of the Bronze – Early Iron Age in the Northern Coniferous Zone of Europe, from the Upper and Middle Volga and Kama Rivers to the Baltic region and Scandinavia. The Textile Ceramics Culture (also known as “Net”, “Pseudo-textile”, “Spun-and-speckled” is often associated with a Finnish-speaking community from the Bronze – beginning of the Iron Age. The earliest date of the Textile Ceramics sites on the Middle Oka River is presumably considered to be the 18 th century BC. Datings of the reference sites in the Middle Volga region were fixed within the 15 th – 8 th centuries BC. Comparing these data with the AMS chronology available for the materials from Finland and Estonia, the authors conclude that appearance of the Textile Ceramics was almost synchronous in the Volga and the Baltic regions, although chronology of the early tradition of the Textile Ceramics seems to be different in these areas. The results of yet a small number of AMS dates should be treated only as preliminary. However, AMS-dating seems to be the most efficient tool for further refining of the Textile Ceramics chronology over a vast territory, including in the Volga region.

  14. Monthly paleostreamflow reconstruction from annual tree-ring chronologies

    Science.gov (United States)

    Stagge, J. H.; Rosenberg, D. E.; DeRose, R. J.; Rittenour, T. M.

    2018-02-01

    Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate-change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually require streamflow input at the monthly scale. This study explores the hypothesis that monthly streamflows can be adequately modeled by statistically decomposing annual flow reconstructions. To test this hypothesis, a multiple linear regression model for monthly streamflow reconstruction is presented that expands the set of predictors to include annual streamflow reconstructions, reconstructions of global circulation, and potential differences among regional tree-ring chronologies related to tree species and geographic location. This approach is used to reconstruct 600 years of monthly streamflows at two sites on the Bear and Logan rivers in northern Utah. Nash-Sutcliffe Efficiencies remain above zero (0.26-0.60) for all months except April and Pearson's correlation coefficients (R) are 0.94 and 0.88 for the Bear and Logan rivers, respectively, confirming that the model can adequately reproduce monthly flows during the reference period (10/1942 to 9/2015). Incorporating a flexible transition between the previous and concurrent annual reconstructed flows was the most important factor for model skill. Expanding the model to include global climate indices and regional tree-ring chronologies produced smaller, but still significant improvements in model fit. The model presented here is the only approach currently available to reconstruct monthly streamflows directly from tree-ring chronologies and climate reconstructions, rather than using resampling of the observed record. With reasonable estimates of monthly flow that extend back in time many centuries, water managers can challenge systems models with a

  15. A sub-fossil kauri (Agathis australis) tree-ring chronology

    International Nuclear Information System (INIS)

    Bridge, M.C.; Ogden, J.

    1986-01-01

    A 491-year floating tree-ring chronology was constructed using sub-fossil bog kauris, Agathis australis, from a site near Huntly, North Island, New Zealand. The chronology has been approximately dated to within the period 3,500 B.P. to 3,000 B.P. by radiocarbon dating. This is the first sub-fossil New Zealand chronology, and shows the potential for the formation of a long chronology from the present back over several millenia. The applications of this chronology and its possible extensions include radiocarbon calibration for the Southern Hemisphere, and climatic reconstructions based on ring-widths. It will also assist interpretation of the history of the Waikato Valley over the last few millenia

  16. Relative chronology of Martian volcanoes

    International Nuclear Information System (INIS)

    Landheim, R.; Barlow, N.G.

    1991-01-01

    Impact cratering is one of the major geological processes that has affected the Martian surface throughout the planet's history. The frequency of craters within particular size ranges provides information about the formation ages and obliterative episodes of Martian geologic units. The Barlow chronology was extended by measuring small craters on the volcanoes and a number of standard terrain units. Inclusions of smaller craters in units previously analyzed by Barlow allowed for a more direct comparison between the size-frequency distribution data for volcanoes and established chronology. During this study, 11,486 craters were mapped and identified in the 1.5 to 8 km diameter range in selected regions of Mars. The results are summarized in this three page report and give a more precise estimate of the relative chronology of the Martian volcanoes. Also, the results of this study lend further support to the increasing evidence that volcanism has been a dominant geologic force throughout Martian history

  17. Grain Drier Project Report for task 2 dated July 1990 edited 1991, 1992. Follow up report

    Energy Technology Data Exchange (ETDEWEB)

    Frye, S.; Hall, R.; Lee, Myoung; Ouyang, Chieh [and others

    1990-07-01

    One of the original projects undertaken under the cooperative agreement No. DE-FC04-87AL42558 between the Massachusetts Photovoltaic Program and the United States Department of Energy was to design, build, and test a grain drier which utilized solar energy effectively. Different grains have different drying requirements, and the grain drier team chose to design the drier for rice because of the worldwide economic importance of this staple food and also because of the challenges that drying rice presents. Rice loses much of its market value if it is exposed to large temperature changes while drying; therefore, a solar rice drier must be designed so as to try to level the temperature variations which naturally arise from the intermittency of the solar source. The design team committed itself early in the project to a hybrid concept, where solar energy is utilized in two ways: it is captured {open_quote}thermally{close_quote} in a rock-bed which acts at the same time as thermal storage and buffer, and it is converted {open_quote}directly{close_quote} in a small photovoltaic panel which generates electricity to power a small fan to circulate air through the rock-bed and the grain during daylight hours. At night, natural convection drives the air flow. The design of most of the system is flexible, in that the drier can be built with materials available at the intended site, with non-specialized labor. The team has purposely avoided any {open_quote}high tech{close_quote} solution which would increase the drier cost for third-world users. Therefore, the drier design does not incorporate selective surfaces or a vacuum, two common methods of enhancing solar thermal performance. The design does incorporate a small but relatively high value element, the PV panel and fan package. A major part of the group effort was devoted to data acquisition, to analyze the effects of different modifications on the drier performance. The results of the effort are summarized in this report.

  18. Integrating chronological uncertainties for annually laminated lake sediments using layer counting, independent chronologies and Bayesian age modelling (Lake Ohau, South Island, New Zealand)

    Science.gov (United States)

    Vandergoes, Marcus J.; Howarth, Jamie D.; Dunbar, Gavin B.; Turnbull, Jocelyn C.; Roop, Heidi A.; Levy, Richard H.; Li, Xun; Prior, Christine; Norris, Margaret; Keller, Liz D.; Baisden, W. Troy; Ditchburn, Robert; Fitzsimons, Sean J.; Bronk Ramsey, Christopher

    2018-05-01

    Annually resolved (varved) lake sequences are important palaeoenvironmental archives as they offer a direct incremental dating technique for high-frequency reconstruction of environmental and climate change. Despite the importance of these records, establishing a robust chronology and quantifying its precision and accuracy (estimations of error) remains an essential but challenging component of their development. We outline an approach for building reliable independent chronologies, testing the accuracy of layer counts and integrating all chronological uncertainties to provide quantitative age and error estimates for varved lake sequences. The approach incorporates (1) layer counts and estimates of counting precision; (2) radiometric and biostratigrapic dating techniques to derive independent chronology; and (3) the application of Bayesian age modelling to produce an integrated age model. This approach is applied to a case study of an annually resolved sediment record from Lake Ohau, New Zealand. The most robust age model provides an average error of 72 years across the whole depth range. This represents a fractional uncertainty of ∼5%, higher than the <3% quoted for most published varve records. However, the age model and reported uncertainty represent the best fit between layer counts and independent chronology and the uncertainties account for both layer counting precision and the chronological accuracy of the layer counts. This integrated approach provides a more representative estimate of age uncertainty and therefore represents a statistically more robust chronology.

  19. Paleotempestological chronology developed from gas ion source AMS analysis of carbonates determined through real-time Bayesian statistical approach

    Science.gov (United States)

    Wallace, D. J.; Rosenheim, B. E.; Roberts, M. L.; Burton, J. R.; Donnelly, J. P.; Woodruff, J. D.

    2014-12-01

    Is a small quantity of high-precision ages more robust than a higher quantity of lower-precision ages for sediment core chronologies? AMS Radiocarbon ages have been available to researchers for several decades now, and precision of the technique has continued to improve. Analysis and time cost is high, though, and projects are often limited in terms of the number of dates that can be used to develop a chronology. The Gas Ion Source at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS), while providing lower-precision (uncertainty of order 100 14C y for a sample), is significantly less expensive and far less time consuming than conventional age dating and offers the unique opportunity for large amounts of ages. Here we couple two approaches, one analytical and one statistical, to investigate the utility of an age model comprised of these lower-precision ages for paleotempestology. We use a gas ion source interfaced to a gas-bench type device to generate radiocarbon dates approximately every 5 minutes while determining the order of sample analysis using the published Bayesian accumulation histories for deposits (Bacon). During two day-long sessions, several dates were obtained from carbonate shells in living position in a sediment core comprised of sapropel gel from Mangrove Lake, Bermuda. Samples were prepared where large shells were available, and the order of analysis was determined by the depth with the highest uncertainty according to Bacon. We present the results of these analyses as well as a prognosis for a future where such age models can be constructed from many dates that are quickly obtained relative to conventional radiocarbon dates. This technique currently is limited to carbonates, but development of a system for organic material dating is underway. We will demonstrate the extent to which sacrificing some analytical precision in favor of more dates improves age models.

  20. Revision of the Martian relative age chronology

    International Nuclear Information System (INIS)

    Barlow, N.G.

    1987-01-01

    This study has provided a more detailed chronology than currently exists in the literature and has created some changes to the currently accepted geological evolutionary sequence of Mars. The period of heavy bombardment, although dominated by impact processes, experienced many forms of volcanic activity and at least one episode of intense fracturing. Most small volcanic constructs and the ridged plains regions are found to date from this early period, contrary to common belief. The fracturing and dissection of the highlands helps to provide further constraints on the timing of events such as the formation of the hemispheric dichotomy and the formation of the Tharsis Bulge. The northern plains are found to consist of a number of differently aged regions. The difference in age between the chaotic terrain and the outflow channels together with differences in the distribution curves among craters of various erosional states found on the channels support the theory of episodic periods of flooding

  1. Astronautics and aeronautics, 1977: A chronology

    Science.gov (United States)

    Ritchie, E. H.

    1986-01-01

    This publication is a chronology of events during the year 1977 in the fields of aeronautical and space research, development, activity, and policy. It includes appendixes, an index, and illustrations. Chronological entries list sources for further inquiry.

  2. Communication dated 22 September 2008 received from the Permanent Mission of Germany to the Agency regarding the German proposal on a Multilateral Enrichment Sanctuary Project

    International Nuclear Information System (INIS)

    2008-01-01

    The Secretariat has received a communication dated 22 September 2008 from the Permanent Mission of Germany, forwarding a paper outlining the German proposal on 'the Multilateral Enrichment Sanctuary Project (MESP)'. As requested in the communication, the paper, entitled 'the Multilateral Enrichment Sanctuary Project (MESP) - a Fresh Look at Ensuring Nuclear Fuel Supply' is circulated herewith for the information of Member States

  3. Insight into the Fulnek Church and Parish Medieval Building Chronology

    Directory of Open Access Journals (Sweden)

    Augustinková Lucie

    2017-06-01

    Full Text Available The church of the Holy Trinity and parish in Fulnek was for nearly four centuries an Augustinian canonry and collegiate church (1293-1389. The medieval church and parish building chronology, however, have not been thus far established. From research between 2015 and 2016 we have been able to identify medieval portions of the buildings, clarify the site medieval construction phases and date the parish buildings (formerly the canonry from dendrochronological analysis of embedded wooden scaffolding.

  4. Events of radioactive waste management - a chronological table

    International Nuclear Information System (INIS)

    1985-01-01

    In chronological order the leaflet abstracted points out the essential data of German radioactive waste management. The data reach from December 1951 with EBR I (Idaho/USA) being the first one to feed electric power to the distribution grid to February 1985 known as the date of the submission of building applications for the first partial license of the Wackersdorf reprocessing plant. (HSCH) [de

  5. Yucca Mountain Project bibliography, January--June 1989

    International Nuclear Information System (INIS)

    Henline, D.M.; Bales, J.D.

    1990-03-01

    This update contains information on the Yucca Mountain Project that was added to the Energy Data Base (EDB) during the first six months of 1989. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. The update is categorized by principal project participant organizations, and items are arranged in chronological order according to publication date. Participant-sponsored subcontractor reports, meeting papers, and journal articles are included with sponsoring organization

  6. A Chronological Estimation of the Ceremonial Center of Campanayuq Rumi, Ayacucho

    OpenAIRE

    Matsumoto, Yuichi; Cavero, Yuri

    2012-01-01

    The main objective of this paper is to construct a site chronology of the Campanayuq Rumi site which is a large ceremonial center of the Formative Period located in the Peruvian south-central highlands. For this purpose, 12 radiocarbon dates obtained from our excavations will be considered in combination with the data of both architectural and ceramic sequences of the site. Through the comprehensive interpretation of these data, we will present a new site chronology of the Campanayuq Rumi sit...

  7. Appendix 2: Chronology of events

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    The accident at the Chernobyl nuclear power plant and its consequences are set in chronological order from April 1986 to March 1988. The loss of confidence in nuclear power is clearly shown in the list of withdrawal or cancellations of reactor orders, especially those soon after the accident. Levels of radioactivity in food monitored in the UK and Europe is also listed. The International Atomic Energy Agency's Conventions on early notification and assistance and similar agreements to improve nuclear safety are included. The list is selective and includes both positive and negative consequences of the accident. (U.K.)

  8. The 40Ar/39Ar dating of core recovered by the Hawaii Scientific Drilling Project (phase 2), Hilo, Hawaii

    Science.gov (United States)

    Sharp, Warren D.; Renne, Paul R.

    2005-04-01

    The Hawaii Scientific Drilling Project, phase 2 (HSDP-2), recovered core from a ˜3.1-km-thick section through the eastern flanks of Mauna Loa and Mauna Kea volcanoes. We report results of 40Ar/39Ar incremental heating by broad-beam infrared laser of 16 basaltic groundmass samples and 1 plagioclase separate, mostly from K-poor tholeiites. The tholeiites generally have mean radiogenic 40Ar enrichments of 1-3%, and some contain excess 40Ar; however, isochron ages of glass-poor samples preserve stratigraphic order in all cases. A 246-m-thick sequence of Mauna Loa tholeiitic lavas yields an isochron age of 122 ± 86 kyr (all errors 2σ) at its base. Beneath the Mauna Loa overlap sequence lie Mauna Kea's postshield and shield sequences. A postshield alkalic lava yields an age of 236 ± 16 kyr, in agreement with an age of 240 ± 14 kyr for a geochemically correlative flow in the nearby HSDP-1 core hole, where more complete dating of the postshield sequence shows it to have accumulated at 0.9 ± 0.4 m/kyr, from about 330 to <200 ka. Mauna Kea's shield consists of subaerial tholeiitic flows to a depth of 1079 m below sea level, then shallow submarine flows, hyaloclastites, pillow lavas, and minor intrusions to core bottom at 3098 m. Most subaerial tholeiitic flows fail to form isochrons; however, a sample at 984 m yields an age of 370 ± 180 kyr, consistent with ages from similar levels in HSDP-1. Submarine tholeiites including shallow marine vitrophyres, clasts from hyaloclastites, and pillow lavas were analyzed; however, only pillow lava cores from 2243, 2614, and 2789 m yield reliable ages of 482 ± 67, 560 ± 150, and 683 ± 82 kyr, respectively. A linear fit to ages for shield samples defines a mean accumulation rate of 8.6 ± 3.1 m/kyr and extrapolates to ˜635 kyr at core bottom. Alternatively, a model relating Mauna Kea's growth to transport across the Hawaiian hot spot that predicts downward accelerating accumulation rates that reach ˜20 m/kyr at core bottom (De

  9. Chronology protection in string theory

    International Nuclear Information System (INIS)

    Dyson, Lisa

    2004-01-01

    Many solutions of General Relativity appear to allow the possibility of time travel. This was initially a fascinating discovery, but geometries of this type violate causality, a basic physical law which is believed to be fundamental. Although string theory is a proposed fundamental theory of quantum gravity, geometries with closed timelike curves have resurfaced as solutions to its low energy equations of motion. In this paper, we will study the class of solutions to low energy effective supergravity theories related to the BMPV black hole and the rotating wave-D1-D5-brane system. Time travel appears to be possible in these geometries. We will attempt to build the causality violating regions and propose that stringy effects prohibit their construction. The proposed chronology protection agent for these geometries mirrors a mechanism string theory employs to resolve a class of naked singularities. (author)

  10. The application of carbon-isotope measurements to dendro- and xylem-chronology

    International Nuclear Information System (INIS)

    Yonenobu, Hitoshi; Hattori, Yoshiaki; Kikata, Yoji; Mitsutani, Takumi; Nakamura, Toshio.

    1990-01-01

    We measured 14 C/ 13 C Ratio of the Teak. The 14 C excess, which reflects the execution of the tropospheric nuclear tests, is stamped in the Teak trunk. In place of the annual rings this stamp can estimate the xylem-chronologies and more accurate growth rates of tropical trees which have no annual rings. And replacing the shot-pinning method we can estimate the growing period in an annual ring formed especially in 1963-1966, when the 14 C concentration in the tropospheric air changes dramatically. And we measured 14 C-chronologies of the annual rings of O-Hinoki, 14 C-chronologies agree well with dendrochronologies for the past 600 years. And the 14 C chronologies support more determinative cross-dating of the archaeological samples. (author)

  11. Summary of theory and techniques, sample selection and project organization for potassium-argon, rubidium-strontium and fission track dating and strontium isotope studies

    International Nuclear Information System (INIS)

    Adams, C.J.; Graham, I.J.; Seward, D.

    1987-02-01

    A brief outline is given of the theory and techniques of the potassium-argon, rubidium-strontium and fission-track dating methods and related isotope studies which are currently in use at the Institute of Nuclear Sciences, DSIR. Some limitations of each technique are set out in terms of age range and materials for dating, and the appropriate choice of various mineral and rock types and subsequent age interpretations are discussed. The organisation of project proposals and categories is described and procedures for sample submission and documentation are given

  12. Make a date with a tree

    International Nuclear Information System (INIS)

    Baillie, M.; Pilcher, J.

    1988-01-01

    The paper concerns the use of dendrochronology to check the accuracy of radiocarbon dating. The Belfast chronology is described - this involves wood samples precisely dated by tree ring analysis and analysed by high-precision radiocarbon analysis. The analysis resulted in the first continuous high-precision calibration of the radiocarbon time-scale, and confirmed the relationship between radiocarbon dates and tree-ring dates. The use of radiocarbon dating to reveal the age of wood samples that have too few rings to produce an accurate date, is also outlined. (U.K.)

  13. The scientific dating of standing buildings.

    Science.gov (United States)

    Alcock, Nathaniel W

    2017-11-17

    The techniques of dendrochronology (tree-ring dating) and radiocarbon (14C) dating are described, as they are applied to historic buildings. Both rely on determining the felling dates of the trees used in their construction. For dendrochronology, the construction of master chronologies and the matching of individual ring-width sequences to them is described and, for radiocarbon dating, the use of tree-ring results in calibration. Results of dating are discussed, ranging from the cathedrals of Peterborough and Beauvais and the development of crown-post roof structures, to the dating and identification of standing medieval peasant houses, particularly those built using cruck construction.

  14. Linguistic dating of biblical texts

    DEFF Research Database (Denmark)

    Young, Ian; Rezetko, Robert; Ehrensvärd, Martin Gustaf

    Since the beginning of critical scholarship biblical texts have been dated using linguistic evidence. In recent years this has become a controversial topic, especially with the publication of Ian Young (ed.), Biblical Hebrew: Studies in Chronology and Typology (2003). However, until now there has...... been no introduction and comprehensive study of the field. Volume 1 introduces the field of linguistic dating of biblical texts, particularly to intermediate and advanced students of biblical Hebrew who have a reasonable background in the language, having completed at least an introductory course...... in this volume are: What is it that makes Archaic Biblical Hebrew archaic , Early Biblical Hebrew early , and Late Biblical Hebrew late ? Does linguistic typology, i.e. different linguistic characteristics, convert easily and neatly into linguistic chronology, i.e. different historical origins? A large amount...

  15. Dating Violence

    Science.gov (United States)

    ... for Teens / Dating Violence Bulletins for Teens: Dating Violence What is it? If you are a victim ... often. If You Are a Victim of Dating Violence, You Might… Think it's your fault. Feel angry, ...

  16. An assessment of variability in radiocarbon dating

    International Nuclear Information System (INIS)

    Scott, E.M.; Baxter, M.S.; Aitchison, T.C.

    1981-01-01

    A series of replicate experiments, involving analysis of homogenized wood and identical tree-ring sections, suggests that the 14 C counting error in radiocarbon dating quantifies only part of the total variability of measurement. Statistical modelling implies that a more realistic assessment of error is provided by a value approximately three times the counting error. The incorporation of this more realistic measure of variability into an appropriate procedure for calibrating a single date and for matching a floating chronology to a master chronology is described. (author)

  17. Establishment of an absolute chronology for the 18th Egyptian Dynasty

    International Nuclear Information System (INIS)

    Quiles, A.

    2011-01-01

    The establishment of an absolute chronology for Ancient Egypt is an ambition which has concentrated efforts of many scholars since the beginning of Egyptology. Thanks to historical and archaeological documents, a relative chronology of the kings has been built. Only some astrophysical points and synchronisms listed in texts (Greek and Egyptian sources) have given some ankle points which have led to some propositions of absolute chronology. At first, we will see how we can re-calculate some ankle points by using Sothic dating and modelling lunar dates with a Bayesian approach. Then, radiocarbon measurements have been done at Laboratoire de Mesure du Carbone 14 (CEA Saclay) on Egyptian short life materials like plants or twigs. These objects come from the Louvre Museum and are attributed to a particular reign and a precise period. With a Bayesian approach, these analyses have been combined with the known succession and length of the reign. Besides, Sothic and lunar dates have been incorporated as a prior in the model. It has led to propose an absolute chronology for the 18th dynasty. Finally, we will discuss the agreement between our results and archaeological evidence and will see if this chronology can highlight points where Egyptologists disagree. (author)

  18. Critical review of a new volcanic eruption chronology

    Science.gov (United States)

    Neuhäuser, Dagmar L.; Neuhäuser, Ralph

    2016-04-01

    Sigl. et al. (2015, Nature) present historical evidence for 32 volcanic eruptions to evaluate their new polar ice core 10-Be chronology - 24 are dated within three years of sulfur layers in polar ice. Most of them can be interpreted as weather phenomena (Babylonia: disk of sun like moon, reported for only one day, e.g. extinction due to clouds), Chinese sunspot reports (pellet, black vapor, etc.), solar eclipses, normal ice-halos and coronae (ring, bow, etc.), one aurora (redness), red suns due to mist drops in wet fog or fire-smoke, etc. Volcanic dust may facilitate detections of sunspots and formation of Bishop's ring, but tend to inhibit ice-halos, which are otherwise often reported in chronicles. We are left with three reports possibly indicating volcanic eruptions, namely fulfilling genuine criteria for atmospheric disturbances due to volcanic dust, e.g. bluish or faint sun, orange sky, or fainting of stars for months (BCE 208, 44-42, and 32). Among the volcanic eruptions used to fix the chronology (CE 536, 626, 939, 1257), the reports cited for the 930s deal only with 1-2 days, at least one reports an eclipse. In the new chronology, there is a sulfur detection eight years after the Vesuvius eruption, but none in CE 79. It may appear surprising that, from BCE 500 to 1, all five northern sulfur peaks labeled in figure 2 in Sigl et al. are systematically later by 2-4 years than the (corresponding?) southern peaks, while all five southern peaks from CE 100 to 600 labeled in figure 2 are systematically later by 1-4 years than the (corresponding?) northern peaks. Furthermore, in most of their six strongest volcanic eruptions, temperatures decreased years before their sulfur dating - correlated with weak solar activity as seen in radiocarbon, so that volcanic climate forcing appears dubious here. Also, their 10-Be peaks at CE 775 and 994 are neither significant nor certain in dating.

  19. The Chronology of Rock Art

    Indian Academy of Sciences (India)

    Such phases are tentatively ascribed to different archaeological cultures on the basis of the contextual availability, stylistic similarities and so on. Ethnographic analogies are also attempted in the dating of rock art .

  20. Age constraints for Palaeolithic cave art by U-Th dating of thin carbonate crusts

    Science.gov (United States)

    Hoffmann, Dirk; Pike, Alistair; Garcia-Diez, Marcos; Pettitt, Paul; Zilhão, João

    2015-04-01

    U-series dating is an important geochronological tool which is widely applied for instance in speleothem based palaeoclimate research. It has also great potential to provide age constraints for Archaeology, especially for sites or artefacts in cave environments. We present our methods to conduct precise U-Th dating of calcite crusts that formed on top of cave paintings. Recent developments in multi-collector (MC) inductively coupled plasma mass spectrometry (ICPMS) U-series dating greatly improved the precision of this method, and sample sizes needed to obtain reliable results were significantly reduced. Based on these developments the U-series technique can be applied for accurate dating of thin calcite crusts covering cave art at many sites, while taking care not to harm the art underneath. The method provides minimum ages for the covered art and, where possible, also maximum ages by dating the flowstone layer the art is painted on. The U-Th method has been used in a number of recent projects to date calcite precipitates above and occasionally below cave paintings in Spain. Initial results from Cantabria have shown that the earliest dated paintings are older than 41.4 ± 0.6 ka, dating at least to the Early Aurignacian period and present a far longer chronology than that based so far on radiocarbon dating. Here we outline our methodology and the steps we take to demonstrate the reliability of U-Th dates, and present some recent results of our ongoing U-Th dating programme.

  1. Chronology of guitarrero cave, peru.

    Science.gov (United States)

    Lynch, T F; Gillespie, R; Gowlett, J A; Hedges, R E

    1985-08-30

    Dating by accelerator mass spectrometry of wooden artifacts, cord, and charcoal samples from Guitarrero Cave, Peru, supports the antiquity of South America's earliest textiles and other perishable remains. The new dates are consistent with those obtained from disintegration counters and leave little doubt about the integrity of the lower Preceramic layers and their early cultivars. Re-evaluation of the mode of deposition suggests that most of the remains resulted from short-term use of the cave in the eighth millennium B.C., with a possible brief human visit as early as 12,560 years ago.

  2. Sedimentology, tephrostratigraphy, and chronology of the DEEP site sediment record, Lake Ohrid (Albania, FYROM)

    Science.gov (United States)

    Leicher, Niklas; Wagner, Bernd; Francke, Alexander; Just, Janna; Zanchetta, Giovanni; Sulpizio, Roberto; Giaccio, Biagio; Nomade, Sebastien

    2017-04-01

    Lake Ohrid, located on the Balkan Peninsula, is one of the very few lakes in the world that provides a continuous and high-resolution record of environmental change of >1.3 Ma. The sedimentary archive was drilled in spring 2013 within the scope of the International Continental Scientific Drilling Program (ICDP) and the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in order to investigate local and regional geological and paleoclimatic processes, as well as triggers of evolutionary patterns and endemic biodiversity. The continuous composite profile (584 m) of the main drill site DEEP was logged (XRF, MSCL) and subsampled for biogeochemical (TIC, TOC, TN, TS) and sedimentological (grain size) analyses. The lithology of the DEEP site indicates that the history of Lake Ohrid can roughly be separated into two parts, with the older section between 584 and 450 m depth being characterised by a sedimentary facies indicating shallow water conditions, which is likely younger than ca. 1.9 Ma. In the lowermost few meters of the succession gravels and pebbles hampered a deeper drilling penetration and indicate that fluvial conditions existed during the onset of lake formation. Together with geotectonic, seismic, and biological information, the data imply that the Ohrid basin formed by transtension during the Miocene, opened during the Pliocene and Pleistocene, and that the lake established between 1.9 and 1.3 Ma ago. The sediments of the younger part (DEEP site sequence and are subject of ongoing investigations aimed at identifying their specific volcanic sources and equivalent known tephra by using geochemical fingerprinting of glass fragments. This was already successfully approved for tephra horizons in the upper 247.8 m of the sequence, obtaining important chronological information from 11 well dated tephra layers. These tephrochronological constraints were complemented by ages obtained from tuning the consistent pattern of the

  3. Extravehicular Activity Fact Sheet: An EVA Chronology

    Data.gov (United States)

    National Aeronautics and Space Administration — Walking to Olympus: An EVA Chronology chronicles the 154 EVAs conducted from March 1965 to April 1997. It is intended to make clear the crucial role played by EVA in...

  4. Atmospheric Heavy Metal Pollution - Development of Chronological ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 4. Atmospheric Heavy Metal Pollution - Development of Chronological Records and Geochemical Monitoring. Rohit Shrivastav. General Article Volume 6 Issue 4 April 2001 pp 62-68 ...

  5. Reassessment of the Upper Fremont Glacier ice-core chronologies by synchronizing of ice-core-water isotopes to a nearby tree-ring chronology

    Science.gov (United States)

    Chellman, Nathan J.; McConnell, Joseph R.; Arienzo, Monica; Pederson, Gregory T.; Aarons, Sarah; Csank, Adam

    2017-01-01

    The Upper Fremont Glacier (UFG), Wyoming, is one of the few continental glaciers in the contiguous United States known to preserve environmental and climate records spanning recent centuries. A pair of ice cores taken from UFG have been studied extensively to document changes in climate and industrial pollution (most notably, mid-19th century increases in mercury pollution). Fundamental to these studies is the chronology used to map ice-core depth to age. Here, we present a revised chronology for the UFG ice cores based on new measurements and using a novel dating approach of synchronizing continuous water isotope measurements to a nearby tree-ring chronology. While consistent with the few unambiguous age controls underpinning the previous UFG chronologies, the new interpretation suggests a very different time scale for the UFG cores with changes of up to 80 years. Mercury increases previously associated with the mid-19th century Gold Rush now coincide with early-20th century industrial emissions, aligning the UFG record with other North American mercury records from ice and lake sediment cores. Additionally, new UFG records of industrial pollutants parallel changes documented in ice cores from southern Greenland, further validating the new UFG chronologies while documenting the extent of late 19th and early 20th century pollution in remote North America.

  6. The absolute chronology and thermal processing of solids in the solar protoplanetary disk

    DEFF Research Database (Denmark)

    Connelly, James; Bizzarro, Martin; Krot, Alexander N.

    2012-01-01

    Transient heating events that formed calcium-aluminum - rich inclusions (CAIs) and chondrules are fundamental processes in the evolution of the solar protoplanetary disk, but their chronology is not understood. Using U-corrected Pb-Pb dating, we determined absolute ages of individual CAIs and cho...

  7. Climatic events and Upper Paleolithic chronology in the Dniester basin : New C-14 results from Cosautsi

    NARCIS (Netherlands)

    Haesaerts, P; Borziak, [No Value; Van Der Plicht, J; Damblon, F; Borziak, Ilic; Mook, W.G.

    1998-01-01

    We discuss the radiocarbon chronology of the loess deposited during the Upper Pleniglacial (Isotope Stage II) for the key site of Cosautsi (Republic of Moldova), which presents some major problems in C-14 dating. Special care was paid to accurate microstratigraphic positioning of samples, collection

  8. Chronological aging-induced apoptosis in yeast

    OpenAIRE

    Fabrizio, Paola; Longo, Valter D.

    2008-01-01

    Saccharomyces cerevisiae is the simplest among the major eukaryotic model organisms for aging and diseases. Longevity in the chronological life span paradigm is measured as the mean and maximum survival period of populations of non-dividing yeast. This paradigm has been used successfully to identify several life-regulatory genes and three evolutionary conserved pro-aging pathways. More recently, Schizosaccharomyces pombe has been shown to age chronologically in a manner that resembles that of...

  9. Risk levels of invasive Fusarium oxysporum f. sp. in areas suitable for date palm (Phoenix dactylifera) cultivation under various climate change projections.

    Science.gov (United States)

    Shabani, Farzin; Kumar, Lalit

    2013-01-01

    Global climate model outputs involve uncertainties in prediction, which could be reduced by identifying agreements between the output results of different models, covering all assumptions included in each. Fusarium oxysporum f.sp. is an invasive pathogen that poses risk to date palm cultivation, among other crops. Therefore, in this study, the future distribution of invasive Fusarium oxysporum f.sp., confirmed by CSIRO-Mk3.0 (CS) and MIROC-H (MR) GCMs, was modeled and combined with the future distribution of date palm predicted by the same GCMs, to identify areas suitable for date palm cultivation with different risk levels of invasive Fusarium oxysporum f.sp., for 2030, 2050, 2070 and 2100. Results showed that 40%, 37%, 33% and 28% areas projected to become highly conducive to date palm are under high risk of its lethal fungus, compared with 37%, 39%, 43% and 42% under low risk, for the chosen years respectively. Our study also indicates that areas with marginal risk will be limited to 231, 212, 186 and 172 million hectares by 2030, 2050, 2070 and 2100. The study further demonstrates that CLIMEX outputs refined by a combination of different GCMs results of different species that have symbiosis or parasite relationship, ensure that the predictions become robust, rather than producing hypothetical findings, limited purely to publication.

  10. Risk Levels of Invasive Fusarium oxysporum f. sp. in Areas Suitable for Date Palm (Phoenix dactylifera) Cultivation under Various Climate Change Projections

    Science.gov (United States)

    Shabani, Farzin; Kumar, Lalit

    2013-01-01

    Global climate model outputs involve uncertainties in prediction, which could be reduced by identifying agreements between the output results of different models, covering all assumptions included in each. Fusarium oxysporum f.sp. is an invasive pathogen that poses risk to date palm cultivation, among other crops. Therefore, in this study, the future distribution of invasive Fusarium oxysporum f.sp., confirmed by CSIRO-Mk3.0 (CS) and MIROC-H (MR) GCMs, was modeled and combined with the future distribution of date palm predicted by the same GCMs, to identify areas suitable for date palm cultivation with different risk levels of invasive Fusarium oxysporum f.sp., for 2030, 2050, 2070 and 2100. Results showed that 40%, 37%, 33% and 28% areas projected to become highly conducive to date palm are under high risk of its lethal fungus, compared with 37%, 39%, 43% and 42% under low risk, for the chosen years respectively. Our study also indicates that areas with marginal risk will be limited to 231, 212, 186 and 172 million hectares by 2030, 2050, 2070 and 2100. The study further demonstrates that CLIMEX outputs refined by a combination of different GCMs results of different species that have symbiosis or parasite relationship, ensure that the predictions become robust, rather than producing hypothetical findings, limited purely to publication. PMID:24340100

  11. A developing chronology for prehistoric 'moated sites' in northeast Thailand

    International Nuclear Information System (INIS)

    McGrath, R.J.; Boyd, W.E.

    1999-01-01

    Full text: Many mounded Iron Age occupation sites in the Mun River Valley,N.E. Thailand are characterised by distinctive encircling earthworks, these are commonly known as 'moated sites'. The first excavations of any significance within the moats themselves at six sites -Noen U-Loke, Non Muang Khao, Ban Non Khrua Chut, Ban Non Ngiu, Ban Makham Thae and Ban Non Wat - in the form of long trenches have been carried out to enable detailed examination of their structure. Significantly, the surficial morphology of the moats, and the notable regularity of shape and patterning of the moats in plan, usually does not accurately reflect the buried sectional morphology of incised channel features, which are in no way expressed on the surface. Buried channels beneath the edge of the mounds as well as the surrounding moat banks have also been revealed. Stratigraphic and geomorphic relationships of the buried features imply critical chronological relationships which need to be tested to allow full development of a model for the evolution of the archaeological sites. Extremely small quantities of charcoal and shells obtained from the buried features has necessitated the need for AMS dating to develop the chronology for the development, use and decline of the moated features and channels. The dating is an ongoing process, however, results thus far obtained supports the development of older channels towards the archaeological mounds, and yet older buried channels under the sites

  12. Chronology of Chichen Izta, evidences by thermoluminescence

    International Nuclear Information System (INIS)

    Ramirez, A.; Schaaf, P.; Gonzalez, P.R.; Chung, H.

    2002-01-01

    The establishment of the chronology of Chichen Itza is argued by its stylistic evocations, architectural and iconographical as well as its history related in the sources, as the Chilam Balam, where is named the arrival of foreign tribes as the Xiu and the Itzaes and its settlement in Chichen Itza as well as the return to its origin place. The material evidence of such transition is reflected in the ceramic change of the Pizarra Puuc to the Pizarra Chichen, however, in 13 stratigraphic wells realized in different points of Chichen Itza, it was not found evidence of the layer of the Pizarra Puuc period. In this work the obtained ages of dating by thermoluminescence (TL) are presented, of four samples of ceramics found in the different wells. When our results are compared with the estimated ages for the different groups of ceramics, it was observed that none of they corresponded to the Pizarra Puuc period. These results strenghten the observations realized during excavations, causing the suggestion of new inferences related to the Chichen Itza boom and its relationship with the Maya Classic Period. The used technique for the TL dating was that of fine grain. The interval of artificial dose, of beta radiation of Strontium 90 was between 2 and 30 Gy. The TL signal was obtained heating the samples at 10 C/s until reaching 500 C in the TL Daybreak reader equipment. In order to know the annual dose rate of concentration of potassium ( 40 K) by means of the microanalysis technique in the scanning electron microscope was determined, while the uranium content (2 38 U) and thorium ( 232 Th) were determined by means of the neutron activation analysis technique using the TRIGA Mark III nuclear reactor. The contribution of the gamma radiation of the soil as well as the contribution of the cosmic radiation was measured with TL dosemeters of CaSO 4 :Dy + Ptfe once the paleodose was known and the annual dose rate of each sample of its age was estimated. (Author)

  13. Dating Violence

    Science.gov (United States)

    Stader, David L.

    2011-01-01

    Dating violence is a form of student-on-student victimization and is a serious school safety issue. Research indicates that at a minimum, 10 percent of high school students are victims of dating violence in one form or another. Among female high school students that date, some data indicate that as many as 30 percent may be victims of dating…

  14. Into the Past: A Step Towards a Robust Kimberley Rock Art Chronology.

    Science.gov (United States)

    Ross, June; Westaway, Kira; Travers, Meg; Morwood, Michael J; Hayward, John

    2016-01-01

    The recent establishment of a minimum age estimate of 39.9 ka for the origin of rock art in Sulawesi has challenged claims that Western Europe was the locus for the production of the world's earliest art assemblages. Tantalising excavated evidence found across northern Australian suggests that Australia too contains a wealth of ancient art. However, the dating of rock art itself remains the greatest obstacle to be addressed if the significance of Australian assemblages are to be recognised on the world stage. A recent archaeological project in the northwest Kimberley trialled three dating techniques in order to establish chronological markers for the proposed, regional, relative stylistic sequence. Applications using optically-stimulated luminescence (OSL) provided nine minimum age estimates for fossilised mudwasp nests overlying a range of rock art styles, while Accelerator Mass Spectrometry radiocarbon (AMS 14C) results provided an additional four. Results confirm that at least one phase of the northwest Kimberley rock art assemblage is Pleistocene in origin. A complete motif located on the ceiling of a rockshelter returned a minimum age estimate of 16 ± 1 ka. Further, our results demonstrate the inherent problems in relying solely on stylistic classifications to order rock art assemblages into temporal sequences. An earlier than expected minimum age estimate for one style and a maximum age estimate for another together illustrate that the Holocene Kimberley rock art sequence is likely to be far more complex than generally accepted with different styles produced contemporaneously well into the last few millennia. It is evident that reliance on techniques that produce minimum age estimates means that many more dating programs will need to be undertaken before the stylistic sequence can be securely dated.

  15. Into the Past: A Step Towards a Robust Kimberley Rock Art Chronology.

    Directory of Open Access Journals (Sweden)

    June Ross

    Full Text Available The recent establishment of a minimum age estimate of 39.9 ka for the origin of rock art in Sulawesi has challenged claims that Western Europe was the locus for the production of the world's earliest art assemblages. Tantalising excavated evidence found across northern Australian suggests that Australia too contains a wealth of ancient art. However, the dating of rock art itself remains the greatest obstacle to be addressed if the significance of Australian assemblages are to be recognised on the world stage. A recent archaeological project in the northwest Kimberley trialled three dating techniques in order to establish chronological markers for the proposed, regional, relative stylistic sequence. Applications using optically-stimulated luminescence (OSL provided nine minimum age estimates for fossilised mudwasp nests overlying a range of rock art styles, while Accelerator Mass Spectrometry radiocarbon (AMS 14C results provided an additional four. Results confirm that at least one phase of the northwest Kimberley rock art assemblage is Pleistocene in origin. A complete motif located on the ceiling of a rockshelter returned a minimum age estimate of 16 ± 1 ka. Further, our results demonstrate the inherent problems in relying solely on stylistic classifications to order rock art assemblages into temporal sequences. An earlier than expected minimum age estimate for one style and a maximum age estimate for another together illustrate that the Holocene Kimberley rock art sequence is likely to be far more complex than generally accepted with different styles produced contemporaneously well into the last few millennia. It is evident that reliance on techniques that produce minimum age estimates means that many more dating programs will need to be undertaken before the stylistic sequence can be securely dated.

  16. Reasons for decision in the matter of Enbridge Pipelines Inc. Line 4 Extension Project : facilities[Application dated 28 June 2007 for the Line 4 Extension Project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-04-15

    In June 2007, Enbridge Pipelines Inc. applied for approval to extend Line 4 of its Mainline pipeline upstream from Hardisty to Edmonton, Alberta. The project would relieve a potential bottleneck and would also add an additional line across this segment to increase system security and flexibility. The average annual capacity of Line 4 would be 140,000 cubic metres per day. The Enbridge Mainline from Edmonton to Hardisty currently includes 3 oil pipelines, while the Enbridge Mainline downstream of Hardisty includes 4 oil pipelines. This document presented the views of the Board regarding the construction and operation of the project facilities; public and Aboriginal consultation; environmental and socio-economic matters; land matters; tolls and tariffs; and, supply, markets, financing and economics. The Board noted that the benefits of this project outweigh the burdens associated with it. The project required an environmental assessment under the Canadian Environmental Assessment Act which found that it is not likely to cause significant adverse environmental effects. In its approval of the project, the Board attached 15 conditions, including a requirement for Enbridge to file an updated Environmental Protection Plan for the Board's approval. The Board also approved Enbridge's application for its tolling method and to reactivate 3 sections of pre-existing pipeline. 3 tabs., 3 figs., 3 appendices.

  17. Missouri Department of Natural Resources Hazardous Waste Program Weldon Spring site remedial action project. Status of project to date January 1997

    International Nuclear Information System (INIS)

    1998-01-01

    This document describes the progress made by the Missouri Department of Natural Resources (MDNR) during the fourth year (1996) of the Agreement in Support (AIS) in its oversight role of the Weldon Springs Site Remedial Action Project (WSSRAP). The fourth year at the Weldon Springs Site shows sustained progress as the project moves through the final design and into the remedial action phases of the Chemical Plant Operable Unit. The remedial action phase includes the Foundations Removal work package, Chemical Solidification and Stabilization, and disposal cell

  18. Missouri Department of Natural Resources Hazardous Waste Program Weldon Spring site remedial action project. Status to date January 1998

    International Nuclear Information System (INIS)

    1998-01-01

    This document describes the progress made by the Missouri Department of Natural Resources (MDNR) during the fifth year (1997) of the Agreement in Support (AIS) in its oversight role of the Weldon Springs Site Remedial Action Project (WSSRAP). Staffing issues this year have been a challenge with the resignation of an Environmental Specialist (ES) in June 1997, and the death of Robert Stovall, an Environmental Engineer (EE) II in August 1997. Progress made during this period includes securing a contract laboratory, participation in several workgroup meetings for activities at the site, oversight of the Feasibility Study/Proposed Plan (FS/PP), coordination between the US Department of Energy and the various State regulatory programs and interactions with the local public drinking water supply agency and health departments

  19. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  20. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2008-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  1. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2012-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  2. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  3. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2013-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  4. Thirty years together: A chronology of U.S.-Soviet space cooperation

    Science.gov (United States)

    Portree, David S. F.

    1993-01-01

    The chronology covers 30 years of cooperation between the U.S. and the Soviet Union (and its successor, the Commonwealth of Independent States, of which the Russian Federation is the leading space power). It tracks successful cooperative projects and failed attempts at space cooperation. Included are the Dryden-Blagonravov talks; the UN Space Treaties; the Apollo Soyuz Test Project; COSPAS-SARSAT; the abortive Shuttle-Salyut discussions; widespread calls for joint manned and unmanned exploration of Mars; conjectural plans to use Energia and other Russian space hardware in ambitious future joint missions; and contemporary plans involving the U.S. Shuttle, Russian Mir, and Soyuz-TM. The chronology also includes events not directly related to space cooperation to provide context. A bibliography lists works and individuals consulted in compiling the chronology, plus works not used but relevant to the topic of space cooperation.

  5. Precise chronologies of Holocene glacial culminations in the Cordillera Vilcabamba of southern Peru

    Science.gov (United States)

    Licciardi, J. M.; Schaefer, J. M.; Schweinsberg, A. D.

    2012-12-01

    Records of past fluctuations in climatically sensitive tropical mountain glaciers are among the best indicators of regional paleoclimatic trends and controls. The majority of the world's present-day tropical glaciers are found in the Peruvian Andes, but accurate and precise chronologies of past glacial activity in this region remain relatively scarce, particularly during the Holocene. Here we present ~50 new 10Be exposure ages derived from boulders on well-preserved moraine successions in several glaciated drainages in the Cordillera Vilcabamba of southern Peru (13°20'S latitude). The new results suggest that prominent moraines in these valleys are correlative with previously published moraine ages near Nevado Salcantay in this range (Licciardi et al., 2009), but also expand on the initial surface exposure chronologies to reveal additional periods of glacier stabilization not found in previous work. A provisional composite chronology that merges the new and previously obtained moraine ages indicates at least five discrete glacial culminations from the Lateglacial to the late Holocene. Forthcoming 10Be ages from an additional ~50 samples collected from moraine boulders will increase the precision and completeness of the Vilcabamba moraine chronologies. Basal radiocarbon ages are being developed from bog and lake sediments in stratigraphic contact with the 10Be-dated moraines. These new 14C age data will help constrain the local cosmogenic 10Be production rate, thereby increasing the accuracy of the 10Be chronologies.

  6. Constraints on the use of 137Cs as a time-marker to support CRS and SIT chronologies

    International Nuclear Information System (INIS)

    Abril, J.M.

    2004-01-01

    CRS and SIT are two 210 Pb-based models widely used in the radiometric dating of recent sediments. 210 Pb chronologies should be validated using at least one independent tracer, such as 137 Cs. This paper demonstrates that simple methods based on the identification of 137 Cs fallout peaks cannot provide a definitive support for CRS and SIT chronologies. Two main arguments will support this assertion: Firstly, the 137 Cs time-marks cannot support a CRS or SIT chronology if the derived sedimentation rates cannot explain the whole 137 Cs activity profile without postulating mixing. Secondly, the support by the 137 Cs time-marks for a given CRS or SIT chronology cannot be considered as definitive if other dating models can equally explain the whole set of data, thereby producing a different chronology. Several case studies selected from the literature are used to support the present discussion. - Simple methods based on the identification of 137 Cs fallout peaks cannot provide a definite support for CRS and SIT chronologies

  7. Landforms, sediments and dates to constrain rates and style of marine-influenced ice sheet decay; the BRITICE-CHRONO project.

    Science.gov (United States)

    Clark, Chris

    2014-05-01

    Uncertainty exists regarding the future mass of the Antarctic and Greenland ice sheets and how they will respond to forcings from sea level, and atmospheric and ocean temperatures. If we want to know more about the mechanisms and rate of change of shrinking ice sheets, then why not examine an ice sheet that has fully disappeared and track its retreat through time? If achieved in enough detail such information on ice retreat could be a data-rich playground for improving the next breed of numerical ice sheet models to be used in ice and sea level forecasting. We regard that the last British-Irish Ice Sheet is a good target for this work, on account of its small size, density of information and with its numerous researchers already investigating it. Geomorphological mapping across the British Isles and the surrounding continental shelf has revealed the nature and distribution of glacial landforms. Here we demonstrate how such data have been used to build a pattern of ice margin retreat. The BRITICE-CHRONO consortium of Quaternary scientists and glaciologists, are now working on a project running from 2012 - 2017 to produce an ice sheet wide database of geochronometric dates to constrain and then understand ice margin retreat. This is being achieved by focusing on 8 transects running from the continental shelf edge to a short distance (10s km) onshore and acquiring marine and terrestrial samples for geochronometric dating. The project includes funding for 587 radiocarbon, 140 OSL and 158 TCN samples for surface exposure dating; with sampling accomplished by two research cruises and 16 fieldwork campaigns. Results will reveal the timing and rate of change of ice margin recession for each transect, and combined with existing landform and dating databases, will be used to build an ice sheet-wide empirical reconstruction of retreat. Simulations using two numerical ice sheet models, fitted against the margin data, will help us understand the nature and significance of sea

  8. Astronautics and aeronautics, 1978: A chronology

    Science.gov (United States)

    Janson, Bette R.

    1986-01-01

    This is the 18th in a series of annual chronologies of significant events in the fields of astronautics and aeronautics. Events covered are international as well as national and political as well as scientific and technical. This series is a reference work for historians, NASA personnel, government agencies, congressional staffs, and the media.

  9. Astronautics and aeronautics, 1985: A chronology

    Science.gov (United States)

    Janson, Bette R.

    1988-01-01

    This book is part of a series of annual chronologies of significant events in the fields of astronautics and aeronautics. Events covered are international as well as national, in political as well as scientific and technical areas. This series is an important reference work used by historians, NASA personnel, government agencies, and congressional staffs, as well as the media.

  10. Astronautics and aeronautics, 1976. A chronology

    Science.gov (United States)

    Ritchie, E. H.

    1984-01-01

    A chronology of events concerning astronautics and aeronautics for the year 1976 is presented. Some of the many and varied topics include the aerospace industry, planetary exploration, space transportation system, defense department programs, politics, and aerospace medicine. The entries are organized by the month and presented in a news release format.

  11. A Chronological History of Puerto Rico.

    Science.gov (United States)

    Tovar, Federico Ribes

    This book presents a chronological history of Puerto Rico from prehistory and discovery through December of 1972. It includes information on the persons and events that influenced the course of Puerto Rican history. A table of contents and a selective index are included. (Author/AM)

  12. Chronology of 3rd–5th Century Female Graves from Tarasovo Burial Ground

    Directory of Open Access Journals (Sweden)

    Goldina Rimma D.

    2017-07-01

    Full Text Available The article represents the concluding part a series of works by the authors on the dating of burials from the unique 1st–5th century Tarasovo burial ground in the Middle Kama region. The first article was dedicated to the chronology of graves dating back to the early Nyrgynda stage (1st–2nd centuries of this monument. The second and third publications feature an analysis of the chronology of 3rd–5th century male burials. The present work describes 160 female burials of 3rd–5th centuries analyzed from the perspective of chronology. Similarly to previous research, the three main methods employed by the authors of this research include those of formal typology, cultural stratigraphy and the nearest neighbour method. A total of 12 chronological groups were singled out as a result: 1st half of 3rd century A.D. (group 1; 2nd half of 3rd century (2; 3rd century (3; 4th century (group 4; 2nd half of 3rd–4th centuries (5а; 3rd–4th centuries (5б; 1st half of 5th century (6; 2nd half of 5th century (7; 5th century (group 8; 2nd half of 4th–5th centuries (9; 4th–5th centuries (10; 2nd half of 3rd–5th centuries

  13. Radiocarbon chronology of Manot Cave, Israel and Upper Paleolithic dispersals

    Science.gov (United States)

    Alex, Bridget; Barzilai, Omry; Hershkovitz, Israel; Marder, Ofer; Berna, Francesco; Caracuta, Valentina; Abulafia, Talia; Davis, Lauren; Goder-Goldberger, Mae; Lavi, Ron; Mintz, Eugenia; Regev, Lior; Bar-Yosef Mayer, Daniella; Tejero, José-Miguel; Yeshurun, Reuven; Ayalon, Avner; Bar-Matthews, Mira; Yasur, Gal; Frumkin, Amos; Latimer, Bruce; Hans, Mark G.; Boaretto, Elisabetta

    2017-01-01

    The timing of archeological industries in the Levant is central for understanding the spread of modern humans with Upper Paleolithic traditions. We report a high-resolution radiocarbon chronology for Early Upper Paleolithic industries (Early Ahmarian and Levantine Aurignacian) from the newly excavated site of Manot Cave, Israel. The dates confirm that the Early Ahmarian industry was present by 46,000 calibrated years before the present (cal BP), and the Levantine Aurignacian occurred at least between 38,000 and 34,000 cal BP. This timing is consistent with proposed migrations or technological diffusions between the Near East and Europe. Specifically, the Ahmarian could have led to the development of the Protoaurignacian in Europe, and the Aurignacian in Europe could have spread back to the Near East as the Levantine Aurignacian. PMID:29152566

  14. The chronology of Moncks Cave, Canterbury, New Zealand

    International Nuclear Information System (INIS)

    Jacomb, C.

    2008-01-01

    Moncks Cave is a key site in understanding the nature and course of change to Maori culture during the early period of New Zealand prehistory because of the range of both perishable and non-perishable artefacts found there in 1889. Understood to have been completely excavated at that time, the interpretation of the material culture of the site has been rendered difficult by the absence of chronological or stratigraphic provenance data. Recent investigations at Moncks Cave revealed several intact cultural deposits, including both faunal and artefactual remains. Eleven radiocarbon determinations on marine shell suggest that the cave was occupied some time between the mid-fourteenth and mid-fifteenth centuries AD. Although the dates cannot be directly correlated with any particular artefact, the results have important implications for the interpretation of the place of the site and its contents as a whole in the context of the New Zealand prehistoric sequence. (author). 22 refs., 5 figs., 1 tab

  15. Communication dated 9 July 2009 received from the Permanent Mission of Germany regarding the German proposal on a Multilateral Enrichment Sanctuary Project

    International Nuclear Information System (INIS)

    2009-01-01

    The Director General received a letter dated 9 July 2009 from the Resident Representative of Germany to the IAEA, transmitting the text of two draft model agreements, which are necessary to implement a Multilateral Enrichment Sanctuary Project (MESP). One model agreement, to be concluded between the Agency and interested States, provides for the establishment of a Group of Interested States and, by them, of a market-oriented Enrichment Company. The other model agreement, to be concluded between the Agency and a host state, provides for the establishment of a Multilateral Enrichment Sanctuary (MES) on a territory to be administered by the Agency, in which the Enrichment Company would be located. The letter, and as requested therein, the above mentioned draft model agreements attached thereto are herewith circulated for the information of all Member States

  16. The EDC3 chronology for the EPICA Dome C ice core

    Directory of Open Access Journals (Sweden)

    F. Parrenin

    2007-08-01

    Full Text Available The EPICA (European Project for Ice Coring in Antarctica Dome C drilling in East Antarctica has now been completed to a depth of 3260 m, at only a few meters above bedrock. Here we present the new EDC3 chronology, which is based on the use of 1 a snow accumulation and mechanical flow model, and 2 a set of independent age markers along the core. These are obtained by pattern matching of recorded parameters to either absolutely dated paleoclimatic records, or to insolation variations. We show that this new time scale is in excellent agreement with the Dome Fuji and Vostok ice core time scales back to 100 kyr within 1 kyr. Discrepancies larger than 3 kyr arise during MIS 5.4, 5.5 and 6, which points to anomalies in either snow accumulation or mechanical flow during these time periods. We estimate that EDC3 gives accurate event durations within 20% (2σ back to MIS11 and accurate absolute ages with a maximum uncertainty of 6 kyr back to 800 kyr.

