Search results for "radiocarbon"

The Chronology of Archaeological Assemblages Based on Automatic Bayesian Procedure: Eastern Iberia as Study Case

2021

The purpose of this work is to show an automatic Bayesian procedure to obtain accurate chronological information of archaeological assemblages characterized by palimpsest or neither radiocarbon dates and whose temporal information comes only from bifacial flint arrowheads.In this work, a classification based on the Dirichlet-multinomial inferential process and its posterior predictive probability distribution are applied. Its purpose is to predict the chronological period of archaeological assemblages (levels or sites) based on the predictive probability distribution of each bifacial flint arrowhead types defined in the Eastern Iberia during the 4th and 3rd millennium cal BC. The results of…

Climate change and the collapse of the Akkadian empire: Evidence from the deep sea

2000

The Akkadian empire ruled Mesopotamia from the headwaters of the Tigris-Euphrates Rivers to the Persian Gulf during the late third millennium B.C. Archeological evidence has shown that this highly developed civilization collapsed abruptly near 4170 ± 150 calendar yr B.P., perhaps related to a shift to more arid conditions. Detailed paleoclimate records to test this assertion from Mesopotamia are rare, but changes in regional aridity are preserved in adjacent ocean basins. We document Holocene changes in regional aridity using mineralogic and geochemical analyses of a marine sediment core from the Gulf of Oman, which is directly downwind of Mesopotamian dust source areas and archeological si…

A continuous multi-millennial record of surficial bivalve mollusk shells from the São Paulo Bight, Brazilian shelf

2014

AbstractTo evaluate the potential of using surficial shell accumulations for paleoenvironmental studies, an extensive time series of individually dated specimens of the marine infaunal bivalve mollusk Semele casali was assembled using amino acid racemization (AAR) ratios (n = 270) calibrated against radiocarbon ages (n = 32). The shells were collected from surface sediments at multiple sites across a sediment-starved shelf in the shallow sub-tropical São Paulo Bight (São Paulo State, Brazil). The resulting 14C-calibrated AAR time series, one of the largest AAR datasets compiled to date, ranges from modern to 10,307 cal yr BP, is right skewed, and represents a remarkably complete time series…

The triumphal cross of the cathedral of Nevers: painting technique and examination

2019

The large polychrome wooden cross preserved in the Saint-Cyr et Sainte-Julitte cathedral in Nevers was badly damaged during the bombing in July 1944. Restored and put on display on a modern cross in front of the choir, the sculpture suffered a new fall in 2015. The conservation of the work, directed by DRAC-CRMH of Burgundy-Franche-Comté, was preceded by a phase of technical study. Micro-stratigraphic, taxonomic and radiometric analyses and the dendrochronology of the cross were carried out. The dendrochronology of the cross of Nevers and the comparison with radiocarbon dating place the elaboration of the work in the last quarter of the 12th century while confirming the contemporaneousness …

Electron Spin Resonance and Thermoluminescence dating of shells and sediments from Sambaqui (shell mound) Santa Marta II, Brazil

2020

In Tupi, the word Sambaqui means “mound of shells”. These archaeological sites are cultural vestiges left by the prehistoric occupation of the Brazilian coast from five to six thousand years ago. Mollusks, fishes, and other marine edible foods were important for the survival of this population. The remains of foods, mainly shells, were heaped up, giving a mound of different proportions, which became part of the landscape of the Brazilian coastal plain. Due to the large number of Sambaquis in Brazil and considering that Sambaqui Santa Marta II, Laguna, SC, has not yet been dated, Electron Spin Resonance (ESR) measurements were performed in aragonite shells collected from different layers of …

Paleogenetic analysis and radiocarbon dating on skeletal remains from the Roman necropolis of Contrada Diana (Lipari Island, Sicily)

2023

Lipari, the largest of the Aeolian Islands, is located in the southern Tyrrhenian Sea. Archeological evidence suggests an early human occupation starting from the Neolithic period. The island, favored by its volcanic history, was an important crossroads of cultures and commerce exchanges during prehistory up to Greek and Roman dominations. In this study, we present multidisciplinary analysis results on four skeletal remains from the necropolis of Contrada Diana attributed to the Roman period. By using Next Generation Sequencing technology we identified the biological sex and reconstructed the complete mitochondrial genome for two individuals. We retrieved the first ancient L3e5a lineage tha…

Pleistocene Glaciations in Latvia

2011

Abstract During the Pleistocene the territory of Latvia was repeatedly overridden by Scandinavian ice sheets, at least from the Elsterian onwards. Extent limit of all glaciations was located far outside of Latvia. Due to vigorous erosion by subsequent glaciations the Pleistocene record is incomplete. Radiocarbon, cosmogenic nuclide and radiation exposure dating methods have been mainly used only for age determination of the upper part of the Pleistocene sequence. Decay of the Late Weichselian glaciation in Latvia is marked by five major ice-marginal zones

Short communication: Driftwood provides reliable chronological markers in Arctic coastal deposits

2021

Originating from the boreal forest and often transported over large distances, driftwood characterizes many Arctic coastlines. Here we present a combined assessment of radiocarbon (14C) and dendrochronological (ring width) age estimates of driftwood samples to constrain the progradation of two Holocene beach-ridge systems near the Lena Delta in the Siberian Arctic (Laptev Sea). Our data show that the 14C ages obtained on syndepositional driftwood from beach deposits yield surprisingly coherent chronologies for the coastal evolution of the field sites. The dendrochronological analysis of wood from modern drift lines revealed the origin and recent delivery of the wood from the Lena River catc…

Combined spatial Radiocarbon density maps and refined SCPD method to explore food production spread through the central and western mediterranean

2018

The neolithisation process in Europe constitutes a fundamental issue of interest in social evolutionary studies. The pioneer work of Ammerman and Cavalli-Sforza (1984) has been considered the basis for discussing the mechanisms involved in the expansion of farming and herding practices in a continental scale, assuming their spread from the Near East domestic core area. From an evolutionary perspective the introduction of agriculture and livestock implies major shifts in social dynamics including changes in demographic patterns as well as in settlement distribution and cultural models. Spatial analysis together with the use of radiocarbon data as a demographic proxy maybe one of the keys to …

2017

Ranking among the largest volcanic eruptions of the Common Era (CE), the ‘Millennium Eruption’ of Changbaishan produced a widely-dispersed tephra layer (known as the B-Tm ash), which represents an important tie point for palaeoenvironmental studies in East Asia. Hitherto, there has been no consensus on its age, with estimates spanning at least the tenth century CE. Here, we identify the cosmogenic radiocarbon signal of 775 CE in a subfossil larch engulfed and killed by pyroclastic currents emplaced during the initial rhyolitic phase of the explosive eruption. Combined with glaciochemical evidence from Greenland, this enables us to date the eruption to late 946 CE. This secure date rules out…