Yuzhniy Oleniy Ostrov in Karelia, northwest Russia, is one of the largest Early Holocene cemeteries in northern Eurasia, with 177 burials recovered in excavations in the 1930s; originally, more than 400 graves may have been present. A new radiocarbon dating programme, taking into account a correction for freshwater reservoir effects, suggests that the main use of the cemetery spanned only some 100-300 years, centring on ca. 8250 to 8000 cal BP.
View Article and Find Full Text PDFOur paper about the impacts of the Laschamps Geomagnetic Excursion 42,000 years ago has provoked considerable scientific and public interest, particularly in the so-called Adams Event associated with the initial transition of the magnetic poles. Although we welcome the opportunity to discuss our new ideas, Hawks’ assertions of misrepresentation are especially disappointing given his limited examination of the material.
View Article and Find Full Text PDFOur study on the exact timing and the potential climatic, environmental, and evolutionary consequences of the Laschamps Geomagnetic Excursion has generated the hypothesis that geomagnetism represents an unrecognized driver in environmental and evolutionary change. It is important for this hypothesis to be tested with new data, and encouragingly, none of the studies presented by Picin . undermine our model.
View Article and Find Full Text PDFGeological archives record multiple reversals of Earth's magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion [41 to 42 thousand years ago (ka)]. We use ancient New Zealand kauri trees () to develop a detailed record of atmospheric radiocarbon levels across the Laschamps Excursion.
View Article and Find Full Text PDFSocial distancing is an important measure in controlling epidemics. This paper presents a simple theoretical model focussed on the implications of the wide range in interaction rates between individuals, both within the workplace and in social settings. The model is based on well-mixed populations and so is not intended for studying geographic spread.
View Article and Find Full Text PDFWe test a recent prediction that stable carbon isotope ratios from UK oaks will display age-trends of more than 4‰ per century by measuring >5400 carbon isotope ratios from the late-wood alpha-cellulose of individual rings from 18 modern oak trees and 50 building timbers spanning the 9th-21st centuries. After a very short (c.5 years) juvenile phase with slightly elevated values, the number of series that show rising and falling trends is almost equal (33:35) and the average trend is almost zero.
View Article and Find Full Text PDFThe new IntCal20 radiocarbon record continues decades of successful practice by employing one calibration curve as an approximation for different regions across the hemisphere. Here we investigate three radiocarbon time-series of archaeological and historical importance from the Mediterranean-Anatolian region, which indicate, or may include, offsets from IntCal20 (~0-22 C years). While modest, these differences are critical for our precise understanding of historical and environmental events across the Mediterranean Basin and Near East.
View Article and Find Full Text PDFThe future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening.
View Article and Find Full Text PDFDenisova Cave in the Siberian Altai (Russia) is a key site for understanding the complex relationships between hominin groups that inhabited Eurasia in the Middle and Late Pleistocene epoch. DNA sequenced from human remains found at this site has revealed the presence of a hitherto unknown hominin group, the Denisovans, and high-coverage genomes from both Neanderthal and Denisovan fossils provide evidence for admixture between these two populations. Determining the age of these fossils is important if we are to understand the nature of hominin interaction, and aspects of their cultural and subsistence adaptations.
View Article and Find Full Text PDFA time frame for late Iroquoian prehistory is firmly established on the basis of the presence/absence of European trade goods and other archeological indicators. However, independent dating evidence is lacking. We use 86 radiocarbon measurements to test and (re)define existing chronological understanding.
View Article and Find Full Text PDFJ World Prehist
May 2018
The great site of Valencina de la Concepción, near Seville in the lower Guadalquivir valley of southwest Spain, is presented in the context of debate about the nature of Copper Age society in southern Iberia as a whole. Many aspects of the layout, use, character and development of Valencina remain unclear, just as there are major unresolved questions about the kind of society represented there and in southern Iberia, from the late fourth to the late third millennium cal BC. This paper discusses 178 radiocarbon dates, from 17 excavated sectors within the c.
View Article and Find Full Text PDFConsiderable work has gone into developing high-precision radiocarbon (C) chronologies for the southern Levant region during the Late Bronze to Iron Age/early Biblical periods (∼1200-600 BC), but there has been little consideration whether the current standard Northern Hemisphere C calibration curve (IntCal13) is appropriate for this region. We measured C ages of calendar-dated tree rings from AD 1610 to 1940 from southern Jordan to investigate contemporary C levels and to compare these with IntCal13. Our data reveal an average offset of ∼19 C years, but, more interestingly, this offset seems to vary in importance through time.