  17. Radiometric dating

    International Nuclear Information System (INIS)

    Das, N.R.

    2017-01-01

    Since the discovery of natural radioactivity in uranium, in the last decade of the nineteenth century, the nuclear property of radioactive decay of radionuclides at immutable rates has been effectively utilized in dating of varieties of naturally occurring geological matrices and the organisms which constantly replenish their "1"4C supply through respiration when alive on earth. During the period, applications of radiometric dating techniques have been extensively diversified and have enabled the geologists to indicate the absolute time scales of geological formations and the evolution of the solar system, the earth, meteorites, lunar rocks, etc. and the archaeologists to record the facts of history of several important events like dinosaur era, Iceman, the Shroud in Turin and many other ancient artefacts. In the development of dating methods, varieties of naturally occurring radio-isotopic systems with favorable half-lives ranging from about 10 years to over 100 billion years have been used as radiometric clocks. (author)

  18. Radiocarbon dating of soils, a review

    International Nuclear Information System (INIS)

    Scharpenseel, H.W.; Schiffmann, H.

    1977-01-01

    The application of radiocarbon dating techniques for pedological purposes is reviewed in chronological sequence of its phases of introduction. Initially dating of charcoal and buried paleosols was dominating and accompanied by few soil dating attempts of recent soil formations on the basis of extracted humic acid-C. The following controversy regarding the potentialities and limitations of recent soil dating, still being involved in the intact turnover processes of modern biodynamics, led to intensive search for the relatively oldest, most favorable C-fraction, particularly a biologically inert C-fraction of the organic C-pool. Inclusion of C-14 dating in pedogenetic working concepts required soil profile date-scanning in order to reveal the age versus depth interdependence. (orig./HK) [de

  19. Radiocarbon measurements on submerged forest floating chronologies

    International Nuclear Information System (INIS)

    Campbell, J.A.; Baxter, M.S.

    1979-01-01

    It is stated that the submerged forests along the west coast of England and Wales provide a unique source of wood for radiocarbon/ dendrochronological studies. 14 C age determinations are reported on sequential growth increments from three 'gloating' chronologies. A sampling frequency of approximately 10 samples per century was used. Fluctuations in atmospheric 14 C levels of 2 to 3% over several decades can occur, these variations being superimposed on a smoothly changing trend. (author)

  20. A chronology of librarianship, 1960-2000

    CERN Document Server

    Wilhite, Jeffrey M

    2009-01-01

    This book covers all areas of library literature that inform the history of librarianship and ranges over multiple continents. Its broad scope lends itself to wide use by scholars and students of library history and library literature. The chronology is presented in a dictionary format and separated into decades. It is complemented by a comprehensive bibliography and both subject and name indexes, which are cross-listed for ease of use.

  1. Quantitative and qualitative approaches to identifying migration chronology in a continental migrant.

    Directory of Open Access Journals (Sweden)

    William S Beatty

    Full Text Available The degree to which extrinsic factors influence migration chronology in North American waterfowl has not been quantified, particularly for dabbling ducks. Previous studies have examined waterfowl migration using various methods, however, quantitative approaches to define avian migration chronology over broad spatio-temporal scales are limited, and the implications for using different approaches have not been assessed. We used movement data from 19 female adult mallards (Anas platyrhynchos equipped with solar-powered global positioning system satellite transmitters to evaluate two individual level approaches for quantifying migration chronology. The first approach defined migration based on individual movements among geopolitical boundaries (state, provincial, international, whereas the second method modeled net displacement as a function of time using nonlinear models. Differences in migration chronologies identified by each of the approaches were examined with analysis of variance. The geopolitical method identified mean autumn migration midpoints at 15 November 2010 and 13 November 2011, whereas the net displacement method identified midpoints at 15 November 2010 and 14 November 2011. The mean midpoints for spring migration were 3 April 2011 and 20 March 2012 using the geopolitical method and 31 March 2011 and 22 March 2012 using the net displacement method. The duration, initiation date, midpoint, and termination date for both autumn and spring migration did not differ between the two individual level approaches. Although we did not detect differences in migration parameters between the different approaches, the net displacement metric offers broad potential to address questions in movement ecology for migrating species. Ultimately, an objective definition of migration chronology will allow researchers to obtain a comprehensive understanding of the extrinsic factors that drive migration at the individual and population levels. As a result

  2. Quantitative and qualitative approaches to identifying migration chronology in a continental migrant

    Science.gov (United States)

    Beatty, William S.; Kesler, Dylan C.; Webb, Elisabeth B.; Raedeke, Andrew H.; Naylor, Luke W.; Humburg, Dale D.

    2013-01-01

    The degree to which extrinsic factors influence migration chronology in North American waterfowl has not been quantified, particularly for dabbling ducks. Previous studies have examined waterfowl migration using various methods, however, quantitative approaches to define avian migration chronology over broad spatio-temporal scales are limited, and the implications for using different approaches have not been assessed. We used movement data from 19 female adult mallards (Anas platyrhynchos) equipped with solar-powered global positioning system satellite transmitters to evaluate two individual level approaches for quantifying migration chronology. The first approach defined migration based on individual movements among geopolitical boundaries (state, provincial, international), whereas the second method modeled net displacement as a function of time using nonlinear models. Differences in migration chronologies identified by each of the approaches were examined with analysis of variance. The geopolitical method identified mean autumn migration midpoints at 15 November 2010 and 13 November 2011, whereas the net displacement method identified midpoints at 15 November 2010 and 14 November 2011. The mean midpoints for spring migration were 3 April 2011 and 20 March 2012 using the geopolitical method and 31 March 2011 and 22 March 2012 using the net displacement method. The duration, initiation date, midpoint, and termination date for both autumn and spring migration did not differ between the two individual level approaches. Although we did not detect differences in migration parameters between the different approaches, the net displacement metric offers broad potential to address questions in movement ecology for migrating species. Ultimately, an objective definition of migration chronology will allow researchers to obtain a comprehensive understanding of the extrinsic factors that drive migration at the individual and population levels. As a result, targeted

  3. Age determination of marine sediments in the western North Pacific by aspartic acid chronology

    International Nuclear Information System (INIS)

    Harada, Naomi; Kusakabe, Masashi; Handa, Nobuhiko; Oba, Tadamichi; Matsuoka, Hiromi; Kimoto, Katsunori.

    1997-01-01

    The ages of fossil planktonic foraminifera, Pulleniatina obliquiloculata, in sediments (core 3bPC) from the western North Pacific were determined by aspartic acid chronology, which uses the racemization reaction rate constant of aspartic acid (k Asp ). Aspartic acid racemization-based ages (Asp ages) ranged from 7,600 yrBP at the surface, to 307,000 yrBP at a depth of 352.9 cm in the sediments. This sediment core was also dated by the glacial-interglacial fluctuation of σ 18 O chronology, and the ages determined by both chronologies were compared. The ages derived from aspartic acid chronology and σ 18 O stratigraphy were more or less consistent, but there appeared to be some differences in age estimates between these two dating methods at some depths within the core. In the core top sediments, the likely cause for the age discrepancy could be the loss of the surface sediment during sampling of the core. At depths of 66.3 and 139 cm within the core, Asp ages indicated reduced sedimentation rates during ca. 60,000-80,000 yrBP and ca. 140,000-190,000 yrBP. The maximum age differences in both chronologies are 33,000 yr and 46,600 yr during each of these periods. These anomalous reductions in sedimentation rates occurring during these periods could possibly be related to some geological events, such as an increased dissolution effect of the calcium carbonate in the western North Pacific. Another possible reason for these age differences could be the unreliability in σ 18 O ages of core 3bPC as they were estimated by σ 18 O ages of another core, 3aPC. (author)

  4. A 9111 year long conifer tree-ring chronology for the European Alps : a base for environmental and climatic investigations

    NARCIS (Netherlands)

    Nicolussi, K.; Kaufmann, M.; Melvin, Thomas M.; van der Plicht, J.; Schiessling, P.; Thurner, A.

    An ultra-long tree-ring width chronology (9111 years long, 7109 BC to AD 2002) has been established based on the analysis and dating of 1432 subfossil/dry dead wood samples and cores from 335 living trees. The material was collected from treeline or near-treeline sites (c. 2000 to 2400 m a.s.l.)

  5. Chronology and pedogenic effects of mid- to late-Holocene conversion of forests to pastures in the French western Pyrenees

    Science.gov (United States)

    David S. Leigh; Theodore L. Gragson; Michael R. Coughlan

    2015-01-01

    This paper presents a place-based examination of the timing and long-term pedogenic effects of human-induced forest to pasture conversion in the French western Pyrenees Mountains, Basque commune of Larrau. We analyzed colluvial stratigraphic sections to derive the chronology of landscape change using radiocarbon dating, charcoal concentrations, magnetic...

  6. Carbon-14 Bomb-Pulse Dating

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, B A

    2007-12-16

    Atmospheric testing of nuclear weapons during the 1950s and early 1960s doubled the concentration of carbon-14 atmosphere and created a pulse that labeled everything alive in the past 50 years as carbon moved up the food chain. The variation in carbon-14 concentration in time is well-documented and can be used to chronologically date all biological materials since the mid-1950s.

  7. Dating cremated bone: the scientific background

    Directory of Open Access Journals (Sweden)

    Lanting, J. N.

    1999-12-01

    Full Text Available A new method of obtaining absolute chronology dates out of burnt or cremated bone is presented. The authors explain their recent experiments and give promising results.

    Los autores presentan un nuevo método para obtener fechas de datación absoluta a partir de restos de hueso sometidos a diferentes grados de combustión y explican algunas de sus recientes experiencias y los resultados obtenidos.

  8. Reconstructing Century-Scale Changes in Nitrogen Cycling in Forests Throughout the United States using Tree-Ring δ15N Chronologies

    Science.gov (United States)

    Gerhart-Barley, L.; McLauchlan, K. K.; Battles, J. J.; Craine, J. M.; Higuera, P. E.; Mack, M. C.; McNeil, B. E.; Nelson, D. M.; Pederson, N.; Perakis, S. S.

    2016-12-01

    In recent decades, human perturbation of the global nitrogen (N) cycle has been immense with reactive nitrogen supply to ecosystems from anthropogenic sources now exceeding that of natural fixation. The impact of these perturbations on ecosystem nutrient cycling and plant communities is limited by the lack of long-term `baseline' assessments of N cycling prior to anthropogenic influences. Stable N isotope analysis (δ15N) of dendrochronological records have the potential to provide this baseline data, but to date have focused on short term, regional assessments. Here, we address this question with a data set incorporating 311 individual trees and 7,661 δ15N measurements from 50 sites throughout the contiguous United States. These sites represent the diversity of US forest types, climate conditions, N deposition, soil types, and disturbance histories. The chronologies span, on average, the last 162 calendar years, with the oldest chronology dating back to 1572 C.E. Consequently, this study is the first century- and continental-scale assessment of ecosystem N cycling using tree-ring chronologies. When aggregated, the chronologies show a consistent decline from 1825 C.E. to present, indicating declining N availability in US forests, despite global increases in N supply. Environmental factors such as mean annual precipitation (MAP), mean annual temperature (MAT), and mean annual nitrogen deposition (Ndep) did not contribute to average site δ15N values; however, MAP and MAT significantly affected temporal trajectories in tree-ring δ15N, with more negative slopes toward present occurring in regions with low MAT and high MAP. Quantity of atmospheric N deposition had no discernible impact on mean δ15N values or on the temporal slope. This lack of response is either because levels of N deposition are too low to produce a discernible response in any meaningful aspects of the N cycle, and/or the δ15N signature of depositional N is similar enough to ecosystem N pools that

  9. Thermoluminescence dating

    International Nuclear Information System (INIS)

    Price, D.M.

    1999-01-01

    Thermoluminescence (TL) dating of sediments depends upon the acquisition and long term stable storage of TL energy by crystalline minerals contained within a sedimentary unit. This energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Prior to the final depositional episode it is necessary that any previously acquired TL is removed by exposure to sunlight. After burial the TL begins to build up again at a rate dependent upon the radiation flux delivered by long-lived isotopes of uranium, thorium and potassium. The presence of rubidium and cosmic radiation generally play a lesser but contributory roll, and the total radiation dose delivered to the TL phosphor is modified by the presence of water. The period since deposition is therefore measured by determining the total amount of stored TL energy, the palaeodose (P), and the rate at which this energy is acquired, the annual radiation dose (ARD). TL dating may be applied to eolian, fluvial, coastal and in some cases, marine sediments. the technique is also successfully applied to volcanic materials and to a certain extent to archeological specimens

  10. Linguistic Dating of Biblical Texts

    DEFF Research Database (Denmark)

    Ehrensvärd, Martin Gustaf

    2003-01-01

    For two centuries, scholars have pointed to consistent differences in the Hebrew of certain biblical texts and interpreted these differences as reflecting the date of composition of the texts. Until the 1980s, this was quite uncontroversial as the linguistic findings largely confirmed the chronol......For two centuries, scholars have pointed to consistent differences in the Hebrew of certain biblical texts and interpreted these differences as reflecting the date of composition of the texts. Until the 1980s, this was quite uncontroversial as the linguistic findings largely confirmed...... the chronology of the texts established by other means: the Hebrew of Genesis-2 Kings was judged to be early and that of Esther, Daniel, Ezra, Nehemiah, and Chronicles to be late. In the current debate where revisionists have questioned the traditional dating, linguistic arguments in the dating of texts have...... come more into focus. The study critically examines some linguistic arguments adduced to support the traditional position, and reviewing the arguments it points to weaknesses in the linguistic dating of EBH texts to pre-exilic times. When viewing the linguistic evidence in isolation it will be clear...

  11. Standard Chronology in Plato’s Dialogues and Stylometric Evidences

    Directory of Open Access Journals (Sweden)

    Mohammad Bagher Ghomi

    2015-09-01

    Full Text Available Abstract What are to be discussed in this article include two main points: i some kind of a fixed structure can be found in all the chronologies that have been proposed from the last quarter of 19th century onward; a structure that is called here “standard” chronology, and ii in spite of the fact that the appearance of this structure owes too much to the stylistic evidences, these evidences themselves do not confirm anything in the structure but the place of the so-called late dialogues. The standard chronology of Plato’s dialogues is inclined to consider Meno and Republic as dialogues that have been composed after so-called Socratic dialogues and before Parmenides and Theaetetus. This chronology also insists that the latter two dialogues must be dated after so-called middle dialogues and before dialogues like Sophist, Timaeus, Philebus and Laws. This papper is to illuminate the fact that except the similarities between the late dialogues and their probable lateness, the place of other dialogues, more importantly among them the so-called middle period dialogues, Theaetetus and Parmenides, cannot be approved by stylistic evidences.

  12. Chronology of the 1st–2nd Century Graves from the Tarasovo Burial Ground

    Directory of Open Access Journals (Sweden)

    Goldina Rimma D.

    2016-03-01

    Full Text Available The article focuses on the chronology of graves dating back to the early (1st – 2nd centuries AD – Nyrgynda stage of the 1st – 5th century Tarasovo burial ground, a classical monument attributed to the Cheganda culture of the Pyany Bor cultural-historical community. Cultural stratigraphy is applied as a research method. Artifacts from the early stage were correlated for 37 male and 102 female complexes, separately. The analysis of grave goods from male burials showed the following three chronological groups, that can be distinguished at the Nyrgynda stage: 1st century (group 1, 2nd century (group 2 and 1st – 2nd centuries AD (group 3. The goods from female graves are more representative and various, so three more groups with shorter chronological lives can be singled out: the fi rst half of the 2nd century (group 2а, the second half of the 2nd century (group 2б and the 1st – fi rst half of the 2nd century (group 4. Certainly, the suggested chronology leaves room for any eventual corrections subject to new findings.

  13. Notes on Glasinac: The chronology of princely graves

    Directory of Open Access Journals (Sweden)

    Vasić Rastko

    2009-01-01

    Full Text Available Princely graves of the Iron Age represent a particular phenomenon in archaeology, which is constantly the subject of interest. They are usually dated to the end of the 6th and the beginning of the 5th century. The author discusses the chronology of princely graves in the Central Balkans and analyses their appearance in each part of this territory: on the Glasinac plateau, in Serbia, Kosovo and Metohija, Montenegro, North Albania and Nordwest Bulgaria. He concludes that they date from the middle of the 7th to the middle of the 4th century, depending on the cultural and socio-economic situation in the respective area. In the middle of the 7th century princely graves in the true sense of the word were known only on the Glasinac plateau, in the Ilijak necropolis. At the end of the 7th and in the beginning of the 6th century they still appear on Glasinac, though in greater number and in various parts of the plateau. In northwest Bulgaria a grave dating to the second half of the 7th century was found, which would, according to grave goods, correspond to the Glasinac princely graves. On the other hand, there are no princely graves in Serbia and north Albania from that time but some outstanding warrior graves are known, belonging possibly to the chiefs of smaller warlike bands, whose power was limited. Princely graves from Arareva gromila on Glasinac, Pilatovići by Požega and Lisijevo Polje by Berane date to the beginning of the second half of the 6th century, and according to their characteristics represent princes, whose power and wealth were considerable and known to the neighbours. Culmination of the rise of the princes in this region was demonstrated by the graves from Novi Pazar, Atenica, and Pećka banja, which date to the end of the 6th and the first quarter of the 5th century. Some decades later there are several rich graves, e.g. the recently discovered grave from Velika Krsna, which could belong to a prince, but can not be compared with the

  14. Recent advances in thermoluminescence dating

    International Nuclear Information System (INIS)

    Aitken, M.J.

    1984-01-01

    Initially the application of thermoluminescent dating was to ancient pottery and other baked clay, the detection of forgeries in art ceramics having a particularly powerful impact. In recent years there has been a growing extension of TL into non-pottery materials. Heated flints from paleolithic fire-places is one application. Another is in the dating of igneous rocks from recent volcanic events; formerly this had been impossible on account of the malign phenomenon of non-thermal ('anomalous') fading exhibited by volcanic minerals but this is now being circumvented by utilising TL in the 600 0 C region of the glow curve. TL dating has also been extended to unburnt calcite, one application being stalagmitic floors in paleolithic caves. Another recent development is the use of TL for dating aeolian sediment and some types of waterborne sediment. These developments give prospect of establishing a TL-based chronology, both for archaeology and quaternary research, extending back well beyond the range of radiocarbon, perhaps reaching a million years ago. (author)

  15. Bomb pulse radiocarbon dating

    International Nuclear Information System (INIS)

    Tuniz, C.; Zoppi, U.; Hotchkis, M.A.C.

    2004-01-01

    Modern forensic science has to deal not only with homicides and other traditional crimes but also with more global threats such as the smuggling of nuclear materials, clandestine production of weapons of mass destruction, stockpiling of illicit drugs by state controlled groups and war crimes. Forensic applications have always benefited from the use of advanced analytical tools that can characterize materials found at crime scenes. In this paper we will discuss the use of accelerator mass spectrometry (AMS) as an ultrasensitive tool for the crime laboratories of the third millennium. An important objective in forensic science is to order past events chronologically by analysing materials associated with criminal actions. Radiocarbon dating is known to the general public for its application to historical and prehistorical investigations. Examples of forensic significance include the assassination of the Inca Atahualpa by Francisco Pizarro in the early 1530s, the possible murder of the Tyrolean Ice Man (Oetzi) 5300 years ago and the analysis of the burial cloths allegedly associated with the crucifixion of Jesus Christ . Recent murders, including those associated with war crimes in the Balkans during the 1990s, can be studied using 14 C bomb pulse dating. This method has other forensic applications, including investigation of frauds related to food and wine counterfeiting, dating of opium crops and dating of substances used in biological warfare. AMS extends the applicability of the radiocarbon method, allowing the analysis of 14 C in submilligram organic samples. Specific molecular compounds extracted from bones, hair, skin and other carbon bearing substances of forensic significance can now be dated, enhancing the sensitivity and reliability of chronological determinations. AMS can also be used to analyse rare actinide isotopes released into the environment during the clandestine production of nuclear weapons or associated with the smuggling of nuclear materials. In

  16. Up-to-date and projected estimates of survival for people with cystic fibrosis using baseline characteristics: A longitudinal study using UK patient registry data.

    Science.gov (United States)

    Keogh, Ruth H; Szczesniak, Rhonda; Taylor-Robinson, David; Bilton, Diana

    2018-03-01

    Cystic fibrosis (CF) is the most common inherited disease in Caucasians, affecting around 10,000 individuals in the UK today. Prognosis has improved considerably over recent decades with ongoing improvements in treatment and care. Providing up-to-date survival predictions is important for patients, clinicians and health services planning. Flexible parametric survival modelling of UK CF Registry data from 2011 to 2015, capturing 602 deaths in 10,428 individuals. Survival curves were estimated from birth; conditional on reaching older ages; and projected under different assumptions concerning future mortality trends, using baseline characteristics of sex, CFTR genotype (zero, one, two copies of F508del) and age at diagnosis. Male sex was associated with better survival, as was older age at diagnosis, but only in F508del non-homozygotes. Survival did not differ by genotype among individuals diagnosed at birth. Median survival ages at birth in F508del homozygotes were 46years (males) and 41years (females), and similar in non-homozygotes diagnosed at birth. F508del heterozygotes diagnosed aged 5 had median survival ages of 57 (males) and 51 (females). Conditional on survival to 30, median survival age rises to 52 (males) and 49 (females) in homozygotes. Mortality rates decreased annually by 2% during 2006-2015. Future improvements at this rate suggest median survival ages for F508del homozygous babies of 65 (males) and 56 (females). Over half of babies born today, and of individuals aged 30 and above today, can expect to survive into at least their fifth decade. Evidence before this study We searched PubMed with terms "(cystic fibrosis survival) and (projection OR model OR registry OR United Kingdom OR UK)" to identify relevant studies on survival estimates for individuals with cystic fibrosis (CF). We also considered the most recent annual report from the UK Cystic Fibrosis Registry (Cystic Fibrosis Trust, 2016), a review by Buzzetti and colleagues (2009), the chapter

  17. CHRONOLOGY AND DYNAMICS OF ANCIENT POTTERY TRADITIONS' DISSEMINATION IN STEPPES OF THE LOWER VOLGA REGION

    DEFF Research Database (Denmark)

    Vybornov, Aleksandr A.; Vasilyeva, Irina N.; Kulkova, Marianna A.

    2018-01-01

    The territory of the Lower Volga plays an important role in the study of the Neolithic of Eastern Europe. The leading indicator of this epoch is pottery. Determining the chronology of pottery making is one of the most complex issues. Over the past ten years, a large number of radiocarbon dates (43......) have been obtained on various materials: coal, bones, organic materials in pottery, crusts, humus. They allowed accurate determining of the initial time of appearance of the most ancient crockery in the Lower Volga region - the middle of the 7th millennium BC. The authors determine the chronological...... analysis made it possible to clarify the genesis, the features of the dynamics and the further destiny of pottery in the region. The combination of the latest data allows referring the Neolithic monuments of steppe territory of the Lower Volga to the area of the ancient pottery in Eastern Europe. A...

  18. Excavations and chronology at the Redcliffs Flat site, Canterbury, New Zealand

    International Nuclear Information System (INIS)

    Jacomb, C.

    2009-01-01

    The Redcliffs Flat site is one of a number of early Maori archaeological sites that cluster near the mouth of the estuary of the Avon and Heathcote rivers. Although several have been the subject of archaeological investigations, the chronology and extent of the Redcliffs Flat site remain poorly understood. Recent excavations associated with the redevelopment of a suburban section allow some progress to be made on both fronts. A small excavation here yielded a surprising amount of faunal, lithic and stratigraphic information. The site is shown to have extended to close to the edge of the estuary at the time of occupation and a radiocarbon date on a fragment of moa eggshell confirms the fourteenth to early fifteenth century status of the site. The radiocarbon chronology of the sites of the wider Redcliffs area is reviewed in light of this result. (author). 41 refs., 6 figs., 3 tabs.

  19. Communication dated 30 May 2008 received from the Permanent Mission of the Federal Republic of Germany to the Agency with regard to the German proposal for a Multilateral Enrichment Sanctuary Project

    International Nuclear Information System (INIS)

    2008-01-01

    The Secretariat has received a communication dated 30 May 2008 from the Permanent Mission of the Federal Republic of Germany, attaching a document entitled 'Ensuring Access to Nuclear Fuel and Enrichment Services Multilateral Enrichment Sanctuary Project (MESP)'. As requested in that communication, the document is herewith circulated for the information of Member States

  20. Time Matters: Increasing the Efficiency of Antarctic Marine Geology and Paleoceanography Expeditions by Providing Improved Sediment Chronology

    Science.gov (United States)

    Rosenheim, B. E.; Domack, E. W.; Shevenell, A.; Subt, C.

    2015-12-01

    To maximize the areal extent of Antarctic sedimentary records of past deglaciation, it is necessary to ensure more sediment cores can be adequately dated. Antarctic margin sediment is challenging to date due to the lack of preserved calcium carbonate, but the records contained in these sediments readily recount the history of deglaciation. Recent and continued development of new chronological methods for Antarctic margin sediments have allowed better use of the efforts of marine geological coring expeditions to the region. The development of Ramped PyrOx radiocarbon dating has allowed us to 1. improve dates in deglacial sediments where no carbonate is preserved, 2. date glacial sediments lying below the tills marking the last glaciation, and 3. compile core chronologies into a regional framework of ice shelf collapse that has eluded many marine geology campaigns over the last few decades. These advances in a fundamental aspect of geological sciences will put the U.S. and international community on a better foothold to interpret the past as it relates to our warming future. We will present these advances in chronology as well as the science that is enabled by them, while arguing that the future of Antarctic marine science also depends on investments in shore-based technologies that come at a relatively low cost.

  1. An optimized multi-proxy, multi-site Antarctic ice and gas orbital chronology (AICC2012): 120-800 ka

    Science.gov (United States)

    Bazin, L.; Landais, A.; Lemieux-Dudon, B.; Toyé Mahamadou Kele, H.; Veres, D.; Parrenin, F.; Martinerie, P.; Ritz, C.; Capron, E.; Lipenkov, V.; Loutre, M.-F.; Raynaud, D.; Vinther, B.; Svensson, A.; Rasmussen, S. O.; Severi, M.; Blunier, T.; Leuenberger, M.; Fischer, H.; Masson-Delmotte, V.; Chappellaz, J.; Wolff, E.

    2013-08-01

    An accurate and coherent chronological framework is essential for the interpretation of climatic and environmental records obtained from deep polar ice cores. Until now, one common ice core age scale had been developed based on an inverse dating method (Datice), combining glaciological modelling with absolute and stratigraphic markers between 4 ice cores covering the last 50 ka (thousands of years before present) (Lemieux-Dudon et al., 2010). In this paper, together with the companion paper of Veres et al. (2013), we present an extension of this work back to 800 ka for the NGRIP, TALDICE, EDML, Vostok and EDC ice cores using an improved version of the Datice tool. The AICC2012 (Antarctic Ice Core Chronology 2012) chronology includes numerous new gas and ice stratigraphic links as well as improved evaluation of background and associated variance scenarios. This paper concentrates on the long timescales between 120-800 ka. In this framework, new measurements of δ18Oatm over Marine Isotope Stage (MIS) 11-12 on EDC and a complete δ18Oatm record of the TALDICE ice cores permit us to derive additional orbital gas age constraints. The coherency of the different orbitally deduced ages (from δ18Oatm, δO2/N2 and air content) has been verified before implementation in AICC2012. The new chronology is now independent of other archives and shows only small differences, most of the time within the original uncertainty range calculated by Datice, when compared with the previous ice core reference age scale EDC3, the Dome F chronology, or using a comparison between speleothems and methane. For instance, the largest deviation between AICC2012 and EDC3 (5.4 ka) is obtained around MIS 12. Despite significant modifications of the chronological constraints around MIS 5, now independent of speleothem records in AICC2012, the date of Termination II is very close to the EDC3 one.

  2. An optimized multi-proxy, multi-site Antarctic ice and gas orbital chronology (AICC2012: 120–800 ka

    Directory of Open Access Journals (Sweden)

    L. Bazin

    2013-08-01

    Full Text Available An accurate and coherent chronological framework is essential for the interpretation of climatic and environmental records obtained from deep polar ice cores. Until now, one common ice core age scale had been developed based on an inverse dating method (Datice, combining glaciological modelling with absolute and stratigraphic markers between 4 ice cores covering the last 50 ka (thousands of years before present (Lemieux-Dudon et al., 2010. In this paper, together with the companion paper of Veres et al. (2013, we present an extension of this work back to 800 ka for the NGRIP, TALDICE, EDML, Vostok and EDC ice cores using an improved version of the Datice tool. The AICC2012 (Antarctic Ice Core Chronology 2012 chronology includes numerous new gas and ice stratigraphic links as well as improved evaluation of background and associated variance scenarios. This paper concentrates on the long timescales between 120–800 ka. In this framework, new measurements of δ18Oatm over Marine Isotope Stage (MIS 11–12 on EDC and a complete δ18Oatm record of the TALDICE ice cores permit us to derive additional orbital gas age constraints. The coherency of the different orbitally deduced ages (from δ18Oatm, δO2/N2 and air content has been verified before implementation in AICC2012. The new chronology is now independent of other archives and shows only small differences, most of the time within the original uncertainty range calculated by Datice, when compared with the previous ice core reference age scale EDC3, the Dome F chronology, or using a comparison between speleothems and methane. For instance, the largest deviation between AICC2012 and EDC3 (5.4 ka is obtained around MIS 12. Despite significant modifications of the chronological constraints around MIS 5, now independent of speleothem records in AICC2012, the date of Termination II is very close to the EDC3 one.

  3. A multi-archive coherent chronology: from Greenland to the Mediterranean sea

    Science.gov (United States)

    Bazin, Lucie; Landais, Amaelle; Lemieux-Dudon, Bénédicte; Siani, Giuseppe; Michel, Elisabeth; Combourieu-Nebout, Nathalie; Blamart, Dominique; Genty, Dominique

    2015-04-01

    Understanding the climate mechanisms requires a precise knowledge of the sequence of events during major climate changes. In order to provide precise relationships between changes in orbital and/or greenhouse gases concentration forcing, sea level changes and high vs low latitudes temperatures, a common chronological framework for different paleoclimatic archives is required. Coherent chronologies for ice cores have been recently produced using a bayesian dating tool, DATICE (Lemieux-Dudon et al., 2010, Bazin et al., 2013, Veres et al., 2013). Such tool has been recently developed to include marine cores and speleothems in addition to ice cores. This new development should enable one to test the coherency of different chronologies using absolute and stratigraphic links as well as to provide relationship between climatic changes recorded in different archives. We present here a first application of multi-archive coherent dating including paleoclimatic archives from (1) Greenland (NGRIP ice core), (2) Mediterranean sea (marine core MD90-917, 41° N17° E, 1010 m) and (3) speleothems from the South of France and North Tunisia (Chauvet, Villars and La Mine speleothems, Genty et al., 2006). Thanks to the good absolute chronological constraints from annual layer counting in NGRIP, 14C and tephra layers in MD90-917 and U-Th dating in speleothems, we can provide a precise chronological framework for the last 50 ka (ie. thousand years before present). Then, we present different tests on how to combine the records from the different archives and give the most plausible scenario for the sequence of events at different latitudes over the last deglaciation. Bazin, L., Landais, A. ; Lemieu¬-Dudon, B. ; Kele, H. T. M. ; Veres, D. ; Parrenin, F. ; Martinerie, P. ; Ritz, C. ; Capron, E. ; Lipenkov, V. ; Loutre, M.-F. ; Raynaud, D. ; Vinther, B. ; Svensson, A. ; Rasmussen, S. ; Severi, M. ; Blunier, T. ; Leuenberger, M. ; Fischer, H. ; Masson-¬-Delmotte, V. ; Chappellaz, J

  4. On the palaeoclimatic potential of a millennium-long oak ring width chronology from Slovakia

    Czech Academy of Sciences Publication Activity Database

    Prokop, O.; Kolář, Tomáš; Büntgen, Ulf; Kyncl, J.; Bošela, M.; Choma, M.; Barta, P.; Rybníček, Michal

    2016-01-01

    Roč. 40, DEC (2016), s. 93-101 ISSN 1125-7865 R&D Projects: GA MŠk(CZ) LO1415; GA ČR GA13-04291S Institutional support: RVO:67179843 Keywords : Composite tree-ring chronology * European oak * Palaeoclimatology * Random update sampling * Ring width * Slovakia Subject RIV: EH - Ecology, Behaviour Impact factor: 2.259, year: 2016

  5. Supported Lead in Pb-210 Chronology

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, D.; Hettwig, B.; Fischer, H. W. [Institute of Environmental Physics, University of Bremen, Bremen (Germany)

    2013-07-15

    A widely applied method of supported lead estimation in sediments using gamma spectrometric {sup 226}Ra determination via {sup 222}Rn short lived daughter products relies on radioactive equilibrium between {sup 226}Ra and {sup 222}Rn being established after sealing the samples. Advantages and disadvantages of methods of {sup 226}Ra estimation in sediments, using either {sup 222}Rn daughter products or direct estimation by 186.2 keV gamma emissions are discussed. An equilibrium experiment was performed using test samples and in one case radioactive equilibrium was not reached. On a theoretical sediment profile it was shown how systematic errors in supported {sup 210}Pb estimation can lead to incorrect interpretations of {sup 210}Pb{sub xs} profiles and therefore affect {sup 210}Pb derived chronologies. (author)

  6. Updated chronology for the Miocene hominoid radiation in Western Eurasia

    Science.gov (United States)

    Casanovas-Vilar, Isaac; Alba, David M.; Garcés, Miguel; Robles, Josep M.; Moyà-Solà, Salvador

    2011-01-01

    Extant apes (Primates: Hominoidea) are the relics of a group that was much more diverse in the past. They originated in Africa around the Oligocene/Miocene boundary, but by the beginning of the Middle Miocene they expanded their range into Eurasia, where they experienced a far-reaching evolutionary radiation. A Eurasian origin of the great ape and human clade (Hominidae) has been favored by several authors, but the assessment of this hypothesis has been hampered by the lack of accurate datings for many Western Eurasian hominoids. Here we provide an updated chronology that incorporates recently discovered Iberian taxa and further reevaluates the age of many previously known sites on the basis of local biostratigraphic scales and magnetostratigraphic data. Our results show that identifiable Eurasian kenyapithecins (Griphopithecus and Kenyapithecus) are much younger than previously thought (ca. 14 Ma instead of 16 Ma), which casts serious doubts on the attribution of the hominoid tooth from Engelswies (16.3–16.5 Ma) to cf. Griphopithecus. This evidence is further consistent with an alternative scenario, according to which the Eurasian pongines and African hominines might have independently evolved in their respective continents from similar kenyapithecin ancestors, resulting from an early Middle Miocene intercontinental range extension followed by vicariance. This hypothesis, which would imply an independent origin of orthogrady in pongines and hominines, deserves further testing by accurately inferring the phylogenetic position of European dryopithecins, which might be stem pongines rather than stem hominines. PMID:21436034

  7. ESR Dating Research of Glacial Tills in Tibetan Plateau

    Science.gov (United States)

    Bi, W.; Yi, C.

    2016-12-01

    In recent years, Quaternary Glacial-chronology has been made remarkable progress in the Tibetan Platean(TP) with the development of several numeric dating techniques, such as cosmogenic nuclides(NC), optically stimulated luminescence(OSL) and 14C. In constrast, the dating of Quaternary glacial tills in 100,000 years even more than million-year has been a challenge, just because the techniques has defects themselves and the sediments were stransformed during the geological and geomorphology progress later. Electron Spin Resonance(ESR) has been becoming one of the key methods of Quaternary Glacial-chronology with wide range of dating, expecially for the sample older than 100,000 years up to million-year scale. The accurate measurement of equivalent dose significantly impacts on accuracy and reliability of ESR dating method. Therefore, the study of the mechanisms of resetting processes is fundamental for accurate and reliable ESR dating. To understand the mechanism and characteristics of quartz ESR signal resetting of different samples, a series of laboratory simulation and field observation studies were carried out, which made lots of important breakthrough. But the research in quartz ESR signal of moraines is less and the test of ESR dating method is still in the qualitative investigation. Therefor, we use ESR dating and study on the mechanism and characteristics of quartz ESR signals in tills in the Tibetan Platean. In the adjust method of Modern, the quartz ESR signals in Modern glacial tills represent residual values which can be adjusted signals in the older glacial tills. As a consequence, ESR dating of the quartz in moraines needs to be explored in deep with building models to adjust ages which are measured by ESR dating. Therefore, ESR dating will become the trusted one of the cross dating methods in Quaternary Glacial-chronology with the adjust mothod improving the accuracy of ESR dating ages.

  8. AMS radiocarbon dating of 'Grotta Cappuccini' in Southern Italy

    International Nuclear Information System (INIS)

    Quarta, G.; Calcagnile, L.; D'Elia, M.; Rizzo, A.; Ingravallo, E.

    2004-01-01

    We present the results of AMS radiocarbon dating of human bones recovered in 'Grotta Cappuccini', a prehistoric cave in Galatone, Lecce (Southern Italy). The AMS analysis has confirmed the archaeological dating of the cave to the period between the end of the Copper Age and the early Bronze Age, and has given a fundamental contribution to the chronological definition of an important cultural aspect of the prehistory of Southern Italy

  9. Monthly paleostreamflow reconstruction from annual tree-ring chronologies

    Science.gov (United States)

    J. H. Stagge; D. E. Rosenberg; R. J. DeRose; T. M. Rittenour

    2018-01-01

    Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually...

  10. Jewish Holocaust Histories and the Work of Chronological Narratives

    Science.gov (United States)

    Silverstein, Jordana

    2012-01-01

    This article examines the ways that, in Holocaust education in Jewish schools in Melbourne and New York at the beginning of the 21st century, knowledge of the Holocaust is transferred to students in chronological form. It begins by asking: What work do chronological narratives do within the Holocaust historical narratives offered within Jewish…

  11. Combined dendrochronological and radiocarbon dating of six Russian icons from the 15th-17th centuries

    Science.gov (United States)

    Dolgikh, A. V.; Matskovsky, V. V.; Voronin, K. V.; Solomina, O. N.

    2017-06-01

    The results of dendrochronological and radiocarbon dating by means of accelerator mass spectrometry (AMS) of six medieval icons, originating from northern European Russia and painted on wooden panels made from Scots pine, dated to the 15th to 17th centuries are presented. The panels of each icon were studied using dendrochronology. Five to six AMS dates were obtained for four icons. Although five icons were dendro-dated successfully, one failed to be reliably cross-dated with the existing master tree-ring chronologies and it was dated by radiocarbon wiggle-matching. Dendrochronological dating and wiggle-matching of radiocarbon dates allowed us to determine the narrow chronological intervals of icon creation.

  12. Lake trout otolith chronologies as multidecadal indicators of high-latitude freshwater ecosystems

    Science.gov (United States)

    Black, B.A.; Von Biela, V.R.; Zimmerman, C.E.; Brown, Randy J.

    2013-01-01

    High-latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments. To address this issue, dendrochronology (tree-ring analysis) techniques were applied to growth-increment widths in otoliths from lake trout (Salvelinus namaycush) from the Chandler Lake system, Alaska (68.23°N, 152.70°W). All otoliths were collected in 1987 and exhibited highly synchronous patterns in growth-increment width. Increments were dated, the widths were measured, and age-related growth declines were removed using standard dendrochronology techniques. The detrended time series were averaged to generate an annually resolved chronology, which continuously spanned 1964–1984. The chronology positively and linearly correlated with August air temperature over the 22-year interval (p fish metabolic rate or lake productivity. Given the broad distribution of lake trout within North America, this study suggests that otolith chronologies could be used to examine responses between freshwater ecosystems and environmental variability across a range of temporal and spatial scales.

  13. Chronological shifts and changing causes of death after radiotherapy for early-stage oral cancer.

    Science.gov (United States)

    Fujisawa, Rina; Shibuya, Hitoshi; Harata, Naoki; Yuasa-Nakagawa, Keiko; Toda, Kazuma; Hayashi, Keiji

    2014-02-01

    Following recent improvements in the curability of oral cancer, chronological shifts and changes in the causes of death after treatment have been observed. We conducted a review of the post-treatment causes of death following radiotherapy for oral cancers. The medical records of 966 patients with early-stage (stage I and II) oral cancer treated at our institute between 1980 and 2001 were reviewed, and the chronological shifts and changes in the causes of death after radiotherapy were assessed. Of the 966 patients enrolled in this study, 365 have died to date. Two hundred and eleven patients died of their primary malignancy; 193 of these deaths occurred within 5 years of treatment for the primary oral cancer. The second most frequent cause of death was second primary cancer (n = 90). Twenty-three patients with head and neck cancers and 18 patients with esophageal cancers died within 10 years of radiotherapy, and six patients with lung cancers died after more than 10 years. Within the first 5 years following treatment, the major cause of death was the primary oral cancer. After 5-10 years, a second primary cancer, such as head and neck cancer or esophageal cancer, became the leading cause of death. Over a 10-year period, the proportion of deaths from a second primary cancer in the lung was significant. We have demonstrated that there are chronological shifts and changes in the causes of death following treatment for early-stage oral cancer.

  14. Lake trout otolith chronologies as multidecadal indicators of high-latitude freshwater ecosystems

    Science.gov (United States)

    Black, B.A.; Von Biela, V.R.; Zimmerman, C.E.; Brown, Randy J.

    2013-01-01

    High-latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments. To address this issue, dendrochronology (tree-ring analysis) techniques were applied to growth-increment widths in otoliths from lake trout (Salvelinus namaycush) from the Chandler Lake system, Alaska (68.23°N, 152.70°W). All otoliths were collected in 1987 and exhibited highly synchronous patterns in growth-increment width. Increments were dated, the widths were measured, and age-related growth declines were removed using standard dendrochronology techniques. The detrended time series were averaged to generate an annually resolved chronology, which continuously spanned 1964–1984. The chronology positively and linearly correlated with August air temperature over the 22-year interval (p otolith chronologies could be used to examine responses between freshwater ecosystems and environmental variability across a range of temporal and spatial scales.

  15. Some Metabolites Act as Second Messengers in Yeast Chronological Aging

    Directory of Open Access Journals (Sweden)

    Karamat Mohammad

    2018-03-01

    Full Text Available The concentrations of some key metabolic intermediates play essential roles in regulating the longevity of the chronologically aging yeast Saccharomyces cerevisiae. These key metabolites are detected by certain ligand-specific protein sensors that respond to concentration changes of the key metabolites by altering the efficiencies of longevity-defining cellular processes. The concentrations of the key metabolites that affect yeast chronological aging are controlled spatially and temporally. Here, we analyze mechanisms through which the spatiotemporal dynamics of changes in the concentrations of the key metabolites influence yeast chronological lifespan. Our analysis indicates that a distinct set of metabolites can act as second messengers that define the pace of yeast chronological aging. Molecules that can operate both as intermediates of yeast metabolism and as second messengers of yeast chronological aging include reduced nicotinamide adenine dinucleotide phosphate (NADPH, glycerol, trehalose, hydrogen peroxide, amino acids, sphingolipids, spermidine, hydrogen sulfide, acetic acid, ethanol, free fatty acids, and diacylglycerol. We discuss several properties that these second messengers of yeast chronological aging have in common with second messengers of signal transduction. We outline how these second messengers of yeast chronological aging elicit changes in cell functionality and viability in response to changes in the nutrient, energy, stress, and proliferation status of the cell.

  16. Radiocarbon dating with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Blake, W. Jr.

    1985-01-01

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) has two great advantages over conventional dating: 1) much smaller samples can be handled and 2) counting time is significantly shorter. Three examples are given for Holocene-age material from east-central Ellesmere Island. The results demonstrate the potential use of this technique as a powerful research tool in studies of Quaternary chronology. Individual fragments of marine shells as small as 0.1 g have been dated successfully at the IsoTrace Laboratory, University of Toronto. In the case of an aquatic moss from a lake sediment core, an increment 0.5 cm thick could be used instead of a 5 cm-thick slice, thus allowing a much more precise estimate of the onset of organic sedimentation

  17. Load structure seismites in the Dead Sea Area, Israel : Chronological benchmarking with C-14 dating

    NARCIS (Netherlands)

    Bowman, D; Bruins, HJ; van der Plicht, J; Boaretto, E.; Bruins, Hendrik J.; Carmi, I.

    2001-01-01

    The Dead Sea is a terminal lake located in the seismically active zone of the Syro-African Rift Valley. The water level of the Dead Sea has been receding dramatically during the last decades, resulting in significant entrenchment of wadis towards its shores. Exposed sections in fan deltas reveal

  18. Spatial variability in growth-increment chronologies of long-lived freshwater mussels: Implications for climate impacts and reconstructions

    Science.gov (United States)

    Black, Bryan A.; Dunham, Jason B.; Blundon, Brett W.; Raggon, Mark F.; Zima, Daniela

    2010-01-01

    Estimates of historical variability in river ecosystems are often lacking, but long-lived freshwater mussels could provide unique opportunities to understand past conditions in these environments. We applied dendrochronology techniques to quantify historical variability in growth-increment widths in valves (shells) of western pearlshell freshwater mussels (Margaritifera falcata). A total of 3 growth-increment chronologies, spanning 19 to 26 y in length, were developed. Growth was highly synchronous among individuals within each site, and to a lesser extent, chronologies were synchronous among sites. All 3 chronologies negatively related to instrumental records of stream discharge, while correlations with measures of water temperature were consistently positive but weaker. A reconstruction of stream discharge was performed using linear regressions based on a mussel growth chronology and the regional Palmer Drought Severity Index (PDSI). Models based on mussel growth and PDSI yielded similar coefficients of prediction (R2Pred) of 0.73 and 0.77, respectively, for predicting out-ofsample observations. From an ecological perspective, we found that mussel chronologies provided a rich source of information for understanding climate impacts. Responses of mussels to changes in climate and stream ecosystems can be very site- and process-specific, underscoring the complex nature of biotic responses to climate change and the need to understand both regional and local processes in projecting climate impacts on freshwater species.

  19. Astronautics and Aeronautics, 1986-1990: A Chronology

    Science.gov (United States)

    Gawdiak, Ihor Y.; Miro, Ramon J.; Stueland, Sam

    1997-01-01

    This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the LibrarY of Congress for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1996-1990 and continues the series of annual chronologies published by NASA. The present volume returns to the format used in the Astronautics and Aeronautics, 1979-1984: A Chronology volume. It also integrates in a single table the information presented in two or three previous publications.

  20. Astronautics and Aeronautics, 1991-1995: A Chronology

    Science.gov (United States)

    Gawdiak, Ihor Y. (Compiler); Shetland, Charles (Compiler)

    2000-01-01

    This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the Library of Congress and RSIS for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1991-1995 and continues the series of annual chronologies published by NASA. The present volume uses the format of the previous edition of this series, Astronautics and Aeronautics, 1986-1990: A Chronology. It also integrates, in the appendices, information presented in previous publication

  1. A brief review of 210Pb sediment dating models and uncertainties in a world of global change

    Science.gov (United States)

    Sanchez-Cabeza, J. A.; Ruiz-Fernandez, A. C.

    2016-12-01

    Irrespective of the model names used, assumptions and (usually forgotten) uncertainties, the fact is that 210Pb sediment dating is an increasingly relevant tool in our world of global change. 210Pb dating results are needed to assess historical trends of sea level rise, quantify blue carbon fluxes and reconstruct environmental records of biogeochemical proxies for diverse processes in the aquatic ecosystems (such as ocean acidification, hypoxia and pollution). Although in the past 210Pb profiles departing from "ideal" decay trends were usually discarded, all profiles have useful information. In this work we review the principles and assumptions of the most common 210Pb dating models, and propose a logical formulation and classification of the models. 210Pb dating models provide two kinds of results: chronologies (i.e. age models) and accumulation rates. In many cases, the use of sediment and/or mass accumulation rates (SAR and MAR) is needed to assess environmental fluxes or, simply, to describe changes, such as catchment erosion or saltmarsh accretion. Although uncertainty quadratic propagation is a well-known technique, it requires that all variables are fully independent and requires demanding mathematical expressions which might lead to wrong results. We present here a Monte Carlo method that makes calculation easier and, likely, error-free. Not unexpectedly, the most important uncertainty sources are measurement uncertainties, which impose limitations on common techniques such as gamma spectrometry. 210Pb chronology does not cover all anthropogenic impacts, such as those caused by ancient civilizations, so radiocarbon also plays an important role in this kind of work. We also conceptually revise the limitations of both techniques and encourage scientists to link both dating techniques with a symmetrically open mind. Acknowledgements: projects CONACYT PDCPN2013-01/214349 and CB2010/153492, UNAM PAPIIT-IN203313, PRODEP network "Aquatic contamination: levels and

  2. Radiocarbon dating in near-Eastern contexts : Confusion and quality control

    NARCIS (Netherlands)

    van der Plicht, J; Bruins, HJ; Bruins, Hendrik J.; Boaretto, E.; Carmi, I.

    2001-01-01

    Near-Eastern archaeology has long remained oblivious to radiocarbon dating as unique historical calendars brought about a perception that C-14 dating is superfluous. Circular chronological reasoning may occur as a result. There is now strong C-14 evidence that the early part of Egyptian history

  3. Astronautics and aeronautics, 1973: Chronology of science, technology and policy. [including artificial satellites, space probes, and manned space flights

    Science.gov (United States)

    1975-01-01

    A brief chronological account is presented of key events of the year in aerospace sciences. Dates, actions, hardware, persons, scientific discoveries are recorded along with plans, decisions, achievements and preliminary evaluations of results. Samples of public reaction and social impact are included. Sources are identified and an index is provided to aid in tracing related events through the year. The index also serves as a glossary of acronyms and abbreviations.

  4. Optically stimulated luminescence dating of rock surfaces

    DEFF Research Database (Denmark)

    Sohbati, Reza

    There are many examples of rock surfaces, rock art and stone structures whose ages are of great importance to the understanding of various phenomena in geology, climatology and archaeology. Optically stimulated luminescence (OSL) dating is a well-established chronological tool that has successfully...... to include the effects of the environmental dose rate. By fitting the model to the dose-depth variation from a single clast, four events (two light exposures of different durations each followed by a burial period) in the history of a single cobble are identified and quantified. However, the use of model...

  5. Dating and Sexual Feelings

    Science.gov (United States)

    ... Home Body Your sexuality Dating and sexual feelings Dating and sexual feelings Thinking about romance, starting to ... you learn how to stay healthy and strong. Dating older guys top If you date someone even ...

  6. High-precision radiocarbon dating of political collapse and dynastic origins at the Maya site of Ceibal, Guatemala.

    Science.gov (United States)

    Inomata, Takeshi; Triadan, Daniela; MacLellan, Jessica; Burham, Melissa; Aoyama, Kazuo; Palomo, Juan Manuel; Yonenobu, Hitoshi; Pinzón, Flory; Nasu, Hiroo

    2017-02-07

    The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the Middle Preclassic Period through the Terminal Classic (1000 BC to AD 950). The Ceibal-Petexbatun Archaeological Project has been conducting archaeological investigations at this site since 2005 and has obtained 154 radiocarbon dates, which represent the largest collection of radiocarbon assays from a single Maya site. The Bayesian analysis of these dates, combined with a detailed study of ceramics, allowed us to develop a high-precision chronology for Ceibal. Through this chronology, we traced the trajectories of the Preclassic collapse around AD 150-300 and the Classic collapse around AD 800-950, revealing similar patterns in the two cases. Social instability started with the intensification of warfare around 75 BC and AD 735, respectively, followed by the fall of multiple centers across the Maya lowlands around AD 150 and 810. The population of Ceibal persisted for some time in both cases, but the center eventually experienced major decline around AD 300 and 900. Despite these similarities in their diachronic trajectories, the outcomes of these collapses were different, with the former associated with the development of dynasties centered on divine rulership and the latter leading to their downfalls. The Ceibal dynasty emerged during the period of low population after the Preclassic collapse, suggesting that this dynasty was placed under the influence from, or by the direct intervention of, an external power.

  7. The Later Stone Age calvaria from Iwo Eleru, Nigeria: morphology and chronology.

    Directory of Open Access Journals (Sweden)

    Katerina Harvati

    Full Text Available BACKGROUND: In recent years the Later Stone Age has been redated to a much deeper time depth than previously thought. At the same time, human remains from this time period are scarce in Africa, and even rarer in West Africa. The Iwo Eleru burial is one of the few human skeletal remains associated with Later Stone Age artifacts in that region with a proposed Pleistocene date. We undertook a morphometric reanalysis of this cranium in order to better assess its affinities. We also conducted Uranium-series dating to re-evaluate its chronology. METHODOLOGY/PRINCIPAL FINDINGS: A 3-D geometric morphometric analysis of cranial landmarks and semilandmarks was conducted using a large comparative fossil and modern human sample. The measurements were collected in the form of three dimensional coordinates and processed using Generalized Procrustes Analysis. Principal components, canonical variates, Mahalanobis D(2 and Procrustes distance analyses were performed. The results were further visualized by comparing specimen and mean configurations. Results point to a morphological similarity with late archaic African specimens dating to the Late Pleistocene. A long bone cortical fragment was made available for U-series analysis in order to re-date the specimen. The results (∼11.7-16.3 ka support a terminal Pleistocene chronology for the Iwo Eleru burial as was also suggested by the original radiocarbon dating results and by stratigraphic evidence. CONCLUSIONS/SIGNIFICANCE: Our findings are in accordance with suggestions of deep population substructure in Africa and a complex evolutionary process for the origin of modern humans. They further highlight the dearth of hominin finds from West Africa, and underscore our real lack of knowledge of human evolution in that region.

