Mid-Wisconsinan eolian deposits of the Kittigazuit Formation, Tuktoyaktuk Coastlands, Northwest Territories, Canada

1997 ◽  
Vol 34 (11) ◽  
pp. 1421-1441 ◽  
Author(s):  
Scott R. Dallimore ◽  
Stephen A. Wolfe ◽  
John V. Matthews Jr. ◽  
Jean-Serge Vincent
Keyword(s):  
Mass Spectrometry ◽  
Late Quaternary ◽  
Surface Characteristics ◽  
Radiocarbon Dates ◽  
Glacial Ice ◽  
Alluvial Sediments ◽  
Summer Climate ◽  
Eolian Deposits ◽  
Glaciogenic Sediments ◽  
Grain Surface

The Kittigazuit Formation is a late Quaternary sand unit commonly observed throughout the Tuktoyaktuk Coastlands and in subbottom sediments of the southern Beaufort Shelf. Stratigraphic and sedimentology data, including sedimentary structures, grain-surface characteristics, and heavy and light mineralogy, assist in characterizing the deposit and indicate that it is eolian in origin. Plant and arthropod macrofossils suggest that, although the summer climate during deposition was as warm or slightly warmer than today, conditions were likely more arid. Permafrost is interpreted as being widespread during deposition. Accelerator mass spectrometry radiocarbon dates indicate that the Kittigazuit Formation was deposited between 37 and 33 ka BP. The unit is therefore interpreted as a Mid-Wisconsinan eolian dune deposit, formed by reworking of underlying alluvial sediments of the Kidluit Formation under nonglacial conditions. Glaciogenic sediments overlying the Kittigazuit Formation indicate that glacial ice covered the Tuktoyaktuk Peninsula, Richards Island, and parts of the Beaufort Shelf sometime after 33 ka BP, whereas several terrestrial dates indicate that the area may have been ice free by about 20 ka BP.

Stratigraphy of the Colorado Creek Mammoth Locality, Alaska

1992 ◽  
Vol 37 (2) ◽  
pp. 214-228 ◽  
Author(s):  
Robert M. Thorson ◽  
R. Dale Guthrie
Keyword(s):  
Regional Climate ◽  
Slope Aspect ◽  
Proxy Record ◽  
Radiocarbon Dates ◽  
West Central ◽  
Permafrost Table ◽  
Eolian Deposits ◽  
Paleoclimatic Proxy

AbstractThe Colorado Creek mammoth locality in west-central Alaska contains the remains of two mammoths that were scavenged by carnivores. Sedimentologic interpretations of the reworked eolian deposits surrounding the bones, supplemented by 10 radiocarbon dates, indicate that the lower and upper mammoths died and were buried within separate, but superimposed, thaw gullies about 23,000 and 16,000 yr ago, respectively. From our results, we propose a polycyclic taphonomic model for thaw gullies governed largely by slope aspect, rather than regional climate, and in which mixing between faunal horizons is more likely than not. Variations in the rate of silt influx and the position of the permafrost table provide a paleoclimatic proxy record that can be correlated to other records in eastern Beringia.

Reconstructing the Chronology of the House XVII-XVIII Complex at Umm el-Jimal, East Jordan: Radiocarbon Dates of Organic Inclusions of Architectural Mortars

Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 245-256 ◽  
Author(s):  
Khaled Al-Bashaireh
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Archaeological Site ◽  
Housing Demand ◽  
Radiocarbon Dates ◽  
Archaeological Data ◽  
Lime Mortars ◽  
Byzantine Period

This article presents accelerator mass spectrometry (AMS) radiocarbon dates of organic inclusions of cement materials from the House XVII-XVIII Complex located in the Umm el-Jimal archaeological site, east Jordan, aiming at refining the unclear chronology of the house. Fine straws and small fragments of charcoal uncovered from preserved architectural lime mortars and plasters were dated without carrying out extensive excavations. The results indicate that the house most probably was initially plastered or built during the middle of the Byzantine period. The results agree with the historical and archaeological data indicating that Umm el-Jimal flourished during this period; therefore, it is probable that the house was established during this time to meet the housing demand for the increased number of its population.

scholarly journals Reliability of Bone Gelatin AMS Dating: Rattus Exulans and Marine Shell Radiocarbon Dates from Pauatahanui Midden Sites in Wellington, New Zealand

Radiocarbon ◽  
1999 ◽  
Vol 41 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Nancy Beavan Athfield ◽  
Bruce McFadgen ◽  
Rodger Sparks
Keyword(s):  
Mass Spectrometry ◽  
New Zealand ◽  
Beta Decay ◽  
Confidence Level ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dates ◽  
Austrovenus Stutchburyi ◽  
Ams Dating ◽  
Marine Shell