View Article and Find Full Text PDFObjectives: San Juan ante Portam Latinam is one of a small number of European Neolithic sites meeting many of the archaeological criteria expected for a mass grave, and furthermore presents evidence for violent conflict. This study aims to differentiate between what is potentially a single episode of deposition, versus deposition over some centuries, or, alternatively, that resulting from a combination of catastrophic and attritional mortality. The criteria developed are intended to have wider applicability to other such proposed events.
View Article and Find Full Text PDFAnthropogenic activity is now recognised as having profoundly and permanently altered the Earth system, suggesting we have entered a human-dominated geological epoch, the 'Anthropocene'. To formally define the onset of the Anthropocene, a synchronous global signature within geological-forming materials is required. Here we report a series of precisely-dated tree-ring records from Campbell Island (Southern Ocean) that capture peak atmospheric radiocarbon (C) resulting from Northern Hemisphere-dominated thermonuclear bomb tests during the 1950s and 1960s.
View Article and Find Full Text PDFThe melting of perennial ice patches globally is uncovering a fragile record of alpine activity, especially hunting and the use of mountain passes. When rescued by systematic fieldwork (glacial archaeology), this evidence opens an unprecedented window on the chronology of high-elevation activity. Recent research in Jotunheimen and surrounding mountain areas of Norway has recovered over 2000 finds-many associated with reindeer hunting (e.
View Article and Find Full Text PDFThe C/C ratio of C plant matter is thought to be controlled by the isotopic composition of atmospheric CO and stomatal response to environmental conditions, particularly mean annual precipitation (MAP). The effect of CO concentration on C/C ratios is currently debated, yet crucial to reconstructing ancient environments and quantifying the carbon cycle. Here we compare high-resolution ice core measurements of atmospheric CO with fossil plant and faunal isotope records.
View Article and Find Full Text PDFStarting from questions about the nature of cultural diversity, this paper examines the pace and tempo of change and the relative importance of continuity and discontinuity. To unravel the cultural project of the past, we apply chronological modelling of radiocarbon dates within a Bayesian statistical framework, to interrogate the Neolithic cultural sequence in Lower Alsace, in the upper Rhine valley, in broad terms from the later sixth to the end of the fifth millennium cal BC. Detailed formal estimates are provided for the long succession of cultural groups, from the early Neolithic Linear Pottery culture (LBK) to the Bischheim Occidental du Rhin Supérieur (BORS) groups at the end of the Middle Neolithic, using seriation and typology of pottery as the starting point in modelling.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
March 2018
Rationale: For radiocarbon results to be accurate, samples must be free of contaminating carbon. Sample pre-treatment using a high-performance liquid chromatography (HPLC) approach has been developed at the Oxford Radiocarbon Accelerator Unit (ORAU) as an alternative to conventional methods for dating heavily contaminated bones. This approach isolates hydroxyproline from bone collagen, enabling a purified bone-specific fraction to then be radiocarbon dated by accelerator mass spectrometry (AMS).
View Article and Find Full Text PDFContrasting Greenland and Antarctic temperatures during the last glacial period (115,000 to 11,650 years ago) are thought to have been driven by imbalances in the rates of formation of North Atlantic and Antarctic Deep Water (the 'bipolar seesaw'). Here we exploit a bidecadally resolved C data set obtained from New Zealand kauri (Agathis australis) to undertake high-precision alignment of key climate data sets spanning iceberg-rafted debris event Heinrich 3 and Greenland Interstadial (GI) 5.1 in the North Atlantic (~30,400 to 28,400 years ago).
View Article and Find Full Text PDFThe Younger Dryas Stadial (YDS) was an episode of northern hemispheric cooling which occurred within the Last Glacial Interglacial Transition (LGIT). A major driver for the YDS climate was a weakening of the Atlantic Meridional Overturning Circulation (AMOC). It has been inferred that the AMOC began to strengthen mid-YDS, producing a bipartite structure of the YDS in records from continental Europe.
View Article and Find Full Text PDFPerhaps nowhere in European prehistory does the idea of clearly-defined cultural boundaries remain more current than in the initial Neolithic, where the southeast-northwest trend of the spread of farming crosses what is perceived as a sharp divide between the Balkans and central Europe. This corresponds to a distinction between the Vinča culture package, named for a classic site in Serbia, with its characteristic pottery assemblage and absence of longhouses, and the (LBK), with equally diagnostic but different pottery, and its apparently culturally-diagnostic longhouses, extending in a more northerly belt through central Europe westward to the Dutch coast. In this paper we question the concept of such a clear division through a presentation of new data from the site of Szederkény-Kukorica-dűlő.
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