  8. Pollution chronology of the Golden Horn sediments

    International Nuclear Information System (INIS)

    Teksoez, G.; Yetis, U.; Tuncel, G.; Balkas, T.I.

    1990-01-01

    Sediment accumulation in the Golden Horn has been established by means of a useful geochronological technique; 210 Pb Radiometric Dating Method. The 210 Pb dating technique revealed a sediment accumulation rate of 3.5 cm yr -1 which is very reasonable given the characteristics of the Golden Horn. The 210 Pb profile also revealed three distinct levels in the sediments of the Golden Horn: a surface layer with nearly uniform activities, an exponential decay interval and a lower region with almost constant low activity. (author)

  9. Astronautics and aeronautics, 1970. Chronology on science, technology, and policy

    Science.gov (United States)

    1972-01-01

    An immediate reference to aerospace-related events of 1970 is provided to help historians in preserving historical accuracy and precision. Chronologies of major NASA launches, and manned space flights for 1970 are included.

  10. Astronautics and Aeronautics, 1979-1984: A chronology

    Science.gov (United States)

    Janson, Bette R.; Ritchie, Eleanor H.

    1989-01-01

    This volume of the Astronautics and Aeronautics series covers 1979 through 1984. The series provides a chronological presentation of all significant events and developments in space exploration and the administration of the space program during the period covered.

  11. Spheroidal Carbonaceous Particles (SCPs) as Chronological Markers in Marine Sediments

    Science.gov (United States)

    Thornalley, D.; Rose, N.; Oppo, D.

    2016-12-01

    Spheroidal carbonaceous particles (SCPs) are a component of fly-ash, the particulate by-product of industrial high-temperature combustion of coal and fuel-oil that is released to the atmosphere with flue-gases. They are morphologically distinct and have no natural sources making them unambiguous markers of contamination from these anthropogenic sources. In naturally accumulating archives, SCPs may be used as a chronological tool as they provide a faithful record of industrial emissions and deposition. While the timing of the first presence of SCP in the 19th century, and the observed sub-surface peak are dependent on factors such as sediment accumulation rates and local industrial history, a rapid increase in SCP inputs in the mid-20thcentury appears to be a global signal corresponding to an acceleration in global electricity demand following the Second World War and the use of fuel-oil in electricity production at an industrial scale for the first time. While this approach has been widely used in lake sediments, it has not been applied to marine sediments, although there is great potential. Improved dating of 19th-20th century marine sediments has particular relevance for developing reconstructions of recent multi-decadal climate and ocean variability, and for studies that aim to place 20thcentury climate change within the context of the last millennium. Here, we present data from three sediment cores from the continental slope south of Iceland to demonstrate the temporal and spatial replicability of the SCP record in the marine environment and compare these data with cores taken from more contaminated areas off the coast of the eastern United States. The improved age model constraints provided by the analysis of SCPs has enabled a more accurate assessment of the timing of recent abrupt climate events recorded in these archives and has thus improved our understanding of likely causal climate mechanisms.

  12. The History of Therapeutic Aerosols: A Chronological Review.

    Science.gov (United States)

    Stein, Stephen W; Thiel, Charles G

    2017-02-01

    In 1956, Riker Laboratories, Inc., (now 3 M Drug Delivery Systems) introduced the first pressurized metered dose inhaler (MDI). In many respects, the introduction of the MDI marked the beginning of the modern pharmaceutical aerosol industry. The MDI was the first truly portable and convenient inhaler that effectively delivered drug to the lung and quickly gained widespread acceptance. Since 1956, the pharmaceutical aerosol industry has experienced dramatic growth. The signing of the Montreal Protocol in 1987 led to a surge in innovation that resulted in the diversification of inhaler technologies with significantly enhanced delivery efficiency, including modern MDIs, dry powder inhalers, and nebulizer systems. The innovative inhalers and drugs discovered by the pharmaceutical aerosol industry, particularly since 1956, have improved the quality of life of literally hundreds of millions of people. Yet, the delivery of therapeutic aerosols has a surprisingly rich history dating back more than 3500 years to ancient Egypt. The delivery of atropine and related compounds has been a crucial inhalation therapy throughout this period and the delivery of associated structural analogs remains an important therapy today. Over the centuries, discoveries from many cultures have advanced the delivery of therapeutic aerosols. For thousands of years, therapeutic aerosols were prepared by the patient or a physician with direct oversight of the patient using custom-made delivery systems. However, starting with the Industrial Revolution, advancements in manufacturing resulted in the bulk production of therapeutic aerosol delivery systems produced by people completely disconnected from contact with the patient. This trend continued and accelerated in the 20th century with the mass commercialization of modern pharmaceutical inhaler products. In this article, we will provide a summary of therapeutic aerosol delivery from ancient times to the present along with a look to the future. We

  13. Climatically sensitive tree-ring chronologies from Crimea, Ukraine

    Science.gov (United States)

    Solomina, O.; Davi, N.; D Arrigo, R.

    2003-04-01

    Several tree species in Crimea can reach ages of 1000 years or more (Crimea..., 1999), including Taxus baccata L., Arbutus andrachne L., Quercus pubescens Willd, Quercus petraea (Mattuschka) Liebl., Quercus robur L., Juniperus excelsa M.B., and Pistacia mutica Fisch.et Mey. In September 2002, we collected samples from several long-lived tree sites described in the literature (Vulf, 1948, Ivanenko, 1951, Ena, 1983, Podgorniy, 1990), located in the mountains of Central Crimea (Sokolinoye, Chufut-Kale, Chelter) and on the coast of the Black Sea (Ai-Todor, Kharaks, Ai-Petri). The trees sampled generally had 300-350 rings. At Ai-Todor, most oaks, junipers, and pistachio showed decay. However, enough samples of oak, juniper and pine were collected to build three chronologies with good replication over the last 350 years. Long meteorological records (for Sevastopol since 1821, Ai-Petri and Yalta since the 1880's) as well as detailed historical data on extreme climatic events since 1687 (summarized by Borisov 1956) are available for this area and can be used to calibrate and verify the tree growth/climate models. Resulting dendroclimatic reconstructions will be the first from this region. The tree-ring time-series may also be used for archaeological dating of historical wood from several medieval fortresses, towns and palaces. In turn, the archaeological wood could be used to extend the tree-ring time series. Stalactites and stalagmites (Dubliansky, 1977) found in numerous caves, as well as 4000-years old laminated lake sediments (Shostakovich, 1934) are also potentially important sources of paleoclimatic information in the area.

  14. Setting a date

    International Nuclear Information System (INIS)

    Moore, Glenis.

    1987-01-01

    Dating techniques are discussed and explained. The age range and sensitivity of different techniques are given. Potassium/argon dating, amino-acid dating, radiocarbon dating, dendrochronology, thermoluminescence and geomagnetic field dating are all mentioned. Each technique is explained and a brief history given. The techniques and equipment used by the British Museum, and some examples of archaeological articles dated are mentioned. (UK)

  15. Chronological changes in hypertensive intracerebral hemorrhages

    International Nuclear Information System (INIS)

    Takasugi, Shinsuke; Kashihara, Michiharu; Okamoto, Junji; Hondo, Hideki; Yamashita, Shigeru

    1983-01-01

    The clinical series consisted of 28 patients with hypertensive intracerebral hematoma observed in the natural course from 1976 through 1978. A total of 114 repeated computer tomographic (CT) examinations were made with an EMI-1010 or an ACTA-0100 scanner. The experimental series consisted of 26 adult mongrel dogs with intracerebral hematoma near the basal ganglia. In 20 dogs, autopsy and histological examinations were performed, and in 12 dogs a total of 31 repeated CT examinations were carried out with an EMI scanner (matrix 320 x 320, high-definition scan). In the clinical series, the time of the decrease in density beginning in the periphery of the hematoma, like the first appearance of ring enhancement and its concentric concentration toward the center of the hematoma, was not affected by the size of the hematoma. However, the time when the intracerebral hematoma was resolved did vary with the size of the hematoma. In the experimental series, the tissue reaction near the periphery of the intracerebral hematoma seemed to be a constant process. First, a necrotic layer appeared, and then this was replaced by immature connective tissue with granular cells, newly formed vessels, and reticulin fibers; finally, the immature layer was gradually transformed into mature connective tissue with collagenous fibers. Moreover, this process of change was not related to the size of the hematoma. The following correlations were suggested by a chronological observation of the CT images and the histological appearance: 1) acute stage - homogeneous high-density extending to the periphery, apperance of a necrotic layer; 2) subacute stage - decreased density spreading from the periphery and formation of ring enhancement, apperance of immature connective tissue with reticulin fibers; 3) chronic stage - concentric concentration of ring enhancement, mature connective tissue with collagenous fibers

  16. Iron Age Mediterranean Chronology : A Reply

    NARCIS (Netherlands)

    Bruins, Hendrik J.; Nijboer, Albert J.; van der Plicht, Johannes

    2011-01-01

    This article is a reply to the preceding rejoinder by Fantalkin et al., which they wrote in response to our article concerning radiocarbon dates of Iron Age sites in the Mediterranean region measured at Groningen (van der Plicht et al. 2009). We do not agree with much of their criticism. Our reply

  17. 210Pb-137Cs dating of glacial lake sediments

    International Nuclear Information System (INIS)

    Graham, I.J.; Ditchburn, R.G.; Barry, B.J.

    2004-01-01

    Sediments deposited in New Zealand lakes in the recent past provide excellent archives of local climate change via their trapped biodiversity, varve structure ad sedimentological composition. To unlock the archival information, accurate and fine-scale dating of the deposits is essential. A combination of 210 Pb and 137 Cs dating provides the most reliable and robust approach. Under favourable conditions, 210 Pb dating can provide a detailed chronology to c.120-140 y, and can be accurately calibrated by 137 Cs for the last 40 y or thereabouts. (author). 6 refs., 4 figs

  18. Towards a new common Greenland Ice Core Chronology for the last 5000 years

    Science.gov (United States)

    Winstrup, Mai; Olander Rasmussen, Sune; Møllesøe Vinther, Bo; Cook, Eliza; Svensson, Anders; McConnell, Joe; Steffensen, Jørgen Peder

    2017-04-01

    Since the development of the Greenland Ice Core Chronology 2005 (GICC05), it has been widely used as a reference chronology in paleoclimate research. However, recent research (Sigl et al, 2015) demonstrated that this timescale has small, but significant, issues over historical time. These discrepancies was found by counting annual layers in high-resolution chemistry records from the NEEM S1 shallow core, and confirmed by linking via 10Be marker horizons to the layer-counted WAIS Divide ice core, Antarctica, and accurately-dated tree-ring series. This work showed that a revision of GICC05 is required prior to 1250AD. We here refine and extend this work. Layer-counting in a single core will always involve some uncertainty, and we hence use data from multiple Greenland ice cores, for which high-resolution impurity records recently have been measured. These ice cores have been synchronized using volcanic marker horizons, and the layer-counting is performed automatically using the StratiCounter algorithm (Winstrup et al, 2012), while ensuring that the number of layers between volcanic horizons are the same in all cores. Based on this extended multiple-core data set, we are further able to extend the new Greenland timescale another few thousand years back in time. This will, among others, provide a new ice-core date for the catastrophic volcanic eruption ( 1600 BC) that destroyed the Greek Minoan culture, an important time marker in Greek history.

  19. Chronology of the early period of the Ananyino cultural and historical area

    Directory of Open Access Journals (Sweden)

    Kuzminykh Sergei V.

    2014-09-01

    Full Text Available Problems related to the chronology of the early period in the Ananyino cultural and historical area development are discussed in the article. The chronology is based upon the objects imported from the Black Sea region, Northern Caucasus and Transcaucasia and their Ananyino replicas or imitations. Radiocarbon dates have also been taken into account. The period under consideration is divided into two stages (I-1 and I-2. They are characterized by differing technological facilities that had determined the appearance of a differing set of material culture objects. The first stage, the transition from the Bronze Age to the Early Iron Age, is dated within the 9th to mid-8th century BC. The second phase (mid-8th to first quarter/first half of the 7th century BC is associated with the spread of Caucasian imports in the Volga-Kama area and mostly in the post-Maklasheevka culture sites. On the basis of these imports it is possible to claim that the Ananyino area was included into the international trade and exchange system of Eastern Europe, the Caucasus and Transcaucasia. Monuments of the early period of the Ananyino cultural and historical area are primarily synchronized with the pre-Scythian funeral monuments of the steppe zone of Eastern Europe and the Caucasus.

  20. Reconstructions of Columbia River streamflow from tree-ring chronologies in the Pacific Northwest, USA

    Science.gov (United States)

    Littell, Jeremy; Pederson, Gregory T.; Gray, Stephen T.; Tjoelker, Michael; Hamlet, Alan F.; Woodhouse, Connie A.

    2016-01-01

    We developed Columbia River streamflow reconstructions using a network of existing, new, and updated tree-ring records sensitive to the main climatic factors governing discharge. Reconstruction quality is enhanced by incorporating tree-ring chronologies where high snowpack limits growth, which better represent the contribution of cool-season precipitation to flow than chronologies from trees positively sensitive to hydroclimate alone. The best performing reconstruction (back to 1609 CE) explains 59% of the historical variability and the longest reconstruction (back to 1502 CE) explains 52% of the variability. Droughts similar to the high-intensity, long-duration low flows observed during the 1920s and 1940s are rare, but occurred in the early 1500s and 1630s-1640s. The lowest Columbia flow events appear to be reflected in chronologies both positively and negatively related to streamflow, implying low snowpack and possibly low warm-season precipitation. High flows of magnitudes observed in the instrumental record appear to have been relatively common, and high flows from the 1680s to 1740s exceeded the magnitude and duration of observed wet periods in the late-19th and 20th Century. Comparisons between the Columbia River reconstructions and future projections of streamflow derived from global climate and hydrologic models show the potential for increased hydrologic variability, which could present challenges for managing water in the face of competing demands

  1. A review of the chronologies and geomorphology of the aeolian landforms in the northwestern Negev dunefield (Israel)

    Science.gov (United States)

    Roskin, Joel

    2015-04-01

    The northwestern (NW) Negev Desert dunefield covering an area of only 1,300 km2, comprises the eastern end of the northern Sinai Peninsula - NW Negev erg and is probably the most densely dated dune body in the INQUA Dunes Atlas chronologic database. Over 230 luminescence ages (TL, IRSL, and mainly OSL) and radiocarbon dates have been retrieved over the past course of 20 years from calcic and sandy palaeosols serving as dune substrates, sand sheets, vegetated linear dunes (VLDs), fluvial deposits, and archaeological sites. Despite being from different deposit types and aeolian morphologies, and based on different methodologies, the chronologies usually show good compatibility. By reviewing and reassessing the significance of the Eastern Mediterranean INQUA Dunes Atlas chronologies, along with detailed stratigraphic, structural and geomorphologic data and understandings, the major, and possibly extreme, episodes of aeolian activity and stability are outlined. Repetitive chronostratigraphic sequences in VLDs indicate that this dune type, at least in the Negev, comprises a reliable recorder of main dune mobilization periods. This presentation demonstrates that certain combinations of research finds, using different OSL dating strategies and other regional and local late Quaternary records and in particular aeolian ones, are required assets for providing for acceptable local and regional palaeoclimatic interpretations. The distribution of the VLD chronologies points to rapid mobilization during the Heinrich 1 and Younger Dryas, characterized by powerful winds, though VLDs also form in late Holocene palaeoenvironments. Time slices illustrate the different sensitivities of the studied aeolian landforms to the source, availability, and supply of sediment; long- and short-term climate change, local human-induced environmental changes and also their joint effects, that enable evaluation of aeolian responses to future environmental and climate changes.

  2. Gamma spectrometry for chronology of recent sediments

    International Nuclear Information System (INIS)

    Pittauerova, Daniela

    2013-01-01

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). 210 Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using 210 Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide 226 Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member 222 Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported 210 Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of 214 Pb and 214 Bi towards radioactive equilibrium with 226 Ra in different containers were evaluated for analyses of 226 Ra. Direct analyses of 226 Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important when combined profiles obtained from short

  3. Gamma spectrometry for chronology of recent sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, Daniela

    2013-12-17

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). {sup 210}Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using {sup 210}Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide {sup 226}Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member {sup 222}Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported {sup 210}Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of {sup 214}Pb and {sup 214}Bi towards radioactive equilibrium with {sup 226}Ra in different containers were evaluated for analyses of {sup 226}Ra. Direct analyses of {sup 226}Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important

  4. Dating methods and their relevance in physics

    International Nuclear Information System (INIS)

    Schneider, H.

    1981-01-01

    The article describes some of the most important radiometric clocks. It is pointed out how much the chronological interpretation of isotopic ratios depends on preconceived models about origin and history of investigated minerals. A number of physico-chemical effects are discussed, which give rise to fictitious datings. The possibility is considered that all the radiometric ages used for establishing the geologic time scale might be due to such effects. The history and foundations of the latter are reviewed, and the possibility of a wrong decision is mentioned. Several results from fossil objects indicate very young ages. The usual treatment of anomalous results is criticised. Long-time clocks fails to reproduce documented young ages. It is suggested that in the age interpretation of isotopic ratios much younger than conventional ages be also taken into consideration. The importance of directly dating fossils is stressed. (orig./HP) [de

  5. Asynchronous Glacial Chronologies in the Central Andes (15-40°S) and Paleoclimatic Implications

    Science.gov (United States)

    Zech, R.; Kull, C.; Kubik, P. W.; Veit, H.

    2006-12-01

    We have established glacial chronologies along a N-S transect over the Central Andes using 10Be surface exposure dating. Our results show that maximum glacial advances occurred asynchronously and reflect the varying influence and shifts of the major atmospheric circulation systems during the Late Quaternary: the tropical circulation in the north and the westerlies in the south. In Bolivia (three research areas in the Cordillera Real and the Cordillera Cochabamba, ~15°S) glacial advances could be dated to ~20 and 12 ka BP. This is in good agreement with published exposure age data from moraines in Bolivia and Peru (provided that all ages are calculated following the same scaling system). Accordingly, the maximum glaciation there probably occurred roughly synchronous to the temperature minimum of the global Last Glacial Maximum (LGM) and the lateglacial cold reversals. Strict correlation with neither the Younger Dryas in the northern hemisphere, nor the Antarctic Cold Reversal is possible due to the current systematic exposure age uncertainties (~10%). Glacier-Climate-Modelling corroborates the sensitivity of the reconstructed glaciers to temperature changes, rather than precipitation. On the contrary, there is good evidence for the dominant role of precipitation changes on the glacial chronologies in the lee of the Cordillera Occidental, i.e. on the Altiplano and further south. The pronounced lateglacial wet phase, which is well documented in lake transgression phases as far south as 28°S (-> tropical moisture source), seems to have caused glacial advances even at ~30°S. In two research areas in Chile at that latitude, we were able to date several lateglacial moraines. Besides, the maximum datable glaciation there occurred at ~30 ka BP. That is significantly earlier than the LGM (sensu strictu) and points to favourable climate conditions for glaciation at that time (particularly increased precipitation). We conclude that the westerlies were more intensive or

  6. Understanding Teen Dating Violence

    Science.gov (United States)

    Understanding Teen Dating Violence Fact Sheet 2014 Dating violence is a type of intimate partner violence. It occurs between two people in a close relationship. The nature of dating violence can be physical, emotional, or sexual. • Physical— This ...

  7. Teen Dating Violence

    Science.gov (United States)

    ... Room Social Media Publications Injury Center Teen Dating Violence Recommend on Facebook Tweet Share Compartir On This ... serious forms of violence. What is teen dating violence? Teen Dating Violence [550 KB, 2 Pages, 508] ...

  8. Chronology of awareness about US National Park external threats.

    Science.gov (United States)

    Shafer, Craig L

    2012-12-01

    The objective of this paper is to raise understanding of the history of protected area external threat awareness in the United States and at World Protected Area Congresses. The earliest concerns about external threats to US national parks began in the late nineteenth century: a potential railroad transgression of Yellowstone National Park in the 1880s. During the early and mid 1930s, George Wright and colleagues focused on outside boundary concerns like of hunting and trapping of furbearers, grazing, logging, disease and hybridization between species. In the 1960s, a worldwide recognition began about the role of outside habitat fragmentation/isolation on nature reserves and human generated stressors crossing their boundaries. The State of the Park Report 1980 added a plethora of threats: oil/gas and geothermal exploration and development, hydropower and reclamation projects, urban encroachment, roads, resorts, and recreational facilities. The early 1980s ushered in political interference with NPS threats abatement efforts as well as Congressional legislative initiatives to support the abatement challenges of the agency. By 1987, the Government Accounting Office issued its first report on National Park Service (NPS) progress in dealing with external threats. Climate change impacts on parks, especially in terms of animals adjusting their temperature and moisture requirements by latitude and altitude, surfaced in the technical literature by the mid-1980s. By 1992, the world parks community stressed the need to integrate protected areas into the surrounding landscape and human community. The importance of the matrix has gradually gained appreciation in the scientific community. This chronology represents one example of national park and protected areas' institutional history contributing to the breath of modern conservation science.

  9. 24 CFR 220.811 - Date of default.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Date of default. 220.811 Section... and Obligations-Projects Insured Project Improvement Loans § 220.811 Date of default. For the purposes of §§ 220.800 et seq., the date of default shall be considered as: (a) The date of the first...

  10. Radiocarbon dating of sediment cores from Hachinohe, the Kamikita Plain

    International Nuclear Information System (INIS)

    Hitoki, Eri; Nakamura, Toshio; Matsumoto, Yui; Tsuji, Sei-ichiro; Fujine, Hisashi

    2013-01-01

    We investigated stratigraphy and chronology by analyses of Holocene sediments and radiocarbon dating of sediment cores from the Kamikita Plain. On the Kamikita Plain, which faces the Pacific coast of Northeast Japan, marine and fluvial terraces covered with tephras derived from Towada and Hakkoda volcanoes are well developed. We clarified that Towada Chuseri tephra and fluvial deposits consisted of volcanic sediments influenced an alluvial depositional system in the Kamikita Plain after a maximum of the Jomon Transgression. (author)

  11. Late Quaternary extinctions: The promise of TAMS 14C dating

    International Nuclear Information System (INIS)

    Martin, P.S.

    1987-01-01

    In the last 30 000 years late Quaternary extinctions eliminated over two-thirds of the large land mammals of America and Australia and most of the endemic land vertebrates on oceanic islands. Specimens of extinct animals yielding too little organic material for measurement in decay counters are suitable for TAMS dating. Initial results support older evidence of an extinction chronology that was catastrophic regionally, transgressive globally, and linked to the spread of prehistoric people. (orig.)

  12. Calibration of C-14 dates: some remaining uncertainties and limitations

    International Nuclear Information System (INIS)

    Burleigh, R.

    1975-01-01

    A brief review is presented of the interpretation of radiocarbon dates in terms of calendar years. An outline is given of the factors that make such correlations necessary and of the work that has so far been done to make them possible. The calibration of the C-14 timescale very largely depends at present on the bristlecone pine chronology, but it is clear that many detailed uncertainties still remain. These are discussed. (U.K.)

  13. From up to date climate and ocean evidence with updated UN emissions projections, the time is now to recommend an immediate massive effort on CO2.

    Science.gov (United States)

    Carter, Peter

    2017-04-01

    This paper provides further compelling evidence for 'an immediate, massive effort to control CO2 emissions, stopped by mid-century' (Cai, Lenton & Lontzek, 2016). Atmospheric CO2 which is above 405 ppm (actual and trend) still accelerating, despite flat emissions since 2014, with a 2015 >3ppm unprecedented spike in Earth history (A. Glikson),is on the worst case IPCC scenario. Atmospheric methane is increasing faster than its past 20-year rate, almost on the worst-case IPCC AR5 scenario (Global Carbon Project, 2016). Observed effects of atmospheric greenhouse gas (GHG) pollution are increasing faster. This includes long-lived atmospheric GHG concentrations, radiative forcing, surface average warming, Greenland ice sheet melting, Arctic daily sea ice anomaly, ocean heat (and rate of going deeper), ocean acidification, and ocean de-oxygenation. The atmospheric GHG concentration of 485 ppm CO2 eq (WMO, 2015) commits us to 'about 2°C' equilibrium (AR5). 2°C by 2100 would require 'substantial emissions reductions over the next few decades' (AR5). Instead, the May 2016 UN update on 'intended' national emissions targets under the Paris Agreement projects global emissions will be 16% higher by 2030 and the November 2016 International Energy Agency update projects energy-related CO2 eq emissions will be 30% higher by 2030, leading to 'around 2.7°C by 2100 and above 3°C thereafter'. Climate change feedback will be positive this century and multiple large vulnerable sources of amplifying feedback exist (AR5). 'Extensive tree mortality and widespread forest die-back linked to drought and temperature stress have been documented on all vegetated continents' (AR5). 'Recent studies suggest a weakening of the land sink, further amplifying atmospheric growth of CO2' (WMO, 2016). Under all but the best-case IPCC AR5 scenario, surface temperature is projected to increase above 2°C by 2100, which is above 3°C (equilibrium) after 2100, with ocean acidification still increasing at

  14. An aerial radiological survey of Project Gasbuggy and surrounding area, Rio Arriba County, New Mexico. Date of survey: October 27, 1994

    International Nuclear Information System (INIS)

    1995-08-01

    An aerial radiological survey was conducted over the Project Gasbuggy site, 55 miles (89 kilometers) east of Farmington, New Mexico, on October 27, 1994. Parallel lines were flown at intervals of 300 feet (91 meters) over a 16-square-mile (41-square-kilometer) area at a 150-foot (46-meter) altitude centered on the Gasbuggy site. The gamma energy spectra obtained were reduced to an exposure rate contour map overlaid on a high altitude aerial photograph of the area. The terrestrial exposure rate varied from 14 to 20 microR/h at 1 meter above ground level. No anomalous or man-made isotopes were found

  15. OU3 sediment dating and sedimentation rates

    International Nuclear Information System (INIS)

    Blair, R.B.; Wolaver, H.A.; Burger, V.M.

    1994-01-01

    Environmental Technologies at Rocky Flats Environmental Technology Site (RFS) investigated the sediment history of Standley Lake, Great Western Reservoir, and Mower Reservoir using 137 Cs and 239,240 Pu global fall-out as dating indicators. These Colorado Front Range reservoirs have been the subject of study by various city, state and national agencies due to suspected Department of Energy Rocky Flats Plant impacts. We performed sediment dating as part of the RCRA Facility Investigation/Remedial Investigation Report for Operable Unit 3. A sediment chronology profile assists scientist in determining the year of sedimentation for a particular peak concentration of contaminants. Radioisotope sediment dating for the three reservoirs indicated sedimentation rates of 0.7 to 0.8 in./yr. for Standley Lake (SL), 0.9 in./yr. for Great Western Reservoir (GWR), and 0.3 in./yr. in Mower Reservoir (MR). RFS sediment dating for Operable Unit 3 compared favorably with the Hardy, Livingston, Burke, and Volchok Standley Lake study. This report describes the cesium/plutonium sediment dating method, estimates sedimentation rates for Operable Unit 3 reservoirs, and compares these results to previous investigations

  16. The Decision to Send Humans Back to the Moon and on to Mars: Space Exploration Initiative History Project

    Science.gov (United States)

    McCurdy, Howard E.

    1992-01-01

    This folder contains working papers collected to date on a NASA-sponsored history project to document the events leading up to the July 20, 1989 speech setting forth the objectives of the Space Exploration Initiative. Included are a chronology of events, briefing papers produced by the NASA Working Group laying out proposal, briefing charts used to present the proposal, a copy of the President's speech, and an essay summarizing the events that led up to the announcement. Additionally, two fo the interviews conducted as part of the project are enclosed.

  17. Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America.

    Science.gov (United States)

    Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

    2014-07-15

    Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910-1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing.

  18. Application of Bomb Radiocarbon Chronologies to Shortfin Mako (Isurus oxyrinchus)

    Energy Technology Data Exchange (ETDEWEB)

    Ardizzone, D; Cailliet, G M; Natanson, L J; Andrews, A H; Kerr, L A; Brown, T A

    2007-07-16

    and the number of samples for MIA analysis was insufficient for some months. Hence, unequivocal validation of shortfin mako age estimates has yet to be accomplished. Atmospheric testing of thermonuclear devices in the 1950s and 1960s effectively doubled the natural atmospheric radiocarbon ({sup 14}C). The elevated {sup 14}C levels were first recorded in 1957-58, with a peak around 1963. As a consequence, {sup 14}C entered the ocean through gas exchange with the atmosphere at the ocean surface and in terrestrial runoff. Despite variable oceanographic conditions, a worldwide rise of the bomb {sup 14}C signal entered the ocean mixed layer as dissolved inorganic carbon (DIC) in 1957-58. The large amounts of {sup 14}C released from the bomb tests produced a signature that can be followed through time, throughout the marine food web, and into deeper waters. The marked increase of radiocarbon levels was first measured in the DIC of seawater and in biogenic marine carbonates of hermatypic corals in Florida. Subsequently, this record was documented in corals from other regions and in the thallus of rhodoliths. The accumulation of radiocarbon in the hard parts of most marine organisms in the mixed layer (such as fish otoliths and bivalves) was synchronous with the coral time-series. This technique has been used to validate age estimates and longevity of numerous bony fishes to date, as well as to establish bomb radiocarbon chronologies from different oceans. In the first application of this technique to lamnoid sharks, validated annual band-pair deposition in vertebral growth bands for the porbeagle (Lamna nasus) aged up to 26 years. Radiocarbon values from samples obtained from 15 porbeagle caught in the western North Atlantic Ocean (some of which were known-age) produced a chronology similar in magnitude to the reference carbonate chronology for that region. The observed phase shift of about 3 years was attributed to different sources of carbon between vertebrae and those for

  19. Toward an integrated ice core chronology using relative and orbital tie-points

    Science.gov (United States)

    Bazin, L.; Landais, A.; Lemieux-Dudon, B.; Toyé Mahamadou Kele, H.; Blunier, T.; Capron, E.; Chappellaz, J.; Fischer, H.; Leuenberger, M.; Lipenkov, V.; Loutre, M.-F.; Martinerie, P.; Parrenin, F.; Prié, F.; Raynaud, D.; Veres, D.; Wolff, E.

    2012-04-01

    Precise ice cores chronologies are essential to better understand the mechanisms linking climate change to orbital and greenhouse gases concentration forcing. A tool for ice core dating (DATICE [developed by Lemieux-Dudon et al., 2010] permits to generate a common time-scale integrating relative and absolute dating constraints on different ice cores, using an inverse method. Nevertheless, this method has only been applied for a 4-ice cores scenario and for the 0-50 kyr time period. Here, we present the bases for an extension of this work back to 800 ka using (1) a compilation of published and new relative and orbital tie-points obtained from measurements of air trapped in ice cores and (2) an adaptation of the DATICE inputs to 5 ice cores for the last 800 ka. We first present new measurements of δ18Oatm and δO2/N2 on the Talos Dome and EPICA Dome C (EDC) ice cores with a particular focus on Marine Isotopic Stages (MIS) 5, and 11. Then, we show two tie-points compilations. The first one is based on new and published CH4 and δ18Oatm measurements on 5 ice cores (NorthGRIP, EPICA Dronning Maud Land, EDC, Talos Dome and Vostok) in order to produce a table of relative gas tie-points over the last 400 ka. The second one is based on new and published records of δO2/N2, δ18Oatm and air content to provide a table of orbital tie-points over the last 800 ka. Finally, we integrate the different dating constraints presented above in the DATICE tool adapted to 5 ice cores to cover the last 800 ka and show how these constraints compare with the established gas chronologies of each ice core.

  20. Chronology of the Middle to Upper Palaeolithic transition at Abric Romaní, Catalunya.

    Science.gov (United States)

    Camps, Marta; Higham, Thomas

    2012-01-01

    This paper presents new data from Abric Romaní, a key site in the region of Catalunya, northeastern Iberia, which is central to discussions of the transition between the Middle and Upper Palaeolithic in Europe. Until now, the Mid-Upper Paleolithic transition had been dated at the site through samples from the remaining baulk sections of levels A and B (typologically classified as 'earliest Aurignacian' and Mousterian, respectively) at the rear of the rockshelter, which were left from excavations in the late 1900s and early 1910s. We dated samples of bone and charcoal from these remnant sections with accelerator mass spectrometry (AMS) methods. We also analysed several humanly-modified artefacts (bone points and perforated shells) excavated from other areas of the same layers. From the initial series, we obtained ages of c. 20 ka BP (thousands of years before present); much younger than expected if they indeed dated to the early Upper Palaeolithic. We sampled additional material to test the robustness of these initial ages, and older determinations that were more comparable with the chronology outlined by Bischoff et al. (1988, 1994) resulted. All of the old and new results have been compared in a Bayesian model using the new INTCAL09 (14)C calibration dataset. The results appear to confirm the suggestion of some researchers (e.g., Zilhão and d'Errico, 1999) that there was no Aurignacian in the north of Iberia until c. 36,500 BP. The chronometric model shows a good level of agreement between the radiocarbon and U-series chronologies previously obtained, and the new results published in this paper. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Aerial radiological survey of the Washington. Date of survey: July 1982 Public Power Supply System (WPPSS) Nuclear Project and surrounding area, Richland, Washington

    International Nuclear Information System (INIS)

    1983-07-01

    An aerial radiological survey was performed from 14 to 20 July 1982 over a 270-square-kilometer area centered on the Washington Public Power Supply System (WPPSS) Nuclear Project located near Richland, Washington. All gamma ray data were collected by flying parallel lines spaed 152 meters (500 feet) apart at an altitude of 91 meters (300 feet) above ground level. Count rates obtained from the aerial platform were converted to total external exposure rates at 1 meter above the ground and are presented in the form of an isoradiation contour map. The observed exposure rates ranged from 5 to 15 microroentgens per hour (μR/h) with the average background ranging from 9 to 12μR/h. These values include an estimated cosmic ray contribution of 3.7 μR/h. The exposure rates obtained from ground-based measurements taken in background locations within the survey area displayed positive agreement the aerial data

  2. Toward a Last Interglacial Compilation Using a Tephra-based Chronology: a Future Reference For Model-data Comparison

    Science.gov (United States)

    Bazin, L.; Govin, A.; Capron, E.; Nomade, S.; Lemieux-Dudon, B.; Landais, A.

    2017-12-01

    The Last Interglacial (LIG, 129-116 ka) is a key period to decipher the interactions between the different components of the climate system under warmer-than-preindustrial conditions. Modelling the LIG climate is now part of the CMIP6/PMIP4 targeted simulations. As a result, recent efforts have been made to propose surface temperature compilations focusing on the spatio-temporal evolution of the LIG climate, and not only on its peak warmth as previously proposed. However, the major limitation of these compilations remains in the climatic alignment of records (e.g. temperature, foraminiferal δ18O) that is performed to define the sites' chronologies. Such methods prevent the proper discussion of phase relationship between the different sites. Thanks to recent developments of the Bayesian Datice dating tool, we are now able to build coherent multi-archive chronologies with a proper propagation of the associated uncertainties. We make the best use of common tephra layers identified in well-dated continental archives and marine sediment cores of the Mediterranean region to propose a coherent chronological framework for the LIG independent of any climatic assumption. We then extend this precise chronological context to the North Atlantic as a first step toward a global coherent compilation of surface temperature and stable isotope records. Based on this synthesis, we propose guidelines for the interpretation of different proxies measured from different archives that will be compared with climate model parameters. Finally, we present time-slices (e.g. 127 ka) of the preliminary regional synthesis of temperature reconstructions and stable isotopes to serve as reference for future model-data comparison of the up-coming CMIP6/PMIP4 LIG simulations.

  3. Progress in radiocarbon dating

    International Nuclear Information System (INIS)

    Hedges, R.E.M.

    1985-01-01

    The article concerns radiocarbon dating, the most important method for dating in archaeology. The principles and practice of the dating method are described. Recent developments in radiocarbon dating due to technical advances, are discussed, and include radiometric counting of small samples and accelerator mass spectrometry. Carbon isotopes and the environment are also discussed. (U.K.)

  4. An Overview of the Use of Absolute Dating Techniques in Ancient Construction Materials

    Directory of Open Access Journals (Sweden)

    Jorge Sanjurjo-Sánchez

    2016-04-01

    Full Text Available The reconstruction of the chronology of historical buildings is a tricky issue, as usually there are not historical documents that allow the assessment of construction phases, and some materials are hardly reliable for the use of dating techniques (e.g., stone. However, in the last two decades, important advances on the use of absolute dating methods on building materials have increased the possibilities of reconstructing building chronologies, although some advances are still scarcely known among archaeologists and architects. Recent studies performed on several kinds of mortars, fired bricks, mud-bricks, and even stone surfaces have shown that it is possible to date them. Both radiocarbon and luminescence dating have been the most frequently used techniques but others such as archaeomagnetism can also be used in some cases. This paper intends to give an overview of the recent achievements on the use of absolute dating techniques for building materials.

  5. The selection of the American-Polish joint venture projects for the Krakow program and results of the efforts to date

    Energy Technology Data Exchange (ETDEWEB)

    Gyorke, D.F.; Butcher, T.A.

    1995-12-31

    To implement the Krakow Clean Fossil Fuels and Energy Efficiency Program, eight U.S. firms were selected by the U.S. Department of Energy to market their technologies to reduce pollution from low emission sources in Krakow. The eight U.S. firms were selected by a competitive solicitation that required the proposing firms to themselves provide funding to match or exceed the funding provided by the Program. These U.S. firms and their Polish partner companies have begun sales and cooperative work efforts in Krakow, and some have already made initial equipment installations with measurable performance improvements. Following their efforts as part of the Program, these U.S.-Polish joint ventures will market their technologies and achieve the associated environmental benefits elsewhere in Poland and Eastern and Central Europe. As part of the Krakow Program a spreadsheet model was developed to compare technological options for supplying heat to the city by calculation and comparing the heating costs and associated emissions reduction for each option. Comparison of options is made on the basis of the user cost-per-metric ton of equivalent emissions reduction. For all options considered in the Krakow Program, this cost parameter has ranged from -$1469 (best) to $2650 (worst). The costs for technologies associated with the eight projects in the Krakow Program are at the lower end of this range placing these technologies among the most cost effective solutions to the pollution problems from the low emission sources.

  6. Upper Palaeolithic and Mesolithic human fossils from Moravia and Bohemia (Czech Republic) : Some new C-14 dates

    NARCIS (Netherlands)

    Svoboda, JA; Van der Plicht, J; Kuzelka, [No Value; Svoboda, Jiři A.; Kuželka, Vítězslav

    2002-01-01

    New radiocarbon dates from four Moravian and bohemian sites are presented and linked to previous work on the depositional contexts of human fossils at similar sites in the region. Whilst dates from Mladec confirm its early Upper Palaeolithic age, the chronologies of the other three sites require

  7. Nuclear techniques for the analysis and dating of cultural heritage with the tandetron accelerator at the CEDAD

    Directory of Open Access Journals (Sweden)

    Lucio Calcagnile

    2014-12-01

    Full Text Available The Accelerator Mass Spectrometry technique for measuring carbon isotopes and dating artifacts, together with nuclear techniques of ion beam analysis are widely used in the field of cultural heritage owing to the great advantage of their being non-destructive. In Italy, CEDAD - CEntro Di DAtazione e Diagnostica of the University of Salento, with its tandetron accelerator of 3MV, has played a major role for over ten years, in studying materials of cultural assets requiring the determination of their elemental composition and determination of absolute chronology using radiocarbon. This study describes the Accelerator Mass Spectrometry technique used with the accelerator at CEDAD to determine age by means of radiocarbon and PIXE-PIGE techniques, and to determine elements, even in traces, present in materials. Some case studies carried out at CEDAD are reported, including those on the Riace Bronzes and Capitoline Wolf. The latter has been definitively dated to the Middle Ages, 17 centuries later than the previously attributed dating by historians. In addition, an important technical innovation is described, achieved within the framework of the IT@CHA Project enabling organic materials to be dated using only 10 μg of carbon.

  8. Radiocarbon dates to access the origin of the ice man

    Energy Technology Data Exchange (ETDEWEB)

    Niklaus, R. [Institute of Particle Physics, ETH Zurich, Hongerberg (Switzerland)]|[Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Bonani, G. [Institute of Particle Physics, ETH Zurich, Hongerberg (Switzerland); Prinoth-Fornwagner, R. [Innsbruck Univ. (Austria)

    1996-12-31

    Different samples from the Late and Final Neolithic in Northern Italy were radiocarbon dated at the AMS Facility in Zurich, Switzerland in order to determine the origin of the Ice Man from the Hauslabjoch. The cultural classification was obtained on the basis of topological studies of the cooper axe and of the flint dagger as well as studies of artefact materials (the flint or the wood of a composite arrow), while the chronological classification of the Ice Man was obtained with the help of new and old radiocarbon dates. 9 refs., 1 tab., 2 figs.

  9. Radiocarbon dates to access the origin of the ice man

    Energy Technology Data Exchange (ETDEWEB)

    Niklaus, R [Institute of Particle Physics, ETH Zurich, Hongerberg (Switzerland); [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Bonani, G [Institute of Particle Physics, ETH Zurich, Hongerberg (Switzerland); Prinoth-Fornwagner, R [Innsbruck Univ. (Austria)

    1997-12-31

    Different samples from the Late and Final Neolithic in Northern Italy were radiocarbon dated at the AMS Facility in Zurich, Switzerland in order to determine the origin of the Ice Man from the Hauslabjoch. The cultural classification was obtained on the basis of topological studies of the cooper axe and of the flint dagger as well as studies of artefact materials (the flint or the wood of a composite arrow), while the chronological classification of the Ice Man was obtained with the help of new and old radiocarbon dates. 9 refs., 1 tab., 2 figs.

  10. Dating a composite ancient wooden artefact and its modifications. A case study

    International Nuclear Information System (INIS)

    Poldi, G.; Quartana, L.; Galli, A.

    2008-01-01

    The recent restoration of the large wooden doors of the medieval St. Ambrogio Basilica in Milan gave the opportunity for a, broad project of scientific examination, including dating with radiocarbon and dendrochronology. The two doors represented a puzzle for art historians, because of the non-documented modifications occurred during their history. In fact; they are composed of various wooden elements, some of them surely modified with the 1750 jubilee restoration, assembled into three layers. The large number of these elements suggested not to restrict the samples only to the main carved scenes, but to extend them to frames and back-boards, in order to obtain a consistent set. of data, and a more reliable chronology. Analytical campaign oriented to dating, coordinated by Quartana Restauri and LAM (University of Bergamo), took into account the different characteristics of woods, needing 24 samples carefully extracted from hidden areas to be radiocarbon dated by ANIS (Accelerator Mass Spectrometry) at CEDAD (Centre for Dating and Diagnostics, University of Salento, Lecce, Italy) laboratories, and two of them dated at LABEC (Laboratory of nuclear techniques for cultural heritage, University of Florence and INFN, Italy) for comparison. The results obtained for the vertical woods of the back, belonging to Renaissance period, suggested further studies employing dendrochronological analyses based on high-resolution photographs, carried out by CUDaM (University of Milano-Bicocca). ED-XRF (Energy Dispersive X-ray Fluorescence) analyses were also carried on, by LAM, with portable instruments. in order to study the composition of the residues of polychromy, where present.

  11. Chronology protection and the stringy exclusion principle

    Czech Academy of Sciences Publication Activity Database

    Raeymaekers, Joris; Van den Bleeken, D.; Vercnocke, B.

    2011-01-01

    Roč. 2011, č. 4 (2011), 1-41 ISSN 1126-6708 R&D Projects: GA ČR GAP203/11/1388 Grant - others:EUROHORC and ESF(XE) EYI/07/E010 Institutional research plan: CEZ:AV0Z10100502 Keywords : Wilson loop * conformal field theory * membrane model * AdS/CFT * Goedel spacetime * supersymmetry * domain wall * unitarity * causality violation Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.831, year: 2011 http://link.springer.com/article/10.1007%2FJHEP04%282011%29037

  12. Astronautics and aeronautics, 1972. [a chronology of events

    Science.gov (United States)

    1974-01-01

    Important events of the U. S. space program during 1972 are recorded in a chronology which encompasses all NASA, NASA related, and international cooperative efforts in aeronautics and astronautics. Personnel and budget concerns are documented, along with the major developments in aircraft research, manned space flight, and interplanetary exploration.

  13. Chronology of p53 protein accumulation in gastric carcinogenesis

    NARCIS (Netherlands)

    Craanen, M. E.; Blok, P.; Dekker, W.; Offerhaus, G. J.; Tytgat, G. N.

    1995-01-01

    p53 Protein accumulation in early gastric carcinoma was studied in relation to the histological type (Lauren classification) and the type of growth pattern, including the chronology of p53 protein accumulation during carcinogenesis. Forty five, paraffin embedded gastrectomy specimens from early

  14. Ages of the solar system: Isotopic dating

    International Nuclear Information System (INIS)

    Turner, G.

    1982-01-01

    The major concern of this section will be to outline the ways in which measurements of isotope abundances have been used to determine the chronology of the origin and evolution of the solar system. In passing it should be remembered that the use of isotopic information is by no means restricted simply to the measurement of time scales and, particularly in recent years, isotope abundances have been used to investigate problems as diverse as the heat sources in the early solar nebula and the chemical evolution of the Earth's mantle. The fundamental property of isotopes which makes them especially useful for dating and other applications is the fact that, apart from a limited amount of mass fractionation, the composition of an isotopic mixture is unaffected by chemical processes. In those cases where mass fractionation does occur this effect may itself be useful, particularly as a source of information on temperatures. Since our main theme is time the events discussed in this section will be most conveniently presented as a chronological sequence, progressing from some time before the solar system existed down to the present day. (orig./WL)

  15. Tritium Measurements in Slovenia - Chronology Till 2004

    International Nuclear Information System (INIS)

    Logar, Jasmina Kozar; Vaupotic, Janja; Kobal, Ivan

    2005-01-01

    Almost all the analyses of tritium in Slovenia have been performed by the tritium laboratory at the Jozef Stefan Institute. Nearly 90 % of its measurements have been covered by two national programs, both approved by the Slovenian Nuclear Safety Administration: the radioactive monitoring program in the environs of Krsko Nuclear Power Plant (KNPP) and the program of global radioactive contamination monitoring in the environment. These programs include samples of groundwaters, surface waters, precipitation and drinking waters, as well as liquid and gaseous effluents from KNPP. Tritium was determined in some research projects and in hydrological studies of thermal waters, groundwater and coalmine waters. Tritium in the Karst region was mapped as well as the springs of entire territory of Slovenia. Around 5500 samples have been analyzed up to 2004

  16. Chronology of the Acheulean to Middle Stone Age transition in eastern Africa

    Science.gov (United States)

    Deino, Alan L.; Behrensmeyer, Anna K.; Brooks, Alison S.; Yellen, John E.; Sharp, Warren D.; Potts, Richard

    2018-04-01

    The origin of the Middle Stone Age (MSA) marks the transition from a highly persistent mode of stone toolmaking, the Acheulean, to a period of increasing technological innovation and cultural indicators associated with the evolution of Homo sapiens. We used argon-40/argon-39 and uranium-series dating to calibrate the chronology of Acheulean and early MSA artifact–rich sedimentary deposits in the Olorgesailie basin, southern Kenya rift. We determined the age of late Acheulean tool assemblages from 615,000 to 499,000 years ago, after which a large technological and faunal transition occurred, with a definitive MSA lacking Acheulean elements beginning most likely by ~320,000 years ago, but at least by 305,000 years ago. These results establish the oldest repository of MSA artifacts in eastern Africa.

  17. State conservation and chronological contextualization of the Bone Collection 'Gustavo Le Paige'

    International Nuclear Information System (INIS)

    Hubbe, Mark; Oviedo, Macarena; Torres-Rouff

    2011-01-01

    Between the 1950s and 1970s Father Gustavo Le Paige excavated one of the largest osteological collections of Latin America, attracting the attention of numerous researchers over the past 40 years. In his field notes, Le Paige recorded the excavation of 5482 skulls and human bodies deposited in the Instituto de Investigaciones Arqueologicas y Museo of the Universidad Catolica del Norte (San Pedro de Atacama). However, cumulative processes of abandonment and the lack of preventive conservation resulted in the loss of context and a decrease in the quality of preservation of a significant portion of this skeletal collection. Here, we present the current state of preservation of this collection, and 50 new radiocarbon dates that helps the chronological contextualization of 21 of the larger and more representative cemeteries in the Le Paige collection

  18. Chronology of the Acheulean to Middle Stone Age transition in eastern Africa.

    Science.gov (United States)

    Deino, Alan L; Behrensmeyer, Anna K; Brooks, Alison S; Yellen, John E; Sharp, Warren D; Potts, Richard

    2018-04-06

    The origin of the Middle Stone Age (MSA) marks the transition from a highly persistent mode of stone toolmaking, the Acheulean, to a period of increasing technological innovation and cultural indicators associated with the evolution of Homo sapiens We used argon-40/argon-39 and uranium-series dating to calibrate the chronology of Acheulean and early MSA artifact-rich sedimentary deposits in the Olorgesailie basin, southern Kenya rift. We determined the age of late Acheulean tool assemblages from 615,000 to 499,000 years ago, after which a large technological and faunal transition occurred, with a definitive MSA lacking Acheulean elements beginning most likely by ~320,000 years ago, but at least by 305,000 years ago. These results establish the oldest repository of MSA artifacts in eastern Africa. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  19. A Companion to Astronomy and Astrophysics Chronology and Glossary with Data Tables

    CERN Document Server

    Lang, Kenneth R

    2006-01-01

    Astronomy and Astrophysics is a comprehensive, fundamental, up-to-date reference book. It is filled with vital information and basic facts for amateur astronomers and professional astrophysicists, and for anyone interested in the Universe, from the Earth and other planets to the stars, galaxies and beyond. Although serious and thorough, the language, and ideas will attract the general reader, as well as students and professionals. Astronomy and Astrophysics consists of two main parts, a Timeline and a Dictionary. The Timeline is a concise history, arranged chronologically, which provides the complete story of cosmic discovery from early Chinese and Greek astronomy to the latest findings of modern astrophysics and robotic spacecraft. It provides a sense of destination and flow in our growing awareness of the Universe. Each entry in the unfolding narrative is written in a concise, light and friendly style that will be appreciated by all, without being weighted down with incomprehensible specialized terms. The s...

  20. Primary Dental Care 1994-2004: the first ten years. A chronology.

    Science.gov (United States)

    Renson, Ted

    2004-10-01

    The prime purpose of a professional journal is to keep its readers informed of changes of importance affecting the practise of that profession. That is the criterion that I have applied in producing this chronology of the papers that have been published in Primary DENTAL CARE during the past decade. The ambition which has guided me since I received the invitation to carry out this review is a simple one: to include as much as may generally be found useful by general dental practitioners (GDPs), who form the bulk of our readership. In 1789 the English philosopher Jeremy Bentham extolled the virtues of utility for mankind when he declared that 'the greatest happiness of the greatest number is the foundation of morals and legislation'. The contributors that I have included, by contrast, think of their utilitarianism as striving after the most practical. The principal purpose of this chronology is to achieve a summary, without weighing causes or consequences. From past experience, an outstanding virtue of such an aggregated record is that it can inspire fresh patterns of thought and thus encourage the submission of manuscripts as a result of those thoughts. I can think of scarcely any facet of the general practice of dentistry that has not been touched upon, for the most part authoritatively. I hope that these brief aide-memoires may persuade old readers to return to those articles of particular interest to them and that new readers will feel informed about past papers. Every issue of the journal to date has been reviewed. Dates, volume and issue numbers and principal authors' names are all included. With these identifying features any paper, to which reference is made, may be quickly found. It would be manifestly absurd to use precious space on a formal listing of more than 250 references and this listing has, therefore, been omitted.

  1. Quantifying bamboo coral growth rate nonlinearity with the radiocarbon bomb spike: A new model for paleoceanographic chronology development

    Science.gov (United States)

    Frenkel, M. M.; LaVigne, M.; Miller, H. R.; Hill, T. M.; McNichol, A.; Gaylord, M. Lardie

    2017-07-01

    Bamboo corals, long-lived cold water gorgonin octocorals, offer unique paleoceanographic archives of the intermediate ocean. These Isididae corals are characterized by alternating gorgonin nodes and high Mg-calcite internodes, which synchronously extend radially. Bamboo coral calcite internodes have been utilized to obtain geochemical proxy data, however, growth rate uncertainty has made it difficult to construct precise chronologies for these corals. Previous studies have relied upon a single tie point from records of the anthropogenic Δ14C bomb spike preserved in the gorgonin nodes of live-collected corals to calculate a mean radial extension rate for the outer 50 years of skeletal growth. Bamboo coral chronologies are typically constructed by applying this mean extension rate to the entire coral record, assuming constant radial extension with coral age. In this study, we aim to test this underlying assumption by analyzing the organic nodes of six California margin bamboo corals at high enough resolution (bomb spike, including two tie points at 1957 and 1970, plus the coral collection date (2007.5) for four samples. Radial extension rates between tie points ranged from 10 to 204 μm/year, with a decrease in growth rate evident between the 1957-1970 and 1970-2007.5 periods for all four corals. A negative correlation between growth rate and coral radius (r =-0.7; p=0.04) was determined for multiple bamboo coral taxa and individuals from the California margin, demonstrating a decline in radial extension rate with specimen age and size. To provide a mechanistic basis for these observations, a simple mathematical model was developed based on the assumption of a constant increase in circular cross sectional area with time to quantify this decline in radial extension rate with coral size between chronological tie points. Applying the area-based model to our Δ14C bomb spike time series from individual corals improves chronology accuracy for all live-collected corals

  2. A new method for measuring bioturbation rates in sandy tidal flat sediments based on luminescence dating

    DEFF Research Database (Denmark)

    Madsen, Anni T.; Murray, Andrew S.; Jain, Mayank

    2011-01-01

    The rates of post-depositional mixing by bioturbation have been investigated using Optically Stimulated Luminescence (OSL) dating in two sediment cores (BAL2 and BAL5), retrieved from a sandy tidal flat in the Danish part of the Wadden Sea. A high-resolution chronology, consisting of thirty-six OSL...

  3. The dating and interpretation of a Mode 1 site in the Luangwa Valley, Zambia

    DEFF Research Database (Denmark)

    Barham, Lawrence; Phillips, William M.; Maher, Barbara A.