A suite of 6 bone gelatin accelerator mass spectrometry (AMS) radiocarbon dates for Rattus exulans Peale and associated beta decay 14C dates for Austrovenus stutchburyi shell are presented for 4 middens at Pauatahanui, Wellington, New Zealand. Mean calibrated age ranges of Rattus exulans (520–435 BP and 350–330 BP at 95% confidence level) and shell (465–375 BP at 95% confidence level) from the 4 midden sites overlap. The agreement between Rattus exulans bone gelatin dates and associated shell provides an inter-sample comparison of 14C dating using both gas counting (beta decay) and AMS dating techniques. We examine the adequacy of the standard gelatinization treatment for bone samples, which has been employed consistently at the laboratory since 1995.

scholarly journals A Protocol for Radiocarbon Dating Tropical Subfossil Cave Guano

Radiocarbon ◽  
2009 ◽  
Vol 51 (3) ◽  
pp. 977-986 ◽  
Author(s):  
Christopher M Wurster ◽  
Michael I Bird ◽  
Ian Bull ◽  
Charlotte Bryant ◽  
Philippa Ascough
Keyword(s):  
Mass Spectrometry ◽  
Southeast Asia ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Saturated Hydrocarbon ◽  
Lipid Fraction ◽  
Bulk Sample ◽  
Radiocarbon Dates ◽  
Organic Fractions ◽  
Age Determinations

We present accelerator mass spectrometry (AMS) radiocarbon dates on several organic fractions isolated from tropical guano deposits recovered from insular Southeast Asia. Differences were observed between 14C measurements made on bulk guano as well as bulk lipids, the saturated hydrocarbon fraction, solvent-extracted guano, and insect cuticles extracted from the same bulk sample. We infer that 14C dates from the bulk lipid fraction and saturated hydrocarbon fractions can be variably contaminated by exogenous carbon. In contrast, 14C measurements on solvent-extracted guano and isolated insect cuticles appear to yield the most robust age determinations.

scholarly journals 14C Ages of Bone Fractions from Armenian Prehistoric Sites

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Alexander Cherkinsky ◽  
Christine Chataigner
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Organic Material ◽  
Separation Technique ◽  
Middle Paleolithic ◽  
Radiocarbon Dates ◽  
Bone Material ◽  
Younger Age ◽  
Archaeological Artifacts ◽  
Good Agreement

Prehistoric cultures in Armenia are still poorly known; thus, accelerator mass spectrometry (AMS) radiocarbon dates are invaluable in constructing an accurate chronology. Bone samples have been collected from sites representing the Middle Paleolithic, Chalcolithic, and Early Bronze periods. Most of the bone samples are poorly preserved. We describe the separation technique for the extraction of both the bioapatite and collagen fractions. In many cases where the bone had very low organic material content, the collagen fractions yielded a younger age, although the ages of bioapatite fractions were found to be in good agreement with associated archaeological artifacts. In cases where bone was well preserved, both fractions exhibited ages in good agreement with the artifacts. The accuracy of 14C dating of bone material always depends on its degree of preservation, and each case should be carefully evaluated to determine which fraction is less contaminated in order to accurately date a burial event.

scholarly journals Late Quaternary Deglaciation, Glaciomarine Sedimentation and Glacioisostatic Recovery in the Rivière Nastapoka Area, Eastern Hudson Bay, Northern Québec

2005 ◽  
Vol 57 (1) ◽  
pp. 65-83 ◽  
Author(s):  
Patrick Lajeunesse ◽  
Michel Allard
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Phase 1 ◽  
Second Phase ◽  
Hudson Bay ◽  
Silty Clay ◽  
Paleoenvironmental Reconstruction ◽  
Relative Sea Level ◽  
Radiocarbon Dates ◽  
Fluvial Terraces

Abstract This study presents a paleoenvironmental reconstruction of deglaciation dynamics and chronology, glaciomarine and postglacial sedimentation, as well as glacioisostatic recovery in the Rivière Nastapoka area, eastern Hudson Bay. Results indicate that the retreat of Québec-Labrador ice was mainly controlled by topography and was marked by four phases. Radiocarbon dates indicate that deglaciation began about 8.3 ka cal. BP and was characterized by a stillstand of the ice margin in the Nastapoka Hills that lead to the deposition of a drift belt in a high relative sea-level (Phase 1). After this stabilisation, the ice margin retreated rapidly eastward in a region of low relief and deposited a drape of silty clay in a falling relative sea-level (Phase 2). A second phase of stabilization of the ice margin lasted until at least 7.2 ka cal.BP on the higher shield peneplaine east of the limit of the Tyrrell Sea (Phase 3). This lead to the deposition of a belt of glaciofluvial deltas in a lower relative sea-level. Following this stillstand, the eastward retreat and subsequent ablation of the ice in central Québec-Labrador generated meltwater that transported large volumes of glacial sediments by fluvial processes and downcutting of fluvial terraces in previously deposited glaciofluvial and marine sediments (Phase 4). Glacioisostatic rebound reached 0.07 m/yr during the early phase of deglaciation and decreased to 0.04 m/yr between 6 and 5 ka cal. BP and 0.016 m/yr in the last 1000 years.