    2011-01-01

    depositional history of the site prevented the calculation of reliable age models. A relative chronology for the full Manzi sequence was constructed, however, from the magnetostratigraphy of the deposit (N>R>N sequence). Isothermal thermoluminescence (ITL) dating of the upper Mode 3 layers also provided...

  4. Projectables

    DEFF Research Database (Denmark)

    Rasmussen, Troels A.; Merritt, Timothy R.

    2017-01-01

    CNC cutting machines have become essential tools for designers and architects enabling rapid prototyping, model-building and production of high quality components. Designers often cut from new materials, discarding the irregularly shaped remains. We introduce ProjecTables, a visual augmented...... reality system for interactive packing of model parts onto sheet materials. ProjecTables enables designers to (re)use scrap materials for CNC cutting that would have been previously thrown away, at the same time supporting aesthetic choices related to wood grain, avoiding surface blemishes, and other...... relevant material properties. We conducted evaluations of ProjecTables with design students from Aarhus School of Architecture, demonstrating that participants could quickly and easily place and orient model parts reducing material waste. Contextual interviews and ideation sessions led to a deeper...

  5. Late Otiran sedimentation and glacial chronology in the Warwick valley, southeast Nelson

    International Nuclear Information System (INIS)

    Mabin, M.C.G.

    1983-01-01

    Approximately 14 m of sediment are exposed in a road cutting beneath a landslide deposit in the Warwick valley, southeast Nelson, New Zealand. Three radiocarbon dates and 5 pollen spectra were obtained from organic horizons in these sediments. The dates indicate that lacustrine sedimentation predominated from before 17 500 until 14 450 years ago. This was interrupted by a brief period of gravel aggradation between 17 500 and 16 650 years ago, which is attributed to a glacial advance. Vegetation at the site was consistently dominated by Cyperaceae, with some Gramineae, suggesting a bleak, treeless landscape. Correlation of this information with other radiocarbon dated sites indicates the need for some revision of the chronology of the late Otira Glaciation. A late phase of the Kumara 2 2 advance occurred between 17 000 and 16 000 years ago, and the Kumara 3 1 advance did not occur until after about 15 000 years ago. The end of the Otira Glaciation probably occurred between 13 000 and 12 500 years ago. (auth)

  6. Late Otiran sedimentation and glacial chronology in the Warwick valley, southeast Nelson

    Energy Technology Data Exchange (ETDEWEB)

    Mabin, M C.G. [Canterbury Univ., Christchurch (New Zealand). Dept. of Geology

    1983-01-01

    Approximately 14 m of sediment are exposed in a road cutting beneath a landslide deposit in the Warwick valley, southeast Nelson, New Zealand. Three radiocarbon dates and 5 pollen spectra were obtained from organic horizons in these sediments. The dates indicate that lacustrine sedimentation predominated from before 17,500 until 14,450 years ago. This was interrupted by a brief period of gravel aggradation between 17,500 and 16,650 years ago, which is attributed to a glacial advance. Vegetation at the site was consistently dominated by Cyperaceae, with some Gramineae, suggesting a bleak, treeless landscape. Correlation of this information with other radiocarbon dated sites indicates the need for some revision of the chronology of the late Otira Glaciation. A late phase of the Kumara 2/sub 2/ advance occurred between 17,000 and 16,000 years ago, and the Kumara 3/sub 1/ advance did not occur until after about 15,000 years ago. The end of the Otira Glaciation probably occurred between 13,000 and 12,500 years ago.

  7. Optical dating of dune ridges on Rømø

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, A. S.; Andersen, Thorbjørn Joest

    2007-01-01

    The application of optically stimulated luminescence (OSL) to the dating of recent aeolian sand ridges on Rømø, an island off the southwest coast of Denmark, is tested. These sand ridges began to form approximately 300 years ago, and estimates of the ages are available from historical records....... Samples for OSL dating were taken ~0.5 m below the crests of four different dune ridges; at least five samples were recovered from each ridge to test the internal consistency of the ages. Additional samples were recovered from the low lying areas in the swales and from the scattered dune formations......-defined building phases separated by inactive periods and the first major ridge formed ~235 years ago. This study demonstrates that optical dating can be successfully applied to these young aeolian sand deposits, and we conclude that OSL dating is a powerful chronological tool in studies of coastal change....

  8. Absolute dating of the Aegean Late Bronze Age

    International Nuclear Information System (INIS)

    Warren, P.M.

    1987-01-01

    A recent argument for raising the absolute date of the beginning of the Aegean Late Bronze (LB) Age to about 1700 B.C. is critically examined. It is argued here that: (1) the alabaster lid from Knossos did have the stratigraphical context assigned to it by Evans, in all probability Middle Minoan IIIA, c. 1650 B.C.; (2) the attempt to date the alabastron found in an early Eighteenth Dynasty context at Aniba to Late Minoan IIIA:1 is open to objections; (3) radiocarbon dates from Aegean LB I contexts are too wide in their calibrated ranges and too inconsistent both within and between site sets to offer any reliable grounds at present for raising Aegean LB I absolute chronology to 1700 B.C. Other evidence, however, suggests this period began about 1600 B.C., i.e. some fifty years earlier than the conventional date of 1550 B.C. (author)

  9. Architecture, cobbled roads and chronology of the main sector of the site Las Mercedes-1, Central Caribbean of Costa Rica

    International Nuclear Information System (INIS)

    Vazquez Leiva, Ricardo; Chapdelaine, Claude

    2008-01-01

    Results from test-pit excavations, survey, and mapping at Las Mercedes-1, plus the center of a paramount chiefly polity in the Central Caribbean region of Costa Rica, are presented. Information on architecture, construction system, ceramic chronology, and funerary features, are reported. Radiocarbon dates have suggested that important construction works at the site's center were carried out circa A.D. 1000. Two cobble-paved, causeways, perpendicular to the river drainage system, were found to be linked to the main monumental compound as roads for formal access. Interest in the site has been revived and points the way to further researches at the site and its regional sphere. (author) [es

  10. Developing a visual moraine classification scheme to support investigations into the Holocene glacier chronology of the Southern Alps, New Zealand

    Science.gov (United States)

    Kaufung, Eva; Winkler, Stefan

    2014-05-01

    The Southern Alps of New Zealand have provided one of only a few suitable study sites for investigating Holocene glacier chronologies in the mid-latitudinal Southern Hemisphere. Although a considerable number of studies have been conducted during the past few decades, these generally focus on a very limited number of glacier forelands. Additionally, those glaciers studied have often been selected because of their accessibility rather than their representativeness for the whole region. A common drawback of many regional studies is the lack of attention to glacial geomorphology and the mode of moraine formation with the dating of such landforms in chronological context. With the Southern Alps characterized by very dynamic geomorphological process-systems and a high seismic activity, this seems unfortunate as it causes a relatively high potential "geomorphological uncertainty" with any published glacier chronology and its subsequent palaeoclimatological interpretation. Future investigations into the Holocene glacier chronology in the Southern Alps need to address those existing shortcomings and, consequently, should achieve a representative spatial distribution of study sites in order to overcome the current strong data bias towards few, albeit relatively well-studied glacier forelands. The specific regional geomorphological environment of the Southern Alps requires, furthermore, a thorough assessment of any moraine selected for the subsequent dating in consideration of its "reliability" if it is considered as evidence of specific former glacier variations. With more than 3000 potential glacier forelands in the entire mountain range, careful selection of future targets for successful chronological field work is essential. We present the preliminary results of an ongoing, time-efficient study to apply different remote sensing sources (aerial photography, Google Earth, satellite images) to evaluate the potential of certain glacier forelands for detailed ground

  11. A 481-year chronology of oak earlywood vessels as an age-independent climatic proxy in NW Iberia

    Science.gov (United States)

    Souto-Herrero, Manuel; Rozas, Vicente; García-González, Ignacio

    2017-08-01

    The earlywood vessels of ring-porous trees can be analyzed dendrochronologically and used as a proxy for environmental information. However, most works deal with the analysis of contemporary climate-growth relationships and do not evaluate their long-term variation. We obtained a 481-year chronology of earlywood vessel size of oak (Quercus robur L.) in the northwestern Iberian Peninsula, investigated its behavior through time, and compared it to a chronology of younger trees developed at the same site. We expressed earlywood vessel size as the hydraulically-weighted diameter (DH) and discriminated between vessels in the first row (r1) and the rest of the vessels (nr1); radial increment was assessed from latewood width (LW). Climate-growth relationships were strong and nearly identical for both age classes. Spring temperature positively affected vessel size, but only for the first row, probably mediating the onset of cambial activity. The chronology of old trees showed an almost flat age trend, except for the first decades, and series were not affected by stand dynamics. In contrast, LW had a weak response to climate, probably because of the high impact of abrupt growth changes. There was a high negative correlation between DH and the winter North Atlantic Oscillation Index (NAO), which was unstable during the 20th century. To our knowledge, this is the longest chronology of earlywood vessel size obtained to date, and offers promising results, as this proxy is shown to be independent of age and forest disturbances, and was strongly correlated to climate across long time spans.

  12. Dating ancient monuments by nuclear radiation

    International Nuclear Information System (INIS)

    Goedicke, C.

    2000-01-01

    In the fifties and sixties several disciplines dealing with chronologies but lacking precise methods of measurements (geology, biology, archaeology and art history) became aware of the radioactive decay as a tool of measuring elapsed time. Among the disciplines that benefit most from physical methods archaeology has to be named first. So was archaeological work revolutionised by the introduction of the C-14 dating method. A wider selection of material became datable after the introduction of luminescence techniques using the effect of nuclear radiation on semiconductors. These minerals are widespread among archaeological materials. In ancient monuments, the objective of this paper, semiconductors almost exclusively form the material basis. Over the last four millennia wood, stone, mortar and fired bricks have been used for the construction of buildings. After discussing methods taking wood as a dating material, a broader view will be given on the results achieved by luminescence dating of fired bricks, mortar and stone. For many years brick dating was performed by thermoluminescence, the recipes followed those of ceramic dating. Preferably multiple aliquot additive dose protocols were used on polymineral fine grain fractions (1-10 μm). It was expected that the error in dating monuments would be smaller compared to ceramic dating, because of the constancy of the environmental conditions which a brick experiences during its lifetime. However, the variability of firing temperatures in brick kilns overthrows this advantage. Therefore, the demands of art historians to fall short of an error margin of 5% could generally not be fulfilled. Especially in medieval or renaissance times the temporal resolution of thermoluminescence is inferior to traditional stylistic dating as long as specific stylistic forms are present. New optical luminescence techniques and a new philosophy of dose evaluation, based on single aliquot regeneration protocols, produce less scatter, and in

  13. On the Chronological Aspect of Productive Economy Origin in the Lower Volga Region

    Directory of Open Access Journals (Sweden)

    Vybornov Aleksandr A.

    2016-09-01

    Full Text Available The Lower Volga region territory plays a large part in studying the origin of producing economy. It is particularly important to determine the time of this process commencement. The researchers assumed the coexistence of the late Neolithic and Early Eneolithic monuments in this area. On that basis they highlighted the Neo-Eneolithic period. The researchers dated it to the middle of the 5 millennium BC. They associated this period and the emergence of producing economy at the territory under discussion. The weak point of this hypothesis was a small number of radiocarbon dates on this issue. Obtained after 2007, the radiocarbon dates on the Neolithic and Eneolithic monuments in the Lower Volga region demonstrate a 500-year chronological gap between them. That is why the hypothesis of the Neo-Eneolithic period is not confirmed. At the same time there is a reason to believe that the Late Neolithic and the Caspian Sea region culture coexisted during 5800-5500 BC. However, the referring of the Caspian Sea region culture to the Eneolithic suffers from the lack of evidence that its carriers were familiar with metal. There is also no evidence that they had cattle breeding. The situation changed after studying the Oroshaemoye I archaeological site in the Lower Volga region in 2014-2015. Cultural layer with materials from only the Caspian Sea region culture was found there. This increases the significance of the monument. The bones of domestic sheep and goats were found in this cultural layer. This is the first significant evidence of producing economy existing among the population of the Lower Volga region. AMS radiocarbon dates 4800 and 4700 BC were obtained from domestic sheep bones from this site. Thus, it is possible to make a reasoned conclusion that producing economy had being formed in the Lower Volga region among the carriers of the Caspian Sea region culture. This process can be reliably dated to the beginning of the 5 millennium BC.

  14. An optical age chronology of late Quaternary extreme fluvial events recorded in Ugandan dambo soils

    Science.gov (United States)

    Mahan, S.A.; Brown, D.J.

    2007-01-01

    There is little geochonological data on sedimentation in dambos (seasonally saturated, channel-less valley floors) found throughout Central and Southern Africa. Radiocarbon dating is problematic for dambos due to (i) oxidation of organic materials during dry seasons; and (ii) the potential for contemporary biological contamination of near-surface sediments. However, for luminescence dating the equatorial site and semi-arid climate facilitate grain bleaching, while the gentle terrain ensures shallow water columns, low turbidity, and relatively long surface exposures for transported grains prior to deposition and burial. For this study, we focused on dating sandy strata (indicative of high-energy fluvial events) at various positions and depths within a second-order dambo in central Uganda. Blue-light quartz optically stimulated luminescences (OSL) ages were compared with infrared stimulated luminescence (IRSL) and thermoluminescence (TL) ages from finer grains in the same sample. A total of 8 samples were dated, with 6 intervals obtained at ???35, 33, 16, 10.4, 8.4, and 5.9 ka. In general, luminescence ages were stratigraphically, geomorphically and ordinally consistent and most blue-light OSL ages could be correlated with well-dated climatic events registered either in Greenland ice cores or Lake Victoria sediments. Based upon OSL age correlations, we theorize that extreme fluvial dambo events occur primarily during relatively wet periods, often preceding humid-to-arid transitions. The optical ages reported in this study provide the first detailed chronology of dambo sedimentation, and we anticipate that further dambo work could provide a wealth of information on the paleohydrology of Central and Southern Africa. ?? 2006 Elsevier Ltd. All rights reserved.

  15. Language evolution and human history: what a difference a date makes

    OpenAIRE

    Gray, Russell D.; Atkinson, Quentin D.; Greenhill, Simon J.

    2011-01-01

    Historical inference is at its most powerful when independent lines of evidence can be integrated into a coherent account. Dating linguistic and cultural lineages can potentially play a vital role in the integration of evidence from linguistics, anthropology, archaeology and genetics. Unfortunately, although the comparative method in historical linguistics can provide a relative chronology, it cannot provide absolute date estimates and an alternative approach, called glottochronology, is fund...

  16. Using design science and artificial intelligence to improve health communication: ChronologyMD case example.

    Science.gov (United States)

    Neuhauser, Linda; Kreps, Gary L; Morrison, Kathleen; Athanasoulis, Marcos; Kirienko, Nikolai; Van Brunt, Deryk

    2013-08-01

    This paper describes how design science theory and methods and use of artificial intelligence (AI) components can improve the effectiveness of health communication. We identified key weaknesses of traditional health communication and features of more successful eHealth/AI communication. We examined characteristics of the design science paradigm and the value of its user-centered methods to develop eHealth/AI communication. We analyzed a case example of the participatory design of AI components in the ChronologyMD project intended to improve management of Crohn's disease. eHealth/AI communication created with user-centered design shows improved relevance to users' needs for personalized, timely and interactive communication and is associated with better health outcomes than traditional approaches. Participatory design was essential to develop ChronologyMD system architecture and software applications that benefitted patients. AI components can greatly improve eHealth/AI communication, if designed with the intended audiences. Design science theory and its iterative, participatory methods linked with traditional health communication theory and methods can create effective AI health communication. eHealth/AI communication researchers, developers and practitioners can benefit from a holistic approach that draws from theory and methods in both design sciences and also human and social sciences to create successful AI health communication. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Energy history chronology from World War II to the present

    Energy Technology Data Exchange (ETDEWEB)

    Dean, P.C.

    1982-08-01

    This report provides a basic guide to the major Presidential, Legislative, Judicial, and Federal agency actions relating to energy policy, research, development, and regulation in recent years. The chronology is arranged synoptically, allowing users to reference easily the historical context in which each event occurred. Summaries of Presidential, Legislative, and Judicial actions relating to energy, rosters of federal energy officials, and a genealogy of federal energy agencies are also provided in separate appendices. The Energy History Chronology was prepared in conjunction with the History Division's series of pamphlets on the Institutional Origins of the Department of Energy. The series includes concise histories of the Department of Energy, the Energy Research and Development Administration, the Federal Energy Administration, and the Atomic Energy Commission. All significant events and achievements noted in the institutional history are also listed.

  18. Chronology and development of the Chalcolithic necropolis of Varna I

    Directory of Open Access Journals (Sweden)

    Raiko Krauß

    2018-01-01

    Full Text Available In the following paper, we present the main results of our now completed studies of the Varna I cemetery, based on the excavations undertaken by Ivan Ivanov in the years 1972–1991. The richness of the assemblages is singular in Old World prehistory. To tackle the question of its inter­nal, chronological development, we applied correspondence analysis (CA to a newly created database that includes the inventories of all presently known graves, symbolic burials and find de­posits. The rank order of the seriated inventories was used to establish a CA-based 14C-age model for wiggle matching. In combination with topographic observations and social network analysis (SNA, our studies provide a new understanding both of the chronological and spatial distribution of the graves and burial goods, as well as new insights into the social structure, gender roles, individual relation­ships and ritual practices of the Chalcolithic community.

  19. The Creation of the world and the birth of chronology

    Science.gov (United States)

    Richet, Pascal

    2017-09-01

    The eternity of the world and, correlatively, the cyclical nature of time were agreed upon by all Greek philosophical schools except the Platonists. As for matter, all of them posited that it was eternal so that the idea that something could be made from nothing was considered as pure absurdity. With the advent of Christianity, however, a matter coeternal with God raised fundamental theological difficulties. Toward the end of the second century, apologists such as Tatian the Assyrian, Theophilus of Antioch, Irenaeus of Lyons or Tertullian thus emphasized God's absolute freedom and power by claiming that Creation had been made from nothing. Along with the Passion of Christ and the Last Judgment, the initial moment defined by the Creation then conferred to time an irreversible, linear orientation and to history both a new sense and an obsessing concern for chronology. Unambiguously, the Creation became the reference point for the world's history. From Scripture analyses, one determined that it took place about 5500 years earlier within a framework where the History of man and that of the earth were not distinct. Having designed a consistent, universal time scale from chronological data recorded for all ancient peoples, Eusebius of Caesarea could thus attribute to the Great Flood the fossils found on the top of Mount Lebanon. The short Mosaic chronologies were eventually rejected during the 18th century, but Eusebius' chronological procedure was unknowingly transposed when a relative geological timescale was then set up from the fossil record. The close association of Creation with Christian dogma in turn induced some circles to reject the second law of thermodynamics at the end of the 19th century and, a few decades later, the thesis of an expanding universe. In both cases, the reason was that continuously increasing entropy would imply some low-entropy initial state akin to a Creation.

  20. On the use of δ18Oatm for ice core dating

    Science.gov (United States)

    Extier, Thomas; Landais, Amaelle; Bréant, Camille; Prié, Frédéric; Bazin, Lucie; Dreyfus, Gabrielle; Roche, Didier M.; Leuenberger, Markus

    2018-04-01

    Deep ice core chronologies have been improved over the past years through the addition of new age constraints. However, dating methods are still associated with large uncertainties for ice cores from the East Antarctic plateau where layer counting is not possible. Indeed, an uncertainty up to 6 ka is associated with AICC2012 chronology of EPICA Dome C (EDC) ice core, which mostly arises from uncertainty on the delay between changes recorded in δ18Oatm and in June 21st insolation variations at 65°N used for ice core orbital dating. Consequently, we need to enhance the knowledge of this delay to improve ice core chronologies. We present new high-resolution EDC δ18Oatm record (153-374 ka) and δO2/N2 measurements (163-332 ka) performed on well-stored ice to provide continuous records of δ18Oatm and δO2/N2 between 100 and 800 ka. The comparison of δ18Oatm with the δ18Ocalcite from East Asian speleothems shows that both signals present similar orbital and millennial variabilities, which may represent shifts in the InterTropical Convergence Zone position, themselves associated with Heinrich events. We thus propose to use the δ18Ocalcite as target for δ18Oatm orbital dating. Such a tuning method improves the ice core chronology of the last glacial inception compared to AICC2012 by reconciling NGRIP and mid-latitude climatic records. It is especially marked during Dansgaard-Oeschger 25 where the proposed chronology is 2.2 ka older than AICC2012. This δ18Oatm - δ18Ocalcite alignment method applied between 100 and 640 ka improves the EDC ice core chronology, especially over MIS 11, and leads to lower ice age uncertainties compared to AICC2012.

  1. Correlates of minimal dating.

    Science.gov (United States)

    Leck, Kira

    2006-10-01

    Researchers have associated minimal dating with numerous factors. The present author tested shyness, introversion, physical attractiveness, performance evaluation, anxiety, social skill, social self-esteem, and loneliness to determine the nature of their relationships with 2 measures of self-reported minimal dating in a sample of 175 college students. For women, shyness, introversion, physical attractiveness, self-rated anxiety, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. For men, physical attractiveness, observer-rated social skill, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. The patterns of relationships were not identical for the 2 indicators of minimal dating, indicating the possibility that minimal dating is not a single construct as researchers previously believed. The present author discussed implications and suggestions for future researchers.

  2. Dating of cremated bones

    OpenAIRE

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a r...

  3. Carbon 14 dating method

    International Nuclear Information System (INIS)

    Fortin, Ph.

    2000-01-01

    This document gives a first introduction to 14 C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the 14 C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of 14 C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  4. Irradiation of dates

    International Nuclear Information System (INIS)

    Farkas, J.; Al-Charchafchy, F.; Al-Shaikhaly, M.H.; Mirjan, J.; Auda, H.

    1974-01-01

    Testing of the technical feasibility of radurization of fresh dates was attempted. In addition preliminary studies were carried out to investigate the applicability of gamma rays to date syrup manufacture. The varieties Zahdi, Lelwi and Tabarzel were studied at different stages of ripening. The eating quality of fresh dates was not affected significantly by irradiation even with doses of 270 and 540 krad. The duration of the softening process, after-ripening, of dates was prolonged by low doses of 10-30 krad in the majority of the experimental batches. The time period of after-ripening was reduced with 270 krad, as well as with 540 krad as a result of shortening of the induction period, i.e. the time after which the date begins to soften. The microbial spoilage of khalaal Lelwi dates was considerably reduced by irradiation with doses above 90 krad. The dibis yield of fully rutab dates was highly increased by the radiation doses of 375 to 2000 krad. The darkness and viable cell count of dibis pressed from irradiated dates were significantly lower than that of untreated dates. (F.J.)

  5. How AMS dating changed my life

    International Nuclear Information System (INIS)

    Spriggs, M.

    2001-01-01

    Accelerator mass spectrometry (AMS) radiocarbon dating was developed in the late 1970s. Remembering back to a time before AMS dating was available to archaeologists is a bit like trying to remember how we ever survived without desktop computers, email or automatic teller machines. My own particular interest in AMS dating was an inevitable offshoot from my long-established interest in chronometric hygiene, or 'getting the dates right'. In this paper I attempt to illustrate that accurate dating matters, by discussing some examples of AMS dating projects with which I have been involved over the last six years or so. In relation to these projects, AMS has given us the ability to date sites which we could not before. It has enabled us to provide more detailed stratigraphies when datable materials are rare. It has allowed us to date materials we could not date before, such as rock art pigments. It has been able to provide indications of the degree of site disturbance in the absence of other obvious forms of evidence. And it has allowed us to assess claims for the antiquity of particular material cultural types and faunal introductions. (author). 41 refs

  6. AMS Radiocarbon Dating at Notre Dame

    Science.gov (United States)

    Howard, Sean

    2014-09-01

    Current development of a local radiocarbon dating method using Accelerator Mass Spectrometry (AMS) at the University of Notre Dame seeks to provide sensitive, reproducible, and accurate measurements for future interdisciplinary projects. While AMS has been the premier radiocarbon dating method for a few decades, repurposing Notre Dame's FN Tandem accelerator for radiocarbon dating has provided many unique challenges. Experiments have shown radiocarbon dating possible and reproducible using the FN Tandem accelerator, found optimal settings for said accelerator, and established sensitivity limits comparable to dedicated radiocarbon dating facilities. In addition, there is ongoing work to create a local chemistry lab to convert organic artifacts into graphite samples to be dated locally. Once the chemistry side has been completed, several artifacts from the IAEA's radiocarbon intercomparison have been procured. Dating these previously studied artifacts will provide an additional measure on the accuracy and repeatability of both the accelerator and chemical treatment. Provided that these IAEA artifacts are dated successfully, exciting projects will ensue, such as the authentication of artwork and dating of anthropological samples.

  7. S K Date

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. S K Date. Articles written in Bulletin of Materials Science. Volume 23 Issue 2 April 2000 pp 97-101 Magnetic Materials. Comparison of the irreversible thermomagnetic behaviour of some ferro- and ferrimagnetic systems · P S Anil Kumar P A Joy S K Date · More Details Abstract ...

  8. Second Quaternary dating workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies emphasizing on the methodologies used and sample preparation

  9. Dating of cremated bones

    NARCIS (Netherlands)

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process.

  10. Second Quaternary dating workshop

    International Nuclear Information System (INIS)

    1999-01-01

    The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies emphasizing on the methodologies used and sample preparation

  11. Chronology and ancient feeding ecology of two upper Pleistocene megamammals from the Brazilian Intertropical Region

    Science.gov (United States)

    de Melo França, Lucas; Trindade Dantas, Mário André; Bocchiglieri, Adriana; Cherckinsky, Alexander; de Souza Ribeiro, Adauto; Bocherens, Hervé

    2014-09-01

    In Brazilian Intertropical Region (BIR) fossil remains of the giant ground sloth Eremotherium laurillardi (Lund, 1842) and of the proboscidean Notiomastodon platensis (Ameghino, 1888) are the most abundant among megaherbivores. However, the paleoecology of both species needs to be better understood to enlighten why these species disappear in the end of the Pleistocene, an issue that is still debated. During the last decades, the carbon and oxygen stable isotopes have been increasingly being used to obtain paleoecological information about extinct animals, although this information is in most cases dissociated from chronological data. Thus, the main objective of this study is to contribute to the knowledge about feeding ecology and chronology of E. laurillardi and N. platensis within BIR. For each fossil sample we performed stable isotopes analyses (δ13C/δ18O) and radiocarbon dating (14C with AMS). The results showed that N. platensis occurred between 12,125 and 19,594 cal yr BP and exhibited a grazer diet (δ13C = -1.1‰-1.3‰), while E. laurillardi lived between 11,084 and 27,690 cal yr BP, with a mixed feeder diet (C3/C4 plants; values ratio δ13C = -7.7‰ to -3.3‰). The δ18O values of N. platensis ranged between 2.20‰ and 3.60‰, while the values of E. laurillardi ranged between -3.10‰ and -1.10‰. Neither species did exhibit differences in its diet through time, which suggests that the vegetational composition of this locality did not vary in the late Pleistocene. Both species were living in an open environment, rich in herbaceous plants (C4 plants) and with tree and shrub with disjoint distribution, maybe similar to some parts of recent Caatinga, where they have partitioned the spatial and feeding niches.

  12. Chronological Trends in Negev Rock Art: The Har Michia Petroglyphs as a Test Case

    Directory of Open Access Journals (Sweden)

    Davida Eisenberg-Degen

    2013-10-01

    Full Text Available Negev rock art comprises a large and diverse corpus of motifs and compositions developed over the course of several millennia. As dating of specific elements is at present not possible, the rock art was analyzed statistically through the study of individual panels where internal sequences of engraving could be discerned. Examining the set of such individual sequences, larger scale reconstruction of engraving phases, sequences and patterns were recognized. Additional chronological markers, such as the presence of domestic camels or other chronologically diagnostic features, offer benchmarks for tying the general trends to more absolute frameworks. The reconstructed patterns reflect the long term history of the Negev and some of the most significant cultural and social transitions in the region are reflected visually through the rock art, notably a form of self-expression, a crucial complement to the historical sequences derived from sedentary peoples living farther north. For example the introduction of the domestic camel and its symbolic and economic significance is well evident in the rock art. Similarly, the emergence of Islam is expressed through the mark makers’ preference for "abstract" (non-figurative motifs. One motif found throughout all engraving phases, transcending the religious, political and economic structures of Negev society, is the “ibex”. Although Negev societies have all focused, to one degree or another, on sheep and goat pastoralism, these animals are rarely present in the Negev rock art and never as herds. Ibex, whose role in the diet and daily subsistence was minimal, was the most commonly depicted zoomorphic motif.

  13. Quaternary dating methods

    International Nuclear Information System (INIS)

    Mahaney, W.C.

    1984-01-01

    The papers in this book cover absolute, relative and multiple dating methods, and have been written by specialists from a number of different earth sciences disciplines - their common interest being the dating of geological materials within the Quaternary. Papers on absolute dating methods discuss radiocarbon, uranium-series, potassium argon, 40 Ar/ 39 Ar, paleomagnetic, obsidian hydration, thermoluminescence, amino acid racemization, tree rings, and lichenometric techniques. Those on relative dating include discussions on various geomorphic relative age indicators such as drainage density changes, hypsometric integrals, bifurcation ratios, stream junction angles, spur morphology, hillslope geometry, and till sheet characteristics. The papers on multiple dating cite examples from the Rocky Mountains, Australia, Lake Agassiz Basin, and the Southern Andes. Also included is the panel discussion which reviews and assesses the information presented, and a field trip guide which discusses the sequences of Wisconian tills and interlayered lacustrine and fluvial sediments. (orig.)

  14. Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia.

    Science.gov (United States)

    Sutikna, Thomas; Tocheri, Matthew W; Morwood, Michael J; Saptomo, E Wahyu; Jatmiko; Awe, Rokus Due; Wasisto, Sri; Westaway, Kira E; Aubert, Maxime; Li, Bo; Zhao, Jian-xin; Storey, Michael; Alloway, Brent V; Morley, Mike W; Meijer, Hanneke J M; van den Bergh, Gerrit D; Grün, Rainer; Dosseto, Anthony; Brumm, Adam; Jungers, William L; Roberts, Richard G

    2016-04-21

    Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.

  15. Application of tandem accelerator mass spectrometor to the chronological study of archaeological samples on Ryukyu Islands

    International Nuclear Information System (INIS)

    Taira, Hatsuo; Higa, Kenichi; Nakai, Nobuyuki; Nakamura, Toshio.

    1987-01-01

    Along with the urbanization of rural areas on Ryukyu Islands, many shell mounds and pre-historic sites have been found in resent years. Chrological studies of shell samples from these mounds will lead to the better understanding of cultural background for the pre-historic human activities on the Ryukyu Islands. C-14 dating by beta counting is the common method to obtain the ages of the archaeological samples. It is, however, very limitted in obtaining the absolute ages by the above mehtod due to the large sample sizes required and time consuming. There are many newly obtained archaeological samples left unstudied in detail. The alternate is a method called Tandem Accelerator Mass Spectrometer (AMS) installed at Nagoya University, which is composed of the tandem type accelerator to measure very low concentration of C-14 in archaeological samples. The system has been designed particularly to measure the radio-carbon and has advantages of being small sample size and very little time consuming for C-14 measurement as compared with the beta counting. It is the aim of this work to apply the above AMS for obtaining the absolute ages of the archaeological samples. The results agreed well with those estimated by the Erthenware method (relative method of dating), which ranged from 500 to 6000 y.b.p. The results may be helpful for the chronological arrangement of the samples and for the understanding of pre-historical human activities on the Ryukyu Islands. (author)

  16. Improvements in the chronology, geochemistry and correlation techniques of tephra in Antarctic ice

    Science.gov (United States)

    Iverson, N. A.; Dunbar, N. W.; McIntosh, W. C.; Pearce, N. J.; Kyle, P. R.

    2013-12-01

    Visible and crypto tephra layers found in West Antarctic ice provide an excellent record of Antarctic volcanism over the past 100ka. Tephra layers are deposited almost instantaneously across wide areas creating horizons that, if found in several locations, provide 'pinning points' to adjust ice time scales that may otherwise be lacking detailed chronology. Individual tephra layers can have distinct chemical fingerprints allowing them to correlate over great distances. Advances in sample preparation, geochemical analyses (major and trace elements) of fine grained tephra and higher precision 40Ar/39Ar dating of young (typically too small to be directly dated by 40Ar/39Ar method, making it very important to geochemically correlate these layers to proximal deposits where more and larger feldspar can be sampled. The correlation of WDC06A-2767.117 to the coarse, proximal BIT-152 provides one such link. The New Mexico Geochronology Research Lab (NMGRL) has two new multi-collector ARGUS VI mass spectrometers that can provide single crystal laser fusion ages that are approximately an order of magnitude more precise than the previous determinations. With these advancements in analytical technology, we hope to improve precision on 'pinning points' in the deep ice cores where annual layer counting becomes less precise.

  17. Glacial Lake Pickering: stratigraphy and chronology of a proglacial lake dammed by the North Sea Lobe of the British-Irish Ice Sheet

    OpenAIRE

    Evans, David J.A.; Bateman, Mark D.; Roberts, David H.; Medialdea, Alicia; Hayes, Laura; Duller, Geoff A.T.; Fabel, Derek; Clark, Chris D.

    2016-01-01

    We report the first chronology, using four new optically stimulated luminescence dates, on the sedimentary record of Glacial Lake Pickering, dammed by the North Sea Lobe of the British–Irish Ice Sheet during the Dimlington Stadial (24–11 ka cal BP). Dates range from 17.6 ± 1.0 to 15.8 ± 0.9 ka for the sedimentation of the Sherburn Sands at East Heslerton, which were formed by multiple coalescing alluvial fans prograding into the falling water levels of the lake and fed by progressively larger...

  18. U-Th dating of speleothems to investigate the evolution of limestone caves in the Gunung Mulu National Park, Sarawak, Malaysia

    OpenAIRE

    Moseley, Gina E.; Richards, David A.; Smith, Christopher; Smart, Peter L.; Hoffmann, Dirk L.; Farrant, Andrew R.

    2013-01-01

    The Gunung Mulu National Park, Sarawak, Malaysia has been a focus of scientific research and exploration for several decades. Previous work investigated the relationship between fluvial incision into the limestone massif and the chronological evolution of the 500m-deep network of cave passages. This study involved analyses of newly available speleothem material using state-of-the-art U-Th dating methods and assessment of the potential for extension of the chronological record using U-Pb datin...

  19. Uranium-series dating of the Mousterian occupation at Abric Romani, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, J L; Julia, R; Mora, R

    1988-03-03

    The precise evolutionary position of the Neanderthal people continues to be a major uncertainty in human evolution. Their origin and their relationship to anatomically modern people are unclear and are clouded by poor chronology. Lithic artefacts of the Mousterian type, found throughout Europe and the Mediterranean Basin, are believed to be the tool kit of the Neanderthals, but dates within Mousterian-bearing deposits are extremely rare. We report here on 20 high-quality uranium-series dates from Mousterian beds at Abric Romani, a rock shelter near Barcelona, Spain. The dates range from 39 to 60 kyr before present in an orderly stratigraphic succession and provide precise chronological control on an important Mousterian archaeological site.

  20. New radiocarbon dates for terminal Pleistocene and early Holocene settlements in West Turkana, northern Kenya

    Science.gov (United States)

    Beyin, Amanuel; Prendergast, Mary E.; Grillo, Katherine M.; Wang, Hong

    2017-07-01

    The Turkana Basin in northern Kenya is located in an environmentally sensitive region along the eastern African Rift system. Lake Turkana's sensitivity to fluctuations in precipitation makes this an ideal place to study prehistoric human adaptations during key climatic transitions. Here we present eleven radiocarbon dates from two recently excavated sites in West Turkana, Kokito 01 and Kokito 02. The sites span the Pleistocene-Holocene transition, a time of fluctuating lake levels and novel cultural responses within the region. Several scenarios are laid out for the interpretation of site chronologies, and these are discussed with reference to the terminal Pleistocene and early Holocene chronological record for the region. Given the paucity of well-dated sites from this timespan in the Turkana Basin, the new radiocarbon dates are an important step toward establishing human settlement history and associated cultural developments in the region.

  1. Not only Chauvet: dating Aurignacian rock art in Altxerri B Cave (northern Spain).

    Science.gov (United States)

    González-Sainz, C; Ruiz-Redondo, A; Garate-Maidagan, D; Iriarte-Avilés, E

    2013-10-01

    The discovery and first dates of the paintings in Grotte Chauvet provoked a new debate on the origin and characteristics of the first figurative Palaeolithic art. Since then, other art ensembles in France and Italy (Aldène, Fumane, Arcy-sur-Cure and Castanet) have enlarged our knowledge of graphic activity in the early Upper Palaeolithic. This paper presents a chronological assessment of the Palaeolithic parietal ensemble in Altxerri B (northern Spain). When the study began in 2011, one of our main objectives was to determine the age of this pictorial phase in the cave. Archaeological, geological and stylistic evidence, together with radiometric dates, suggest an Aurignacian chronology for this art. The ensemble in Altxerri B can therefore be added to the small but growing number of sites dated in this period, corroborating the hypothesis of more complex and varied figurative art than had been supposed in the early Upper Palaeolithic. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Thermoluminescence as a dating method applied to the Morocco Neolithic

    International Nuclear Information System (INIS)

    Ousmoi, M.

    1989-09-01

    Thermoluminescence is an absolute dating method which is well adapted to the study of burnt clays and so of the prehistoric ceramics belonging to the Neolithic period. The purpose of this study is to establish a first absolute chronology of the septentrional morocco Neolithic between 3000 and 7000 years before us and some improvements of the TL dating. The first part of the thesis contains some hypothesis about the morocco Neolithic and some problems to solve. Then we study the TL dating method along with new process to ameliorate the quality of the results like the shift of quartz TL peaks or the crushing of samples. The methods which were employed using 24 samples belonging to various civilisations are: the quartz inclusion method and the fine grain technique. For the dosimetry, several methods were used: determination of the K 2 O contents, alpha counting, site dosimetry using TL dosimeters and a scintillation counter. The results which were found bring some interesting answers to the archeologic question and ameliorate the chronologic schema of the Northern morocco Neolithic: development of the old cardial Neolithic in the North, and perhaps in the center of Morocco (the region of Rabat), between 5500 and 7000 before us. Development of the recent middle Neolithic around 4000-5000 before us, with a protocampaniforme (Skhirat), little older than the campaniforme recognized in the south of Spain. Development of the bronze age around 2000-4000 before us [fr

  3. Luminescence dating in archaeology

    International Nuclear Information System (INIS)

    Wintle, A.G.

    2001-01-01

    Thermoluminescence (TL) dating is routinely applied to burnt lithic material. Simple fires are capable of enabling stones weighing a few hundred grams to reach 450 o C, thus zeroing the TL signal. TL dates have been obtained for Upper and Lower Paleolithic sites in Europe and the Near East. TL dating continues to be used for dating pottery and for authentification of ceramic works of art. Some recent studies report the use of optically stimulated luminescence (OSL) (also know as photoluminescence) for dating very small samples of quartz, e.g. from small pieces of pottery or frm metallurgical slag The major recent advance has been in the development of a reliable laboratory procedure for using the OSL signal from quartz to obtain the past radiation exposure. The quartz OSL signal is extremely sensitive to light and is reduced to a negligible level on exposure to direct sunlight for radionuclides during burial, signal to date san.sized quartz grains extracted from sediments, The OSL signal is stimulated by 470 nm light from emitting diodes and the detected using flirters centred on 340 nm A similar signal can be obtained from feldspar grain when are exposed to infrared wavelengths around 880 nm. The infrared stimulated luminescence (IRSL) signals is also rapidly depleted by exposure to sunlight, and dating of colluvial deposits from archaeological sites has been reported

  4. Uranium/thorium dating of Late Pleistocene peat deposits in NW Europe, uranium/thorium isotope systematics and open-system behaviour of peat layers

    NARCIS (Netherlands)

    Heijnis, H.; Plicht, J. van der

    1992-01-01

    The possibility of dating peat by the uranium-series disequilibrium method is discussed. In principle, this method can be used to date peat to approximately 350 ka. The application of the U/Th disequilibrium method (UTD) on peat provides us with the probability of constructing a new chronology for

  5. Thermoluminescence dating of loess from the Potwar Plateau, northern Pakistan

    International Nuclear Information System (INIS)

    Rendell, H.M.; Gamble, I.J.A.; Townsend, P.D.

    1983-01-01

    The loess deposits of northern Pakistan present a good opportunity for establishing a chronology using fine grain TL dating. The TL response of the 2-10 μm size fraction of polymineral (predominantly quartz/feldspar) mixtures is well behaved with linear dose-dependence and no anomalous fading. The loess horizons have very similar uranium and thorium contents, thus minimising dosimetry problems, and the fairly arid climatic conditions reduce the errors in water content estimation, at least for the uppermost horizons. A series of laboratory bleaching experiments reveal uncertainties in the absolute age estimates but not in their relative values. (author)

  6. Chronology of Mercury's geological and geophysical evolution - the Vulcanoid hypothesis

    International Nuclear Information System (INIS)

    Leake, M.A.; Chapman, C.R.; Weidenschilling, S.J.; Davis, D.R.; Greenberg, R.

    1987-01-01

    The possibility that constraints on Mercury's chronology can be relaxed through reference to a Mercury-specific bombarding population of planetesimals interior to its orbit, and therefore only occasionally encountering the planet at times of secular perturbations, is investigated. While such vulcanoids may have been a significant source of early cratering, those in the pertinent orbits are depleted by mutual collisions and can therefore only furnish a modest extension of the heavy bombardment period. A search is conducted for vulcanoids further within Mercury's orbit; evidence that Mercury's intercrater plains are of volcanic origin is discussed. 99 references

  7. Gödel metrics with chronology protection in Horndeski gravities

    Science.gov (United States)

    Geng, Wei-Jian; Li, Shou-Long; Lü, H.; Wei, Hao

    2018-05-01

    Gödel universe, one of the most interesting exact solutions predicted by General Relativity, describes a homogeneous rotating universe containing naked closed time-like curves (CTCs). It was shown that such CTCs are the consequence of the null energy condition in General Relativity. In this paper, we show that the Gödel-type metrics with chronology protection can emerge in Einstein-Horndeski gravity. We construct such exact solutions also in Einstein-Horndeski-Maxwell and Einstein-Horndeski-Proca theories.

  8. Astronautics and Aeronautics: A Chronology, 1996-2000

    Science.gov (United States)

    Lewis, Marieke; Swanson, Ryan

    2009-01-01

    This report is a chronological compilation of narrative summaries of news reports and government documents highlighting significant events and developments in United States and foreign aeronautics and astronautics. It covers the years 1996 through 2000. These summaries provide a day-by-day recounting of major activities, such as administrative developments, awards, launches, scientific discoveries, corporate and government research results, and other events in countries with aeronautics and astronautics programs. Researchers used the archives and files housed in the NASA History Division, as well as reports and databases on the NASA Web site.

  9. Astronautics and Aeronautics: A Chronology, 2001-2005

    Science.gov (United States)

    Ivey, William Noel; Lewis, Marieke

    2010-01-01

    This report is a chronological compilation of narrative summaries of news reports and government documents highlighting significant events and developments in U.S. and foreign aeronautics and astronautics. It covers the years 2001 through 2005. These summaries provide a day-by-day recounting of major activities, such as administrative developments, awards, launches, scientific discoveries, corporate and government research results, and other events in countries with aeronautics and astronautics programs. Researchers used the archives and files housed in the NASA History Division, as well as reports and databases on the NASA Web site.

  10. Date Rape (For Teens)

    Science.gov (United States)

    ... owe" someone sex, even if you're a couple. Rape is not always violent. If you say " ... date rape" drugs like: rohypnol , called roofies, lunch money, or mind erasers GHB (gamma hydroxybutyric acid), called ...

  11. Methods of dating

    Energy Technology Data Exchange (ETDEWEB)

    Gatty, B

    1986-04-01

    Scientific methods of dating, born less than thirty years ago, have recently improved tremendously. First the dating principles will be given; then it will be explained how, through natural radioactivity, we can have access to the age of an event or an object; the case of radiocarbon will be especially emphasized. The principle of relative methods such as thermoluminescence or paleomagnetism will also be shortly given. What is the use for dating. The fields of its application are numerous; through these methods, relatively precise ages can be given to the major events which have been keys in the history of universe, life and man; thus, dating is a useful scientific tool in astrophysics, geology, biology, anthropology and archeology. Even if certain ages are still subject to controversies, we can say that these methods have confirmed evolution's continuity, be it on a cosmic, biologic or human scale, where ages are measured in billions, millions or thousands of years respectively.

  12. Radiometric dating methods

    International Nuclear Information System (INIS)

    Bourdon, B.

    2003-01-01

    The general principle of isotope dating methods is based on the presence of radioactive isotopes in the geologic or archaeological object to be dated. The decay with time of these isotopes is used to determine the 'zero' time corresponding to the event to be dated. This paper recalls the general principle of isotope dating methods (bases, analytical methods, validation of results and uncertainties) and presents the methods based on natural radioactivity (Rb-Sr, Sm-Nd, U-Pb, Re-Os, K-Ar (Ar-Ar), U-Th-Ra- 210 Pb, U-Pa, 14 C, 36 Cl, 10 Be) and the methods based on artificial radioactivity with their applications. Finally, the methods based on irradiation damages (thermoluminescence, fission tracks, electron spin resonance) are briefly evoked. (J.S.)

  13. NAIP 2012 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2012 National Agriculture Imagery Program (NAIP)...

  14. NAIP 2014 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2014 National Agriculture Imagery Program (NAIP)...

  15. Food Product Dating

    Science.gov (United States)

    ... Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District Offices ... Web Content Viewer (JSR 286) Actions ${title} Loading... Food Product Dating "Best if Used By" is a ...

  16. NAIP 2013 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2013 National Agriculture Imagery Program (NAIP)...

  17. NAIP 2011 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2011 National Agriculture Imagery Program (NAIP)...

  18. New data on OSL dating of Early Khalynian deposits of Northern Caspian

    Science.gov (United States)

    Sychev, Nikita; Yanina, Tamara; Svitoch, Alexander; Kurbanov, Redzhep; Badyukova, Ekaterina

    2016-04-01

    Ponto-Caspian region is the key region the study of which can provide information about the paleogeographic history of the central Eurasia, particularly revealing the history of the East European Plain, the Caucasus and Central Asia. However, despite the long history of the study, today there is no accepted general stratigraphic scheme of the Caspian Sea. One of the most interesting and important stages of Late Pleistocene history of Caspian is Khalynian transgression which is divided into two major phases: early and ate. In the Caspian lowland Lower Khalynian stage are represented by a unique type of deposit - "chocolate clays". A distinctive feature of these sediments is widely distributed among Lower Khalynian deposits of Northern Caspian and the Volga region. All clay deposits are confined to the diverse origins of depression before-Khalynian relief. Chocolate clays formation consists of facies: mono-clay (typological), layered, sand- and silty-clay (Svitoch, Yanina, 1997). Determining the age of chocolate clays by optically stimulated luminescence (OSL) in our view will allow bettering the understanding of their genesis. Age of chocolate clays of Lower Volga was widely dated using the radiocarbon. However, the existing chronology is controversial, raises a number of issues, primarily due to the material of which are used for dating - thin shells of Caspian mollusks of the Didacna Eichw. genus, which are characterized by a significant isotopic exchange with the enclosing sediments (Arslanov, 2015). Lower Volga region is characterized by very complex geological structure of the Late Pleistocene deposits (alternating continental aeolian, alluvial and slope sediments with marine Caspian deposits of different age). There are many conflicting opinions, not only with respect to paleogeographic features of the area, but also to its precise chronology. The differences in opinion over the age of the individual stages of development of the Caspian Sea (transgressions and

  19. Improving the {sup 210}Pb-chronology of Pb deposition in peat cores from Chao de Lamoso (NW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Olid, Carolina, E-mail: carolina.olid@emg.umu.se [Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå (Sweden); Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Garcia-Orellana, Jordi, E-mail: jordi.garcia@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Masqué, Pere, E-mail: pere.masque@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Cortizas, Antonio Martínez, E-mail: antonio.martinez.cortizas@usc.es [Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela (Spain); and others

    2013-01-15

    The natural radionuclide {sup 210}Pb is commonly used to establish accurate and precise chronologies for the recent (past 100–150 years) layers of peat deposits. The most widely used {sup 210}Pb-dating model, Constant Rate of Supply (CRS), was applied using data from three peat cores from Chao de Lamoso, an ombrotrophic mire in Galicia (NW Spain). On the basis of the CRS-chronologies, maximum Pb concentrations and enrichment factors (EFs) occurred in the 1960s and late 1970s, consistent with the historical use of Pb. However, maximum Pb fluxes were dated in the 1940s and the late 1960s, 10 to 20 years earlier. Principal component analysis (PCA) showed that, although the {sup 210}Pb distribution was mainly (74%) controlled by radioactive decay, about 20% of the {sup 210}Pb flux variability was associated with atmospheric metal pollution, suggesting an extra {sup 210}Pb supply source and thus invalidating the main assumption of the CRS model. When the CRS-ages were recalculated after correcting for the extra input from the {sup 210}Pb inventory of the uppermost peat layers of each core, Pb flux variations were consistent with the historical atmospheric Pb deposition. Our results not only show the robustness of the CRS model to establish accurate chronologies of recent peat deposits but also provide evidence that there are confounding factors that might influence the calculation of reliable peat accumulation rates (and thus also element accumulation rates/fluxes). This study emphasizes the need to verify the hypotheses of {sup 210}Pb-dating models and the usefulness of a full geochemical interpretation of peat bog records. - Highlights: ► Peat cores collected in NW Spain were used to reconstruct recent Pb deposition. ► Applicability of {sup 210}Pb-dating models (CRS) in bogs is discussed based on PCA results. ► Results showed that ∼ 20% of the {sup 210}Pb flux was related to anthropogenic metal pollution. ► Geochemical analysis of bogs is useful to

  20. Luminescence chronology of loess-paleosol sequences from Canterbury, South Island, New Zealand

    International Nuclear Information System (INIS)

    Berger, G.W.; Pillans, B.J.; Tonkin, P.J.

    2001-01-01

    The extensive Quaternary loess-paleosol deposits of South Island, New Zealand, represent one of the major proxy records of paleoclimatic changes in the Southern Hemisphere. We attempted to produce the first numeric chronology of these subaerial sequences in the Canterbury region by using thermoluminescence and infrared-stimulated luminescence dating methods. We examined five exposures: a 6 m thick section at Cust, north of Christchurch; two thicker (c. 14 m) sequences on Banks Peninsula (Barrys Bay and Onawe sites); farther south, a c. 12 m sequence in Timaru; and a c. 7 m sequence on the coast at the Normanby site near Timaru. Our results are largely based on single experiments per sample, and therefore provide imprecise ages for several of the older samples. The most satisfactory results are those from the youngest site (Cust), for which three samples were dated. Here, phases of maximum loess deposition are dated at 73 +/- 13 ka (basal loess-paleosol unit L3), 41 +/- 5 ka (basal L2), and 27 +/- 3 ka (basal L1). At Barrys Bay an age of 70 +/- 15 ka was obtained in the basal L1, and at Timaru two separate samples in the base of L1 also yielded ages of c. 70 ka, thus correlating the entire Cust loess sequence with the L1 loess unit at these two other study sites. Only at Barrys Bay were ages (c. 130-250 ka) in stratigraphic order obtained for older samples (units L2 and deeper). At the other sites, some samples in the sub-L1 units gave age reversals, and some (including the oldest sample at Barrys Bay) yielded poor precision (e.g., 20%). Units L2 at Timaru and Barrys Bay may correlate to all or part of MIS 6; however, the poor precision and some age reversals in other units at these sites and at Normanby and Onawe preclude any unambiguous correlations between sites or to the MIS time-scale. Nevertheless, in the absence of any prior numeric ages, these first results serve as a basis for more precise future dating of these units. Although these reconnaissance dating

  1. Developing occupational chronologies for surface archaeological deposits from heat retainer hearths on Pine Point and Langwell stations, Far Western New South Wales, Australia

    International Nuclear Information System (INIS)

    Shiner, J.

    2003-01-01

    The archaeological record of arid Australia is dominated by deflated distributions of stone artefacts and heat retainer hearths covering many thousands of square metres. These deposits have often been over-looked by archaeologists in preference for stratified deposits, which are regarded as more appropriate for investigating temporal issues. In recent years this situation had slowly begun to change with the large-scale dating of heat retainer hearths from surface contexts. The work of of Fanning and Holdaway (2001) and Holdaway et al. (2002) in Far Western New South Wales has demonstrated that through the dating of large numbers of hearths it is possible to develop occupational chronologies for surface deposits. At a wider landscape scale these chronologies reflect the timing and tempo of the occupation of different places. A major component of my doctoral fieldwork on Pine Point and Langwell stations, 50 km south of Broken Hill in Western New South Wales, aimed to establish occupational chronologies from hearths for surface archaeological distributions. This paper reports on radiocarbon results from this investigation. (author). 6 refs., 2 figs., 1 tab

  2. High-precision chronology for Central American maize diversification from El Gigante rockshelter, Honduras.

    Science.gov (United States)

    Kennett, Douglas J; Thakar, Heather B; VanDerwarker, Amber M; Webster, David L; Culleton, Brendan J; Harper, Thomas K; Kistler, Logan; Scheffler, Timothy E; Hirth, Kenneth

    2017-08-22

    The first steps toward maize ( Zea mays subspecies mays ) domestication occurred in the Balsas region of Mexico by ∼9,000 calendar years B.P. (cal B.P.), but it remains unclear when maize was productive enough to be a staple grain in the Americas. Molecular and microbotanical data provide a partial picture of the timing and nature of morphological change, with genetic data indicating that alleles for some domestication traits were not yet fixed by 5,300 cal B.P. in the highlands of Mexico. Here, we report 88 radiocarbon dates on the botanical remains from El Gigante rockshelter (Honduras) to establish a Bayesian chronology over the past ∼11,000 y spanning the transition to maize-based food production. Botanical remains are remarkably well preserved and include over 10,000 maize macrofossils. We directly dated 37 maize cobs to establish the appearance and local change of maize at the site. Cobs are common in deposits dating between 4,340 and 4,020 cal B.P., and again between 2,350 and 980 cal B.P. The earliest cobs appear robustly domesticated, having 10-14 rows, suggesting strong selection for increased yield. The later cobs are comparable to these earliest ones, but show clear emergence of diverse traits, including increased cob width, rachis segment length, and cupule width. Our results indicate that domesticated landraces of maize productive enough to be a staple grain existed in Central America by 4,300 cal B.P.

  3. Recent growth coherence in long-term oak (Quercus spp.) ring width chronologies in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Dobrovolný, Petr; Rybníček, Michal; Büntgen, Ulf; Trnka, Miroslav; Brázdil, Rudolf; Stachoň, Z.; Prokop, O.; Kolář, Tomáš

    2016-01-01

    Roč. 70, 2-3 (2016), s. 133-141 ISSN 0936-577X R&D Projects: GA MŠk(CZ) LO1415; GA ČR GA13-04291S; GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : Tree-ring width chronology * Oak species * Tree-age structure * Site-specific conditions * Hydroclimate sensitivity * Czech Republic Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.578, year: 2016

  4. Dating fossil opal phytoliths

    International Nuclear Information System (INIS)

    Lentfer, C.; Boyd, B.; Torrence, R.

    1999-01-01

    Full text: Opal phytoliths are microscopic silica bodies formed by the precipitation of hydrated silica dioxide (SiO 2 nH 2 0) in, around and between cell walls. They are relatively resistant to degradation in most environments and thus, can occur in large quantities in palaeosediments. Consequently, they are valuable tools for environmental reconstruction. Furthermore, phytoliths are often the only recoverable organic material in well oxidised sediments, the occluded carbon provides the opportunity for dating sediment whose ages have previously been difficult to determine, and thus, increase the potential for fine resolution determination of environmental change. This poster describes the results of an investigation assessing the viability of AMS radiocarbon dating of fossil phytolith inclusions using samples from Garua Island, West New Britain, PNG. Thirteen phytolith samples, isolated from sediments previously dated using tephrastratigraphy and C14 dating of macroremains of nutshells and wood charcoal, were used in the analysis. As a control measure, thirteen parallel samples of microscopic charcoal were also dated using AMS. The results show that the AMS dates for the microscopic charcoal samples are consistent with ages anticipated from the other dating methods, for all but one sample. However, the dates for eight of the thirteen phytolith samples are considerably younger than expected. This bias could be explained by several factors, including downwashing of phytolith through soils, bioturbation, carbon exchange through the siliceous matrix of the phytolith bodies, and contamination from extraneous sources of modern carbon retained in the samples. Research is currently focusing on the investigation of these issues and selected samples are in the process of being retreated with strong oxidising agents to clear contaminants prior to re-dating. Further to this, a full investigation of one profile with a long sequence is underway. High concentrations of

  5. Distribution and migration chronology of Eastern population sandhill cranes

    Science.gov (United States)

    Fronczak, David L.; Andersen, David; Hanna, Everett E.; Cooper, Thomas R.

    2017-01-01

    The Eastern Population (EP) of greater sandhill cranes (Antigone canadensis tabida; cranes) is expanding in size and geographic range. Little information exists regarding the geographic extent of breeding, migration, and wintering ranges, migration chronology, or use of staging areas for cranes in the EP. To obtain these data, we attached solar global positioning system (GPS) platform transmitting terminals (PTTs) to 42 sandhill cranes and monitored daily locations from December 2009 through August 2014. On average, tagged cranes settled in summer areas during late‐March in Minnesota (7%), Wisconsin (29%), Michigan, USA (21%), and Ontario, Canada (38%) and arrived at their winter terminus beginning mid‐December in Indiana (15%), Kentucky (3%), Tennessee (45%), Georgia (5%), and Florida (32%). Cranes initiated spring migration beginning mid‐February to their respective summer areas on routes similar to those used during fall migration. Twenty‐five marked cranes returned to the same summer area after a second spring migration, of which 19 (76%) settled cranes in the EP, we estimated that approximately 29–31% of cranes that summered in both Wisconsin and the Lower Peninsula of Michigan were not in areas included in the survey. The information we collected on crane movements provides insight into distribution and migration chronology that will aid in assessment of the current USFWS fall survey. In addition, information on specific use sites can assist state and federal managers to identify and protect key staging and winter areas particularly during current and future recreational harvest seasons.

  6. Chronological alterations of diagnostic imaging of renal cell carcinoma

    International Nuclear Information System (INIS)

    Arima, Kiminobu; Sugimura, Yoshiki; Yanagawa, Makoto; Tochigi, Hiromi; Kawamura, Juichi

    1994-01-01

    A review of 156 cases of renal cell carcinoma diagnosed during a 20-year period demonstrated the changes of initial signs/symptoms and imaging modalities for detection and definition. According to the imaging modality used for diagnosing renal cell carcinoma, clinical pictures were chronologically examined over 4 periods: 1973 to 1979 (before CT era), 1980 to 1984 (early CT era), 1985 to 1987 (CT era) and 1988 to 1992 (CT/MRI era). With regards to initial signs or symptoms, the proportion of classical trials has gradually decreased, while that of tumors noted incidentally has increased. As for imaging modalities for detection, the proportion of IVP has gradually decreased and that of CT and US has increased over the periods. With regard to imaging modalities for definition, the proportion of angiography has decreased and that of CT has increased. From chronological changes in clinical pictures and imaging modalities, we suggested a decision tree of imaging modalities for detection and definition of renal cell carcinoma. (author)

  7. Chronologic changes of free fat graft in rabbit using CT

    International Nuclear Information System (INIS)

    Kondo, Norihiro; Kurita, Kenichi; Yajima, Tetsuya; Izumi, Masahiro

    2008-01-01

    Free fat grafts are now used for preventing osteal readhesion, filling dead space, and protecting grafted nerves and vessels. However, it is reported that grafted fat tissue is unstable resulting in high risk of cicatrization and infection. We grafted free fat to a rabbit's back and observed the chronologic change using CT. Ten adult male Japanese white rabbits (3.5 kg) were used. In five rabbits, fat tissue was obtained from the back under general anaesthesia, and transplanted into the back about 50 mm posterior from the donor site. CT was taken in the fixed scan condition five times (preoperation, immediate postoperation, postoperative 1-month, 2-month, and 3-month). In the remaining five rabbits, only CT scan was taken three times as a control. It was observed that we compared preoperative fat volume with the postoperative volume using RealINTAGE. Grafted fat tissue decreased postoperatively at 1-month and completely disappeared at 3-months. We were able to prove that CT scan is effective to observe the chronologic change of grafted fat tissue. Techniques of tissue engineering are necessary for survival of grafted fat tissue. (author)

  8. Dental and Skeletal Maturity- A Biological Indicator of Chronologic Age

    Science.gov (United States)

    Saha, Sonali; Yadav, Gunjan; Tripathi, Abhay Mani; Grover, Kavita

    2014-01-01

    Introduction: Precise evaluation of the developmental stage of a child is not only an integral part of both diagnosis and treatment of paediatric patients; it is also essential in Forensic Medicine and Dentistry. Physiologic age can be estimated by somatic, sexual, skeletal and dental maturity. Aim: Investigate the relationship between the dental age (DA) and skeletal age (SA) of children and comparing it with the chronological age (CA). Materials and Methods: The dental age estimation methods of Schour and Massler (S&M), and Demirjian and Goldstien (D&G) and skeletal assessment methods of Greulich and Pyle (G&P), and Tanner et al., (TW2) were used to analyze the orthopantomograms and hand-wrist radiographs respectively of 150 healthy subjects within the age range of 5-15 y and compared with the Chronological Age. Statistical Analysis: Data collected was statistically analysed using the SPSS version 15.0 Statistical Analysis Software. For all tests p-value of <0.05 were considered statistically significance. Results: Dental age estimation techniques were found comparable and equally reliable as the skeletal age estimation methods. Strong correlations between dental and skeletal maturation were demonstrated. PMID:25386525

  9. The Composition of Cigarette Smoke: A Chronology of the Studies of Four Polycyclic Aromatic Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Rodgman A

    2014-12-01

    Full Text Available Among the polycyclic aromatic hydrocarbons (PAHs, a major class of identified cigarette mainstream smoke (MSS components, are several shown to be tumorigenic in laboratory animals and suspect as possible tumorigens to humans. To date, nearly 540 PAHs have been completely or partially identified in tobacco smoke [Rodgman and Perfetti (1]. A detailed chronology is presented of studies on four much discussed PAHs identified in tobacco smoke, namely, benz[a]anthracene (B[a]A, its 7,12-dimethyl derivative (DMB[a]A, dibenz[a, h]anthracene (DB[a, h]A, and benzo[a]pyrene (B[a]P. Of the four, DMB[a]A, DB[a, h]A, and B[a]P are considered to be potently tumorigenic on mouse skin painting and subcutaneous injection. Opinions on the tumorigenicity of B[a]A to mouse skin vary. DMB[a]A is frequently used in tumorigenicity studies as an initiator. Examination of the number of tobacco smoke-related citations listed for these four PAHs reveals the enormous effort devoted since the early 1950s to B[a]P vs. the other three. An annotated chronology from 1886 to date describes the tobacco smoke-related research pertinent to these four PAHs, their discovery, isolation and/or identification, quantitation, and contribution to the observed biological activity of MSS or cigarette smoke condensate (CSC. Much of the major literature on these four PAHs in tobacco smoke is presented in order to permit the reader to decide whether the current evidence is sufficient to classify them as a health risk to smokers. There has certainly been a tremendous effort by researchers to learn about these PAHs over the past several decades. Each of these PAHs when tested individually has been shown to possess the following biological properties: 1 Mutagenicity in certain bacterial situations, 2 tumorigenicity in certain animal species, to varying degrees under various administration modes, and 3 a threshold limit below which no tumorigenesis occurs. For more than five decades, it has been

  10. Glacial chronology and palaeoclimate in the Bystra catchment, Western Tatra Mountains (Poland) during the Late Pleistocene

    Science.gov (United States)

    Makos, Michał; Rinterknecht, Vincent; Braucher, Régis; Żarnowski, Michał

    2016-02-01

    Deglaciation chronology of the Bystra catchment (Western Tatra Mountains) has been reconstructed based on 10Be exposure age dating. Fourteen rock samples were collected from boulders located on three moraines that limit the horizontal extent of the LGM maximum advance and the Lateglacial recessional stage. The oldest preserved, maximum moraine was dated at 15.5 ± 0.8 ka, an age that could be explained more likely by post-depositional erosion of the moraine. Such scenario is supported by geomorphologic and palaeoclimatological evidence. The younger cold stage is represented by well-preserved termino-lateral moraine systems in the Kondratowa and Sucha Kasprowa valleys. The distribution of the moraine ridges in both valleys suggest a complex history of deglaciation of the area. The first Late-glacial re-advance (LG1) was followed by a cold oscillation (LG2), that occurred at around 14.0 ± 0.7-13.7 ± 1.2 ka. Glaciers during both stages had nearly the same horizontal extent, however, their thickness and geometry changed significantly, mainly due to local climatic conditions triggered by topography, controlling the exposition to solar radiation. The LG1 stage occurred probably during the pre-Bølling cold stage (Greenland Stadial 2.1a), however, the LG2 stage can be correlated with the cooling at around 14 ka during the Greenland Interstadial 1 (GI-1d - Older Dryas). This is the first chronological evidence of the Older Dryas in the Tatra Mountains. The ELA of the maximum Bystra glacier was located at 1480 m a.s.l. in accordance with the ELA in the High Tatra Mountains during the LGM. During the LG1 and LG2 stages, the ELA in the catchment rose up to 1520-1530 m a.s.l. and was located approximately 100-150 m lower than in the eastern part of the massif. Climate modelling results show that the Bystra glacier (maximum advance) could have advanced in the catchment when mean annual temperature was lower than today by 11-12 °C and precipitation was reduced by 40-60%. This

  11. Language evolution and human history: what a difference a date makes.

    Science.gov (United States)

    Gray, Russell D; Atkinson, Quentin D; Greenhill, Simon J

    2011-04-12

    Historical inference is at its most powerful when independent lines of evidence can be integrated into a coherent account. Dating linguistic and cultural lineages can potentially play a vital role in the integration of evidence from linguistics, anthropology, archaeology and genetics. Unfortunately, although the comparative method in historical linguistics can provide a relative chronology, it cannot provide absolute date estimates and an alternative approach, called glottochronology, is fundamentally flawed. In this paper we outline how computational phylogenetic methods can reliably estimate language divergence dates and thus help resolve long-standing debates about human prehistory ranging from the origin of the Indo-European language family to the peopling of the Pacific.

  12. The Thera eruption: continuing discussion of the dating

    International Nuclear Information System (INIS)

    Aitken, M.J.; Betancourt, P.P.

    1988-01-01

    Until recently it had been generally accepted that the radiocarbon dates for the destruction levels at Akrotiri resulting from the Minoan eruption of Thera on the Aegean island of Santorini 'did not make sense', interference by carbon dioxide emanations from the volcano, deficient in carbon-14, sometimes being suggested as the cause (as recently discussed by Olsson 1987). The scatter was said to be unacceptably large, but above all, after calibration the majority of dates were at least a century earlier than expected on the basis of the accepted Minoan chronology, established by archaeological linkages to the Egyptian astronomically-anchored calendar. The situation has now been changed. First, from a reassessment of linkages it has been proposed (Betancourt 1987) that the relevant Late Minoan period (LM IA) started at least a century earlier than according to the usual chronology. Secondly, accurate high-precision calibration curves have become available (e.g. Pearson and Stuiver 1986); although previous curves are generally concordant with these, for the relevant period the new calibration has the effect of making calibrated dates more recent by about half a century. The purpose of the present note is to bring together the various datings that are now extant. Although a shift of a century may seem trivial to those remote from Aegean archaeology the topic is of more than local interest on account of the tendency for opponents of radiocarbon to use the dates as 'yet another example of failure' and of the challenge to science-based techniques to provide an unambiguous result for this major natural catastrophy. (author)

  13. Changes in solar activity and Holocene climatic shifts derived from C-14 wiggle-match dated peat deposits

    NARCIS (Netherlands)

    Mauquoy, D; van Geel, B; Speranza, A; van der Plicht, J; Blaauw, Maarten

    Closely spaced sequences of accelerator mass spectrometer (AMS) C-14 dates of peat deposits display century-scale wiggles which can be fitted to the radiocarbon calibration curve. By wiggle-matching such sequences, high-precision calendar age chronologies can be generated which show that changes in

  14. Changes in solar activity and Holocene climatic shifts derived from 14C wiggle-match dated peat deposits

    NARCIS (Netherlands)

    Mauquoy, Dmitri; Geel, Bas van; Blaauw, Maarten; Speranza, Alessandra; Plicht, Johannes van der

    2004-01-01

    Closely spaced sequences of accelerator mass spectrometer (AMS) 14C dates of peat deposits display century-scale wiggles which can be fitted to the radiocarbon calibration curve. By wiggle-matching such sequences, high-precision calendar age chronologies can be generated which show that changes in

  15. The Middle to Upper Paleolithic transition: dating, stratigraphy, and isochronous markers.

    Science.gov (United States)

    Blockley, S P E; Ramsey, C Bronk; Higham, T F G

    2008-11-01

    Accurate and precise dating is vital to our understanding of the Middle to Upper Paleolithic transition. There are, however, a number of uncertainties in the chronologies currently available for this period. We attempt to examine these uncertainties by utilizing a number of recent developments in the field. These include: the precise dating of the Campanian Ignimbrite (CI) tephra by 40Ar/39Ar; the tracing of this tephra to a number of deposits that are radiocarbon dated; the publication of revised radiocarbon calibration data for the period, showing a much better convergence with other available data than during the recent IntCal comparison; and a layer-counted ice-core chronology extending beyond 40,000cal BP. Our data comparisons suggest that a reasonable overall convergence between calibrated radiocarbon ages and calendar dates is possible using the new curves. Additionally, we suggest that charcoal-based radiocarbon ages, as well as bone-based radiocarbon determinations, require cautious interpretation in this period. Potentially, these issues extend far beyond the sites in this study and should be of serious concern to archaeologists studying the Middle to Upper Paleolithic. We conclude by outlining a strategy for moving the science forward by a closer integration of archaeology, chronology, and stratigraphy.

  16. History of radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Libby, W F [Department of Chemistry and Institute of Geophysics, University of California, Los Angeles, CA (United States)

    1967-08-15

    The development is traced of radiocarbon dating from its birth in curiosity regarding the effects of cosmic radiation on Earth. Discussed in historical perspective are: the significance of the initial measurements in determining the course of developments; the advent of the low-level counting technique; attempts to avoid low-level counting by the use of isotopic enrichment; the gradual appearance of the environmental effect due to the combustion of fossil fuel (Suess effect); recognition of the atmosphere ocean barrier for carbon dioxide exchange; detailed understanding of the mixing mechanism from the study of fallout radiocarbon; determination of the new half-life; indexing and the assimilation problem for the massive accumulation of dates; and the proliferation of measurement techniques and the impact of archaeological insight on the validity of radiocarbon dates. (author)

  17. Single amino acid radiocarbon dating of Upper Paleolithic modern humans

    Science.gov (United States)

    Marom, Anat; McCullagh, James S. O.; Higham, Thomas F. G.; Sinitsyn, Andrey A.; Hedges, Robert E. M.

    2012-01-01

    Archaeological bones are usually dated by radiocarbon measurement of extracted collagen. However, low collagen content, contamination from the burial environment, or museum conservation work, such as addition of glues, preservatives, and fumigants to “protect” archaeological materials, have previously led to inaccurate dates. These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. Here we describe a method to date hydroxyproline found in collagen (∼10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. These dates contribute considerably to our understanding of the emergence of the Mid-Upper Paleolithic and the complex suite of burial behaviors that begin to appear during this period. PMID:22517758

  18. A Proof of Concept for In-Situ Lunar Dating

    Science.gov (United States)

    Anderson, F. S.; Whitaker, T.; Levine, J.; Draper, D. S.; Harris, W.; Olansen, J.; Devolites, J.

    2015-12-01

    We have obtained improved 87Rb-87Sr isochrons for the Duluth Gabbro, an analog for lunar KREEP rocks, using a prototype spaceflight laser ablation resonance ionization mass spectrometer (LARIMS). The near-side of the Moon comprises previously un-sampled, KREEP rich, young-lunar basalts critical for calibrating the dating to constrain lunar history. Using a novel normalization approach, and by correcting for matrix-dependent isotope effects, we have been able to obtain a date of 1100 ± 200 Ma (Figure 1), compared to the previously established thermal ionization mass spectrometry measurement of 1096 ± 14 Ma. The precision of LARIMS is sufficient to constrain the current 1 Ga uncertainty of the lunar flux curve, allowing us to reassess the timing of peak lunar volcanism, and constrain lunar thermal evolution. Furthermore, an updated lunar flux curve has implications throughout the solar system. For example, Mars could have undergone a longer epoch of voluminous, shield-forming volcanism and associated mantle evolution, as well as a longer era of abundant volatiles and hence potential habitability. These alternative chronologies could even affect our understanding of the evolution of life on Earth: under the classic chronology, life is thought to have originated after the dwindling of bombardment, but under the alternative chronology, it might have appeared during heavy bombardment. In order to resolve the science questions regarding the history of the Moon, and in light of the Duluth Gabbro results, we recently proposed a Discovery mission called MARE: The Moon Age and Regolith Explorer. MARE would accomplish these goals by landing on a young, nearside lunar basalt flow southwest of Aristarchus that has a crater density corresponding to a highly uncertain absolute age, collecting >10 rock samples, and assessing their radioisotopic age, geochemistry, and mineralogy.

  19. New luminescence ages for the Galería Complex archaeological site: resolving chronological uncertainties on the acheulean record of the Sierra de Atapuerca, northern Spain.

    Science.gov (United States)

    Demuro, Martina; Arnold, Lee J; Parés, Josep M; Pérez-González, Alfredo; Ortega, Ana I; Arsuaga, Juan L; Bermúdez de Castro, José M; Carbonell, Eudald

    2014-01-01

    The archaeological karstic infill site of Galería Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range luminescence dating techniques, namely post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains, were applied to fossil-bearing sediments at Galería. The luminescence dating results are in good agreement with published chronologies derived using alternative radiometric dating methods (i.e., ESR and U-series dating of bracketing speleothems and combined ESR/U-series dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new luminescence ages are significantly (∼50%) younger than previously published polymineral thermoluminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galería deposits. The luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galería have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galería Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT

  20. Chronology of neoproterozoic-cambrian granitic magmatism in the Aracuai Belt, Eastern Brazil, based on single zircon evaporating dating

    International Nuclear Information System (INIS)

    Noce, Carlos Mauricio; Soares, Antonio Carlos Pedrosa; Macambira, Moacir Jose Buenano

    2000-01-01

    Granitic magmatism related to the orogenic stages of the Aracuai Belt took place at 595-575 Ma, and are represented by two distinct suites. One is composed of I-type granitoids and includes the following plutons: Brasilandia (595±3 Ma), Sao Vitor (576±4 Ma) and Guarataia (574± 2 Ma). The other suite comprises S-type granites like the Ataleia (591±5 Ma) and Wolf (582±5 Ma) plutons. After a long period of magnetic quiescence, a batholith composed of the Caladao granite and Padre Paraiso charnockite intruded at 519±2 Ma. This magmatic episode is probably associated to the collapse of the orogen. (author)

  1. Late Quaternary geomorphic history of a glacial landscape - new sedimentary and chronological data from the Cordillera de Cochabamba (Bolivia)

    Science.gov (United States)

    May, J.-H.; Preusser, F.; Zech, R.; Ilgner, J.; Veit, H.

    2009-04-01

    Throughout the Central Andes, glacial landscapes have long been used for the reconstruction of Late Quaternary glaciations and landscape evolution. Much work has focused on the Andes in Peru, Chile and the Bolivian Altiplano, whereas relatively little data has been published on glaciation history in the eastern Andean ranges and slopes. Even less is known with regard to the postglacial evolution of these glacial landscapes. In the Cordillera de Cochabamba (Bolivia), local maximum advances probably peaked around 20-25 ka BP and were followed by significant readvances between ~12-16 ka BP. This generally points to temperature controlled maximum glacial advances along the humid eastern slopes of the Central Andes, which is supported by glacier-climate-modelling studies. However, most studies include only marginal information with regard to the complex geomorphic and sedimentary situation in the Cordillera de Cochabamba. Furthermore, the chronological results are afflicted with several methodological uncertainties inherent to surface exposure dating and call for application of alternative, independent age dating methods. Therefore this study aims at i) documenting and interpreting the complex glacial geomorphology of the Huara Loma valley in the Cordillera de Cochabamba (Bolivia), ii) analyzing the involved units of glacial sediments, and iii) improving the chronological framework by applying optically stimulated luminescence (OSL) and radiocarbon dating (14C). For this purpose, geomorphic mapping was combined with field documentation of sedimentary profiles. The involved sediments were subject to geochemical and mineralogical analysis in order to deduce information on their erosional and weathering histories. In addition, the interpretation of OSL ages from glacial and proglacial sediments integrated several methodological procedures with regard to sample preparation and statistical analysis of the measurements in order to increase the degree of confidence. These

  2. A coherent high-precision radiocarbon chronology for the Late-glacial sequence at Sluggan Bog, Co. Antrim, Northern Ireland

    Science.gov (United States)

    Lowe, J. J.; Walker, M. J. C.; Scott, E. M.; Harkness, D. D.; Bryant, C. L.; Davies, S. M.

    2004-02-01

    Seventy-five radiocarbon dates are presented from Sluggan Bog in Co. Antrim, Northern Ireland. The Holocene peats are underlain by Late-glacial sediments, which also appear to have accumulated largely in a mire environment. The radiocarbon dates, from the Late-glacial and early Holocene part of the profile, were obtained from the humic and humin fractions of the sedimentary matrix, and from plant macrofossils. The last-named were dated by AMS and the sediment samples by radiometric (beta counting) methods. Age-depth models for the three dating series show a very high level of agreement between the two fractions and the macrofossils. No statistically significant difference is found between the beta counting and AMS results. Three tephras were located in the profile, the uppermost of which is in a stratigraphical position suggestive of the Vedde Ash, but the geochemical and radiocarbon evidence do not support this interpretation. The lower ashes are in the correct stratigraphical position for the Laacher See and Borrobol tephras, attributions substantiated by the radiocarbon evidence, but not by the geochemical data. The Sluggan sequence has generated one of the most internally consistent radiocarbon chronologies for any Late-glacial site in the British Isles, and it is suggested that in future more effort should be devoted to the search for, and analysis of, Late-glacial mire sequences, rather than the limnic records that have formed the principal focus of Late-glacial investigations hitherto. Copyright

  3. Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania

    Science.gov (United States)

    Ranhorn, Kathryn L.; Kwekason, Amandus; Alex, Bridget; Laird, Myra F.; Marean, Curtis W.; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z. P.

    2018-01-01

    The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46–42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39–34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa. PMID:29489827

  4. Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania.

    Science.gov (United States)

    Tryon, Christian A; Lewis, Jason E; Ranhorn, Kathryn L; Kwekason, Amandus; Alex, Bridget; Laird, Myra F; Marean, Curtis W; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z P

    2018-01-01

    The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46-42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39-34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa.

  5. Obsidian dating prospects

    International Nuclear Information System (INIS)

    Ambrose, W.

    1997-01-01

    Full text: Developments in the nuclear industry have shown that some of the problems related to the glassification of waste for long term storage are centred on the rate of glass weathering in various repositories. Long term weathering of artificial glasses is paralleled by the archaeological problem of determining hydration rates in obsidian artefacts as a means of dating their manufacture. Figures available for sites in Papua New Guinea indicate that the weathering rate is sufficiently fast to render conventional hydration measurement completely unreliable. This follows from the range of calculated surface reduction rates which range between .0002μ to .004μ per year depending on the site's location and the obsidian source. Hydration rates for key Papua New Guinea obsidians have been determined from long term experimental laboratory exposure and these are used to evaluate the age of obsidians from selected archaeological sites. By adopting a strategy of measuring hydration in concealed fissures both the weathering rate and the dating of the Papua New Guinea obsidians have been successfully achieved. The dissolution rates of natural obsidians could be useful in considering weathering rates for artificial glasses. An improved system for calculating the annual effective hydration temperature is presented which gives a better control of micro-environmental temperature in its crucial rate determining role. The combined result of these developments gives obsidian hydration dating an enhanced capacity to be a useful and independent dating system

  6. Confronting Dating Violence.

    Science.gov (United States)

    McNulty, Raymond J.; Heller, Daniel A.; Binet, Tracy

    1997-01-01

    To be safe havens for children, schools cannot address the intellect only. Brattleboro (Vermont) Union High School went beyond academics by sponsoring a performance of "The Yellow Dress," a powerful one-woman play about a teenage victim of dating violence. The production challenged participants to unite school and community, intellect…

  7. The Realities of Date Rape.

    Science.gov (United States)

    Presley, Cara; Watson, Jennifer; Williams, Audrey R.

    This poster presentation addresses the issue of date rape, specifically in the college environment. Highlighted are date rape statistics, demographics, and date rape drugs. Also discussed are date rape warnings and prevention strategies. It is concluded that college and university administrators must place the issue of date rape and acquaintance…

  8. ŞTEFANIA CRISTESCU-GOLOPENŢIA’S CHRONOLOGY

    Directory of Open Access Journals (Sweden)

    Professor Emerita Sanda Golopentia

    2013-05-01

    Full Text Available The present Chronology brings together data from the personal archive of Şt. C.-G. with data accumulated during the editing of her published and posthumous work that Sanda Golopenţia undertook after 1989. The author specifically calls attention to the new data regarding Şt. C.-G.’s 1938 and 1939 regional research in Ţara Oltului (the Olt County, the research she conducted in 1945 and 1947 in the Gurghiu Valley, and the social inquiry on the daily lives of her students in the Industrial Colege “Protopopul Tudor Economul” from Bucharest (1942–1943. The bibliography of Şt. C.-G.’s sociological, pedagogical and literary works was updated

  9. Cortical laminar necrosis in brain infarcts: chronological changes on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, M. [Department of Neurosurgery, Osaka City General Hospital, 2-13-22, Miyakojima-Hondouri, Miyakojima, Osaka 534 (Japan); Nishikawa, M. [Department of Neurosurgery, Osaka City General Hospital, 2-13-22, Miyakojima-Hondouri, Miyakojima, Osaka 534 (Japan); Yasui, T. [Department of Neurosurgery, Osaka City General Hospital, 2-13-22, Miyakojima-Hondouri, Miyakojima, Osaka 534 (Japan)

    1997-07-10

    We studied the MRI characteristics of cortical laminar necrosis in ischaemic stroke. We reviewed 13 patients with cortical laminar high signal on T1-weighted images to analyse the chronological changes in signal intensity and contrast enhancement. High-density cortical lesions began to appear on T1-weighted images about 2 weeks after the ictus. At 1-2 months they were prominent. They began to fade from 3 months but could be seen up to 11 months. These cortical lesions showed isointensity or high intensity on T2-weighted images and did not show low intensity at any stage. Contrast enhancement of the laminar lesions was prominent at 1-2 months and became less apparent from 3 months, but could be seen up to 8 months. (orig.). With 6 figs., 1 tab.

  10. Chronology of lead pollution contained in banded coral skeletons

    Energy Technology Data Exchange (ETDEWEB)

    Dodge, R E; Gilbert, T R

    1984-08-01

    The possibility of the annual skeletal growth bands of reef-building corals containing a record of lead additions to the marine environment was investigated using coral skeletons from St. Croix, Virgin Islands. Concentrations of lead within a coral from a polluted reef averaged 395 ng/g, five fold higher than within a coral from a pristine site, 87 ng/g. The lead chronologies of both corals showed a significant increase in concentration towards the present during the past 26 yr. The increase in lead concentration in the coral from the pristine site is suggested to represent the increase in lead availability from global pollution. Coral skeletons offer the probability of development into tools for long term chemical recorders of levels of lead and possibly other metals or compounds in seawater. 50 references, 3 figures, 1 table.

  11. Thermoluminescence dating of pottery

    International Nuclear Information System (INIS)

    Higashimura, Takenobu; Ichikawa, Yoneta.

    1978-01-01

    This report is divided into two parts. The first half describes on the history of thermoluminescence dating, and the latter half, the principle and measurement examples. It was in late 1955 that the measurement of radiation dose using thermoluminescence began. The method to thermoluminescence dating was developed when it was found that most natural stones emit the thermoluminescence. About Greek earthen wares, the study of which was presented in 1961 by G. Kennedy of University of California, the dating was able to be made within the standard deviation of 10%. Since then, this dating method progressed rapidly, and a number of laboratories are now forwarding the investigation. In the samples of natural materials, intensity of thermoluminescence I is proportional to natural radiation dose D which has been absorbed by the samples, i.e. I = kD, where k is the susceptibility of thermoluminescence of the samples. Since k is different in each sample, D can be determined by irradiating the sample with β or γ ray of known dose D 0 , measuring its luminescence I 0 , and eliminating k through these two equations, because i 0 = kD 0 . Next, if t is assumed to be the time passed since a pottery was made, D is expressed as Rt, where R is the natural radiation dose per year absorbed by the pottery. Thus t is determined if R is known. The report describes on the method of measuring R. As an example, the results of measurement of the potteries excavated at Iwakura remains, Yorikura, Taishaku-kyo, are listed. Results by 14 C dating are also described for reference. (Wakatsuki, Y.)

  12. Chronology of deep nodes in the neotropical primate phylogeny: insights from mitochondrial genomes.

    Science.gov (United States)

    Schrago, Carlos G; Menezes, Albert N; Moreira, Miguel A M; Pissinatti, Alcides; Seuánez, Hector N

    2012-01-01

    The evolution of Neotropical Primates (NP) is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. These questions can be better understood by providing a robust estimate of the chronological scenario of NP evolution, a reason why molecular dating methods have been widely applied. One aspect of especial interest is the timing of diversification of the major NP lineages (pitheciids, atelids and cebids), which may have resulted from rapid episodes of adaptive radiation, a question that requires NP divergence time estimates with accurate statistical certainty. In this study, we evaluated the primate timescale focused on the age of nodes of NP radiation. We investigated the performance of complete primate mitochondrial genomes as traditional molecular markers of primate evolution and further including original mitochondrial data from the endangered muriqui, Brachyteles arachnoides (Accession No. JX262672). Comparisons of the age estimates at NP nodes based on mitochondrial genomes with those obtained from a nuclear supermatrix showed similar degrees of uncertainty. Further molecular data and more informative calibration priors are required for a more precise understanding of the early NP diversification.

  13. Chronology of deep nodes in the neotropical primate phylogeny: insights from mitochondrial genomes.

    Directory of Open Access Journals (Sweden)

    Carlos G Schrago

    Full Text Available The evolution of Neotropical Primates (NP is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. These questions can be better understood by providing a robust estimate of the chronological scenario of NP evolution, a reason why molecular dating methods have been widely applied. One aspect of especial interest is the timing of diversification of the major NP lineages (pitheciids, atelids and cebids, which may have resulted from rapid episodes of adaptive radiation, a question that requires NP divergence time estimates with accurate statistical certainty. In this study, we evaluated the primate timescale focused on the age of nodes of NP radiation. We investigated the performance of complete primate mitochondrial genomes as traditional molecular markers of primate evolution and further including original mitochondrial data from the endangered muriqui, Brachyteles arachnoides (Accession No. JX262672. Comparisons of the age estimates at NP nodes based on mitochondrial genomes with those obtained from a nuclear supermatrix showed similar degrees of uncertainty. Further molecular data and more informative calibration priors are required for a more precise understanding of the early NP diversification.

  14. Chronological study of 137Cs input to the Black Sea deep and shelf sediments

    International Nuclear Information System (INIS)

    Gulin, S.B.; Polikarpov, G.G.; Egorov, V.N.; Aarkrog, A.; Nielsen, S.P.

    1997-01-01

    The chart of the post-Chernobyl 137 Cs distribution in the upper Black Sea sediments was made. The field of sediments with the highest 137 Cs activity was found near the Danube River mouth. The age of sediment layers as well as the sedimentation rates were calculated from 137 Cs vertical profiles in the top of the uncompacted sediments nearby the Danube (11.5 mm yr -1 ), the NW Black Sea slope (2.2 mm yr -1 ) and the deepest western area (0.4 mm yr -1 ). Subsequent assessments showed the high distinction of 137 Cs sedimentary fluxes and inventories between these sites related to different contributions of terrigenous matter in the sediments, as traced by 40 K. The results allow to reconstruct chronology of 137 Cs input to the Black Sea over the last decades. The traced three most notable phases correspond well with the periods of active nuclear weapon testings in the 1950's and 1960's as well as of the Chernobyl NPP accident. The post-Chernobyl dynamics of 137 Cs activity in the near Danube sediments traced from its dated profile was like that observed during the annual monitoring. (author)

  15. Gamma Spectrometry for Chronology of Recent Sediments. Tracing Human Induced Climate Change in NW Africa

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, D.; Fischer, H. W. [Institute of Environmental Physics, University of Bremen, Bremen (Germany); Mulitza, S. [MARUM - Center for Marine Environmental Sciences, University of Bremen, (Germany)

    2013-07-15

    Gamma spectroscopy was used for the determination of radionuclides in sediment cores from the continental shelf off northwest africa to provide age control of the sediment record used for a study of aridification of the Sahel zone. {sup 210}Pb, {sup 226}Ra and {sup 137}Cs were measured in the upper part of a gravity core and the associated multicorer and used for aligning these cores. This provided information about the amount of sediment loss due to the sampling procedure in the upper part of the gravity core. The age model based on the matched profiles extended to 140 years B.P. and the rest of the gravity core was dated by {sup 14}C. The {sup 210}Pb age allowed the estimation of the local radiocarbon reservoir age. Application of {sup 210}Pb and {sup 137}Cs chronology helps to significantly extend paleoclimatic proxy data into the Anthropocene, thereby allowing the comparison of human induced climate change with natural climate variability. (author)

  16. Correlating Ice Cores from Quelccaya Ice Cap with Chronology from Little Ice Age Glacial Extents

    Science.gov (United States)

    Stroup, J. S.; Kelly, M. A.; Lowell, T. V.

    2010-12-01

    Proxy records indicate Southern Hemisphere climatic changes during the Little Ice Age (LIA; ~1300-1850 AD). In particular, records of change in and around the tropical latitudes require attention because these areas are sensitive to climatic change and record the dynamic interplay between hemispheres (Oerlemans, 2005). Despite this significance, relatively few records exist for the southern tropics. Here we present a reconstruction of glacial fluctuations of Quelccaya Ice Cap (QIC), Peruvian Andes, from pre-LIA up to the present day. In the Qori Kalis valley, extensive sets of moraines exist beginning with the 1963 AD ice margin (Thompson et al., 2006) and getting progressively older down valley. Several of these older moraines can be traced and are continuous with moraines in the Challpa Cocha valley. These moraines have been dated at chronology of past ice cap extents are correlated with ice core records from QIC which show an accumulation increase during ~1500-1700 AD and an accumulation decrease during ~1720-1860 AD (Thompson et al., 1985; 1986; 2006). In addition, other proxy records from Peru and the tropics are correlated with the records at QIC as a means to understand climate conditions during the LIA. This work forms the basis for future modeling of the glacial system during the LIA at QIC and for modeling of past temperature and precipitation regimes at high altitude in the tropics.

  17. Early hominins in north-west Europe: A punctuated long chronology?

    Science.gov (United States)

    Hosfield, Rob; Cole, James

    2018-06-01

    In light of changing views regarding the identity and evolutionary positions of Europe's Lower Palaeolithic hominins, a re-consideration of the hominin occupation of north-west Europe from c. 1 million years ago (mya) to c. 400 thousand years ago (kya) is timely. A change in the scale and character of the overall European Palaeolithic record around c. 800-600 kya has been well documented and argued over since the mid-1990s. Hominin expansion into the European north-west, potentially from southern Europe, Africa or south-western Asia, has been linked to the introduction of a new lithic technology in the form of the biface. We evaluate three potential drivers for this northern range expansion: changing palaeo-climatic conditions, the emergence of an essentially modern human life history, and greater hominin behavioural plasticity. Our evaluation suggests no major changes in these three factors during the c. 800-600 kya period other than enhanced behavioural plasticity suggested by the appearance of the biface. We offer here a model of hominin occupation for north-west Europe termed the 'punctuated long chronology' and suggest that the major changes in the European Lower Palaeolithic record that occur at a species-wide level may post-date, rather than precede, the Anglian Glaciation (marine isotope stage (MIS) 12).

  18. Chronology of the Third – Fifth Centuries Male Graves from the Tarasovo Burial Ground

    Directory of Open Access Journals (Sweden)

    Goldina Rimma D.

    2016-09-01

    Full Text Available The article focuses on the chronological attribution of male graves from the late Mazunino stage of the Tarasovo burial ground and is a sequel to an earlier article about dating of the early Nyrgynda stage (1st – 2nd centuries of the same site. The three main methods employed in this research include those of formal typology, cultural stratigraphy and the nearest neighbor method. Eighty-six male graves of the third-fifth centuries were analyzed, with 12 identified as a result: first half of the 3rd c. AD (group 1, second half of the 3rd c. AD (2; 3rd c. (3; first half of the 4th c. (group 4; second half of the 3rd – 4th c. (5; third quarter of the 4th c. (6; fourth quarter of the 4th c. (group 7; second half of the 4th c. (8; second half of the 4th – 5th c. (9; 4th – 5th cc. (10; second half of the 3rd – 5th cc. (11 and 3rd – 5th cc. (12. This article minutes investigates the first six groups, while the rest will be covered in the next publication. Artifacts form the third – fifth century female graves of the Tarasovo burial ground will be studied separately.

  19. Time in tortoiseshell: a bomb radiocarbon-validated chronology in sea turtle scutes.

    Science.gov (United States)

    Van Houtan, Kyle S; Andrews, Allen H; Jones, T Todd; Murakawa, Shawn K K; Hagemann, Molly E

    2016-01-13

    Some of the most basic questions of sea turtle life history are also the most elusive. Many uncertainties surround lifespan, growth rates, maturity and spatial structure, yet these are critical factors in assessing population status. Here we examine the keratinized hard tissues of the hawksbill (Eretmochelys imbricata) carapace and use bomb radiocarbon dating to estimate growth and maturity. Scutes have an established dietary record, yet the large keratin deposits of hawksbills evoke a reliable chronology. We sectioned, polished and imaged posterior marginal scutes from 36 individual hawksbills representing all life stages, several Pacific populations and spanning eight decades. We counted the apparent growth lines, microsampled along growth contours and calibrated Δ(14)C values to reference coral series. We fit von Bertalanffy growth function (VBGF) models to the results, producing a range of age estimates for each turtle. We find Hawaii hawksbills deposit eight growth lines annually (range 5-14), with model ensembles producing a somatic growth parameter (k) of 0.13 (range 0.1-0.2) and first breeding at 29 years (range 23-36). Recent bomb radiocarbon values also suggest declining trophic status. Together, our results may reflect long-term changes in the benthic community structure of Hawaii reefs, and possibly shed light on the critical population status for Hawaii hawksbills. © 2016 The Author(s).

  20. The origin and chronology of medieval silver coins based on the analysis of chemical composition

    Directory of Open Access Journals (Sweden)

    Pańczyk Ewa

    2015-09-01

    Full Text Available Medieval Central Europe coins - the Saxon coins, also called as the Otto and Adelheid denarii, as well as the Polish ones, the Władysław Herman and Bolesław Śmiały coins - were examined to determine their provenance and dating. Their attribution and chronology often constitute a serious problem for historians and numismatists. For hundreds of years, coins were in uncontrolled conditions and in variable environment. Destructed and inhomogeneous surface were the effect of corrosion processes. Electron microscopy with energy dispersive X-ray analysis (scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS, X-ray fluorescence (XRF analysis (energy dispersive X-ray fluorescence (EDXRF and total reflection X-ray fluorescence (TXRF, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS were applied. The results of these investigations are significant for our knowledge of the history of Central European coinage, especially of Polish coinage

  1. Geological reconnaissance and chronologic studies. Technical report No. 33

    International Nuclear Information System (INIS)

    Davis, J.

    1983-03-01

    There are several possible scenarios by which a radioactive waste storage facility in the unsaturated zone could be compromised; among them erosion, water table rise, or downward percolation of water. In order to assess these risks, the geologic and climatic events of the past few million years can be used to project the future of the unsaturated deposits. Geologic reconnaissance on and around the NTS was undertaken to identify specific evidence of depositional, erosional, and hydrologic events, as well as to develop an understanding of the timing of these events. Several kinds of evidence were noted and studied: layers or volcanic ash in the basin-fill sediments were discovered and dated at 11 to 5 m.y. old, showing the modern valleys and ranges are at least 11 m.y. old. Exposure of these ash layers by erosion has taken 5 m.y., implying that additional millions of years must pass before modern closed basins on the NTS are eroded. Detailed study of young sediments in Las Vegas Valley suggest that water tables stood at 926 m as recently as 14,000 y ago. To the northeast or the NTS, sediments in basin bottoms also reflect high water tables until about 7000 y ago, but sediments on the NTS proper do not show this effect during the last 700,000 y. The observed relation between erosion due to downwearing or mountain ranges and infilling of valleys suggests that these processes continue, only the uppermost parts of present alluvial fans will be eroded

  2. Towards a sustainable healthy working life : associations between chronological age, functional age and work outcomes

    NARCIS (Netherlands)

    Koolhaas, Wendy; van der Klink, Jac J. L.; Groothoff, Johan W.; Brouwer, Sandra

    Background: The aims of this study were: (i) to determine the relation between chronological and functional age; (ii) to examine the association between chronological age and work outcomes; and (iii) to examine the association between functional age and work outcomes. An overview of the most

  3. Archaeomagnetic studies in central Mexico—dating of Mesoamerican lime-plasters

    Science.gov (United States)

    Hueda-Tanabe, Y.; Soler-Arechalde, A. M.; Urrutia-Fucugauchi, J.; Barba, L.; Manzanilla, L.; Rebolledo-Vieyra, M.; Goguitchaichvili, A.

    2004-11-01

    For the first time results of an archaeomagnetic study of unburned lime-plasters from Teotihuacan and Tenochtitlan in central Mesoamerica are presented. Plasters made of lime, lithic clasts and water, appear during the Formative Period and were used for a variety of purposes in floors, sculptures, ceramics and supporting media for mural paintings in the Oaxaca and Maya area. In Central Mexico, grinded volcanic scoria rich in iron minerals is incorporated into the lime-plasters mixture. Samples were selected from two archaeological excavation projects in the Teopancazco residential compound of Teotihuacan and the large multi-stage structure of Templo Mayor in Tenochtitlan, where chronological information is available. The intensity of remanent magnetization (natural remanent magnetization (NRM)) and low-field susceptibility are weak reflecting low relative content of magnetic minerals. NRM directions are well grouped and alternating field demagnetization shows single or two-component magnetizations. Rockmagnetic experiments point to fine-grained titanomagnetites with pseudo-single domain behavior. Anisotropy of magnetic susceptibility (AMS) measurements document a depositional fabric, with normal to free-surface minimum AMS axes. Characteristic mean site directions were correlated to the paleosecular variation curve for Mesoamerica. Data from Templo Mayor reflect recent tilting of the structures. Teopancazco mean site declinations show good correspondence with the reference curve, in agreement with the radiocarbon dating. Dates for four stages of Teotihuacan occupancy based on the study of lime-plasters range from AD 350 to 550. A date for a possible Mazapa occupation around AD 850 or 950 is also suggested based on the archaeomagnetic correlation. The archaeomagnetic record of a plaster floor in Teopancazco differed from the other nearby sites pointing to a thermoremanent magnetization; comparison with the reference curve suggests dates around AD 1375 or 1415. The

  4. Late Quaternary chronology of paleo-climatic changes in Caspian Sea region based on Lower Volga sections

    Science.gov (United States)

    Kurbanov, Redzhep; Yanina, Tamara; Murray, Andrew; Svitoch, Alexander; Tkach, Nikolai

    2017-04-01

    Lower Volga is a unique region for understanding the history of the Caspian Sea in the Pleistocene, its correlation of paleogeographic events with glacial-interglacial rhythms of the East European Plain and the global and regional climate changes. The reason is representativeness of Quaternary sections, their completeness, presence of both marine and subaerial sediments, paleontological richness of the materials and available for study. The purpose of this work is to reconstruct the paleogeographic events in the Late Pleistocene of the Lower Volga region on the basis of summarizing the study results for the Srednyaya Akhtuba reference section. Located near city of Volgograd, at Khvaynian plain natural outcrop of Srednyaya Akhtuba section, reveals in a series of exposures a unique to the region series of marine Caspian continental deposits with four levels of buried soil horizons and loess. The results were obtained during 2015 and 2016 complex field research with application of lithological, paleopedological, paleontological, paleocryological, OSL-dating, paleomagnetic methods, that allowed more fundamental approach to the chronological assessment of individual horizons. The structure of the Srednyaya Akhtuba reference section reflects a number of paleogeographic stages of development of the study area. The oldest phase (layers 22-19) is not characterized by OSL dating or faunal material. Based on the sequence of dated layers, we assume its Middle Pleistocene age (MIS-6 stage), corresponding to Moscow stage of the Dnieper glaciation of the East European Plain and the final stage of Early Khazarian transgressive era of Caspian sea. The next stage (layers 18-14), represented by three horizons of paleosols, refers to the first half of the Late Pleistocene (MIS 5). Epoch of soil formation, based on the results the OSL-dating, can be referred to the warm sub-stages (MIS 5c and 5a), with unstable climatically transitional phase from Mikulino (Eemian) interglacial to the

  5. Multi-method chronological investigation of a Middle Paleolithic stratigraphic context in Eastern Transylvania, Romania

    Science.gov (United States)

    Veres, Daniel; Cosac, Marian; Muratoreanu, George; Niţǎ, Loredana; Schmidt, Christoph; Hambach, Ulrich; Hubay, Katalin; Alexandru, Radu; Cuculici, Roxana; Lucian Buzea, Dan; Dumitraşcu, Valentin

    2016-04-01

    The Middle to Upper Paleolithic transition is one of the crucial periods of change in the prehistory of Europe due to the full emergence, continent-wide, of modern human technologies, detrimental of Neanderthal survival. Knowledge about the transition is vast, however, the evidence for cultural and technological developments in the Carpathian - Lower Danube area is still rather sparse. Here we discuss latest results arising from an archaeological-chronological investigation of a Middle Paleolithic context within the Varghis karst, eastern Transylvania, Romania. Combining our results with these of previous excavations, we can distinguish several stages of habitation in the area comprising a rock shelter connected to a newly discovered filled-in cave entrance. Reanalysis of the deeper stratigraphy previously unexcavated shows that at least two main habitation levels have been preserved. In both levels, the bone assemblages (Bos/Bison, Capra, Canis lupus, Ursus spaeleus) directly associated with lithics point to human-accumulation of material. In order to augment the typological cultural considerations, we applied direct radiocarbon dating on bones from within the occupation layers and on scattered charcoal, for the latter following a two-step combustion protocol (1). Radiocarbon dating on bones suggests the lowermost occupation layer is >43.4 radiocarbon kyr BP old, whereas the preliminary infrared stimulated luminescence (IRSL) ages on the lowermost productive layer and above it indicate surprisingly old ages of ca. 120 kyr and respectively, ca. 70 kyr. Multiple-protocol dating of charcoal found within the two habitation layers produced ages >38 radiocarbon kyr BP, suggesting that the lowermost habitation layer unequivocally pertains to the Middle Paleolithic industries. For the upper productive layer, radiocarbon dating of charcoal found 20 cm above it produced a surprisingly young age of 17.4 radiocarbon kyr BP. However, as the carbon content of this sample was

  6. Dating recent floodplain sediments in the Hawkesbury-Nepean River system, eastern Australia using single-grain quartz OSL

    DEFF Research Database (Denmark)

    Sim, Anna K.; Thomsen, Kristina Jørkov; Murray, K.J.

    2014-01-01

    Two fluvial sediment cores taken from a floodplain of the Hawkesbury-Nepean River system in the Sydney region, eastern Australia are dated using Optically Stimulated Luminescence (OSL) to provide a reliable chronology essential for the management and planning of water resources. Nine charcoal 14C...... in an average apparent age overestimation of ~200 years, which is significant for these samples, but negligible for sediments older than a few thousand years. The intention is that the chronology obtained in this study will be used in conjunction with a proxy flood record, derived from floodplain sediments...

  7. It's about time? Testing the Dawson ceramic seriation using luminescence dating, Southern Nasca Region, Peru

    OpenAIRE

    Vaughn, KJ; Eerkens, JW; Lipo, C; Sakai, S; Schreiber, K

    2014-01-01

    Copyright © 2014 by the Society for American Archaeology. The Dawson seriation of Nasca ceramics has long been assumed to be an accurate marker of temporal changes in the pre-hispanic south coast of Peru. We test this assumption by directly dating a sample of sherds using Optically Stimulated Luminescence (OSL). Our results suggest that while some phases of the seriation are valid chronological markers, others appear to be the result of factors other than time. We discuss the implications of ...

  8. Amino acid racemisation dating

    International Nuclear Information System (INIS)

    Murray-Wallace, C.V.

    1999-01-01

    The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject

  9. Dating fractures in infants

    Energy Technology Data Exchange (ETDEWEB)

    Halliday, K.E., E-mail: kath.halliday@nuh.nhs.uk [Department of Radiology, Nottingham University Hospitals, Queen' s Medical Centre, Nottingham (United Kingdom); Broderick, N J; Somers, J M [Department of Radiology, Nottingham University Hospitals, Queen' s Medical Centre, Nottingham (United Kingdom); Hawkes, R [Department of Radiology, Paul O' Gorman Building, Bristol (United Kingdom)

    2011-11-15

    Aim: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. Materials and methods: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. Results: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. Conclusion: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.

  10. Dating fractures in infants

    International Nuclear Information System (INIS)

    Halliday, K.E.; Broderick, N.J.; Somers, J.M.; Hawkes, R.

    2011-01-01

    Aim: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. Materials and methods: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. Results: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. Conclusion: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.

  11. Thermoluminescence dating method

    International Nuclear Information System (INIS)

    Zink, A.

    2004-01-01

    A crystal that is submitted to radiation stores energy and releases this energy under the form of light whenever it is heated. These 2 properties: the ability to store energy and the ability to reset the energy stored are the pillars on which time dating methods like thermoluminescence are based. A typical accuracy of the thermoluminescence method is between 5 to 7% but an accuracy of 3% can be reached with a sufficient number of measurement. This article describes the application of thermoluminescence to the dating of a series of old terra-cotta statues. This time measurement is absolute and does not require any calibration, it represents the time elapsed since the last heating of the artifact. (A.C.)

  12. Radiocarbon dating for contributors

    International Nuclear Information System (INIS)

    Jansen, H.S.

    1984-06-01

    This report describes the radiocarbon facility at the Institute of Nuclear Sciences, and is written for potential contributors, current users, and for those who advise others. The report briefly outlines the principles and practices of C-14 dating; with emphasis on factors that enable contributors to judge whether C-14 work is appropriate, and to assist them with the procedures to be followed in order to get the best results. Age determinations, being the main requirements by contributors, have been discussed in detail

  13. Chronology of fast climatic changes during the last glacial period; Chronologie des variations climatiques rapides pendant la derniere periode glaciaire

    Energy Technology Data Exchange (ETDEWEB)

    Bard, E.; Rostek, F.; Menot-Combes, G. [Cerege, UMR 6635 et College de France, 13 - Aix-en-Provence (France)

    2006-01-15

    The history of the glacial climate is punctuated by events occurring at the scale of a human life. They are characterised by temperature changes of large amplitude, simultaneously in Greenland and the North Atlantic. These events affected not only the surface hydrology, but also the deep circulation of this oceanic basin. A by-product of the obvious correspondence between Dansgaard-Oeschger and Heinrich in the polar ice and marine sediments is to allow, by correlation, the construction of a calendar chronology for the marine records. This chronostratigraphic approach was validated by means of radiocarbon dating of deep-sea sediments raised on the Iberian Margin. Our study also contributes to the international effort of calibration of the radiocarbon time scale by providing significant results in the interval between 33000 and 41000 years calendar BP. (authors)

  14. A comparison of U/Th and rapid-screen 14C dates from Line Island fossil corals

    Science.gov (United States)

    Grothe, Pamela R.; Cobb, Kim M.; Bush, Shari L.; Cheng, Hai; Santos, Guaciara M.; Southon, John R.; Lawrence Edwards, R.; Deocampo, Daniel M.; Sayani, Hussein R.