scholarly journals A Review of the Radiocarbon Dates for the Afanasyevo Culture (Central Asia): Shifting Towards the “Shorter” Chronology

Radiocarbon ◽  
2018 ◽  
Vol 61 (1) ◽  
pp. 243-263 ◽  
Author(s):  
Andrey V Poliakov ◽  
Svetlana V Svyatko ◽  
Nadezhda F Stepanova
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
Archaeological Data ◽  
Depth Analysis ◽  
Over Time ◽  
Ams Dates

ABSTRACTThis article provides a summary and in-depth analysis of all existing radiocarbon (14C) dates for the Afanasyevo Culture of the Paleometal period. The previous “long” chronology of the culture was widely criticized and contradicted many archaeological observations. The exceedingly wide ranges of the liquid scintillation counting (LSC) dates from bone samples produced in several laboratories and the systematically older ages for the wood/charcoal samples finally reveal the shortcomings of the conventional “long” chronology. From accelerator mass spectrometry (AMS), the Afanasyevo burials of the Altai are dated to the 31st–29th century BC, whereas those of the Middle Yenisei Region to the 29th–25th century BC, which confirms the relatively earlier age of the Altai monuments. The “short” chronology removes the incompatibility of deriving the Afanasyevo Culture from the Yamnaya Culture, which previously appeared “younger” than the Afanasyevo, and also contradictions with the archaeological data. It also explains the small number of sites, the small size of the cemeteries and the lack of the internal periodization. We can now clearly move, from the earlier understanding that the Afanasyevo chronology is too broad, towards a different perception. The new AMS dates only represent a “core” for the Afanasyevo chronology, which cannot be narrowed down, but could be slightly expanded over time.

scholarly journals Nonlinear response of the Antarctic Ice Sheet to late Quaternary sea level and climate forcing

2019 ◽  
Vol 13 (10) ◽  
pp. 2615-2631 ◽  
Author(s):  
Michelle Tigchelaar ◽  
Axel Timmermann ◽  
Tobias Friedrich ◽  
Malte Heinemann ◽  
David Pollard
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Volume Changes ◽  
Antarctic Ice Sheet ◽  
Glacial Ice ◽  
Ice Volume ◽  
Global Sea Level ◽  
The Individual ◽  
The Antarctic

Abstract. Antarctic ice volume has varied substantially during the late Quaternary, with reconstructions suggesting a glacial ice sheet extending to the continental shelf break and interglacial sea level highstands of several meters. Throughout this period, changes in the Antarctic Ice Sheet were driven by changes in atmospheric and oceanic conditions and global sea level; yet, so far modeling studies have not addressed which of these environmental forcings dominate and how they interact in the dynamical ice sheet response. Here, we force an Antarctic Ice Sheet model with global sea level reconstructions and transient, spatially explicit boundary conditions from a 408 ka climate model simulation, not only in concert with each other but, for the first time, also separately. We find that together these forcings drive glacial–interglacial ice volume changes of 12–14 ms.l.e., in line with reconstructions and previous modeling studies. None of the individual drivers – atmospheric temperature and precipitation, ocean temperatures, or sea level – single-handedly explains the full ice sheet response. In fact, the sum of the individual ice volume changes amounts to less than half of the full ice volume response, indicating the existence of strong nonlinearities and forcing synergy. Both sea level and atmospheric forcing are necessary to create full glacial ice sheet growth, whereas the contribution of ocean melt changes is found to be more a function of ice sheet geometry than climatic change. Our results highlight the importance of accurately representing the relative timing of forcings of past ice sheet simulations and underscore the need for developing coupled climate–ice sheet modeling frameworks that properly capture key feedbacks.

scholarly journals Centre of Research and Restoration of the Museums of France: AMS Radiocarbon Dates List 1

Radiocarbon ◽  
2010 ◽  
Vol 52 (4) ◽  
pp. 1689-1700 ◽  
Author(s):  
P Richardin ◽  
N Gandolfo ◽  
B Moignard ◽  
C Lavier ◽  
C Moreau ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Scientific Community ◽  
Archaeological Remains ◽  
Radiocarbon Dates ◽  
National Project ◽  
Historical Monuments ◽  
Museum Objects

The national project for the measurement of radiocarbon includes different scientific partners for the accelerator named ARTEMIS (French acronym for Accélérateur pour la Recherche en sciences de la Terre, Environnement, Muséologie Installé à Saclay), available to the scientific community since 2004 (Cottereau et al. 2007). The French Ministry of Culture uses this accelerator mass spectrometry (AMS) facility at the request of archaeologists or curators of museums or of historical monuments. For the preparation of some samples, a laboratory has been installed at the Centre of Research and Restoration of the Museums of France, located in the Louvre Palace. In this report, the first data carried out on vegetal samples from museum objects or archaeological remains, dates are presented in terms of yr BP (before AD 1950).

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