    2016-03-01

    Time-consuming and expensive radiometric dating techniques limit the number of dates available to construct absolute chronologies for high-resolution paleoclimate reconstructions. A recently developed rapid-screen 14C dating technique reduces sample preparation time and per sample costs by 90%, but its accuracy has not yet been tested on shallow-water corals. In this study, we test the rapid-screen 14C dating technique on shallow-water corals by comparing 44 rapid-screen 14C dates to both high-precision 14C dates and U/Th dates from mid- to late-Holocene fossil corals collected from the central tropical Pacific (2-4°N, 157-160°W). Our results show that 42 rapid-screen 14C and U/Th dates agree within uncertainties, confirming closed-system behavior and ensuring chronological accuracy. However, two samples that grew ˜6500 years ago have calibrated 14C ages ˜1000 years younger than the corresponding U/Th ages, consistent with diagenetic alteration as indicated by the presence of 15-23% calcite. Mass balance calculations confirm that the observed dating discrepancies are consistent with 14C addition and U removal, both of which occur during diagenetic calcite recrystallization. Under the assumption that aragonite-to-calcite replacement is linear through time, we estimate the samples' true ages using the measured 14C and U/Th dates and percent calcite values. Results illustrate that the rapid-screen 14C dates of Holocene-aged fossil corals are accurate for samples with less than 2% calcite. Application of this rapid-screen 14C method to the fossil coral rubble fields from Kiritimati Island reveal significant chronological clustering of fossil coral across the landscape, with older ages farther from the water's edge.

  15. Sediment dating in review

    International Nuclear Information System (INIS)

    Prescott, J.R.; Robertson, G.B.

    1997-01-01

    The paper will comment on a few issues of particular relevance to Australasia. Thermoluminescent (TL) methods applied to open sites have been demonstrated to be effective. A particularly good example of this is to be found in the South East of South Australia, where a sequence of low ranges runs roughly parallel with the coast. They represent relict sand dunes left behind, on a slowly rising land surface by successive interglacial incursions of the sea at roughly 120 ka intervals. Comparison with ages established on independent geological grounds allows a test of quartz TL and IRSL ages that is believable back to 500 ka. Older than this, we do not yet understand the physics of the quartz well enough to go unequivocally forward (backward?). Similar results are emerging elsewhere. With dating limits being pushed ever further back, the time variation of the environmental radiation giving rise to the stored luminescent energy needs to be addressed. Particularly at wet sites, radioactive disequilibrium must be considered. In any case, a time profile of the radiation dose rate needs to be determined.In dating a given site or sites the value of ages obtained by any dating method,including C-14, is enhanced by parallel measurements with an different method

  16. Surface dating of bricks, an application of luminescence techniques

    Science.gov (United States)

    Galli, Anna; Martini, Marco; Maspero, Francesco; Panzeri, Laura; Sibilia, Emanuela

    2014-05-01

    Luminescence techniques are a powerful tool to date archaeological ceramic materials and geological sediments. Thermoluminescence (TL) is widely used for bricks dating to reconstruct the chronology of urban complexes and the development of human cultures. However, it can sometimes be inconclusive, since TL assesses the firing period of bricks, which can be reused, even several centuries later. This problem can be circumvented using a dating technique based on a resetting event different from the last heating. OSL (Optically Stimulated Luminescence) exploits the last light exposition of the brick surface, which resets the light-sensitive electron traps until the surface is definitely shielded by mortar and superimposed bricks. This advanced application (surface dating) has been successfully attempted on rocks, marble and stone artifacts, but not yet on bricks. A recent conservation campaign at the Certosa di Pavia gave the opportunity to sample some bricks belonging to a XVII century collapsed wall, still tied to their mortars. This was an advantageous condition to test this technique, comparing the dating results with precise historical data. This attempt gave satisfactory results, allowing to identify bricks surely reused and to fully confirm that the edification of the perimetral wall occurred at the end of XVII century.

  17. Sun, Ocean, Nuclear Bombs, and Fossil Fuels: Radiocarbon Variations and Implications for High-Resolution Dating

    Science.gov (United States)

    Dutta, Koushik

    2016-06-01

    Radiocarbon, or 14C, is a radiometric dating method ideally suited for providing a chronological framework in archaeology and geosciences for timescales spanning the last 50,000 years. 14C is easily detectable in most common natural organic materials and has a half-life (5,730±40 years) relevant to these timescales. 14C produced from large-scale detonations of nuclear bombs between the 1950s and the early 1960s can be used for dating modern organic materials formed after the 1950s. Often these studies demand high-resolution chronology to resolve ages within a few decades to less than a few years. Despite developments in modern, high-precision 14C analytical methods, the applicability of 14C in high-resolution chronology is limited by short-term variations in atmospheric 14C in the past. This article reviews the roles of the principal natural drivers (e.g., solar magnetic activity and ocean circulation) and the anthropogenic perturbations (e.g., fossil fuel CO2 and 14C from nuclear and thermonuclear bombs) that are responsible for short-term 14C variations in the environment. Methods and challenges of high-resolution 14C dating are discussed.

  18. Radiocarbon dating of Sphagnum cellulose from Mohos peat bog, East Carpathians

    Science.gov (United States)

    Hubay, Katalin; Braun, Mihály; Harangi, Sándor; Palcsu, László; Túri, Marianna; Rinyu, László; Molnár, Mihály

    2015-04-01

    This work focuses on building a high-resolution age-depth model for quantitative paleoclimate study from the Mohos peat bog, East Carpathians. Peats are important archives for Quaternary science, because they preserve environmental changes. To study the chronology of peat profiles the key is in the precise coring and reliable dating. However, many studies dealing with coring and radiocarbon dating of peat deposits they often shown problems with the proper methods and material. With our novel coring technique we reached undisturbed and uncompressed peat cores from the Mohos bog. A 10 meter deep peat profile was drilled in 2012 using a modified technique of a piston corer. The core presents a continuous peat profile from the last 11.500 cal. yr BP. The chronology was based on AMS radiocarbon analyses of the separated Sphagnum samples from different depths of the profile. The peat samples were wet sieved (40-280 μm) to avoid contamination by rootlets. Dry Sphagnum samples for AMS dating were prepared using the classical acid-base-acid (ABA) method completed with an oxidative bleaching step to get clean cellulose. Sphagnum cellulose samples were converted to CO2 and later graphite and measured by EnvironMICADAS accelerator mass spectrometry (AMS) in Hertelendi Laboratory (Debrecen, Hungary). Fine peat accumulation rate changes (sections with lowest accumulation values) were observed along the profile. Based on the chronology in further studies we want to focus special intervals to investigate environmental changes in the Holocene. Key words: peat, radiocarbon, cellulose

  19. A New Chronology for Rhafas, Northeast Morocco, Spanning the North African Middle Stone Age through to the Neolithic.

    Science.gov (United States)

    Doerschner, Nina; Fitzsimmons, Kathryn E; Ditchfield, Peter; McLaren, Sue J; Steele, Teresa E; Zielhofer, Christoph; McPherron, Shannon P; Bouzouggar, Abdeljalil; Hublin, Jean-Jacques

    Archaeological sites in northern Africa provide a rich record of increasing importance for the origins of modern human behaviour and for understanding human dispersal out of Africa. However, the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb), and their relationship to local environmental conditions, remain poorly understood. The cave of Rhafas (northeast Morocco) provides valuable chronological information about cultural changes in the Maghreb during the Palaeolithic due to its long stratified archaeological sequence comprising Middle Stone Age (MSA), Later Stone Age (LSA) and Neolithic occupation layers. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz grains to the cave deposits of Rhafas, as well as to a recently excavated section on the terrace in front of the cave entrance. We hereby provide a revised chronostratigraphy for the archaeological sequence at the site. We combine these results with geological and sedimentological multi-proxy investigations to gain insights into site formation processes and the palaeoenvironmental record of the region. The older sedimentological units at Rhafas were deposited between 135 ka and 57 ka (MIS 6 -MIS 3) and are associated with the MSA technocomplex. Tanged pieces start to occur in the archaeological layers around 109 ka, which is consistent with previously published chronological data from the Maghreb. A well indurated duricrust indicates favourable climatic conditions for the pedogenic cementation by carbonates of sediment layers at the site after 57 ka. Overlying deposits attributed to the LSA technocomplex yield ages of ~21 ka and ~15 ka, corresponding to the last glacial period, and fall well within the previously established occupation phase in the Maghreb. The last occupation phase at Rhafas took place during the Neolithic and is dated to ~7.8 ka.

  20. Air content and O2/N2 tuned chronologies on local insolation signatures in the Vostok ice core are similar

    Science.gov (United States)

    Lipenkov, V.; Raynaud, D.; Loutre, M.-F.; Duval, P.; Lemieux-Dudon, B.

    2009-04-01

    An accurate chronology of ice cores is needed for interpreting the paleoclimatic record and understanding the relation between insolation and climate. A new domain of research in this area has been initially stimulated by the work of M. Bender (2002) linking the record of O2/N2 ratio in the air trapped in the Vostok ice with the local insolation. More recently, it has been proposed that the long-term changes in air content, V, recorded in ice from the high Antarctic plateau is also dominantly imprinted by the local summer insolation (Raynaud et al., 2007). The present paper presents a new V record from Vostok, which is compared with the published Vostok O2/N2 record for the same period of time (150-400 ka BP) by using the same spectral analysis methods. The spectral differences between the two properties and the possible mechanisms linking them with insolation through the surface snow structure and the close-off processes are discussed. The main result of our study is that the two experimentally independent local insolation proxies lead to absolute (orbital) time scales, which agree together within a standard deviation of 0.6 ka. This result strongly adds credibility to the air content of ice and the O2 to N2 ratio of the air trapped in ice as equally reliable and complementary tools for accurate dating of existing and future deep ice cores. References: M. Bender, Orbital tuning chronology for the Vostok climate record supported by trapped gas composition, Earth and Planetary Science Letters 204(2002) 275-289. D. Raynaud, V. Lipenkov, B. Lemieux-Dudon, P. Duval, M.F. Loutre, N. Lhomme, The local insolation signature of air content in Antarctic ice: a new step toward an absolute dating of ice records, Earth and Planetary Science Letters 261(2007) 337-349.

  1. A New Chronology for Rhafas, Northeast Morocco, Spanning the North African Middle Stone Age through to the Neolithic.

    Directory of Open Access Journals (Sweden)

    Nina Doerschner

    Full Text Available Archaeological sites in northern Africa provide a rich record of increasing importance for the origins of modern human behaviour and for understanding human dispersal out of Africa. However, the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb, and their relationship to local environmental conditions, remain poorly understood. The cave of Rhafas (northeast Morocco provides valuable chronological information about cultural changes in the Maghreb during the Palaeolithic due to its long stratified archaeological sequence comprising Middle Stone Age (MSA, Later Stone Age (LSA and Neolithic occupation layers. In this study, we apply optically stimulated luminescence (OSL dating on sand-sized quartz grains to the cave deposits of Rhafas, as well as to a recently excavated section on the terrace in front of the cave entrance. We hereby provide a revised chronostratigraphy for the archaeological sequence at the site. We combine these results with geological and sedimentological multi-proxy investigations to gain insights into site formation processes and the palaeoenvironmental record of the region. The older sedimentological units at Rhafas were deposited between 135 ka and 57 ka (MIS 6 -MIS 3 and are associated with the MSA technocomplex. Tanged pieces start to occur in the archaeological layers around 109 ka, which is consistent with previously published chronological data from the Maghreb. A well indurated duricrust indicates favourable climatic conditions for the pedogenic cementation by carbonates of sediment layers at the site after 57 ka. Overlying deposits attributed to the LSA technocomplex yield ages of ~21 ka and ~15 ka, corresponding to the last glacial period, and fall well within the previously established occupation phase in the Maghreb. The last occupation phase at Rhafas took place during the Neolithic and is dated to ~7.8 ka.

  2. Chronology of Eocene-Miocene sequences on the New Jersey shallow shelf: implications for regional, interregional, and global correlations

    Science.gov (United States)

    Browning, James V.; Miller, Kenneth G.; Sugarman, Peter J.; Barron, John; McCarthy, Francine M.G.; Kulhanek, Denise K.; Katz, Miriam E.; Feigenson, Mark D.

    2013-01-01

    Integrated Ocean Drilling Program Expedition 313 continuously cored and logged latest Eocene to early-middle Miocene sequences at three sites (M27, M28, and M29) on the inner-middle continental shelf offshore New Jersey, providing an opportunity to evaluate the ages, global correlations, and significance of sequence boundaries. We provide a chronology for these sequences using integrated strontium isotopic stratigraphy and biostratigraphy (primarily calcareous nannoplankton, diatoms, and dinocysts [dinoflagellate cysts]). Despite challenges posed by shallow-water sediments, age resolution is typically ±0.5 m.y. and in many sequences is as good as ±0.25 m.y. Three Oligocene sequences were sampled at Site M27 on sequence bottomsets. Fifteen early to early-middle Miocene sequences were dated at Sites M27, M28, and M29 across clinothems in topsets, foresets (where the sequences are thickest), and bottomsets. A few sequences have coarse (∼1 m.y.) or little age constraint due to barren zones; we constrain the age estimates of these less well dated sequences by applying the principle of superposition, i.e., sediments above sequence boundaries in any site are younger than the sediments below the sequence boundaries at other sites. Our age control provides constraints on the timing of deposition in the clinothem; sequences on the topsets are generally the youngest in the clinothem, whereas the bottomsets generally are the oldest. The greatest amount of time is represented on foresets, although we have no evidence for a correlative conformity. Our chronology provides a baseline for regional and interregional correlations and sea-level reconstructions: (1) we correlate a major increase in sedimentation rate precisely with the timing of the middle Miocene climate changes associated with the development of a permanent East Antarctic Ice Sheet; and (2) the timing of sequence boundaries matches the deep-sea oxygen isotopic record, implicating glacioeustasy as a major driver

  3. A Chronologic Dual-Hemisphere Approach to the Last Glacial Termination from the Southern Alps of New Zealand and the Altai Mountains of Western Mongolia

    Science.gov (United States)

    Strand, P.; Putnam, A. E.; Schaefer, J. M.; Denton, G.; Barrell, D.; Putnam, D.; Schwartz, R.; Sambuu, O.; Radue, M. J.; Lindsay, B. J.; Stevens, J.

    2017-12-01

    Understanding the processes that drove the last glacial termination in the tropics and mid-latitudes is a major unresolved problem in paleoclimate. The most recent glacial to interglacial transition represents the last great global warming and the last time CO2 rose by a substantial amount before the industrial period. Determining the speed of this warming will help refine the global climate system sensitivity to CO2 and will place ongoing global warming into a paleoclimatic context. Here, we test possible drivers of the last glacial termination by comparing chronologies of mountain glaciers, which are highly sensitive to changes in atmospheric temperature, in the middle latitudes of both polar hemispheres. The dating of glacier landforms, such as moraine ridges constructed along glacier margins, affords quantitative insight into past climate conditions. We present 10Be surface-exposure chronologies and glacial geomorphologic maps of mountain glacier recession since the Last Glacial Maximum in the Southern Alps of New Zealand (44°S, 170°E) and in the Altai Mountains of western Mongolia (49°N, 88°E). On the basis of these chronologies from opposing hemispheres, we evaluate the relative roles of rising atmospheric CO2, local insolation forcing, and ocean-atmosphere reorganizations in driving the global warming that ended the last ice age.

  4. The Late Glacial Chronology from Lake Suigestu: A new approach to varve interpolation using frequency distributions of annual sub-layers

    Science.gov (United States)

    Schlolaut, Gordon; Marshall, Michael; Brauer, Achim; Nakagawa, Takeshi; Lamb, Henry; Staff, Richard; Bronk Ramsey, Christopher; Brock, Fiona; Bryant, Charlotte; 2006 Project Members, Suigetsu

    2010-05-01

    by neighbouring sections or by subjective interpretation. Sedimentation rates are calculated from the independent varve counts and are then combined. The application of these sedimentation rates (combined and independent) to the raw counts yields a varve count synthesis as well as an error estimate for the age model. Comparison of the varve count synthesis with the Late Glacial radiocarbon dates calibrated using Intcal04 (Reimer et al. 2004) and Fairbanks et al. (2005) shows a good agreement between the chronologies. Reference: R.G. Fairbanks, R.A. Mortlock, T.-C. Chiu, L. Cao, A. Kaplan, T.P. Guilderson, T.W. Fairbanks, A.L. Bloom, P.M. Grootes, M.-J. Nadeau, (2005), Radiocarbon calibration curve spanning 0 to 50,000 years bp based on paired 230Th/234U/238U and 14C dates on pristine corals, Quaternary Science Reviews 24 H. Kitagawa, J. van der Plicht, (2000), Atmospheric radiocarbon calibration beyond 11,900 cal BP from Lake Suigetsu laminated sediments, Radiocarbon 42(3) P.J. Reimer, M.G.L. Baillie, E. Bard, A. Bayliss, J.W. Beck, C.J.H. Bertrand, P.G. Blackwell, C.E. Buck, G.S. Burr, K.B. Cutler, P.E. Damon, R.L. Edwards, R.G. Fairbanks, M. Friedrich, T.P. Guilderson, A.G. Hogg, K.A. Hughen, B. Kromer, G. McCormac, S. Manning, C. Bronk Ramsey, R.W. Reimer, S. Remmele, J.R. Southon, M. Stuiver, S. Talamo, F.W. Taylor, J. van der Plicht, C.E. Weyhenmeyer, (2004), IntCal04 terrestrial radiocarbon age calibration, 0-26 cal kyr bp, Radiocarbon 46(3) R.A. Staff, C. Bronk Ramsey, T. Nakagawa and Suigetsu 2006 Project members, (2009), A re-analysis of the Lake Suigetsu terrestrial radiocarbon calibration dataset, Nuclear Instruments and Methods in Physics Research B

  5. Complexity, Sustainability, Justice, and Meaning: Chronological Versus Dynamical Time

    Directory of Open Access Journals (Sweden)

    Horacio Velasco

    2009-11-01

    Full Text Available

    Abstract: It is shown that time may be appreciated in at least two senses: chronological and dynamical. Chronological time is the time of our naïve acquaintance as transient beings. At its most extensive scale, it corresponds to history encompassing both the abiotic and the biotic  universe. Dynamical time, deriving from classical mechanics, is the time embraced by most of the laws of physics. It concerns itself only with present conditions since it is held that that the past may be reconstructed from the present (literally and the future predicted from the present, a position known as Laplacian determinism.

     

    Nonlinear dynamics has shown the fallacy of this supposition because, of necessity, the concrete values that may be assumed in the variables of the equations of motion constituting the laws of physics (i.e. the present or starting conditions as a result of the spontaneous or intentional interaction of subject (or measuring systems and of object (or measured systems, cannot be of infinite precision. Indeed, even if they could be, it is not at all clear that they would permit Laplacian determinism because of what is thought to be the ubiquity of K-flow dynamics in nature in which even infinite past information leading to the present cannot yield prediction of the future. In consequence, nonlinear dynamics, in rebellion against dynamical time, generates a primitive form of history distinguishing past, present, and future that may be termed nonlinear dynamical hysteresis.

  6. Fallout isotope chronology of the near-surface sediment record of Lake Bolătău.

    Science.gov (United States)

    Bihari, Árpád; Karlik, Máté; Mîndrescu, Marcel; Szalai, Zoltán; Grădinaru, Ionela; Kern, Zoltán

    2018-01-01

    Fallout isotope ( 210 Pb ex, 137 Cs and 241 Am) based dating has been carried out on the near-surface sediment core collected from Lake Bolătău-Feredeu (Bukovina, Romania). The motivation was to improve the chronology of this recent section in connection with significant fluctuations observed in sediment accumulation rates, particle size distribution and primordial radioisotope (i.e. 40 K and 232 Th) composition. Previously only an extrapolation of a broad-range OxCal age-depth model, which was based on 8 AMS radiocarbon dates from the deeper part of a parallel sediment sequence and tentatively validated for the upper part using the double peaks of the 137 Cs activity concentration distribution, was available for the studied section (1-24 cm). Parallel to the previous 137 Cs measurement, 210 Pb and 226 Ra (for a more detailed, 210 Pb ex -based chronology), 241 Am (for an additional time-marker), as well as 40 K and 232 Th concentrations have also been determined by gamma-spectrometry. In case of the 210 Pb ex -based chronology, due to a large deviation from a pure exponential distribution, the Constant Flux (CF) model has been used for the calculation of sediment ages and accumulation rates. Although the broad-range OxCal and the CF model were broadly similar down to 22 cm, the 210 Pb ex -based ages are clearly superior in terms of uncertainty in the uppermost 12 cm, while the broad-range model has smaller uncertainty below 20 cm (>150 years). The CF model gave an average mass accumulation rate of (0.08 ± 0.03) g cm -2 yr -1 for sections 0-11 cm, and (0.03 ± 0.01) g cm -2 yr -1 for sections 12-22 cm, respectively. Significant changes have been observed in the depth distribution of both the particle size distribution and the elemental/isotopic composition of the sediment record, most likely related to the variation observable in the intensity and volume of precipitation in the catchment. The obtained high-resolution records of Lake Bolătău, including

  7. Dating Violence among College Students

    Science.gov (United States)

    Iconis, Rosemary

    2013-01-01

    Dating violence is a significant problem on college campuses. More than one-fifth of the undergraduate dating population are physically abused by their dating partners and an even greater percentage are psychologically abused. Researchers have identified risk factors for college student dating violence. Preventive interventions are strongly…

  8. Flirting in Online Dating

    DEFF Research Database (Denmark)

    Mortensen, Kristine Køhler

    2017-01-01

    Various fields have examined the activity of flirting, predominantly based on experimental and reported data; the interactional workings are therefore often overlooked. Based on emails and chats from two Danish online dating sites, this article investigates how users negotiate romantic connections...... through the flirting strategy of ‘imagined togetherness’, linguistically constructing imagery of a shared future. Using the notion of the chronotope, turn-by-turn analysis demonstrates how users, embedded in the activity of getting to know each other, tenuously communicate romantic interest by alluding...

  9. The diagnostic performance of chronologic age in the assessment of skeletal maturity.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; De Toffol, Laura; Ghiozzi, Bruno; Cozza, Paola

    2006-01-01

    The aim of this study was to analyze the relationship between chronologic age the and individual skeletal maturity as assessed by means of the cervical vertebral maturation (CVM) method during the circumpubertal period. The evaluated sample of 600 subjects consisted of 100 subjects (50 males and 50 females) for each of 6 age groups, from 9 years through 14 years of age. Individual skeletal maturity for all subjects was determined by using the CVM method. The relationship between chronologic age and the most prevalent CVM stage at each age group was evaluated statistically by means of indicators of diagnostic test performance that specify the ability of a diagnostic test to identify a condition. The diagnostic performance of chronologic age for the detection of the onset of the adolescent peak in skeletal maturation was very low both in males and in females. In male subjects, the chronologic age of 9 years +/- 6 months presented with strong diagnostic power for the identification of a pre-pubertal stage in skeletal maturation. In female subjects, the chronologic age of 14 years +/- 6 months corresponded with a strong probability of a postpubertal stage in skeletal maturation. In males, chronologic age can identify a pre-pubertal stage of skeletal development, and in females a post-pubertal stage. In both males and females, chronologic age cannot recognize the onset of the adolescent peak in skeletal maturation.

  10. Updating dating down under

    International Nuclear Information System (INIS)

    Bristow, J.W.

    1986-01-01

    The article deals with the Sensitive High Resolution Ion Microprobe (SHRIMP), Australia's only microprobe and its applications for geochronology. SHRIMP has the ability to analyse tiny areas (less than 30μm across) within crystals directly, the only sample preparation required being polishing of the crystal surface. Most analyses so far have been done on separated crystals prepared as grain mounts, although an increasing number of analyses are now being made of crystals in rock thin sections where their textural associations can be established. Important features of SHRIMP are its double-focusing mass spectrometer and great physical size, more than 8 meters long, employing a magnet weighing six tons. This enables the machine to distinguish ions with atomic masses differing by less than one part in ten thousand while at the same time having a very great sensitivity. SHRIMP was used for dating crustal zircons from southern African Kimberlites. Although low U and Pb abundances presents problems in peak selection and focusing on SHRIMP its was found that kimberlitic zircons could be dated successfully

  11. Chronologic and actinically induced aging in human facial skin

    International Nuclear Information System (INIS)

    Gilchrest, B.A.; Szabo, G.; Flynn, E.; Goldwyn, R.M.

    1983-01-01

    Clinical and histologic stigmata of aging are much more prominent in habitually sun-exposed skin than in sun-protected skin, but other possible manifestations of actinically induced aging are almost unexplored. We have examined the interrelation of chronologic and actinic aging using paired preauricular (sun-exposed) and postauricular (sun-protected) skin specimens. Keratinocyte cultures derived from sun-exposed skin consistently had a shorter in vitro lifespan but increased plating efficiency compared with cultures derived from adjacent sun-protected skin of the same individual, confirming a previous study of different paired body sites. Electron microscopic histologic sections revealed focal abnormalities of keratinocyte proliferation and alignment in vitro especially in those cultures derived from sun-exposed skin and decreased intercellular contact in stratified colonies at late passage, regardless of donor site. One-micron histologic sections of the original biopsy specimens revealed no striking site-related keratinocyte alterations, but sun-exposed specimens had fewer epidermal Langerhans cells (p less than 0.001), averaging approximately 50 percent the number in sun-protected skin, a possible exaggeration of the previously reported age-associated decrease in this cell population. These data suggest that sun exposure indeed accelerates aging by several criteria and that, regardless of mechanism, environmental factors may adversely affect the appearance and function of aging skin in ways amenable to experimental quantitation

  12. Holographic Protection of Chronology in Universes of the Godel Type

    Energy Technology Data Exchange (ETDEWEB)

    Boyda, Edward; Ganguli, Surya; Horava, Petr; Varadarajan, Uday

    2002-12-07

    We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on"phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of"microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T-dual to pp-waves, and use this fact to generate new Godel-like solutions of string and M-theory by T-dualizing known supersymmetric pp-wave solutions.

  13. Solutrean Chronology & Lithic Variability in Vasco-Cantabrian Spain

    Directory of Open Access Journals (Sweden)

    Lawrence Guy STRAUS

    2009-10-01

    Full Text Available RESUMEN: Recientes excavaciones en la zona cantábrica suministran datos que apuntan a una variabilidad en las industrias del Solutrense. Basado en pruebas de radiocarbono parece evidenciarse una contemporaneidad entre el fenómeno solutrense de la España Cantábrica y el Rhone Valley. La industria de puntas diagnostican un resultado de un proceso tecnológico convergente.ABSTRACT: Recent excavations in Cantabrian cave deposits provide evidence of Solutrean industrial variability and provocative chronological information. On the basis of radiocarbon there is strong evidence for contemporeanity between the Solutrean phenomena of Cantabrian Spain and in the Rhone Valley. The stone-points diagnostic would probably be the result of convergent technology. There is considerable evidence for variability among artifacts assemblages (shown in their respective coefficients of variation. It is therefore difficult to characterize Cantabrian collections from the time range in question in a general way. It seems more fruitful to try and demonstrate the existence of functional parameters for observed artifact variability.

  14. Chronology of petroleum geophysics; Sekiyu butsuri tansa nenpyo

    Energy Technology Data Exchange (ETDEWEB)

    Kametani, T

    1996-10-01

    A table, chronology of petroleum geophysics in overseas and in Japan, has been prepared for the convenience of checking events, which are thought to be important as notable affairs in application, success, and technical innovation. In overseas, successes in the 1920s were remarkable, when the US modern geophysical exploration made a start. Successes in determining the position of exploratory drilling by means of the gravity torsion balance, fan shooting seismic refraction method, and seismic reflection method occurred one after another. The USA has kept its situation stably as the number one by the seismic reflection method occurred most lately, and its life has been further elongated by adopting digital techniques. The CDP technique which became to be used simultaneously, and the seismic sources without using explosives, such as vibro-seismic source and air gun, extended the success of digital techniques drastically. In the future, the progress of 3-D exploration technology is expected. In Japan, about 18 years lag in the seismic reflection method is observed when compared with the USA. Japan has provided leading techniques in the shallow layer seismic reflection method and S-wave exploration. 40 refs., 1 tab.

  15. Precise chronology of differentiation of developing human primary dentition.

    Science.gov (United States)

    Hu, Xuefeng; Xu, Shan; Lin, Chensheng; Zhang, Lishan; Chen, YiPing; Zhang, Yanding

    2014-02-01

    While correlation of developmental stage with embryonic age of the human primary dentition has been well documented, the available information regarding the differentiation timing of the primary teeth was largely based on the observation of initial mineralization and varies significantly. In this study, we aimed to document precise differentiation timing of the developing human primary dentition. We systematically examined the expression of odontogenic differentiation markers along with the formation of mineralized tissue in each developing maxillary and mandibular teeth from human embryos with well-defined embryonic age. We show that, despite that all primary teeth initiate development at the same time, odontogenic differentiation begins in the maxillary incisors at the 15th week and in the mandibular incisors at the 16th week of gestation, followed by the canine, the first primary premolar, and the second primary premolar at a week interval sequentially. Despite that the mandibular primary incisors erupt earlier than the maxillary incisors, this distal to proximal sequential differentiation of the human primary dentition coincides in general with the sequence of tooth eruption. Our results provide an accurate chronology of odontogenic differentiation of the developing human primary dentition, which could be used as reference for future studies of human tooth development.

  16. Chronological aging in conidia of pathogenic Aspergillus: Comparison between species.

    Science.gov (United States)

    Oliveira, Manuela; Pereira, Clara; Bessa, Cláudia; Araujo, Ricardo; Saraiva, Lucília

    2015-11-01

    Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger are common airborne fungi, and the most frequent causative agents of human fungal infections. However, the resistance and lifetime persistence of these fungi in the atmosphere, and the mechanism of aging of Aspergillus conidia are unknown.With this work, we intended to study the processes underlying conidial aging of these four relevant and pathogenic Aspergillus species. Chronological aging was therefore evaluated in A. fumigatus, A. flavus, A. terreus and A. niger conidia exposed to environmental and human body temperatures. The results showed that the aging process in Aspergillus conidia involves apoptosis,with metacaspase activation, DNA fragmentation, and reactive oxygen species production, associated with secondary necrosis. Distinct results were observed for the selected pathogenic species. At environmental conditions, A. niger was the species with the highest resistance to aging, indicating a higher adaption to environmental conditions, whereas A. flavus followed by A. terreus were the most sensitive species. At higher temperatures (37 °C), A. fumigatus presented the longest lifespan, in accordance with its good adaptation to the human body temperature. Altogether,with this work new insights regarding conidia aging are provided, which may be useful when designing treatments for aspergillosis.

  17. Holographic protection of chronology in universes of the Goedel type

    International Nuclear Information System (INIS)

    Boyda, Edward K.; Ganguli, Surya; Horava, Petr; Varadarajan, Uday

    2003-01-01

    We analyze the structure of supersymmetric Goedel-like cosmological solutions of string theory. Just as the original four-dimensional Goedel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on the 'phenomenological' aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Goedel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Goedel universes has many features in common with de Sitter space, suggesting that Goedel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of 'microscopic' aspects of holography of Goedel universes in string theory. We show that Goedel universes are T dual to pp waves, and use this fact to generate new Goedel-like solutions of string and M theory by T dualizing known supersymmetric pp-wave solutions

  18. Assessing the chronology of bedrock landslides in the Oregon Coastal Range using visible near-infrared spectroscopy

    Science.gov (United States)

    Mathabane, N.; Cerovski-Darriau, C.; Sweeney, K. E.; Roering, J. J.

    2013-12-01

    Obtaining accurate chronological data for landslides is critical to understanding their causes as well as their dynamics. The ability to easily and inexpensively date various parts of a landslide can provide insight not only into the 'When' of landslides but also on the 'How' and 'Why' as well. In this study, we apply visible near-infrared (VisNIR) spectroscopy as a means to date landslide soils in a setting with uniform climate and bedrock lithology. In our Oregon Coast Range site, as sandstone-derived soils weather over time, pedogenic hematite accumulates and alters the color of the soil at a quantifiable and discernable rate. This rate having already been established through a soil chronosequence study, we can use the redness of a soil as a proxy for soil age. This is a potentially economical dating method as it does not rely on expensive radioisotopes and requires only a small amount of sample to process. We collected 39 B-horizon soil samples from 7 different slides and used VisNIR spectroscopy to identify the soil residence time of the landslides. The majority of the samples possessed ages between 75,000 and 150,000 years of age, though several slides registered ages over 200,000 years. The average percent error associated with the landslide ages was ~30-35%, although this value was lower for younger slides (200,000 years). Younger slides were more homogenous in age while older slides exhibited more variability. Additionally, there was lower variability in auger-collected samples when compared to samples collected from road-cuts. Our results suggest that VisNIR spectroscopy may prove a more useful dating method on younger, less disturbed landslides but fail to truly capture the age of older, more complicated slides due to its reliance on a specific pedogentic model for hematite weathering as well as the increased risk for complex slide history. This method could be useful in a regional characterization of landslide chronology for similar biomes and provide

  19. The radiocarbon dating of the neolithic flint mines at Krzemionki in central Poland

    International Nuclear Information System (INIS)

    Babel, J.; Braziewicz, J.; JaskoIa, M.; Kretschmer, W.; Pajek, M.; Semaniak, J.; Scharf, A.; Uhl, T.

    2005-01-01

    Ten samples taken from wooden torches and small fireplaces discovered at the Krzemionki neolithic flint mine localized in central Poland were dated using the AMS facility at Erlangen University. The radiocarbon results points two main periods of exploitation of studied mines, i.e. approximately to 3500-3100 BC and to 3100-2900 BC. The results are discussed in the aspect of the mine chronology. The new radiocarbon dates confirm the previous radiocarbon data obtained from other mine units in this part of the Krzemionki mine complex

  20. The Trojan war dated by two solar eclipses.

    Science.gov (United States)

    Henriksson, Goran

    The Trojan War was very significant for the ancient Greeks and they dated historical events according to the number of years after the fall of Troy. However, there was already in antiquity no consensus as to the exact date of the war when compared with different epochs. Even after the modern discovery of the ancient city, there has been disagreement among different excavators as to which layer corresponds to the city mentioned in the Iliad attributed to Homer. In this paper an attempt is made to identify the strange obscuration of the sun that occurred during the final battle of the Iliad as a total solar eclipse close to the southern border of the zone of totality. There exists only one solar eclipse that corresponds to the description in the text and this is the total solar eclipse of June 11, in 1312 BC. When I first presented this date in 1986, there was a difference of about 60 years compared with the most common archaeological dating at that time. My date is now fully supported by the latest results from the German-American excavation that identifies the fall of Homer's Troy with the destruction of the archaeological layer Troy VIh, dated to about 1300 BC. Further independent support is provided by another solar eclipse that dates the reign of the Hittite king Muwatalli II. This king wrote a letter to king Alaksandu in Wilusa, identified as the Hittite name for Ilios, the most frequently used name for Troy in the Iliad. Alexander was another name for Paris who abducted Helen, the crime that resulted in the war. Muwatalli II was king 1315-1297 BC, according to the chronology for the Hittite Kingdom based on a solar eclipse in 1335 BC, during the tenth year of King Mursili II (1345- 1315 BC), the father of Muwatalli II.

  1. Radiocarbon dates XXI

    International Nuclear Information System (INIS)

    Lowdon, J.A.; Blake, W. Jr.

    1981-01-01

    This list includes 105 radiocarbon age determinations on 104 geological samples made by the Radiocarbon Dating Laboratory. They are on samples from various areas as follows: Labrador Shelf (2); Newfoundland (12); Nova Scotia (2); New Brunswick (1); Quebec (3); Ontario (1); Manitoba (1); Alberta (2); British Columbia (15); Yukon Territory (35); Northwest Territories, Mainland (10); Northwest Territories, Arctic Archipelago (21). Details of background and standard for the 2 L and 5 L counters during the period from November 4, 1980 to October 31, 1981 are summarized in Tables 1 and 2; Table 3 gives the number of counts used to determine the average background and standard counting rates; and Table 4 lists the number of different background and standard gas preparations used for counting

  2. Dynamic of an intra-continental orogenic prism: thermo-chronologic (apatite fission tracks) and tectonic evolution of the axial zone and the piedmont of the west-central Pyrenees

    International Nuclear Information System (INIS)

    Meresse, F.

    2013-02-01

    This work illustrates the application of thermo chronology to the study of the following geologic issue: the tectonic evolution of the Pyrenean oncologic prism. Thermo-chronology gives information on the vertical movements at the scale of geological eras. Thermo-chronology is based on the following principle: the decay of a nucleus gives birth to a daughter nucleus. Above a specific temperature named closure temperature, the daughter element can diffuse outside the system while below the closure temperature, diffusion is not possible. Consequently thermo-chronology can be considered to date the moment when a mineral goes below a a specific closure temperature. Minerals have different closure temperatures and so by using a suite of thermo-chronometers on a single sample, its cooling path through the crust can be reconstructed. This work focuses on apatite fission track (AFT)analysis which is a low temperature thermo-chronometer. In apatites the temperature range between 60 and 120 Celsius degrees corresponds to the partial annealing zone. The spontaneous fission of one U 238 nucleus entails the formation of one fission track. The determination of the initial quantity of U 238 is based on the natural steady ratio U 238 /U 235 which equals 137.88. The initial quantity of U 235 is determined through the neutron irradiation of the sample. The knowledge of the initial quantity of U 238 and the number of tracks in the sample allows the dating of the sample. In this work we combine AFT thermo- chronology with a detailed structural analysis to describe vertical movements related to the thrusting system evolution, and to determine the influence of the latter on the sedimentation/burial/exhumation cycle of the syn-orogenic deposits of the southern fore-land basin

  3. Dates fruits classification using SVM

    Science.gov (United States)

    Alzu'bi, Reem; Anushya, A.; Hamed, Ebtisam; Al Sha'ar, Eng. Abdelnour; Vincy, B. S. Angela

    2018-04-01

    In this paper, we used SVM in classifying various types of dates using their images. Dates have interesting different characteristics that can be valuable to distinguish and determine a particular date type. These characteristics include shape, texture, and color. A system that achieves 100% accuracy was built to classify the dates which can be eatable and cannot be eatable. The built system helps the food industry and customer in classifying dates depending on specific quality measures giving best performance with specific type of dates.

  4. Effect of chronological age of beef steers of different maturity types ...

    African Journals Online (AJOL)

    Effect of chronological age of beef steers of different maturity types on their growth ... and carcass studies have been conducted in the sourveld regions of the country. ... different beef maturity types which differ in body frame size were used, viz.

  5. Chronology of the cave interior sediments at Gran Dolina archaeological site, Atapuerca (Spain)

    Science.gov (United States)

    Parés, J. M.; Álvarez, C.; Sier, M.; Moreno, D.; Duval, M.; Woodhead, J. D.; Ortega, A. I.; Campaña, I.; Rosell, J.; Bermúdez de Castro, J. M.; Carbonell, E.

    2018-04-01

    The so-called "Gran Dolina site" (Atapuerca mountain range, N Spain) is a karstic cavity filled by sediments during the Pleistocene, some of which contain a rich ensemble of archaeological and paleontological records. These sediments have contributed significantly to our understanding of early human dispersal in Europe but, in contrast, older, interior facies deposits have received much less of attention. The stratigraphy of Gran Dolina reveals an abrupt sedimentary change of interior to entrance facies from bottom to top, reflecting a significant paleoenvironmental change that promoted the accumulation of sediments transported from the vicinity of the cave by water or "en masse". Since the major magnetic polarity reversal known as the Matuyama-Brunhes boundary (0.78 Ma) was detected within the TD7 unit in the middle of the stratigraphic section, we carried out a new combined paleomagnetic, radiometric (U-Pb), and electron spin resonance (ESR) dating study of the lower part of the sequence in order to constrain the chronology of the interior facies at Gran Dolina. U-Pb analysis of speleothems did not produce age information as the samples proved to be extremely unradiogenic. The magnetic stratigraphy of the cave interior sediments reveals a dominant reverse magnetic polarity, coherent with a Matuyama age, and interrupted by a normal polarity magnetozone interpreted as the Jaramillo Subchron (1.0-1.1 Ma). ESR ages on quartz grains from the upper part of the interior facies sediments are coherent with such an interpretation. We conclude that the fluvial deposits (interior facies) that constitute the cave floor began accumulating before 1.2 Ma. The development of large cave entrances at Gran Dolina occurred shortly after the Jaramillo Subchron but before ca 900 ka ago.

  6. Chronological development avenues in biotechnology across the world

    Directory of Open Access Journals (Sweden)

    Prashant Y Mali

    2011-01-01

    Full Text Available Biotechnology is expected to be a great technological revolution followed by information technology. It is an application of scientific and engineering principles to the processing of material by biological agents to provide better goods and services to mankind. Commercially its techniques are applied long back in 6 th century in the art of brewing, wine making and baking. It has progressed there after crossing different land marks. Modern biotechnology has developed significantly in the late 19 th century with groundbreaking discoveries applicable in medicine, food, agriculture, chemistry, environmental protection and many more industries. It is widely used in the development of high-yielding, disease-resistant, better quality varieties by applying tissue culture and recombinant DNA techniques. It has wide application in animal breeding using techniques such as artificial insemination, in vitro fertilization and embryo transfer. Specific enzymes used in laundry, fuel and leather industries for better quality, economically feasible and environmental friendly production. Biotechnology in healthcare system uses body′s own tools and weapons to fight against diseases, manufacturing of targeted therapeutic proteins, gene therapy and so on. Novel approaches such as proteomics and structural biology are contributing to understanding the chemistry of life and diseases. Malfunctioning gene replaced with correctly functioning gene by using gene therapy. Tissue engineering has opened up the use of in vitro developed tissue or organ in repairing wounded tissue and system biology which is a computer-based approach to understand cell functions. Although every new discovery related to biology and its implications is significant and has taken the technology ahead. This includes applications, commercialization, controversies, media exposure and so on. Hence, we have enlisted some of the chronological development avenues in biotechnology across the world.

  7. Crosstalk between mitochondrial stress signals regulates yeast chronological lifespan.

    Science.gov (United States)

    Schroeder, Elizabeth A; Shadel, Gerald S

    2014-01-01

    Mitochondrial DNA (mtDNA) exists in multiple copies per cell and is essential for oxidative phosphorylation. Depleted or mutated mtDNA promotes numerous human diseases and may contribute to aging. Reduced TORC1 signaling in the budding yeast, Saccharomyces cerevisiae, extends chronological lifespan (CLS) in part by generating a mitochondrial ROS (mtROS) signal that epigenetically alters nuclear gene expression. To address the potential requirement for mtDNA maintenance in this response, we analyzed strains lacking the mitochondrial base-excision repair enzyme Ntg1p. Extension of CLS by mtROS signaling and reduced TORC1 activity, but not caloric restriction, was abrogated in ntg1Δ strains that exhibited mtDNA depletion without defects in respiration. The DNA damage response (DDR) kinase Rad53p, which transduces pro-longevity mtROS signals, is also activated in ntg1Δ strains. Restoring mtDNA copy number alleviated Rad53p activation and re-established CLS extension following mtROS signaling, indicating that Rad53p senses mtDNA depletion directly. Finally, DDR kinases regulate nucleus-mitochondria localization dynamics of Ntg1p. From these results, we conclude that the DDR pathway senses and may regulate Ntg1p-dependent mtDNA stability. Furthermore, Rad53p senses multiple mitochondrial stresses in a hierarchical manner to elicit specific physiological outcomes, exemplified by mtDNA depletion overriding the ability of Rad53p to transduce an adaptive mtROS longevity signal. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. A chronology of El niño events from primary documentary sources in northern Peru

    OpenAIRE

    García Herrera, Ricardo; Díaz, H. F.; García, R. R.; Prieto, M. R.; Barriopedro Cepero, David; Moyano, R.; Hernández Martín, Emiliano

    2008-01-01

    The authors present a chronology of El Niño (EN) events based on documentary records from northern Peru. The chronology, which covers the period 1550-1900, is constructed mainly from primary sources from the city of Trujillo (Peru), the Archivo General de Indias in Seville (Spain), and the Archivo General de la Nacion in Lima (Peru), supplemented by a reassessment of documentary evidence included in previously published literature. The archive in Trujillo has never been systematically evaluat...

  9. Reasons for decision in the matter of Enbridge Southern Lights GP on behalf of Enbridge Southern Lights LP and Enbridge Pipelines Inc. : facilities[Application dated 9 March 2007 for the Southern Lights Project consisting of the: 1. Diluent Pipeline Project, and 2. Capacity Replacement Project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-02-15

    In March 2007, Enbridge Southern Lights (ESL) GP on behalf of Enbridge Southern Lights LP and Enbridge Pipelines Inc. (EPI) applied for approvals related to the Southern Lights Project. The first component of the project involves the construction of a pipeline to transport diluent from Chicago, Illinois to Edmonton on Line 13, an existing EPI Mainline pipeline. The second component of the project involves a Capacity Replacement Project to replace the loss of southbound capacity on the EPI Mainline system resulting from the transfer of Line 13 to diluent service. The application required Board approvals for several related project components, including the transfer of ownership of EPI's Line 13 to ESL; the removal of Line 13 from southbound crude oil delivery service; reversing the flow on Line 13 to carry diluent from the Canada/US border northbound to Edmonton, Alberta; constructing a new oil pipeline to transport light sour crude oil; physical changes and alterations to EPI's Line 2; and, appropriate tolls and tariffs. The Board determined that the Southern Lights Project is an innovative and cost-effective solution to transport diluent. The applicants demonstrated sufficient diluent shipping commitments to ensure the long term viability of the pipeline. The Board found that the proposal to build new facilities on existing EPI sites and right-of-way should minimize negative impacts on area landowners, and also judged that mitigation planned for the construction phase will minimize potential adverse effects. The Board will require ESL to conduct an emergency response exercise where Line 13 crosses the South Saskatchewan River. Ongoing discussions between the applicants and Aboriginal groups, and a Heritage Resource Discovery Contingency Plan, will reduce potential impacts to traditional use sites. Having reviewed all evidence, the Board approved applications for the Southern Lights Pipeline Project, worth an estimated $247.5 million in Canadian spending

  10. Desarrollo de cronologías de ancho de anillos para alerce (Fitzroya cupressoides en Contao y Mirador, Chile Development of tree-ring chronologies for alerce (Fitzroya Cupressoides in Contao and Mirador, Chile

    Directory of Open Access Journals (Sweden)

    EDUARDO NEIRA

    2000-12-01

    Full Text Available Se desarrollaron dos cronologías de ancho de anillos de crecimiento a partir de muestras de alerce (Fitzroya cupressoides (Molina Johnston, colectadas en dos sitios: Contao, Cordillera de los Andes (41º 33'S, 72º 38'W, y Mirador, en la Cordillera de la Costa (40º 10'S, 73º 42'W. En la elaboración de las cronologías se utilizó el programa COFECHA para verificar el cofechado y se desarrolló para cada sitio una cronología utilizando el programa computacional ARSTAN. Se compararon las cronologías Contao y Mirador, con otras existentes para alerce encontrándose una alta similitud de la cronología Contao con la desarrollada para Lenca (41º 33'S, 72º 36' W. Contao presentó los valores más altos en los estadígrafos analizados con relación a las demás cronologías. Se observaron diferencias entre las cronologías provenientes de la Cordillera de la Costa y de los Andes en los últimos 150 años, probablemente producto de explotaciones humanas e incendios ocurridos en la cordillera de la Costa. La correlación con variables climáticas fue similar en su tendencia a la de otros estudios previos, documentando una correlación negativa con las temperaturas y positiva con las precipitaciones del verano anterior al período de crecimientoTwo ring-width chronologies were developed using samples from alerce (Fitzroya cupressoides (Molina Johnston. These were collected from two different sites; Contao, in the Andean Range and Mirador, in the Coastal Range. The series from the each site were cross-dated and COFECHA program was used to verify this process. Once correctly cross-dated, ARSTAN program was used to build up a chronology for each site (Contao and Mirador. These chronologies were compared with other existing chronologies. Contao presented the best statistics when compared to the other chronologies. Differences between chronologies from the Coastal and Andes Ranges were detected mainly during the last 150 years. Before this period

  11. Study of a metallurgical site in Tuscany (Italy) by radiocarbon dating

    International Nuclear Information System (INIS)

    Cartocci, A.; Fedi, M.E.; Taccetti, F.; Benvenuti, M.; Chiarantini, L.; Guideri, S.

    2007-01-01

    Tuscany represents one of the most important ancient mining districts of Italy. Metalworking activities have been present in the area since ancient times and several mining centres have been active in the region since the Etruscan period. Two of the more notable mining locations are the island of Elba and the towns of Populonia and Massa Marittima. In order to reconstruct the development of metallurgical techniques in the past, a multi-disciplinary approach is required, involving both archaeological study and archaeometric analysis of the sites of interest. One of the most complex problems is establishing the chronological history of metallurgical exploitation in ancient sites: archaeological remains are sometimes incomplete and the stratigraphy of archaeological horizons might have been deeply altered. Thus, direct dating of metallurgical slags and other remains of mining and metalworking activities using radiocarbon measurements is particularly useful for developing site chronologies. Charcoal samples from a recent excavation in Populonia were dated by AMS radiocarbon in order to reconstruct the chronological evolution of ancient metallurgical production; results reported here are consistent with archaeological observations

  12. Study of a metallurgical site in Tuscany (Italy) by radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Cartocci, A. [Dipartimento di Fisica dell' Universita e I.N.F.N. Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Florence (Italy); Fedi, M.E. [Dipartimento di Fisica dell' Universita e I.N.F.N. Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Florence (Italy)]. E-mail: fedi@fi.infn.it; Taccetti, F. [Dipartimento di Fisica dell' Universita e I.N.F.N. Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Florence (Italy); Benvenuti, M. [Dipartimento di Scienze della Terra dell' Universita di Firenze, via La Pira 4, 50121 Florence (Italy); Chiarantini, L. [Dipartimento di Scienze della Terra dell' Universita di Firenze, via La Pira 4, 50121 Florence (Italy); Guideri, S. [Societa Parchi Val di Cornia S.p.a., via G. Lerario, Piombino, Livorno (Italy)

    2007-06-15

    Tuscany represents one of the most important ancient mining districts of Italy. Metalworking activities have been present in the area since ancient times and several mining centres have been active in the region since the Etruscan period. Two of the more notable mining locations are the island of Elba and the towns of Populonia and Massa Marittima. In order to reconstruct the development of metallurgical techniques in the past, a multi-disciplinary approach is required, involving both archaeological study and archaeometric analysis of the sites of interest. One of the most complex problems is establishing the chronological history of metallurgical exploitation in ancient sites: archaeological remains are sometimes incomplete and the stratigraphy of archaeological horizons might have been deeply altered. Thus, direct dating of metallurgical slags and other remains of mining and metalworking activities using radiocarbon measurements is particularly useful for developing site chronologies. Charcoal samples from a recent excavation in Populonia were dated by AMS radiocarbon in order to reconstruct the chronological evolution of ancient metallurgical production; results reported here are consistent with archaeological observations.

  13. Correlation of chronological, skeletal, and dental age in North Indian population

    Directory of Open Access Journals (Sweden)

    Madhurima Nanda

    2017-01-01

    Full Text Available Aim and Objectives: The aim of the study was to find out the correlation between chronological, dental, and skeletal age. Materials and Methods: Lateral cephalograms and orthopantomograms of 100 subjects of age ranging 9–14 years were obtained for the estimation of skeletal and dental age. Dental age was assessed using Demirjian's method; skeletal age was assessed using the new improved version of the cervical vertebral maturation method given by Baccetti, Franchi, and McNamara. Statistical analysis was carried out. Student's t-test and Spearman's coefficient correlation were used to assess the relation between chronological, skeletal, and dental age. Results: The Spearman's correlation coefficient was 0.777 (P < 0.001 between chronological and dental age, 0.516 (P < 0.001 between chronological and skeletal age, and 0.563 (P < 0.001 between dental and skeletal age. Conclusion: There is a good correlation between chronological and dental age in North Indian population which was higher for males as compared to females. A moderate correlation was found between chronological and skeletal age as well as between dental and skeletal age.

  14. A Study of Correlation of Various Growth Indicators with Chronological Age.

    Science.gov (United States)

    Singh, Sarabjeet; Sandhu, Navreet; Puri, Taruna; Gulati, Ritika; Kashyap, Rita

    2015-01-01

    The aim of this study was to assess the relationship of chronological age with cervical vertebrae skeletal maturation, frontal sinus width and antegonial notch depth and a correlation, if any, among the three variables. The samples were derived from lateral cephalometric radiographs of 80 subjects (40 males, 40 females; age range: 10 to 19 years). Cervical vertebral development was evaluated by the method of Hassel and Farman, frontal sinus width was measured by the method described by Ertürk and antegonial notch depth as described by Singer et al. The Pearson's correlation coefficients were estimated to assess the relationship of chronological age with cervical vertebrae skeletal maturation, frontal sinus width and antegonial notch depth. The Pearson's correlation coefficient were 0.855 (p correlation was found between chronological age and cervical vertebrae skeletal maturation, and between chronological age and frontal sinus width. Nonsignificant correlation was found between chronological age and antegonial notch depth. How to cite this article: Singh S, Sandhu N, Puri T, Gulati R, Kashyap R. A Study of Correlation of Various Growth Indicators with Chronological Age. Int J Clin Pediatr Dent 2015;8(3): 190-195.

  15. Dating technique tested

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    An analytical technique for dating ground water and polar ice up to a million years old has been successfully tested by scientists at Oak Ridge National Laboratory (ORNL). The system, known as a rare gas atom counter, extends the capabilities of resonance ionization mass spectrometry to include counting single atoms of krypton-81. The counter is composed of a pulsed dye laser operated in tandem with a mass spectrometer to separate the various isotopes of krypton. In a collaborative study, ORNL scientists recently used the method for the first time to count krypton-81 in a liter of ground water removed from a sandstone aquifer near Zurich. Fewer than 1000 krypton-81 atoms were isolated from the ground water samples. According to Bernard Lehman, a collaborating geochemist at the University of Bern, this first test proved that counting the small numbers of krypton-81 atoms necessary to make an estimate of the age of water could actually be done. Among the applications of this method, Lehman says, could be improved siting of locations for the disposal of radioactive wastes

  16. Temperature under the Tongue: A paleotemperature record of the Drygalksi Ice Tongue with improved chronology of ice retreat

    Science.gov (United States)

    Subt, C.; Rosenheim, B. E.; Lee, J. I.; Yoo, K. C.; Browne, I. M.; Shevenell, A.

    2017-12-01

    The Ross Embayment is among the most well-studied regions in Antarctica. Despite the relative abundance of data, the style and forcing of deglaciation of the Ross Sea sector following the Last Glacial Maximum (LGM; 23-19 ka) is challenging due to the region's considerable size, complex geometry, and the difficulties in dating Antarctic glaciomarine sedimentary sequences. Ross Sea sediments indicate a dynamic glacial retreat in the western Ross Sea, whereas regional glacial systems may have retreated and advanced multiple times during the last deglaciation. Two marine sediment cores collected near the Drygalski Ice Tongue in the western Ross Sea during 2012 and 2015 Korea Polar Research Institute (KOPRI) expeditions reveal a sequence of alternating diatomaceous muds and oozes interbedded with diamict, which suggest dynamic post-LGM grounded ice retreat in the Ross Sea. Dynamic retreat is hypothesized to have been driven by rising sea levels and warmer ocean waters on the continental shelf, thus a record of upper ocean temperatures should reflect this. Here we present the first post-LGM upper ocean temperature record from the Ross Sea, developed using the TEX86 (tetraether index of lipids consisting of 86 carbons) paleothermometer. To overcome the difficulties of dating these sediments using traditional methods, we apply specialized Ramped PyrOx 14C dating for sediments with high proportions of relict carbon . This technique is particularly well-suited for the post-LGM retreat sedimentary sequences from Antarctic margins because it allows for separation of autochthonous and relict material for dating. By combining organic paleothermometry and state-of-the-art chronologic techniques, we gain a more thorough understanding of upper ocean temperatures in the Ross Sea during the last deglaciation, and their implications for ice retreat.

  17. Desert Habitation History by 14C Dating of Soil Layers in Rural Building Structures (Negev, Israel) : Preliminary Results from Horvat Haluqim

    NARCIS (Netherlands)

    Bruins, Hendrik J.; van der Plicht, Johannes; Haiman, Mordechai

    2012-01-01

    Traditional archaeological approaches in the central Negev Desert used to employ excavation techniques in post-prehistoric periods in which stratigraphy is based on architecture, while material culture forms the basis for dating assessment and chronology. Such an approach was understandable, as it

  18. Santorini eruption radiocarbon dated to 1627-1600 B.C.

    Science.gov (United States)

    Friedrich, Walter L; Kromer, Bernd; Friedrich, Michael; Heinemeier, Jan; Pfeiffer, Tom; Talamo, Sahra

    2006-04-28

    Precise and direct dating of the Minoan eruption of Santorini (Thera) in Greece, a global Bronze Age time marker, has been made possible by the unique find of an olive tree, buried alive in life position by the tephra (pumice and ashes) on Santorini. We applied so-called radiocarbon wiggle-matching to a carbon-14 sequence of tree-ring segments to constrain the eruption date to the range 1627-1600 B.C. with 95.4% probability. Our result is in the range of previous, less precise, and less direct results of several scientific dating methods, but it is a century earlier than the date derived from traditional Egyptian chronologies.

  19. Radiocarbon dating and 13 C/12 C ratio of soils under tropical and subtropical climates

    International Nuclear Information System (INIS)

    Valencia, Edwin P.E.

    1993-01-01

    It was used an association radiocarbon dates with the carbon isotopic composition of soil organic matter, where 14 C dating gives elements of chronology, and δ 13 C is used as indicator of the vegetation types in the environment. The total soil organic matter was dried, floated and sieved. The humin fraction was extracted from the 0,250 mm fraction. Radiocarbon datings were performed by a liquid scintillation method. The carbon of the soil organic matter and humin fraction are transformed into benzene, that was analyzed in low level liquid scintillation spectrometer. Based on results of carbon isotope analysis and Radiocarbon dating of soil samples of Londrina, Piracicaba and Altamira, it is concluded that probable changes of vegetation and climate occurred in the South and Southeast regions of Brazil in the mid-Holocene. (author). 81 refs., 16 figs., 7 tabs

  20. Dating of some fossil Romanian bones by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Olariu, Agata; Skog, Goeran; Emilian Alexandrescu; Hellborg, Ragnar; Stenstroem, Krstina; Faarinen, Mikko; Persson, Per

    2002-01-01

    Some fossil bones from Romanian territories have been dated by accelerator mass spectrometry (AMS) using the pelletron system from Lund University. The preparation of samples has been the classical procedure to produce pure graphite from bones specimens, The Paleolithic site from Malu Rosu, near Giurgiu was thoroughly analyzed. Two human fossil skulls from Cioclovina and Baia de Fier of special archaeological importance have been estimated to be of around 30 000 years old, a conclusion with great implications for the history of ancient Romania. By this physical analysis, a long scientific dispute was settled. The two fossil human skulls are the only ones of this age from Romania. One could advance the hypothesis that the skulls belong to a certain type of a branch of Central European Cro-Magon, the classical western type, considering both the chronological and the anthropological features. They constitute eastern limit of the Cro-Magnon man type. (authors)

  1. Developing a postglacial rockfall chronology in the mountainous fjord landscape of western Norway

    Science.gov (United States)

    Laute, Katja; Beylich, Achim A.; Winkler, Stefan

    2015-04-01

    Large areas of glacially sculpted mountain landscapes worldwide exhibit a high spatial density of postglacial rockfalls and rock-slope failures. However, the temporal patterns of rock-slope failure frequencies after Deglaciation are still fairly unknown. The mountainous fjord landscape in western Norway represents a suitable study area as it exhibits a high number of rockfalls and rock-slope failures within a region with a well known Deglaciation history. Two steep, parabolic-shaped and glacier-connected neighbouring drainage basins, Erdalen (79.5 km2) and Bødalen (60.1 km2), located on the western side of the Jostedalsbreen ice cap in western Norway are selected as study areas. The focus of this study is on (i) the temporal reconstruction of rockfalls and rock-slope failures within the two defined and nearly lithologically homogenous study areas and (ii) the identification and explanation of possible triggering and controlling factors of the investigated rock-slope failures. First investigations have started by applying Schmidt-hammer exposure-age dating (SHD) at seven larger rockfall deposits as well as at five moraines of known age within both study areas. During the sampling 50 to 100 impacts using a mechanical Proceq N-type instrument were taken from the surface of 5 to 50 single rockfall boulders located at the outer margin of the rockfall deposits. In order to avoid sampling of more recent rockfalls or redistributed debris material the sampling strategy selected preferred a larger number of individual boulders sampled with few impacts over sampling just a small number of boulders with a high number of multiple impacts. First results show that the mean rebound (R-) values measured at the seven rockfall deposits fall into recognizably different age categories. Based on the SHD measurements obtained from the moraines of known age, the determined rockfall age categories are situated between the Preboral and Little Ice Age period. The chronology and possible

  2. A genetic chronology for the Indian Subcontinent points to heavily sex-biased dispersals.

    Science.gov (United States)

    Silva, Marina; Oliveira, Marisa; Vieira, Daniel; Brandão, Andreia; Rito, Teresa; Pereira, Joana B; Fraser, Ross M; Hudson, Bob; Gandini, Francesca; Edwards, Ceiridwen; Pala, Maria; Koch, John; Wilson, James F; Pereira, Luísa; Richards, Martin B; Soares, Pedro

    2017-03-23

    India is a patchwork of tribal and non-tribal populations that speak many different languages from various language families. Indo-European, spoken across northern and central India, and also in Pakistan and Bangladesh, has been frequently connected to the so-called "Indo-Aryan invasions" from Central Asia ~3.5 ka and the establishment of the caste system, but the extent of immigration at this time remains extremely controversial. South India, on the other hand, is dominated by Dravidian languages. India displays a high level of endogamy due to its strict social boundaries, and high genetic drift as a result of long-term isolation which, together with a very complex history, makes the genetic study of Indian populations challenging. We have combined a detailed, high-resolution mitogenome analysis with summaries of autosomal data and Y-chromosome lineages to establish a settlement chronology for the Indian Subcontinent. Maternal lineages document the earliest settlement ~55-65 ka (thousand years ago), and major population shifts in the later Pleistocene that explain previous dating discrepancies and neutrality violation. Whilst current genome-wide analyses conflate all dispersals from Southwest and Central Asia, we were able to tease out from the mitogenome data distinct dispersal episodes dating from between the Last Glacial Maximum to the Bronze Age. Moreover, we found an extremely marked sex bias by comparing the different genetic systems. Maternal lineages primarily reflect earlier, pre-Holocene processes, and paternal lineages predominantly episodes within the last 10 ka. In particular, genetic influx from Central Asia in the Bronze Age was strongly male-driven, consistent with the patriarchal, patrilocal and patrilineal social structure attributed to the inferred pastoralist early Indo-European society. This was part of a much wider process of Indo-European expansion, with an ultimate source in the Pontic-Caspian region, which carried closely related Y

  3. Chronology of Chichen Izta, evidences by thermoluminescence; Cronologia de Chichen Izta, evidencias por termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A.; Schaaf, P. [Laboratorio de Termoluminiscencia, Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico); Gonzalez, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Chung, H. [Facultad de Filosofia y Letras, UNAM, 04510 Mexico D.F. (Mexico)

    2002-07-01

    The establishment of the chronology of Chichen Itza is argued by its stylistic evocations, architectural and iconographical as well as its history related in the sources, as the Chilam Balam, where is named the arrival of foreign tribes as the Xiu and the Itzaes and its settlement in Chichen Itza as well as the return to its origin place. The material evidence of such transition is reflected in the ceramic change of the Pizarra Puuc to the Pizarra Chichen, however, in 13 stratigraphic wells realized in different points of Chichen Itza, it was not found evidence of the layer of the Pizarra Puuc period. In this work the obtained ages of dating by thermoluminescence (TL) are presented, of four samples of ceramics found in the different wells. When our results are compared with the estimated ages for the different groups of ceramics, it was observed that none of they corresponded to the Pizarra Puuc period. These results strenghten the observations realized during excavations, causing the suggestion of new inferences related to the Chichen Itza boom and its relationship with the Maya Classic Period. The used technique for the TL dating was that of fine grain. The interval of artificial dose, of beta radiation of Strontium 90 was between 2 and 30 Gy. The TL signal was obtained heating the samples at 10 C/s until reaching 500 C in the TL Daybreak reader equipment. In order to know the annual dose rate of concentration of potassium ({sup 40} K) by means of the microanalysis technique in the scanning electron microscope was determined, while the uranium content (2{sup 38} U) and thorium ({sup 232} Th) were determined by means of the neutron activation analysis technique using the TRIGA Mark III nuclear reactor. The contribution of the gamma radiation of the soil as well as the contribution of the cosmic radiation was measured with TL dosemeters of CaSO{sub 4} :Dy + Ptfe once the paleodose was known and the annual dose rate of each sample of its age was estimated. (Author)

  4. Dating sediment cores from Hudson River marshes

    International Nuclear Information System (INIS)

    Robideau, R.; Bopp, R.F.

    1993-01-01

    There are several methods for determining sediment accumulation rates in the Hudson River estuary. One involves the analysis of the concentration of certain radionuclides in sediment core sections. Radionuclides occur in the Hudson River as a result of: natural sources, fallout from nuclear weapons testing and low level aqueous releases from the Indian Point Nuclear Power Facility. The following radionuclides have been studied in the authors work: Cesium-137, which is derived from global fallout that started in the 1950's and has peaked in 1963. Beryllium-7, a natural radionuclide with a 53 day half-life and found associated with very recently deposited sediments. Another useful natural radionuclide is Lead-210 derived from the decay of Radon-222 in the atmosphere. Lead-210 has a half-life of 22 years and can be used to date sediments up to about 100 years old. In the Hudson River, Cobalt-60 is a marker for Indian Point Nuclear Reactor discharges. The author's research involved taking sediment core samples from four sites in the Hudson River Estuarine Research Reserve areas. These core samples were sectioned, dried, ground and analyzed for the presence of radionuclides by the method of gamma-ray spectroscopy. The strength of each current pulse is proportional to the energy level of the gamma ray absorbed. Since different radionuclides produce gamma rays of different energies, several radionuclides can be analyzed simultaneously in each of the samples. The data obtained from this research will be compared to earlier work to obtain a complete chronology of sediment deposition in these Reserve areas of the river. Core samples may then by analyzed for the presence of PCB's, heavy metals and other pollutants such as pesticides to construct a pollution history of the river

  5. Accelerator mass spectrometry 14C dating of lime mortars: Methodological aspects and field study applications at CIRCE (Italy)

    Science.gov (United States)

    Marzaioli, Fabio; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Ricci, Paola; Lubritto, Carmine; De Cesare, Nicola; Eramo, Giacomo; Quirós Castillo, Juan Antonio; Terrasi, Filippo

    2013-01-01

    Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) has, recently, obtained some promising results in testing the feasibility of mortar radiocarbon dating by means of an ad hoc developed purification procedure (CryoSoniC: Cryobraking, Sonication, Centrifugation) applied to a series of laboratory mortars. Observed results encouraged CryoSoniC accuracy evaluation on genuine mortars sampled from archeological sites of known or independently constrained age (i.e., other 14C dates on different materials). In this study, some 14C measurements performed on genuine mortars will be discussed and compared with independently estimated (i.e., radiocarbon/archaeometrical dating) absolute chronologies of two Spanish sites. Observed results confirm the agreement of the CryoSoniC mortar dates with the archaeological expectations for both examined cases. Several authors reported the possibility of obtaining accurate radiocarbon dates of mortar matrices by analyzing lime lumps: binder-related particles of different sizes exclusively composed of calcium carbonate. In this paper, preliminary data for the absolute chronology reconstruction of the Basilica of the cemetery complex of Ponte della Lama (Canosa di Puglia, Italy) based on lime lumps will also be discussed. Dating accuracy will be quantified by comparing 14C data on mortar lime lumps from a funerary inscription of known age found near the Basilica, in the same study site. For this site, a comparison between absolute chronologies performed by bulk and CryoSoniC purified lime lumps, and charcoal incased in mortars (when found) will also be discussed. Observed results for this site provide evidence of how bulk lime lump dating may introduce systematic overestimations of the analyzed sample while CryoSoniC purification allows accurate dating.

  6. Accelerator mass spectrometry {sup 14}C dating of lime mortars: Methodological aspects and field study applications at CIRCE (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, Fabio, E-mail: fabio.marzaioli@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Nonni, Sara, E-mail: sara.nonni@uniroma1.it [Dipartimento di Scienze della Terra, ' Sapienza' Universita di Roma (Italy); Passariello, Isabella, E-mail: isabella.passariello@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Capano, Manuela, E-mail: manuela.capano@unina2.it [CIRCE, INNOVA and Dipartimento di Studio delle Componenti Culturali del Territorio, Seconda Universita degli Studi di Napoli, Santa Maria Capua Vetere, Caserta (Italy); Ricci, Paola, E-mail: paola.ricci@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Lubritto, Carmine, E-mail: carmine.lubritto@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); De Cesare, Nicola, E-mail: nicola.decesare@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze della Vita, Caserta (Italy); Eramo, Giacomo, E-mail: giacomo.eramo@uniba.it [Dipartimento di Scienze della Terra e Geoambientali, Universita degli Studi di Bari ' Aldo Moro' , Bari (Italy); Quiros Castillo, Juan Antonio, E-mail: quiros.castillo@ehu.es [Universidad del Pais Vasco-Euskal Herriko Unibertsitatea, Dipartimento di Geografia, Prehistoria y Arqueologia, Vitoria-Gasteiz (Spain); and others

    2013-01-15

    Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) has, recently, obtained some promising results in testing the feasibility of mortar radiocarbon dating by means of an ad hoc developed purification procedure (CryoSoniC: Cryobraking, Sonication, Centrifugation) applied to a series of laboratory mortars. Observed results encouraged CryoSoniC accuracy evaluation on genuine mortars sampled from archeological sites of known or independently constrained age (i.e., other {sup 14}C dates on different materials). In this study, some {sup 14}C measurements performed on genuine mortars will be discussed and compared with independently estimated (i.e., radiocarbon/archaeometrical dating) absolute chronologies of two Spanish sites. Observed results confirm the agreement of the CryoSoniC mortar dates with the archaeological expectations for both examined cases. Several authors reported the possibility of obtaining accurate radiocarbon dates of mortar matrices by analyzing lime lumps: binder-related particles of different sizes exclusively composed of calcium carbonate. In this paper, preliminary data for the absolute chronology reconstruction of the Basilica of the cemetery complex of Ponte della Lama (Canosa di Puglia, Italy) based on lime lumps will also be discussed. Dating accuracy will be quantified by comparing {sup 14}C data on mortar lime lumps from a funerary inscription of known age found near the Basilica, in the same study site. For this site, a comparison between absolute chronologies performed by bulk and CryoSoniC purified lime lumps, and charcoal incased in mortars (when found) will also be discussed. Observed results for this site provide evidence of how bulk lime lump dating may introduce systematic overestimations of the analyzed sample while CryoSoniC purification allows accurate dating.

  7. Quartz OSL dating of late Holocene beach ridges from the Magdalen Islands (Quebec, Canada)

    DEFF Research Database (Denmark)

    Remillard, A.M.; Buylaert, Jan-Pieter; Murray, Andrew

    2015-01-01

    Quartz optically stimulated luminescence (OSL) dating has been applied to sandy beach ridge systems from the Magdalen Islands in the center of the Gulf of St. Lawrence (Quebec, Canada) to provide the first chronological framework for these features. Nineteen beach ridges (22 samples) from four......). The OSL ages indicate that the ridges were built between 2.6 ± 0.2 ka and 0.40 ± 0.10 ka, i.e. during a period of sea level rise. This rise eroded adjacent sandstone cliffs, which contributed a significant sediment supply to the littoral drift and beaches. Some low-lying coasts in the archipelago...... great potential in this area, and is an appropriate method for establishing precise chronologies for coastal sediments in this region of the Gulf of St. Lawrence. © 2015 Elsevier B.V. All rights reserved....

  8. 42 CFR 456.128 - Initial continued stay review date.

    Science.gov (United States)

    2010-10-01

    ... norms to assign the initial continued stay review date, the number of days between the individual's... and criteria required to be described under § 456.129; (2) The individual's condition; and (3) The individual's projected discharge date; (c)(1) The committee uses any available appropriate regional medical...

  9. Natural Besnoitia besnoiti infections in cattle: chronology of disease progression.

    Science.gov (United States)

    Gollnick, Nicole S; Scharr, Julia C; Schares, Gereon; Langenmayer, Martin C

    2015-02-14

    Bovine besnoitiosis is an emerging protozoan disease in cattle. Neither vaccines nor chemotherapeutic drugs are currently available for prevention and treatment of Besnoitia besnoiti infections. Therefore the implementation of appropriate disease management strategies is of utmost importance. The aim of this longitudinal study was to complement current knowledge on the chronology of disease progression. This was realized by correlating clinical findings in early stages of naturally acquired bovine besnoitiosis with results of real-time PCR of skin biopsies and of two western immunoblots and an immunofluorescent antibody test (IFAT). Animals for this study were obtained by i) closely monitoring a cow-calf operation with a high prevalence of bovine besnoitiosis for cases of acute disease, and by ii) conducting a 12-week cohabitation experiment on pasture with five healthy heifers, a healthy bull and five B. besnoiti infected cows. A control group of six healthy heifers was kept at a minimal distance of 20 m. Further, the spectrum of potential insect vectors was determined. Infected cattle were followed up to a maximum of 221 days after first detection of B. besnoiti antibodies. Two severely affected cows developed visible and palpable alterations of skin, a decrease in body condition despite good feed intake, and chronic bovine besnoitiosis-associated laminitis leading to non-healing sole ulcers. The cows also had high reciprocal IFAT titers and high loads of parasite DNA in skin samples. Two heifers developed a mild clinical course characterized by few parasitic cysts visible in the scleral conjunctivae and vestibula vaginae. Both heifers became infected during the time of high insect activity of the species Musca domestica, Musca autumnalis, Haematobia irritans, and Stomoxys calcitrans. When a third heifer became subclinically infected, low insect activity was recorded. None of the six control heifers contracted a B. besnoiti infection. In chronic besnoitiosis

  10. Help-Seeking and Help-Giving for Teen Dating Violence

    Science.gov (United States)

    Weisz, Arlene N.; Black, Beverly M.

    2009-01-01

    This article is based on numerous research projects conducted by the authors on adolescent dating violence. It reviews the results of those projects as they relate to how teens seek help for dating violence and how teens provide help to their friends in violent dating relationships. It concludes with helpful strategies for adults who work with…

  11. Direct dating of Early Upper Palaeolithic human remains from Mladec.

    Science.gov (United States)

    Wild, Eva M; Teschler-Nicola, Maria; Kutschera, Walter; Steier, Peter; Trinkaus, Erik; Wanek, Wolfgang

    2005-05-19

    The human fossil assemblage from the Mladec Caves in Moravia (Czech Republic) has been considered to derive from a middle or later phase of the Central European Aurignacian period on the basis of archaeological remains (a few stone artefacts and organic items such as bone points, awls, perforated teeth), despite questions of association between the human fossils and the archaeological materials and concerning the chronological implications of the limited archaeological remains. The morphological variability in the human assemblage, the presence of apparently archaic features in some specimens, and the assumed early date of the remains have made this fossil assemblage pivotal in assessments of modern human emergence within Europe. We present here the first successful direct accelerator mass spectrometry radiocarbon dating of five representative human fossils from the site. We selected sample materials from teeth and from one bone for 14C dating. The four tooth samples yielded uncalibrated ages of approximately 31,000 14C years before present, and the bone sample (an ulna) provided an uncertain more-recent age. These data are sufficient to confirm that the Mladec human assemblage is the oldest cranial, dental and postcranial assemblage of early modern humans in Europe and is therefore central to discussions of modern human emergence in the northwestern Old World and the fate of the Neanderthals.

  12. Electron spin resonance dating of megafauna from Lagoa dos Porcos, Piauí, Brazil.

    Science.gov (United States)

    Kinoshita, Angela; Mayer, Elver; Ribau Mendes, Vinícius; Figueiredo, Ana Maria G; Baffa, Oswaldo

    2014-06-01

    Excavations performed at Lagoa dos Porcos site revealed a vast amount of extinct mammal fossil remains, becoming one of the richest palaeontological occurrences in the Serra da Capivara National Park region, a UNESCO World Heritage. Although anatomic and taxonomic aspects of extinct Quaternary mammals are relatively well known, chronologic information for deposits is rare. In this context, electron spin resonance (ESR) dating of megafauna samples provides important information for establishing a chronological background. This work presents the ESR dating of two teeth, one of Gomphotheriidae and other of Toxodontinae. Dose-response curves of each sample were constructed using spectra acquired with a JEOL FA-200 X-Band spectrometer resulting in equivalent dose (De) of 220 ± 40 Gy and 39 ± 2 Gy for Toxodontinae and Gomphotheriidae tooth, respectively. The conversion of De in age was made using ROSY ESR dating software resulting in 26 ± 4 and 22 ± 3 ka. These results place Lagoa dos Porcos fossil assemblage within the Late Pleistocene. These dates overlap with a period of abrupt increase in rainfall in northeast Brazil, and it is possible that this environmental change is related to the formation of this deposit. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Dating the last Neanderthals in Central Iberia - New evidence from Abrigo del Molino, Segovia, Spain

    Science.gov (United States)

    Kehl, Martin; Álvarez-Alonso, David; de Andrés-Herrero, María; Díez-Herrero, Andrés; Klasen, Nicole; Rojo-Hernández, Julio; Weniger, Gerd-Christian

    2017-04-01

    The timing of Neanderthal disappearance in the Iberian Peninsula is a hotly debated subject in Palaeolithic archaeology. Several studies suggested a late survival in South and Central Iberia until about 32,000 year ago (ka), but were probably subject to significant age underestimation due to contamination of dating samples and/or lack of stratigraphic integrity. More recently, Late Neanderthal presence was dated to no later than 38 ka. In Central Iberia, few archaeological sites contain Mousterian levels attesting occupation by Neanderthals. The newly discovered rock shelter of Abrigo del Molino contains chronologically well-constraint Mousterian levels, which, according to radiocarbon dating on bone, place the latest Neanderthal occupation to around 42-44 ka and within Greenland interstadial 11. Accumulation of these levels took place after deposition of fluvial and slope sediments, dated to around 46 ± 3.5 ka using luminescence techniques, and probably correlating with Greenland stadial 13 including Heinrich event 5. Micromorphological evidence of banded sediment fabrics suggests frost dynamics pointing to cold climate conditions during that time in Central Spain. Abrigo del Molino thus provides a detailed and chronologically well-constrained record on Late Neanderthal presence and morphodynamic change in Central Iberia during times of millennial-scale climate changes. The site gives further evidence for an early rather than late disappearance of Neanderthals in Iberia.

  14. Electron spin resonance dating of mega-fauna from Lagoa dos Porcos, Piaui (Brazil))

    International Nuclear Information System (INIS)

    Kinoshita, Angela; Mayer, Elver; Ribau Mendes, Vinicius; Figueiredo, Ana Maria G.; Baffa, Oswaldo

    2014-01-01

    Excavations performed at Lagoa dos Porcos site revealed a vast amount of extinct mammal fossil remains, becoming one of the richest palaeontological occurrences in the Serra da Capivara National Park region, a UNESCO World Heritage. Although anatomic and taxonomic aspects of extinct Quaternary mammals are relatively well known, chronologic information for deposits is rare. In this context, electron spin resonance (ESR) dating of mega-fauna samples provides important information for establishing a chronological background. This work presents the ESR dating of two teeth, one of Gomphotheriidae and other of Toxodontinae. Dose-response curves of each sample were constructed using spectra acquired with a JEOL FA-200 X-Band spectrometer resulting in equivalent dose (D e ) of 220±40 Gy and 39±2 Gy for Toxodontinae and Gomphotheriidae tooth, respectively. The conversion of D e in age was made using ROSY ESR dating software resulting in 26±4 and 22±3 ka. These results place Lagoa dos Porcos fossil assemblage within the Late Pleistocene. These dates overlap with a period of abrupt increase in rainfall in northeast Brazil, and it is possible that this environmental change is related to the formation of this deposit. (authors)

  15. A multi-method luminescence dating of the Palaeolithic sequence of La Ferrassie based on new excavations adjacent to the La Ferrassie 1 and 2 skeletons

    DEFF Research Database (Denmark)

    Guerin, Guillaume; Frouin, Marine; Talamo, Sahra

    2015-01-01

    A new interdisciplinary project was initiated to excavate a portion of the Palaeolithic site of La Ferrassie left intact by earlier excavations. One of the aims of this project was to provide chronological information on the succession of Middle and Upper Palaeolithic layers, as well as on the sk...

  16. First Direct Dating for the Construction and Modification of the Baphuon Temple Mountain in Angkor, Cambodia.

    Science.gov (United States)

    Leroy, Stéphanie; Hendrickson, Mitch; Delqué-Kolic, Emmanuelle; Vega, Enrique; Dillmann, Philippe

    2015-01-01

    Architecture represents key evidence of dynastic practice and change in the archaeological world. Chronologies for many important buildings and sequences, including the iconic temples of medieval Angkor in Cambodia, are based solely on indirect associations from inscriptions and architectural styles. The Baphuon temple, one of the last major buildings in Angkor without textual or scientifically-derived chronological evidence, is crucial both for the context and date of its construction and the period when its western façade was modified into a unique, gigantic Reclining Buddha. Its construction was part of a major dynastic change and florescence of the Hindu-Mahayana Buddhist state and the modification is the key evidence of Theravada Buddhist power after Angkor's decline in the 15th century. Using a newly-developed approach based on AMS radiocarbon dating to directly date four iron crampons integrated into the structure we present the first direct evidence for the history of the Baphuon. Comprehensive study of ferrous elements shows that both construction and modification were critically earlier than expected. The Baphuon can now be considered as the major temple associated with the imperial reformations and territorial consolidation of Suryavarman I (1010-1050 AD) for whom no previous building to legitimize his reign could be identified. The Theravada Buddhist modification is a hundred years prior to the conventional 16th century estimation and is not associated with renewed use of Angkor. Instead it relates to the enigmatic Ayutthayan occupation of Angkor in the 1430s and 40s during a major period of climatic instability. Accurately dating iron with relatively low carbon content is a decisive step to test long-standing assumptions about architectural histories and political processes for states that incorporated iron into buildings (e.g., Ancient Greece, medieval India). Furthermore, this new approach has the potential to revise chronologies related to iron

  17. First Direct Dating for the Construction and Modification of the Baphuon Temple Mountain in Angkor, Cambodia.

    Directory of Open Access Journals (Sweden)

    Stéphanie Leroy

    Full Text Available Architecture represents key evidence of dynastic practice and change in the archaeological world. Chronologies for many important buildings and sequences, including the iconic temples of medieval Angkor in Cambodia, are based solely on indirect associations from inscriptions and architectural styles. The Baphuon temple, one of the last major buildings in Angkor without textual or scientifically-derived chronological evidence, is crucial both for the context and date of its construction and the period when its western façade was modified into a unique, gigantic Reclining Buddha. Its construction was part of a major dynastic change and florescence of the Hindu-Mahayana Buddhist state and the modification is the key evidence of Theravada Buddhist power after Angkor's decline in the 15th century. Using a newly-developed approach based on AMS radiocarbon dating to directly date four iron crampons integrated into the structure we present the first direct evidence for the history of the Baphuon. Comprehensive study of ferrous elements shows that both construction and modification were critically earlier than expected. The Baphuon can now be considered as the major temple associated with the imperial reformations and territorial consolidation of Suryavarman I (1010-1050 AD for whom no previous building to legitimize his reign could be identified. The Theravada Buddhist modification is a hundred years prior to the conventional 16th century estimation and is not associated with renewed use of Angkor. Instead it relates to the enigmatic Ayutthayan occupation of Angkor in the 1430s and 40s during a major period of climatic instability. Accurately dating iron with relatively low carbon content is a decisive step to test long-standing assumptions about architectural histories and political processes for states that incorporated iron into buildings (e.g., Ancient Greece, medieval India. Furthermore, this new approach has the potential to revise chronologies

  18. Dating Last Interglacial Coastal Systems Using New Feldspar Luminescence Technologies

    Science.gov (United States)

    Lamothe, M.

    2017-12-01

    The recent explosion in new luminescence dating technologies offers new opportunities to explore Quaternary marine coastal facies and landforms. However, tectonic and climatic processes controlling the development of Pleistocene coastal lithosomes are commonly obscured by their poorly constrained geological age. Luminescence dating of feldspar probes one order of magnitude deeper into geological time than radiocarbon and more than 5 times the current age range of quartz optically-stimulated luminescence, routinely used in luminescence dating. However, feldspar luminescence stimulated by infrared photons (eg IRSL) is hampered by anomalous fading. Successful correction methods developed by us over the last 15 years did produce sound chronologies but the fading-corrected ages carried large uncertainties. New approaches initiated by other laboratories, mainly in Europe, have isolated high temperature post-IRSL luminescence as this signal seems to be only slightly affected by fading. However, the gain in stability seems to be lessened due to bleachibility issues, generating age overestimations. We developed a novel protocol known as post-isothermal IRSL dating (Pit-IR) that focuses on a dual system of luminescence signals, probing low (50C) and medium (225C) temperature IRSL signals following isothermal treatments of various intensities. These protocols have been tested on Last interglacial coastal sediments in strikingly different GIA contexts along the Atlantic coastal areas of SE USA as well as from Morocco, Brazil and LIG sites in the Mediterranean basin. A systematic analysis of these results would suggest that a) falling-stages sequences are more commonly preserved as the OSL/IRSL ages are preferentially dating from the end of the MIS5e high stand and b) MIS5a marine sediments may be detectable away from areas generally thought to be affected by peripheral bulge collapse.

  19. Atom and pre-history: the geological framework of fossil man in the light of dating and isotopic data

    International Nuclear Information System (INIS)

    Miskovsky, J.C.; Gibert, E.

    1994-01-01

    The discovery of natural radioactivity and the applications of nuclear physics to the study of sediments and sediment content, allow for the delimitation of the chrono-stratigraphic and paleoclimatic framework of fossil Man. This chronology is based on the development of continental glacial phenomena and is specified through comparison with various methods: paleomagnetic inversion, the variation of oxygen isotopic composition of marine biogenic carbonates and the dating methods. Pleistocene and Holocene era are reviewed. (authors). 9 figs., 90 refs

  20. Compilation of reports of the Advisory Committee on Reactor Safeguards, 1957-1984. Volume 2. Project Reviews G-P

    International Nuclear Information System (INIS)

    1985-04-01

    This six-volume compilation contains over 1000 reports prepared by the Advisory Committee on Reactor Safeguards from September 1957 through December 1984. The reports are divided into two groups: Part 1: ACRS Reports on Project Reviews, and Part 2: ACRS Reports on Generic Subjects. Part 1 contains ACRS reports alphabetized by project name and within project name by chronological order. Part 2 categorizes the reports by the most appropriate generic subject area and within subject area by chronological order

  1. Lead concentration and isotope chronology in two coastal environments in Western and South East Asia

    Science.gov (United States)

    Carrasco, G. G.; Chen, M.; Boyle, E. A.; Zhao, N.; Nurhati, I. S.; Gevao, B.; al Ghadban, A.; Switzer, A.; Lee, J. M.

    2014-12-01

    Lead is a trace metal that is closely related to anthropogenic activity, mainly via leaded gasoline and coal combustion. The study of lead concentrations and isotopes in seawater, sediments, corals and aerosols allows for a systematic look at its sources and their time evolution in a natural environment. We will discuss results from two projects in Western and South East Asia, regions that have seen dramatic socio-economical changes over the past half-century that may have left environmental signals. These results highlight the usefulness of the method, indicate the degree of complexity of these systems, and point to the need for a continuous monitoring of anthropogenic trace metals in the small-medium coastal scale to be able to asses the larger scale effects of human activity. On the one hand, coastal Kuwait is heavily influenced by the Shat al-Arab river and shows a clear anthropogenic signature from Kuwait city. A mix of two sources can be tracked through the coral and sediment chronological records, with Pb206/Pb207 ratios (1.202 and 1.151) that approach the suspected source values (1.21 and 1.12) and eliminate the possibility of other sources. Through a wide sediment geographic distribution, the strength of the anthropogenic signature is modulated. On the other hand, Singapore offers a more complex system, where an apparent mix of two sources (extreme isotope ratios 1.215 and ~1.14) occurs also, but where either an unresolved potentially important third source (isotope ratio ~1.18), or an isotope exchange process should be invoked. The sediment and coral records allows us to track the changes through time; however, there seems to be incongruence with the aerosol isotope record. Further potential sources are being explored currently and will be discussed.

  2. Maintenance of cellular ATP level by caloric restriction correlates chronological survival of budding yeast

    International Nuclear Information System (INIS)

    Choi, Joon-Seok; Lee, Cheol-Koo

    2013-01-01

    Highlights: •CR decreases total ROS and mitochondrial superoxide during the chronological aging. •CR does not affect the levels of oxidative damage on protein and DNA. •CR contributes extension of chronological lifespan by maintenance of ATP level -- Abstract: The free radical theory of aging emphasizes cumulative oxidative damage in the genome and intracellular proteins due to reactive oxygen species (ROS), which is a major cause for aging. Caloric restriction (CR) has been known as a representative treatment that prevents aging; however, its mechanism of action remains elusive. Here, we show that CR extends the chronological lifespan (CLS) of budding yeast by maintaining cellular energy levels. CR reduced the generation of total ROS and mitochondrial superoxide; however, CR did not reduce the oxidative damage in proteins and DNA. Subsequently, calorie-restricted yeast had higher mitochondrial membrane potential (MMP), and it sustained consistent ATP levels during the process of chronological aging. Our results suggest that CR extends the survival of the chronologically aged cells by improving the efficiency of energy metabolism for the maintenance of the ATP level rather than reducing the global oxidative damage of proteins and DNA

  3. Maintenance of cellular ATP level by caloric restriction correlates chronological survival of budding yeast

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon-Seok; Lee, Cheol-Koo, E-mail: cklee2005@korea.ac.kr

    2013-09-13

    Highlights: •CR decreases total ROS and mitochondrial superoxide during the chronological aging. •CR does not affect the levels of oxidative damage on protein and DNA. •CR contributes extension of chronological lifespan by maintenance of ATP level -- Abstract: The free radical theory of aging emphasizes cumulative oxidative damage in the genome and intracellular proteins due to reactive oxygen species (ROS), which is a major cause for aging. Caloric restriction (CR) has been known as a representative treatment that prevents aging; however, its mechanism of action remains elusive. Here, we show that CR extends the chronological lifespan (CLS) of budding yeast by maintaining cellular energy levels. CR reduced the generation of total ROS and mitochondrial superoxide; however, CR did not reduce the oxidative damage in proteins and DNA. Subsequently, calorie-restricted yeast had higher mitochondrial membrane potential (MMP), and it sustained consistent ATP levels during the process of chronological aging. Our results suggest that CR extends the survival of the chronologically aged cells by improving the efficiency of energy metabolism for the maintenance of the ATP level rather than reducing the global oxidative damage of proteins and DNA.

  4. Dating human occupation and adaptation in the southern European last glacial refuge: The chronostratigraphy of Grotta del Romito (Italy)

    Science.gov (United States)

    Blockley, Simon; Pellegrini, Maura; Colonese, Andre C.; Lo Vetro, Domenico; Albert, Paul G.; Brauer, Achim; Di Giuseppe, Zelia; Evans, Adrian; Harding, Poppy; Lee-Thorp, Julia; Lincoln, Paul; Martini, Fabio; Pollard, Mark; Smith, Victoria; Donahue, Randolph

    2018-03-01

    Grotta del Romito has been the subject of numerous archaeological, chronological and palaeoenvironmental investigations for more than a decade. During the Upper Palaeolithic period the site contains evidence of human occupation through the Gravettian and Epigravettian periods, multiple human burials, changes in the pattern of human occupation, and faunal, isotopic and sedimentological evidence for local environmental change. In spite of this rich record, the chronological control is insufficient to resolve shifts in subsistence and mobility patterns at sufficiently high resolution to match the abrupt climate fluctuations at this time. To resolve this we present new radiocarbon and tephrostratigraphic dates in combination with existing radiocarbon dates, and develop a Bayesian age model framework for the site. This improved chronology reveals that local environmental conditions reflect abrupt and long-term changes in climate, and that these also directly influence changing patterns of human occupation of the site. In particular, we show that the environmental record for the site, based on small mammal habitat preferences, is chronologically in phase with the main changes in climate and environment seen in key regional archives from Italy and Greenland. We also calculate the timing of the transitions between different cultural phases and their spans. We also show that the intensification in occupation of the site is chronologically coincident with a rapid rise in Mesic Woody taxa seen in key regional pollen records and is associated with the Late Epigravettian occupation of the site. This change in the record of Grotta del Romito is also closely associated stratigraphically with a new tephra (the ROM-D30 tephra), which may act as a critical marker in environmental records of the region.

  5. Establishing the chronology of explosive super-eruptions in the record of the Yellowstone hotspot track (Invited)

    Science.gov (United States)

    Reichow, M. K.; Branney, M. J.; Knott, T.; Storey, M.; Finn, D. R.; Coe, R. S.; McCurry, M. O.; Bonnichsen, B.

    2013-12-01

    Although caldera-forming super-eruptions (≥450 km3) are amongst the most catastrophic events to affect the Earth's surface, we do not know how often they occur globally, and how large the individual eruptions are. This is because, with a few exceptions, the vast volcanic stratigraphies at many large igneous provinces have not yet been resolved in sufficient detail to isolate and quantify the individual events. Much progress is needed on this if we are to verify the past and potential environmental and climatic impact of these super-eruptions. We are reconstructing the history of catastrophic eruptions in the youngest and best-preserved large intra continental volcanic province worldwide, by resolving the vast Miocene rhyolitic volcanic stratigraphy of the central Snake River Plain, Idaho. Large explosive eruptions, several previously un-documented, generated an unusually hot (searing-hot rhyolitic glass 5-100 m thick. The density currents also generated thermal atmospheric plumes (phoenix clouds) that dispersed 100's to 1000's of km3 rhyolitic ash 1000's of km across continental USA and beyond. High-precision chronology and quantification of the erupted volumes and the frequency of eruptions is needed to assess the likely significant wider impact of these events on climate and ecosystems. To determine the size of the individual events, we have been correlating each soil-bounded eruption-unit regionally. This is hindered by their abundance, and closely similar appearance within monotonous successions exposed in distant (50-200 km) mountain ranges. To tackle this we are employing a combination of tools to isolate and correlate individual layers: field logging coupled with characterization of the whole-rock, glass, and mineral chemistries, together with high-precision 40Ar/39Ar dating, U-Pb zircon dating, with detailed paleomagnetic characterisation of polarities and secular variations. This multidisciplinary approach is yielding robust ';fingerprints'; to

  6. ESR dating a quaternary travertine

    International Nuclear Information System (INIS)

    Lopez Carranza, E.; Amosse, J.; Bouchez, R.

    1987-10-01

    To study the chronology of the quarternary glaciations in the high Peruvian Andes (3.5-4.0 Km high) a number of samples of travertines was collected in the Oroya-Tarma-Huancayo region. We report, in particular, the ESR measurements realized on samples from Santa Rosa de Sacco, which contain 99% of calcite and show a line of g=2.0046 and of width 8.3G, stable, at least, until ∼ 270 deg C. Using the additive dose method to obtain the paleodose and measuring the annual dose by spectrometry gamma of high resolution we obtain for the samples, as a preliminary result, an age between 260,000 and 340,000 a. (author). 7 refs, 6 figs

  7. 10Be dating of late-glacial moraines near the Cordillera Vilcanota and the Quelccaya Ice Cap, Peru

    Science.gov (United States)

    Kelly, M. A.; Thompson, L. G.

    2004-12-01

    The surface exposure method, based on the measurement of cosmogenic 10Be produced in quartz, is applied to determine the age of deposition of glacial moraines near the Cordillera Vilcanota and the Quelccaya Ice Cap (about 13° S, 70° W) in southeastern Peru. These data are useful for examining the timing of past glaciation in the tropical Andes and for comparison with chronologies of glaciation at higher latitudes. The preliminary data set consists of more than ten surface exposure ages. Samples used for dating are from the surfaces of boulders on a set of prominent moraines about four kilometers away from the present ice margins. The age of the moraine set was previously bracketed by radiocarbon dating of peat associated with the glacial deposits. Based on radiocarbon ages, these moraines were formed during the late-glacial period, just prior to the last glacial-interglacial transition. The surface exposure dating method enables the direct dating of the moraines. Surface exposure dates are cross-checked with the previously existing radiocarbon dates and provide a means to improve the chronology of past glaciation in the tropical Andes.

  8. On the chronology of lunar origin and evolution. Implications for Earth, Mars and the Solar System as a whole

    Science.gov (United States)

    Geiss, Johannes; Rossi, Angelo Pio

    2013-11-01

    An origin of the Moon by a Giant Impact is presently the most widely accepted theory of lunar origin. It is consistent with the major lunar observations: its exceptionally large size relative to the host planet, the high angular momentum of the Earth-Moon system, the extreme depletion of volatile elements, and the delayed accretion, quickly followed by the formation of a global crust and mantle. According to this theory, an impact on Earth of a Mars-sized body set the initial conditions for the formation and evolution of the Moon. The impact produced a protolunar cloud. Fast accretion of the Moon from the dense cloud ensured an effective transformation of gravitational energy into heat and widespread melting. A "Magma Ocean" of global dimensions formed, and upon cooling, an anorthositic crust and a mafic mantle were created by gravitational separation. Several 100 million years after lunar accretion, long-lived isotopes of K, U and Th had produced enough additional heat for inducing partial melting in the mantle; lava extruded into large basins and solidified as titanium-rich mare basalt. This delayed era of extrusive rock formation began about 3.9 Ga ago and may have lasted nearly 3 Ga. A relative crater count timescale was established and calibrated by radiometric dating (i.e., dating by use of radioactive decay) of rocks returned from six Apollo landing regions and three Luna landing spots. Fairly well calibrated are the periods ≈4 Ga to ≈3 Ga BP (before present) and ≈0.8 Ga BP to the present. Crater counting and orbital chemistry (derived from remote sensing in spectral domains ranging from γ- and x-rays to the infrared) have identified mare basalt surfaces in the Oceanus Procellarum that appear to be nearly as young as 1 Ga. Samples returned from this area are needed for narrowing the gap of 2 Ga in the calibrated timescale. The lunar timescale is not only used for reconstructing lunar evolution, but it serves also as a standard for chronologies of the

  9. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  10. Luminescence dating of Netherland's sediments

    NARCIS (Netherlands)

    Wallinga, J.; Davids, F.; Dijkmans, J.W.A.

    2007-01-01

    Over the last decades luminescence dating techniques have been developed that allow earth scientists to determine the time of deposition of sediments. In this contribution we revity: 1) the development of the methodology, 2) tests of the reliability of luminescence dating on Netherlands' sediments;

  11. The isotopic dating of crystals

    International Nuclear Information System (INIS)

    Giuliani, G.; Cheilletz, A.

    1995-01-01

    The first part of this work deals with the answer to the question : why are the crystals dated ? Then, some isotopic dating methods are described : U-Th-Pb, K-Ar, 40 Ar/ 39 Ar, Rb-Sr, Sm-Nd, fission traces, carbon 14 methods. Examples concerning emeralds and diamonds are given. (O.L.). 12 refs., 2 figs

  12. The comparison of absolute dating (Radiocarbon dating) and relative dating of Pringapus and Gondosuli temples

    International Nuclear Information System (INIS)

    Faisal, W; Arumbinang, H; Taftazani, A; Widayati, S; Sumiyatno; Suhardi

    1996-01-01

    The absolute dating (radiocarbon, 14 C dating) and relative dating of Pringapus and Gondosuli temples in Temanggung regency (district) of Central Java Province have been carried out. The field sampling was done especially with the purpose to obtain vertical data, so that excavation method was adopted in the case. The main data were the ecofacts of organic habitation such as bones, woods, charcoals, shells, and paper artefacts. The artefacts data were used as a comparison. The comparative data analysis were conducted at Yogyakarta archaeological Department Laboratory, thus included dating of artefacts which were performed according to archaeological analysis procedures, generally based on the attributes attached to the artefacts, whereas the absolute dating of charcoal samples were performed in the Radiocarbon Dating Laboratory at Yogyakarta Nuclear Research Centre. Based on the relative dating of epigraphy content on the andesit rock from Gondosuli Temple which showed the year of 754 Saka or 832 AD, the Pringapus Temple was estimated to be built in the 850 AD. According to the absolute dating (Radiocarbon Dating with delta 13 C and tree ring corrections) the age for Gondosuli temple based on GDS/LU-2/Spit-7 samples is (384 -602) AD and from GDS/LU-2/Spit-8 = (452 - 652) AD. With these significant differences in the results obtained, it can be concluded that culture environment where the sample were collected already existed before the temple was built. Further investigation is still required

  13. Correlation between chronological age, cervical vertebral maturation and Fishman's skeletal maturity indicators in southern Chinese.

    Science.gov (United States)

    Alkhal, Hessa Abdulla; Wong, Ricky W K; Rabie, A Bakr M

    2008-07-01

    To investigate the correlation between chronological age, cervical vertebral maturation (CVM), and Fishman's hand-wrist skeletal maturity indicators in southern Chinese. Four hundred contemporary hand-wrist and lateral cephalometric radiographs of southern Chinese subjects were randomly selected and analyzed. The female subjects were between 10 and 15 years of age, and the male subjects were between 12 and 17 years of age; all subjects were within the circumpubertal period. The CVM was assessed using the method developed by Baccetti and coworkers, but the hand-wrist maturation was assessed using the method developed by Fishman. These two methods and the chronological age were correlated using the Spearman rank correlation analysis. The CVM was significantly correlated with the hand-wrist skeletal age (Spearman r male = 0.9206, female = 0.9363). All patients in the cervical maturation stage (CS3) of CVM were discovered to be in the skeletal maturational indicator (SMI2 or SMI3) stages of hand-wrist maturation (HWM), which was around the peak of the growth spurt. Low correlations were found between the CVM and chronological age (male r = 0.7577; female r = 0.7877) and between the HWM and chronological age (male r = 0.7492; female r = 0.7758). CVM is a valid indicator of skeletal growth during the circumpubertal and has a high correlation with the HWM for the southern Chinese population. However, the low correlations found between the chronological age and both CVM and HWM showed that the chronological age was not suitable to measure skeletal maturity.

  14. The eruptive chronology of the Ampato-Sabancaya volcanic complex (Southern Peru)

    Science.gov (United States)

    Samaniego, Pablo; Rivera, Marco; Mariño, Jersy; Guillou, Hervé; Liorzou, Céline; Zerathe, Swann; Delgado, Rosmery; Valderrama, Patricio; Scao, Vincent

    2016-09-01

    We have reconstructed the eruptive chronology of the Ampato-Sabancaya volcanic complex (Southern Peru) on the basis of extensive fieldwork, and a large dataset of geochronological (40K-40Ar, 14C and 3He) and geochemical (major and trace element) data. This volcanic complex is composed of two successive edifices that have experienced discontinuous volcanic activity from Middle Pleistocene to Holocene times. The Ampato compound volcano consists of a basal edifice constructed over at least two cone-building stages dated at 450-400 ka and 230-200 ka. After a period of quiescence, the Ampato Upper edifice was constructed firstly during an effusive stage (80-70 ka), and then by the formation of three successive peaks: the Northern, Southern (40-20 ka) and Central cones (20-10 ka). The Southern peak, which is the biggest, experienced large explosive phases, resulting in deposits such as the Corinta plinian fallout. During the Holocene, eruptive activity migrated to the NE and constructed the mostly effusive Sabancaya edifice. This cone comprised many andesitic and dacitic blocky lava flows and a young terminal cone, mostly composed of pyroclastic material. Most samples from the Ampato-Sabancaya define a broad high-K magmatic trend composed of andesites and dacites with a mineral assemblage of plagioclase, amphibole, biotite, ortho- and clino-pyroxene, and Fe-Ti oxides. A secondary trend also exists, corresponding to rare dacitic explosive eruptions (i.e. Corinta fallout and flow deposits). Both magmatic trends are derived by fractional crystallisation involving an amphibole-rich cumulate with variable amounts of upper crustal assimilation. A marked change in the overall eruptive rate has been identified between Ampato ( 0.1 km3/ka) and Sabancaya (0.6-1.7 km3/ka). This abrupt change demonstrates that eruptive rates have not been homogeneous throughout the volcano's history. Based on tephrochronologic studies, the Late Holocene Sabancaya activity is characterised by strong

  15. ESR dating method and the age determination of Peking-Man

    International Nuclear Information System (INIS)

    Jin Sizhao; Liang Renyou; Huang Peihua

    1991-01-01

    ESR dating method and the age determination of the first skull of Zhoukoudian Beijing-Man have been introduced in this paper. Some animal fossil teeth, which are contemporaneous with the Beijing-Man, were used for determination of accumulative dose. The internal and environmental doses of the tooth samples were determined by neutron activation analysis and embeded thermoluminescence dosimeter at the site, respectively. The age of 578 ka of the first skull of Beijing-Man is calculated by the linear uranium accumulation model. According to the ESR dating results, author has given a chronological scale of the cave deposits Loc. 1, Beijing-man site and discussed the mean-life of trapped electron for dating

  16. DNA damage markers in dermal fibroblasts in vitro reflect chronological donor age

    DEFF Research Database (Denmark)

    Waaijer, Mariëtte E C; Croco, Eleonora; Westendorp, Rudi G J

    2016-01-01

    The aging process is accompanied by an accumulation of cellular damage, which compromises the viability and function of cells and tissues. We aim to further explore the association between in vitro DNA damage markers and the chronological age of the donor, as well as long-lived family membership...... markers and long-lived family membership or cardiovascular disease. Results were comparable when fibroblasts were stressed in vitro with rotenone. In conclusion, we found that DNA damage foci of cultured fibroblasts are significantly associated with the chronological age, but not biological age...

  17. Radioactive waste inventories and projections

    International Nuclear Information System (INIS)

    McLaren, L.H.

    1982-11-01

    This bibliography contains information on radioactive waste inventories and projections included in the Department of Energy's Energy Data Base from January 1981 through September 1982. The arrangement is by report number for reports, followed by nonreports in reverse chronological order. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. (25 abstracts)

  18. AHP 47: A NIGHT DATE

    Directory of Open Access Journals (Sweden)

    Phun tshogs dbang rgyal ཕུན་ཚོགས་དབང་རྒྱལ།

    2017-04-01

    Full Text Available The author was born in 1993 in Ska chung (Gaqun Village, Nyin mtha' (Ningmute Township, Rma lho (Henan Mongolian Autonomous County, Rma lho (Huangnan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province, PR China. Night dating was popular for teenage boys some years ago. They rode horses and yaks when they went night dating. They generally rode yaks, because horses were important for their families and used for such important tasks as pursuing bandits and going to the county town for grain and supplies. An early experience with night dating is described.

  19. Radiocarbon dates from the holocene levels at Nelson Bay Cave, and an interim report on their associations

    International Nuclear Information System (INIS)

    Inskeep, R.R.; Vogel, J.C.

    1985-01-01

    Various changes in the cultural material derived from the later Holocene levels of Nelson Bay Cave can be pinpointed in temporal context by means of a large series of radiocarbon dates, such as Carbon 13 and Carbon 14 covering the past 6 000 years. As excavations and analysis of the recovered materials proceeded, radiocarbon dates were sought in order to provide a chronological frame work for what are taken to be significant features in the history of the site, and these are discussed in the article. Several pottery and assumed sheep remains were recorded. Six human burials were also recovered and this helps with the characterization of Holocene burial practices

  20. Bat guano deposit Holocene datings in the south Carpathian mountains (Romania). Tectonic implications

    International Nuclear Information System (INIS)

    Carbonnel, J.P.; Olive, Ph.; Klein, D.

    1999-01-01

    Two 14 C datings in a 2.5 m thick bat guano deposit indicate the Boreal period for the beginning of the deposit. The bat colony of the cave of Adam (Pestera lui Adam, Baile Herculane, south Carpathian Mountains) is one of the oldest permanent bat colonies in Europe, probably established just after the last Ice Age. Evidence of palaeo-seismic activity inside the guano deposit allow a chronology of regional seismic events during the Holocene Period to be drawn up. (authors)

  1. Radiocarbon dating in the quarternary geology and archaeology of Estonia

    International Nuclear Information System (INIS)

    Ilves, Eh.; Liiva, A.; Punning, Ya.M.

    1974-01-01

    Work of the Tartusk radiocarbon laboratory for the last 15 years is presented. Methodological problems of the radiocarbon method are discussed. The geochemistry of carbon isotopes, principles of radiocarbon dating, and areas of its application are considered. Methods of recording natural radiocarbon and materials used for radiocarbon dating are discussed. Preliminary treatment of the samples and synthesis of the radioactive carbon carrier are presented. The preparation of the counter compound in the form of a liquid scintillator from the synthesized natural radiocarbon carrier is described. The scintillator efficiencies of different scintillators are compared. Data are given on the development of criteria for selecting the photoelectron multiplier. Construction of alumina cuvettes used for scintillation counting is described. It is noted that, in the counter apparatus system, amplitude analyzers with two differential discriminators are used, which allows directing the recording of activity to two 14 C regions. The results of using the radiocarbon method for different aspects of natural science and archeology are considered. Problems of geology of the late Pleistocene and the Pre-Baltic Holocene are considered: base of the mid-Valdaisk Karukyulask interglacier, history of deterioration of the final glacial mantle, development of a drainage system and late glacier, development and paleography of the Holocene, and others. New material on the chronology of primeval cultures in the Estonia region and on growth of meteoric craters are presented

  2. Luminescence (IRSL) dating of Yeni Rabat church in Artvin, Turkey

    Science.gov (United States)

    Şahiner, Eren; Meriç, Niyazi; Uygun, Selda

    2013-05-01

    Luminescence dating is a chronological method that has been used extensively in terrestrial materials. In this study, we present Infrared Stimulated Luminescence (IRSL) dating results obtained for sediment and pottery samples taken from Yeni Rabat Church, Ardanuç, Artvin, Turkey. For this purpose, equivalent dose (ED) and annual dose rate (AD) of samples were measured. For annual dose rate, concentrations of radioactive isotopes (U, Th, K) were determined by using a high-purity germanium detector. For the equivalent dose, polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used. The optimal preheat temperature was determined for sediment and pottery samples. Ages were calculated by Aitken's luminescence age calculation method, which found 710±190 years for the pottery sample and 1450±370 years, 1390±420 years, 1430±310 years, 2210±520 years and 1640±390 years for different sediment samples, respectively. These estimated age ranges support the theory that Yeni Rabat Church could have been constructed in medieval times.

  3. Luminescence (IRSL) dating of Yeni Rabat church in Artvin, Turkey

    International Nuclear Information System (INIS)

    Şahiner, Eren; Meriç, Niyazi; Uygun, Selda

    2013-01-01

    Luminescence dating is a chronological method that has been used extensively in terrestrial materials. In this study, we present Infrared Stimulated Luminescence (IRSL) dating results obtained for sediment and pottery samples taken from Yeni Rabat Church, Ardanuç, Artvin, Turkey. For this purpose, equivalent dose (ED) and annual dose rate (AD) of samples were measured. For annual dose rate, concentrations of radioactive isotopes (U, Th, K) were determined by using a high-purity germanium detector. For the equivalent dose, polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used. The optimal preheat temperature was determined for sediment and pottery samples. Ages were calculated by Aitken's luminescence age calculation method, which found 710±190 years for the pottery sample and 1450±370 years, 1390±420 years, 1430±310 years, 2210±520 years and 1640±390 years for different sediment samples, respectively. These estimated age ranges support the theory that Yeni Rabat Church could have been constructed in medieval times. - Highlights: ► The luminescence (IRSL) ages of the samples, taken from in Yeni Rabat church in Artvin-Turkey were found. ► Equivalent doses and annual doses were determined. ► Polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used

  4. Trace elements in a dated ice core from Antarctica

    International Nuclear Information System (INIS)

    Keshin, S.S.; Xudong Huang; Olmez, I.; Langway, C.C. Jr.

    1992-01-01

    Aerosol particles from both natural and anthropogenic sources are emitted into the atmosphere and transported by wind systems by various mechanisms. Once airborne, the particles, which contain various trace elements, accumulate on the earth's surface as either condensation nuclei or by dry fallout processes. In the polar regions, these particles are incorporated and deposited in snow layers in sequential time-unit increments. The trace analysis of elements contained in dated annual snow layers provides a measure of the elemental chemistry content of the atmosphere for the same time interval. A 164-m-deep, 10-cm-diam ice core was obtained at Byrd Station, Antarctica, in November 1989. Other physical and chemistry studies on this ice core have identified its detailed chronology in annual increments for the past 1360 yr. This study presents the results of the instrumental neutron activation analysis (INAA) measurements made on 26 individually dated samples of this core, selected between the 6.43- and 118.15-m depths

  5. ESR/U-series chronology of the Lower Palaeolithic palaeo-anthropological site of Visogliano, Trieste, Italy

    International Nuclear Information System (INIS)

    Falgueres, C.; Bahain, J.J.; Yokoyama, Y.; Tozzi, C.; Boschian, G.; Dolo, J.M.; Mercier, N.; Valladas, H.

    2008-01-01

    The Visogliano shelter, in north-eastern Italy, is an important Middle Pleistocene occupation site where human remains were found together with an archaic lithic industry, including choppers, chopping tools and a few proto-bifaces. It is of utmost importance to try to document this period, when a second wave of settlement colonised Western Europe, carrying new flaking techniques and tools. Combined ESR/U-series analyses, integrated with bio-stratigraphical and environmental data, define a chronological frame for the layers from which the artefacts were unearthed. The lower levels, including human remains, can be dated to the 350-500 kyr time span, in agreement with micro-mammal and stratigraphical studies. These data make Visogliano one of the oldest palaeo-anthropological sites in Italy, where human remains are directly associated with proto-bifaces, choppers and chopping tools. In Western Europe, Visogliano is contemporaneous to the G soil of the Arago Cave, France, with which it shares several similarities in faunal assemblages and radiometric data, and which contains human remains also. These data make Visogliano as one of the oldest sites in Europe where the Acheulian culture is observed. (authors)

  6. Initial chronology of a recently discovered hydrothermal field at 14°45‧N, Mid-Atlantic Ridge

    Science.gov (United States)

    Lalou, Claude; Reyss, Jean Louis; Brichet, Evelyne; Krasnov, Sergey; Stepanova, Tamara; Cherkashev, Georgiy; Markov, Vladimir

    1996-11-01

    Two expeditions of the 'Sevmorgeologija' association (1991-1994) led to the discovery of two new hydrothermal sites on the Mid Atlantic Ridge (MAR), south of the 15°20‧ North Fracture Zone, one around 14°45‧N and the other around 14°42‧N. The northern one, between 14°45‧ and 14°45.3‧N has been studied in detail. About 12 mounds have been mapped and 3 of them have been sampled using a large hydraulic grab sampler. The largest one is about 200 m long and 200 m wide. When progressively moving up on the slope of an uplifted block of the rift valley floor, the sulphide samples have revealed ages ranging from about 10 ka to 60 ka. The ages were obtained using the 230Th/234U dating method used for chronological studies of diverse hydrothermal fields. The general picture of this lateral location of the samples of different ages provides evidence of a shift in the focus of hydrothermal activity with time. Moreover, there were rejuvenation stages of hydrothermal activity, including black and white smokers.

  7. 226Ra chronology of a coastal marine sediment

    International Nuclear Information System (INIS)

    Koide, M.; Bruland, K.; Goldberg, E.D.

    1976-01-01

    Unsupported 226 Ra (tsub (1/2) = 1620 years) in marine sediments can provide a basis for measuring rates of accumulation of the order of centimeters per thousand years. The excess radium apparently enters the sediments incorporated in phytoplankton. The sensitivity of the method depends upon the initial value of the unsupported 226 Ra and of the value of 230 Th, a parent of 226 Ra, in the sedimentary components. 226 Ra dating was applied to a sediment taken from the slope of the San Clemente Basin in the Southern California coastal region. Rates of sedimentation over two half-lives of the nuclide were found to be either 5.2 or 5.3 cm/1000 years depending upon which of two models for the geochronology is used. One model assumes that the 230 Th brings to the deposit an amount of 226 Ra in equilibrium with it. The other is based upon the growth of the 226 Ra from the 230 Th in the sedimentary components. 238+239 Pu and 210 Pb levels in the upper strata indicated sedimentation rates of the order of 100-500 cm/1000 years, i.e. much faster accumulations. It is suggested that these derived rates are spurious and reflect bioturbative activities of surface-living organisms. (Auth.)

  8. Dating the humans by radiocarbon

    International Nuclear Information System (INIS)

    Fedi, M.E.

    2011-01-01

    Radiocarbon has become a very powerful tool used for dating. This paper deals with a specific application of 1 4C i.e. dating of humans. Attention is focused on those aspects that, if neglected, might lead to a misinterpretation of the results or to an unsatisfying accuracy of the measurement. After a brief description of the main principles on which the radiocarbon method is based and of Accelerator Mass Spectrometry, examples taken from the research activity of INFN-LABEC (Laboratorio di Tecniche Nucleari per I Beni Culturali) in Florence are presented. The case of the relic of St. Francis represents an example of dating not directly human remains but other objects that can be associated to them. The case of two burials from the archaeological area of Baratti-Populonia, in Tuscany, gives the possibility to show the importance of estimating the human palaeodiet when dating bone samples.

  9. A detailed post-IR IRSL chronology for the last interglacial soil at the Jingbian loess site (northern China)

    DEFF Research Database (Denmark)

    Buylaert, Jan-Pieter; Yeo, Eun-Young; Thiel, Christine

    2015-01-01

    The chronology of dust deposition and climate during the last interglacial is poorly known on the Chinese Loess Plateau. Here, 51 samples were taken from the ~5 m S1 palaeosol (MIS5) at the desert marginal Jingbian site to develop what is currently the most detailed S1 chronology on the Plateau...

  10. Dating by electron paramagnetic resonance

    International Nuclear Information System (INIS)

    Poupeau, G.; Rossi, A.M.

    1984-01-01

    Some natural materials behave like dosimeters in front of the ionizing particle flux coming from environmental radioactivity and the cosmic radiation. This property is used for the dating by Electron Paramagnetic Resonance (EPR). Before presenting the basic principles of the EPR analysis and the dating method which uses such a phenomenous, it is reviewed several types of application currently in course of development. (L.C.) [pt

  11. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  12. Radiocarbon dating of iron artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, R. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1997-12-31

    Iron artefacts are generally dated by association or on stylistic grounds. This may not give a true indication of the date of manufacture, or may not be possible if the piece is out of context, ambiguous in style, or a copy. Obtaining a direct date on the artefact would be preferable. During the processes of manufacture, carbon is incorporated into the iron from the fuel source. If the fuel is of a material containing contemporaneous carbon, i.e. has an ambient radiocarbon signature, e.g. charcoal, then we may reliably radiocarbon date the artefact by extracting this carbon. Care must be taken, however, to ensure that re-working has not introduced multiple sources of carbon that would give an erroneous date. Detailed chemical analysis must precede radiocarbon analysis. Sample size is determined by carbon content, and before the advent of accelerator mass spectrometry, several tens of grams of carbon were required for radiocarbon dating (van der Merwe, 1969), prohibiting this method except for high-carbon cast-irons and bulk samples, e.g. caches of nails. AMS permits the analysis of sub-gram pieces of iron (Cresswell, 1991), thereby permitting the analysis of museum pieces with only minimal loss of material, and small fragments of iron recovered from archaeological sites. A few examples are given to illustrate these points. Paper no. 41; Extended abstract. 6 refs.

  13. Radiocarbon dating of iron artefacts

    International Nuclear Information System (INIS)

    Cresswell, R.

    1997-01-01

    Iron artefacts are generally dated by association or on stylistic grounds. This may not give a true indication of the date of manufacture, or may not be possible if the piece is out of context, ambiguous in style, or a copy. Obtaining a direct date on the artefact would be preferable. During the processes of manufacture, carbon is incorporated into the iron from the fuel source. If the fuel is of a material containing contemporaneous carbon, i.e. has an ambient radiocarbon signature, e.g. charcoal, then we may reliably radiocarbon date the artefact by extracting this carbon. Care must be taken, however, to ensure that re-working has not introduced multiple sources of carbon that would give an erroneous date. Detailed chemical analysis must precede radiocarbon analysis. Sample size is determined by carbon content, and before the advent of accelerator mass spectrometry, several tens of grams of carbon were required for radiocarbon dating (van der Merwe, 1969), prohibiting this method except for high-carbon cast-irons and bulk samples, e.g. caches of nails. AMS permits the analysis of sub-gram pieces of iron (Cresswell, 1991), thereby permitting the analysis of museum pieces with only minimal loss of material, and small fragments of iron recovered from archaeological sites. A few examples are given to illustrate these points

  14. Microscale radiocarbon dating of paintings

    International Nuclear Information System (INIS)

    Hendriks, Laura; Hajdas, Irka; McIntyre, Cameron; Kueffner, Markus; Ferreira, Ester S.B.; Scherrer, Nadim C.

    2016-01-01

    In this paper, radiocarbon dating of paintings using minimal sample sizes has been investigated, in an effort to address the problem of limited access to sample material in paintings. 14 C analyses were conducted on signed and dated paintings from two Swiss artists of the twentieth century. The selected paintings dated from the 1930s and 1960s, provided the opportunity to evaluate the dating accuracy on paintings realized before and after 1950 AD when the 14 C bomb peak was created, as a result of the nuclear tests conducted in the 1950/1960s. The work focused on the one hand on minimizing the size of the canvas sample required for accelerator mass spectrometer radiocarbon measurement on the gas ion source of the MICADAS and, on the other hand, on testing the possibility of dating the organic binder of the paint. Following careful characterization of the paint composition by X-ray fluorescence spectroscopy, Fourier transformed infrared spectroscopy, and Raman spectroscopy, paints containing no other carbon source than the natural organic binder were identified and dated. (orig.)

  15. Direct dating of human fossils.

    Science.gov (United States)

    Grün, Rainer

    2006-01-01

    The methods that can be used for the direct dating of human remains comprise of radiocarbon, U-series, electron spin resonance (ESR), and amino acid racemization (AAR). This review gives an introduction to these methods in the context of dating human bones and teeth. Recent advances in ultrafiltration techniques have expanded the dating range of radiocarbon. It now seems feasible to reliably date bones up to 55,000 years. New developments in laser ablation mass spectrometry permit the in situ analysis of U-series isotopes, thus providing a rapid and virtually non-destructive dating method back to about 300,000 years. This is of particular importance when used in conjunction with non-destructive ESR analysis. New approaches in AAR analysis may lead to a renaissance of this method. The potential and present limitations of these direct dating techniques are discussed for sites relevant to the reconstruction of modern human evolution, including Florisbad, Border Cave, Tabun, Skhul, Qafzeh, Vindija, Banyoles, and Lake Mungo. (c) 2006 Wiley-Liss, Inc.

  16. Microscale radiocarbon dating of paintings

    Energy Technology Data Exchange (ETDEWEB)

    Hendriks, Laura; Hajdas, Irka; McIntyre, Cameron [ETH Zurich, Ion Beam Physics, Zurich (Switzerland); Kueffner, Markus; Ferreira, Ester S.B. [SIK-ISEA, Zurich, Zurich (Switzerland); Scherrer, Nadim C. [Bern University of Applied Sciences, HKB, Bern (Switzerland)

    2016-03-15

    In this paper, radiocarbon dating of paintings using minimal sample sizes has been investigated, in an effort to address the problem of limited access to sample material in paintings. {sup 14}C analyses were conducted on signed and dated paintings from two Swiss artists of the twentieth century. The selected paintings dated from the 1930s and 1960s, provided the opportunity to evaluate the dating accuracy on paintings realized before and after 1950 AD when the {sup 14}C bomb peak was created, as a result of the nuclear tests conducted in the 1950/1960s. The work focused on the one hand on minimizing the size of the canvas sample required for accelerator mass spectrometer radiocarbon measurement on the gas ion source of the MICADAS and, on the other hand, on testing the possibility of dating the organic binder of the paint. Following careful characterization of the paint composition by X-ray fluorescence spectroscopy, Fourier transformed infrared spectroscopy, and Raman spectroscopy, paints containing no other carbon source than the natural organic binder were identified and dated. (orig.)

  17. An Old Fad of Great Promise: Reverse Chronology History Teaching in Social Studies Classes

    Science.gov (United States)

    Misco, Thomas; Patterson, Nancy C.

    2009-01-01

    This article revisits and explores the promises and challenges of reverse chronology history instruction within the social studies. In response to student disinterest in social studies, changes in our educational culture that often value content knowledge exclusively, and marginalization of instructional time stemming from testing burdens, reverse…

  18. Correlation between cervical vertebral maturation and chronological age in a group of Iranian females

    Directory of Open Access Journals (Sweden)

    Seyed Mohammadreza Safavi

    2015-01-01

    Full Text Available Background: Correlation between chronological age at different stages of cervical vertebral maturation (CVM is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. Materials and Methods: This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. Results: The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62. The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Conclusion: Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.

  19. Lack of Ach1 CoA-Transferase Triggers Apoptosis and Decreases Chronological Lifespan in Yeast

    International Nuclear Information System (INIS)

    Orlandi, Ivan; Casatta, Nadia; Vai, Marina

    2012-01-01

    ACH1 encodes a mitochondrial enzyme of Saccharomyces cerevisiae endowed with CoA-transferase activity. It catalyzes the CoASH transfer from succinyl-CoA to acetate generating acetyl-CoA. It is known that ACH1 inactivation results in growth defects on media containing acetate as a sole carbon and energy source which are particularly severe at low pH. Here, we show that chronological aging ach1Δ cells which accumulate a high amount of extracellular acetic acid display a reduced chronological lifespan. The faster drop of cell survival is completely abrogated by alleviating the acid stress either by a calorie restricted regimen that prevents acetic acid production or by transferring chronologically aging mutant cells to water. Moreover, the short-lived phenotype of ach1Δ cells is accompanied by reactive oxygen species accumulation, severe mitochondrial damage, and an early insurgence of apoptosis. A similar pattern of endogenous severe oxidative stress is observed when ach1Δ cells are cultured using acetic acid as a carbon source under acidic conditions. On the whole, our data provide further evidence of the role of acetic acid as cell-extrinsic mediator of cell death during chronological aging and highlight a primary role of Ach1 enzymatic activity in acetic acid detoxification which is important for mitochondrial functionality.

  20. What about time? : Examining chronological and subjective age and their relation to work motivation.

    NARCIS (Netherlands)

    Akkermans,; De Lange,; Van der Heijden,; Kooij, T.A.M.; Jansen,; Dikkers,

    2016-01-01

    Purpose The aging workforce is becoming an increasingly important topic in today’s labor market. However, most scientific research and organizational policies focus on chronological age as the main determinant of successful aging. Based on life span developmental theories – primarily socioemotional

  1. The effects of chronological age and size on toxicity of zinc to juvenile brown trout

    Science.gov (United States)

    A series of toxicity tests were conducted to investigate the role of chronological age and organism weight on zinc tolerance in juvenile brown trout (Salmo trutta). Four different incubation temperatures were used to control the maturation of the juveniles prior to zinc exposure...

  2. Current issues in late Middle Palaeolithic chronology : New assessments from Northern Iberia

    NARCIS (Netherlands)

    Maroto, Julia; Vaquero, Manuel; Arrizabalaga, Alvaro; Baena, Javier; Baquedano, Enrique; Jorda, Jesus; Julia, Ramon; Montes, Ramon; Van Der Plicht, Johannes; Rasines, Pedro; Wood, Rachel

    2012-01-01

    The Iberian Peninsula plays a central role in the current debates on the Middle-Upper Palaeolithic transition and the Neanderthal extinction. This is largely due to the chronological data which some authors have suggested show a clear divide between Northern Iberia, where the Upper Palaeolithic

  3. Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration

    Science.gov (United States)

    Anteau, M.J.; Anteau, A.C.E.; Afton, A.D.

    2011-01-01

    We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinis) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis. ?? The Cooper Ornithological Society 2011.

  4. Correlation between cervical vertebral maturation and chronological age in a group of Iranian females

    Science.gov (United States)

    Safavi, Seyed Mohammadreza; Beikaii, Hanie; Hassanizadeh, Raheleh; Younessian, Farnaz; Baghban, Alireza Akbarzadeh

    2015-01-01

    Background: Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. Materials and Methods: This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. Results: The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Conclusion: Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients. PMID:26604958

  5. Nicotinamide supplementation phenocopies SIR2 inactivation by modulating carbon metabolism and respiration during yeast chronological aging.

    Science.gov (United States)

    Orlandi, Ivan; Pellegrino Coppola, Damiano; Strippoli, Maurizio; Ronzulli, Rossella; Vai, Marina

    2017-01-01

    Nicotinamide (NAM), a form of vitamin B 3 , is a byproduct and noncompetitive inhibitor of the deacetylation reaction catalyzed by Sirtuins. These represent a family of evolutionarily conserved NAD + -dependent deacetylases that are well-known critical regulators of metabolism and aging and whose founding member is Sir2 of Saccharomyces cerevisiae. Here, we investigated the effects of NAM supplementation in the context of yeast chronological aging, the established model for studying aging of postmitotic quiescent mammalian cells. Our data show that NAM supplementation at the diauxic shift results in a phenocopy of chronologically aging sir2Δ cells. In fact, NAM-supplemented cells display the same chronological lifespan extension both in expired medium and extreme Calorie Restriction. Furthermore, NAM allows the cells to push their metabolism toward the same outcomes of sir2Δ cells by elevating the level of the acetylated Pck1. Both these cells have the same metabolic changes that concern not only anabolic pathways such as an increased gluconeogenesis but also respiratory activity in terms both of respiratory rate and state of respiration. In particular, they have a higher respiratory reserve capacity and a lower non-phosphorylating respiration that in concert with a low burden of superoxide anions can affect positively chronological aging. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration

    Science.gov (United States)

    Anteau, Michael J.; Anteau, Andrea C.E.; Afton, Alan D.

    2011-01-01

    We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinisK/i>) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis.

  7. Time and Chronology in Modern Novels: An Example of Woolf and ...

    African Journals Online (AJOL)

    Time and Chronology in Modern Novels: An Example of Woolf and Joyce. ... It is in this context that this article attempts to provide a brief survey of two modern ... the displacement feature of language to defamiliarize our conception of time and

  8. What about time? Examining chronological and subjective age and their relation to work motivation

    NARCIS (Netherlands)

    Akkermans, J.; Lange, A.H. de; Heijden, B.I.J.M. van der; Kooij, D.T.A.M.; Jansen, P.G.W.; Dikkers, J.S.E.

    2016-01-01

    PURPOSE - The aging workforce is becoming an increasingly important topic in today’s labor market. However, most scientific research and organizational policies focus on chronological age as the main determinant of successful aging. Based on life span developmental theories – primarily

  9. What about Time? Examining Chronological and Subjective Age and their Relation to Work Motivation

    NARCIS (Netherlands)

    Akkermans, J.; de Lange, A.H.; Van der Heijden, B.I.J.M.; Kooij, T.A.M.; Jansen, P.G.W.; Dikkers, J.

    2016-01-01

    Purpose: The aging workforce is becoming an increasingly important topic in today’s labor market. However, most scientific research and organizational policies focus on chronological age as the main determinant of successful aging. Based on life span developmental theories – primarily socioemotional

  10. Correlation between cervical vertebral maturation and chronological age in a group of Iranian females.

    Science.gov (United States)

    Safavi, Seyed Mohammadreza; Beikaii, Hanie; Hassanizadeh, Raheleh; Younessian, Farnaz; Baghban, Alireza Akbarzadeh

    2015-01-01

    Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.

  11. Chronological overlap between humans and megafauna in Sahul (Pleistocene Australia New Guinea): A review of the evidence

    Science.gov (United States)

    Field, Judith; Fillios, Melanie; Wroe, Stephen

    2008-08-01

    Over 60 faunal species disappeared from the Australian continent during the Middle-Late Pleistocene. Most of these animals were large to gigantic marsupials, birds and reptiles. A terminal extinction date of 46.4 kyr has been proposed for the megafauna, with all sites containing younger fossil megafauna dismissed by some researchers because of questions over stratigraphic integrity or chronologies. The timing of the extinctions is argued to be broadly coincident with estimates of first colonization of the continent by modern humans, and explanatory extinction models involving humans have subsequently gained currency. However there is considerable evidence to suggest that in some parts of the continent, people and some species of megafauna may have co-existed well beyond 46.4 kyr. In other places, such as Tasmania and the north of the continent, there is no known record of a human-megafauna temporal overlap. A review of the available evidence indicates that only 13 species of megafauna were extant on human arrival in Australia. The archaeology of this period indicates that rather than a focus on big game hunting or 'firestick farming', it was characterized by regional variability in subsistence strategies consistent with the range of environmental zones. At the present time there is no substantive argument for a terminal extinction date of 46.4 kyr, the current evidence indicating that there is no specific time period that correlates to any single mass extinction event. On the basis of available evidence arguments for either human or climatic causation are entirely circumstantial and implicitly require acceptance of many unproven assumptions. Claims to have eliminated climate as a primary driver are premature and the recent focus on delivering 'proof' of human causation in Pleistocene faunal extinctions diverts attention from achieving a better understanding of the differential impacts of climate change and short term climatic flux in a land of environmental

  12. Recalibration of the yellow Rhizocarpon growth curve in the Cordillera Blanca (Peru) and implications for LIA chronology

    Science.gov (United States)

    Jomelli, V.; Grancher, D.; Brunstein, D.; Solomina, O.

    2008-01-01

    A new lichen dating method and new moraine observations enabled us to improve the chronology of glacier advances in the Cordillera Blanca (Peru) during the Little Ice Age (LIA). Our results reveal that an early LIA glacial advance occurred around AD 1330 ± 29. However, a second major glacial advance at the beginning of the 17th century overlapped the earlier stage for most glaciers. Hence, this second glacial stage, dated from AD 1630 ± 27, is considered as the LIA maximum glacial advance in the Cordillera Blanca. During the 17th-18th centuries, at least three glacial advances were recorded synchronously for the different glaciers (AD 1670 ± 24, 1730 ± 21, and 1760 ± 19). The moraines corresponding to the two first stages are close to the one in 1630 suggesting a slow recession of about 18% in the total length of the glacier. From the LIA maximum extent to the beginning of the 20th century, the 24 glaciers have retreated a distance of about 1000 m, corresponding to a reduction of 30% in their length. This rate is comparable to that observed during the 20th century. Estimates of palaeo-Equilibrium Line Altitudes show an increase in altitude of about 100 m from the LIA maximum glacial extension at the beginning of the 17th century to the beginning of the 20th century. Because long time series are not available for precipitation and temperature, this glacial retreat is difficult to explain by past climate changes. However, there is a fair correspondence between changes in glacier length and the δ18O recorded in the Quelccaya ice core at a century timescale. Our current knowledge of tropical glaciers and isotope variations leads us to suggest that this common tropical signal reflects a change from a wet LIA to the drier conditions of today. Finally, a remarkable synchronicity is observed with glacial variations in Bolivia, suggesting a common regional climatic pattern during the LIA.

  13. Combined ESR/U-series chronology of Acheulian hominid-bearing layers at Trinchera Galeria site, Atapuerca, Spain

    International Nuclear Information System (INIS)

    Falgueres, Christophe; Bahain, Jean-Jacques; Shao, Qingfeng; Bischoff, James L.; Perez-Gonzalez, Alfredo; Ortega, Ana Isabel; Bermudez de Castro, Jose Maria; Olle, Andreu; Vallverdu, Josep; Quiles, Anita; Ghaleb, Bassam; Moreno, Davinia; Dolo, Jean-Michel; Vallverdu, Josep; Carbonell, Eudald; Arsuaga, Juan Luis

    2013-01-01

    The Sierra de Atapuerca, northern Spain, is known from many prehistoric and paleontologic sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galeria and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galeria archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galeria sites. The authors proposed for Galeria an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (≥530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galeria site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350-450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galeria and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data. (authors)

  14. Toward unified ice core chronologies with the DatIce tool

    Science.gov (United States)

    Toye Mahamadou Kele, H.; Lemieux-Dudon, B.; Blayo, E.

    2012-04-01

    Antarctic and Greenland ice cores provide a means to study the phase relationships of climate changes in both hemispheres. They also enable to study the timing between climate, and greenhouse gases or orbital forcings. One key step for such studies is to improve the absolute and relative precisions of ice core age scales (for ice and trapped gas), and beyond that, to try to reach the best consistency between chronologies of paleo records of any kind. The DatIce tool is designed to increase the consistency between pre-existing (also called background) core chronologies. It formulates a variational inverse problem which aims at correcting three key quantities that uniquely define the core age scales: the accumulation rate, the total thinning function, and the close-off depth. For that purpose, it integrates paleo data constraints of many types among which age markers (with for instance documented volcanoes eruptions), and stratigraphic links (with for instance abrupt changes in methane concentration). A cost function is built that enables to calculate new chronologies by making a trade-off between all the constraints (background chronologies and paleo data). The method presented in Lemieux-Dudon et al (2010) has already been applied simultaneously to EPICA EDML and EDC, Vostok and NGRIP. Currently, on going works are conducted at LSCE Saclay and LGGE Grenoble laboratories to construct unified Antarctic chronologies by applying the DatIce tool with new ice cores and new sets of paleo measurements. We here present the DatIce tool, the underlying methodology, and its potential applications. We further show some improvements that have been made recently. We especially adress the issue related to the calibration of the error of pre-existing core chronologies. They are inputs that may have a strong impact on the results. However these uncertainties are uneasy to analyze, since prior chronologies are most of the time assessed on the basis of glaciological models (firn

  15. Why would we use the Sediment Isotope Tomography (SIT) model to establish a 210Pb-based chronology in recent-sediment cores?

    International Nuclear Information System (INIS)

    Abril Hernández, José-María

    2015-01-01

    After half a century, the use of unsupported 210 Pb ( 210 Pb exc ) is still far off from being a well established dating tool for recent sediments with widespread applicability. Recent results from the statistical analysis of time series of fluxes, mass sediment accumulation rates (SAR), and initial activities, derived from varved sediments, place serious constraints to the assumption of constant fluxes, which is widely used in dating models. The Sediment Isotope Tomography (SIT) model, under the assumption of non post-depositional redistribution, is used for dating recent sediments in scenarios in that fluxes and SAR are uncorrelated and both vary with time. By using a simple graphical analysis, this paper shows that under the above assumptions, any given 210 Pb exc profile, even with the restriction of a discrete set of reference points, is compatible with an infinite number of chronological lines, and thus generating an infinite number of mathematically exact solutions for histories of initial activity concentrations, SAR and fluxes onto the SWI, with these two last ranging from zero up to infinity. Particularly, SIT results, without additional assumptions, cannot contain any statistically significant difference with respect to the exact solutions consisting in intervals of constant SAR or constant fluxes (both being consistent with the reference points). Therefore, there is not any benefit in its use as a dating tool without the explicit introduction of additional restrictive assumptions about fluxes, SAR and/or their interrelationship. - Highlights: • The 210 Pb-based method for dating recent sediments is of a widespread use. • Recent results limit the use of the simplifying assumption of constant fluxes. • SIT model claims to solve scenarios where fluxes and SAR independently vary with time. • The paper shows how SIT model lacks of sound physical basis. • A dating tool is only possible by introducing additional restrictive assumptions

  16. Preliminary study of the chronology of the sedimentation process in lakes

    International Nuclear Information System (INIS)

    Patrocinio Junior, Antonio C.; Andrello, Avacir C.

    2009-01-01

    The soil erosion accelerated which produces the presence of sediment in rivers is one of the main environmental problems and represents a challenge for the sustainable use of soil and water resources. The problems associated with the increased sediments production are mainly related to the rivers siltation, reduced storage capacity of dams and reservoirs and reduction in the quality of aquatic environment. Thus, further information on sedimentation rates in lakes and reservoirs are required, as a parameter for estimating the chronology of production rates of sediment. Therefore, methods to establish the chronology of recent sediments are central base for such research. The cesium-137 is an artificial radionuclide with a half life of 30.2 years, inserted in the environment through the 'fallout' radioactive between the 1950's and 1970's, with two predominant peaks of deposition in 1959 and 1964. The basis for using the cesium-137 in this context (chronology of sediments) is that the cesium-137 is rapidly and strongly adsorbed to fine particles of soil and its distribution in the sediment profile directly reflects the chronology of sediment deposition. The purpose of this work is to use the cesium-137 profile in lake sediments to assess the history of deposition and to obtain information about the erosive process. For this, lake sediments of a mini-hydroelectric power plant built in the 1940's in the city of Londrina-PR were analyzed, showing that cesium-137 can be used as a source of data for chronological assessment of erosive processes occurring in the vicinity of the lake. (author)

  17. Chronology of last earthquake on Firouzkuh Fault using by C14

    Science.gov (United States)

    Nazari, H.; Ritz, J.-F.; Walker, R.; Alimohammadian, H.; Salamati, R.; Shahidi, A.; Patnaik, R.; Talebian, M.

    2009-04-01

    study during last 5 years on Firouzkuh fault (Nazari, 2006) reveal seismic activity of this area and the rate of movement in young event is about 2 mm/yr. The Firouzkuh fault is close to Firouzkuh, Damavand, Semnan and Tehran cities, therefore, gathering information about the geometry, mechanism and characteristics of activity of Firouzkuh active fault, will help us possible to prediction of fault activity and minimize the resulted damage. Therefore chronology of last event is quit important. In this paper to date the last seismic event in Firouzkuh fault. We have used C14 dating on human bones recovered from F2 trench, along with Quaternary sedimentology of young alluvium deposits of eastern Firouzkuh city. Paleoseismic analysis and C14 dating along the Firouzkuh left -Latural Strike-slip fault indicates the central Alborz has been witnessed large earthquakes during the late Holocene. Here we provide data from one of the two excavated trenches with 15 m length, 2m width and 4 m depth dug across the gauge zone in east Firouzkuh city, where we found some evidence for last paleoearthquake associated to seismic re-activity of Firouzkuh fault. The last seismic event is evidenced by cutting young superficial deposits and overlaid by alluvium deposits which yielded fragments of human bones. The generated C14 date from human bones, found at palaeoseismological trench (F2) on Firouzkuh fault, indicates an age of 1131-1187 B.P. year for alluvium deposits bearing these bones since from stratigraphical point view, this alluvium deposits (unit 4) are overlaid by faulted recent sediments (unit 1, and these recent sediments are cut due to recent activity of Firouzkuh fault, which are younger than human bone bearing alluvium, we may come to conclusion that the time event of this earth quake must be younger than obtained C14 date (1159 ± 28). In other hand since the human bones have been found in a place not similar to grave, we may assume that the body was on the surface at the time

  18. The nuclear present. A guide to recent books on nuclear war, weapons, the peace movement, and related issues, with a chronology of nuclear events, 1789-1991

    International Nuclear Information System (INIS)

    Burns, G.

    1992-01-01

    The Nuclear Present brings the interested reader up-to-date on significant English-language books about nuclear weapons and related topics, identifying primarily important works of nuclear non-fiction that have come out since 1984. Each reference has a paragraph of comment about its subject and value. General organizational areas include the following: Reference Works; Nuclear weapons and Nuclear war (14 sub-headings including overviews, development, effects, tests, arms race, prospectives, legal considerations etc.); Strategy; proliferation; Stratigic Defense; Arms control and disarmament; ethical, pholosophical and religous perspectives; new paths to peace; periodic guide; the Chernobyl Disaster. An extensive Nuclear Chronology (1789-1991) written by the author allows a fairly detailed sense of the historical record of nuclear weapons, including testing, manufacture, use and movements for arms control and disarmament

  19. Dating Saharan dust deposits on Lanzarote (Canary Islands) by luminescence dating techniques and their implication for palaeoclimate reconstruction of NW Africa

    Science.gov (United States)

    von Suchodoletz, H.; Fuchs, M.; ZöLler, L.

    2008-02-01

    Lava flow dammed valleys (Vegas) on Lanzarote (Canary Islands) represent unique sediment traps, filled with autochthonous volcanic material and allochthonous Saharan dust. These sediments and the intercalated palaeosoil sediments document past environmental change of the last glacial-interglacial cycles, both on Lanzarote and in NW Africa. A reliable chronology must be established to use these sediment archives for palaeoclimate reconstructions. Owing to the lack of organic material and the limiting time range of the 14C-dating method, luminescence dating is the most promising method for these sediments. However, the fluvio-eolian character of these sediments is a major problem for luminescence dating, because these sediments are prone to insufficient resetting of the parent luminescence signal (bleaching) prior to sedimentation. To check for the best age estimates, we compare the bleaching behavior of (1) different grain sizes (coarse- versus fine-grain quartz OSL) and (2) different minerals (fine-grain feldspar IRSL versus fine-grain quartz OSL). The results show that owing to its bleaching characteristics, quartz is the preferable mineral for luminescence dating. On the basis of the fine- and coarse-grain quartz OSL age estimates, a chronostratigraphy up to 100 ka could be established. Beyond this age limit for OSL quartz, the chronostratigraphy could be extended up to 180 ka by correlating the vega sediments with dated marine sediment archives.

  20. Chronological constraints on the Paleoproterozoic Francevillian Group in Gabon

    Directory of Open Access Journals (Sweden)

    Yusuke Sawaki

    2017-03-01

    Full Text Available The Francevillian Group in Gabonese Republic was recently established as a typical sedimentary sequence for the Paleoproterozoic. However, its age is rather poorly constrained, mainly based on Rb-Sr and Nd-Sm datings. This study reports new zircon data obtained from Chaillu massif and N'goutou complex, which constrain the protolith age of the basement orthogneisses and the igneous age of an intrusive granite, respectively. Most zircons from the orthogneisses are blue and exhibit oscillatory zoning in cathode-luminescence images. Zircons with lower common lead abundances tend to be distributed close to the concordia curve. Two age clusters around 2860 Ma and 2910 Ma are found in zircons plotted on the concordia curve. Based on the Th/U ratios of zircons, these ages correspond to the protolith ages of the orthogneisses, and the zircons are not metamorphic in origin. Syenites and granites were collected from the N'goutou complex that intrudes into the FA and FB units of the Francevillian Group. The granitoids exhibit chemical composition of A-type granite affinity. Half of zircons separated from the granite are non-luminous, and the remaining half exhibit obscure internal textures under cathode-luminescence observation. All zircon grains contain significant amounts of common lead; the lead isotopic variability is probably attributed to the mixing of two components in the zircons. The zircon radiogenic 207Pb/206Pb ratio is 0.13707 ± 0.0010, corresponding to a 207Pb/206Pb age of 2191 ± 13 Ma. This constrains the minimum depositional age of the FA and FB units. Furthermore, the FB unit consists of manganese-rich carbonate rocks and organic carbon-rich black shales with macroscopic fossils. Based on our age constraints, these organisms appeared in the study area just after the last Paleoproterozoic Snowball Earth event, in concert with global scale oxidation event encompassing the Snowball Earth.

  1. Summer half-year hailstorms in South Moravia, Czech Republic: a long-term chronology

    Science.gov (United States)

    Chromá, Kateřina; Brázdil, Rudolf; Valášek, Hubert; Dolák, Lukáš; Řezníčková, Ladislava; Zahradníček, Pavel; Dobrovolný, Petr

    2017-04-01

    Hailstorms are natural phenomena of local or regional significance causing great material damage in present time, similarly as it was in the past. In Moravia (eastern part of the Czech Republic), systematic meteorological observations started generally in the latter half of the 19th century. Therefore, it is necessary to search for other sources of information in order to create long-term series of hailstorms. Documentary evidence is used in this study to extend the hailstorm information before the period of systematic observations and to complement existing systematic data. It allowed to compile a long-term series of summer half-year hailstorms in South Moravia using various types of documentary evidence (out of them taxation records, family archives, chronicles and newspapers are the most important) and systematic meteorological observations in the station network. Although available hailstorm data cover the 1435-2015 period, incomplete documentary evidence allows reasonable analysis of fluctuations in hailstorm frequency only since the 18th century (the frequency of hailstorms increases with the number of surviving documents). The long-term series compiled from documentary data and systematic meteorological observations is used to identify periods of lower and higher hailstorm frequency. The best temporal coverage of summer half-year hailstorm days in South Moravia starts in 1925 with a general decreasing trend of -0.05 days per 10 years up to 2015, more evident after 1961 (-1.4 days per 10 years). Existing data may also be used for the study of spatial hailstorm variability which is demonstrated on four particularly damaging hailstorms (on 20 June 1848, 1 July 1902, 10 July 1902 and 19 July 1903). Finally, uncertainties in the hailstorm chronology are discussed and differences related to various aspects of hailstorms detected from documentary and meteorological data in three 40 year periods are analysed. Despite some bias in hailstorm data, South

  2. Thermoluminescence dating in the South-West Pacific region

    International Nuclear Information System (INIS)

    Prescott, J.R.

    1982-01-01

    The archaeometry laboratory of the University of Adelaide has undertaken a variety of dating projects for archaeologists in the region. For example, a survey of Pacific Island pottery has shown that themoluminescence dating is likely to be severely limited in usefulness on islands remote from the continental shelf i.e., the andesitic island arcs and oceanic islands. On the mainland of Australia, we have dated prehistoric campsites using ovenstones from fireplaces and have compared C-14 ages with themoluminescent ages. Where there is a close stratigraphic association of the C-14 and TL materials, there is good agreement between the two methods. (author)

  3. ESR dating of fault rocks

    International Nuclear Information System (INIS)

    Lee, Hee Kwon

    2002-03-01

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene

  4. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2002-03-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.

  5. 32Si dating of sediments

    International Nuclear Information System (INIS)

    Morgenstern, U.

    2004-01-01

    Brief explanation of the use of 32 Si in the dating of sediments. 32 Si , with a half-life of c.140 years, can be applied in the age range 30-1000 years. An appropriate dating tool for that time range is essential because it includes three very important epochs: the impact of human colonisation and industrialisation during the last 150 years, the Little Ice Age between about 1650 AD and 1850 AD, and the last part of the Medieval Climatic Optimum. 23 refs

  6. The complexity behind the date

    CERN Multimedia

    2009-01-01

    For the waiting world, and indeed for most of us here at CERN, ‘the LHC schedule’ simply means the date that the LHC will restart - and we only take notice when that end-date changes. But in fact the schedule is a constantly evolving intricate document coordinating all the repairs, consolidation and commissioning in every part of the machine. So, what actually goes on behind the scenes in timing and planning all the work on one of the most complex scientific instruments ever built?

  7. Early Upper Paleolithic chronology in the Levant: new ABOx-SC accelerator mass spectrometry results from the Mughr el-Hamamah Site, Jordan.

    Science.gov (United States)

    Stutz, Aaron Jonas; Shea, John J; Rech, Jason A; Pigati, Jeffrey S; Wilson, Jim; Belmaker, Miriam; Albert, Rosa Maria; Arpin, Trina; Cabanes, Dan; Clark, Jamie L; Hartman, Gideon; Hourani, Fuad; White, Chantel E; Nilsson Stutz, Liv

    2015-08-01

    Methodological developments and new paleoanthropological data remain jointly central to clarifying the timing and systemic interrelationships between the Middle-Upper Paleolithic (MP-UP) archaeological transition and the broadly contemporaneous anatomically modern human-archaic biological turnover. In the recently discovered cave site of Mughr el-Hamamah, Jordan, in situ flint artifacts comprise a diagnostic early Upper Paleolithic (EUP) assemblage. Unusually well-preserved charcoal from hearths and other anthropogenic features associated with the lithic material were subjected to acid-base-wet oxidation-stepped combustion (ABOx-SC) pretreatment. This article presents the ABOx-SC accelerator mass spectrometry (AMS) radiocarbon dates on nine charcoal specimens from a single palimpsest occupation layer. Date calibration was carried out using the INTCAL13 radiocarbon calibration dataset. With the bulk of the material dating to 45-39 ka cal BP (thousands of years calibrated before present), the Mughr el-Hamamah lithic artifacts reveal important differences from penecontemporaneous sites in the region, documenting greater technological variability than previously known for this time frame in the Levant. The radiocarbon data from this EUP archaeological context highlight remaining challenges for increasing chronological precision in documenting the MP-UP transition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Sedimentation rates and trace metal input history in intertidal sediments from San Simon Bay (Ria de Vigo, NW Spain) derived from 210Pb and 137Cs chronology

    International Nuclear Information System (INIS)

    Alvarez-Iglesias, Paula; Quintana, Begona; Rubio, Belen; Perez-Arlucea, Marta

    2007-01-01

    210 Pb and 137 Cs dating methods, accompanied by a high-resolution geochemical study, were applied to intertidal sediments containing both fine and coarse-grained particles and also, anthropogenic Pb in order to establish sedimentation rates and historical trends in heavy metal input. Sedimentation rates were established according to the 'Constant Flux:Constant Sedimentation' (CF:CS) 210 Pb dating model, which was preferred rather than the 'Constant Rate of Supply-Minimum Variance' (CRS-MV) model. Variations in sediment grain-size were accounted for by application of several normalization procedures. Al was selected for grain-size correction. Corrected sedimentation rates obtained from 210 Pb dating were corroborated through a second independent radionuclide tracer and by comparison of peak trace metal inputs into the environment with peaks in the sediment. The Chernobyl maximum was identified in the normalized 137 Cs activity profile. Sedimentation rates of 6.2 ± 1.2 mm y -1 and 3.1 ± 0.5 mm y -1 for the upper (two muddy layers) and 6.0 ± 2.0 mm y -1 for the lower (sandy) intertidal mud flat deposits of San Simon Bay were determined. According to the established chronology, human-induced environmental changes were detected in total metal concentrations (Cu, Pb, Zn) and in sediment grain-size and composition

  9. The hypothesis of a postpositional compensatory lengthening (so-called van Wijk’s law vs. the relative chronology of Common Slavic phonologi­cal devel­opments – in search of inconsistencies

    Directory of Open Access Journals (Sweden)

    Zbigniew Babik

    2018-02-01

    Full Text Available “Van Wijk’s law” is currently defined by its advocates as a lengthening of short or shortened medial and final vowels due to an assimilation of the postconsonantal *j to them. In the present paper I am trying to demonstrate that this assumption is at variance with the relative chronology of Slavic, according to which the loss of yod after liquids and nasals must be dated before the rise of new timbre distinctions and before the shortening of final long vowels.

  10. ARTIST Project

    CSIR Research Space (South Africa)

    Ferguson, K

    2012-10-01

    Full Text Available Biennial Conference Presented by: Keith Ferguson Date: 9 October 2012 Mobile IPTV Broadcasting Platform Consortium: CSIR, UCT, ECA Funded by TIA 2008-2011 ARTIST Project Min time - sacrifice quality Max quality - sacrifice time Application Context... idth > ARTIST Platform Advertiser Client 1 Client 2 Client 3 Client 4 Sport channel News channel Wildlife channel Advert database Transaction database Transcoder Servers Media Switching Servers INTERNET Channel viewing Advert upload...

  11. Sexual Intimacy in Dating Relationships

    Science.gov (United States)

    Peplau, Letitia Anne; And Others

    1977-01-01

    The patterning of sexual interaction in male-female dyads and the links between sexual behavior and emotional intimacy were investigated as part of a two-year study of college dating couples. Traditional sexual role playing was found to be common. (Author/AM)

  12. Online Dating and Conjugal Bereavement

    Science.gov (United States)

    Young, Dannagal Goldthwaite; Caplan, Scott E.

    2010-01-01

    This study examined self-presentation in the online dating profiles of 241 widowed and 280 divorced individuals between 18 and 40 years old. A content analysis of open-ended user-generated profiles assessed the presence or absence of various themes, including the user's marital status, the backstory of their lost relationship, and whether they…

  13. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.

  14. Comparative study of radioimmunoassay dates

    International Nuclear Information System (INIS)

    Venegas Sanchez, Ruth.

    1986-01-01

    The radioimmunoassay is frequently used in clinical chemistry for the concentration determination of several substances like hormones as thyrotropine and thyroxine. In this experiment the dates of tyroxine radioimmunoassay are processed by three methods: a) like the recommendation of the IAEA, b) Dr. G. Chase method, c) according to the provider. The best method was Dr. Chase's. (author)

  15. Peer Group Influences on Adolescent Dating Aggression

    Science.gov (United States)

    Connolly, Jennifer; Friedlander, Laura

    2009-01-01

    The peer group is a critical social context for dating and romantic relationships. Peer groups provide opportunities to meet potential dating partners and set norms for acceptable dating behaviors. This article explores how peer groups influence dating and dating aggression, as well as how they can be used in prevention efforts. It also reviews…

  16. The onset of the volcanism in the Ciomadul Volcanic Dome Complex (Eastern Carpathians): Eruption chronology and magma type variation

    Science.gov (United States)

    Molnár, Kata; Harangi, Szabolcs; Lukács, Réka; Dunkl, István; Schmitt, Axel K.; Kiss, Balázs; Garamhegyi, Tamás; Seghedi, Ioan

    2018-04-01

    Combined zircon U-Th-Pb and (U-Th)/He dating was applied to refine the eruption chronology of the last 2 Myr for the andesitic and dacitic Pilişca volcano and Ciomadul Volcanic Dome Complex (CVDC), the youngest volcanic area of the Carpathian-Pannonian region, located in the southernmost Harghita, eastern-central Europe. The proposed eruption ages, which are supported also by the youngest zircon crystallization ages, are much younger than the previously determined K/Ar ages. By dating every known eruption center in the CVDC, repose times between eruptive events were also accurately determined. Eruption of the andesite at Murgul Mare (1865 ± 87 ka) and dacite of the Pilişca volcanic complex (1640 ± 37 ka) terminated an earlier pulse of volcanic activity within the southernmost Harghita region, west of the Olt valley. This was followed by the onset of the volcanism in the CVDC, which occurred after several 100s kyr of eruptive quiescence. At ca. 1 Ma a significant change in the composition of erupted magma occurred from medium-K calc-alkaline compositions to high-K dacitic (Baba-Laposa dome at 942 ± 65 ka) and shoshonitic magmas (Malnaş and Bixad domes; 964 ± 46 ka and 907 ± 66 ka, respectively). Noteworthy, eruptions of magmas with distinct chemical compositions occurred within a restricted area, a few km from one another. These oldest lava domes of the CVDC form a NNE-SSW striking tectonic lineament along the Olt valley. Following a brief (ca. 100 kyr) hiatus, extrusion of high-K andesitic magma continued at Dealul Mare (842 ± 53 ka). After another ca. 200 kyr period of quiescence two high-K dacitic lava domes extruded (Puturosul: 642 ± 44 ka and Balvanyos: 583 ± 30 ka). The Turnul Apor lava extrusion occurred after a ca. 200 kyr repose time (at 344 ± 33 ka), whereas formation of the Haramul Mic lava dome (154 ± 16 ka) represents the onset of the development of the prominent Ciomadul volcano. The accurate determination of eruption dates shows that the

  17. K/AR dating of clinoptilolite, mordenite, and associated clays from Yucca Mountains, Nevada

    International Nuclear Information System (INIS)

    WoldeGabriel, G.

    1993-01-01

    Zeolites are abundant in the geologic record in both continental and marine environments. The purpose of the present study is to evaluate the utility of K-bearing zeolites for dating by the K/Ar method to determine the time of zeolite diagenesis at Yucca Mountain, Nevada (Fig. 1). At Yucca Mountain, K-rich clinoptilolite and possibly mordenite are the only potentially K/Ar dateable secondary minerals present in the zeolite-rich tuffs except for some illite/smectites (≥10% illite layers) associated with these minerals. Direct dating of K-rich clinoptilolite, the most abundant zeolite in the altered tuffs, is important to delineate zeolite chronology as part of the site characterization of Yucca Mountain

  18. U-series dating of Paleolithic art in 11 caves in Spain.

    Science.gov (United States)

    Pike, A W G; Hoffmann, D L; García-Diez, M; Pettitt, P B; Alcolea, J; De Balbín, R; González-Sainz, C; de las Heras, C; Lasheras, J A; Montes, R; Zilhão, J

    2012-06-15

    Paleolithic cave art is an exceptional archive of early human symbolic behavior, but because obtaining reliable dates has been difficult, its chronology is still poorly understood after more than a century of study. We present uranium-series disequilibrium dates of calcite deposits overlying or underlying art found in 11 caves, including the United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage sites of Altamira, El Castillo, and Tito Bustillo, Spain. The results demonstrate that the tradition of decorating caves extends back at least to the Early Aurignacian period, with minimum ages of 40.8 thousand years for a red disk, 37.3 thousand years for a hand stencil, and 35.6 thousand years for a claviform-like symbol. These minimum ages reveal either that cave art was a part of the cultural repertoire of the first anatomically modern humans in Europe or that perhaps Neandertals also engaged in painting caves.

  19. The evolution of competitive settlement strategies in Fijian prehistory : results of excavations and radiometric dating

    International Nuclear Information System (INIS)

    Field, J.S.

    2003-01-01

    A series of excavations were completed between June 2001 and March 2002 in the Fiji Islands. The goal of this research was to investigate the evolution of competitive settlement strategies in Fijian prehistory from an archaeological and evolutionary ecological perspective. Twelve sites were excavated and mapped in the Sigatoka Valley, located in the southwestern corner of the main island of Viti Levu. Excavations were focused on determining the chronology of fortifications in the region, and the collected samples were compared to expectations based on GIS-based analyses of land productivity and historical documents pertaining to late-period warfare. Over four hundred archaeological sites have been identified in the Sigatoka Valley, and of these roughly one-third are purely defensive in configuration, with no immediate access to water or arable land. The Waikato Archaeological Dating Fund provided four radiometric dates for three defensive sites, and one site associated with a production area. (author). 6 refs., 1 fig

  20. Radiocarbon dating the end of moa-hunting in New Zealand prehistory

    International Nuclear Information System (INIS)

    Schmidt, M.

    2000-01-01

    For over 150 years, New Zealand scientists and prehistorians have investigated and debated when the last moa (Aves : Dinornithiformes) was hunted and killed by humans (see Anderson 1989). Prior to the introduction of radiocarbon dating into New Zealand archaeology in the mid-1950s, theories on when moa predation ended were based on Maori oral tradition, dubious eye witness accounts, moa bones found on the surface of the ground and arbitrary archaeological excavations of large culling sites. Radiocarbon dating provided an absolute chronological tool for determining when the remains of moa found in prehistoric context were deposited, meaning the activity of moa-hunting could be more easily attributed to a particular period in New Zealand prehistory. (author)