Accurate Radiocarbon Dating of Archaeological Ash Using Pyrogenic Aragonite

Radiocarbon ◽  
2017 ◽  
Vol 59 (1) ◽  
pp. 231-249 ◽  
Author(s):  
Michael B Toffolo ◽  
Lior Regev ◽  
Eugenia Mintz ◽  
Kristin M Poduska ◽  
Ruth Shahack-Gross ◽  
...  
Keyword(s):  
Human Activities ◽  
Radiocarbon Dating ◽  
Isotopic Exchange ◽  
New Method ◽  
Mineral Phase ◽  
Density Separation ◽  
The Past ◽  
Main Component ◽  
Unsolved Issue ◽  
Age Determinations

AbstractObtaining accurate age determinations from minerals in archaeological ash is a major unsolved issue in radiocarbon (14C) dating. This is because the original 14C content of calcite, the main component of ash, is altered by isotopic exchange. Pyrogenic aragonite, another mineral phase recently discovered in ash, might preserve its 14C signature through time. Using a new method based on density separation and step combustion, we were able to isolate and date aragonitic ash from an archaeological destruction horizon of known age. Here we show that the 14C age of aragonite matches the age of the destruction horizon. Our results demonstrate that pyrogenic aragonite is a short-lived material suitable for 14C dating and directly related to human activities involving the use of fire, thus bearing major implications for the establishment of absolute chronologies for the past 50,000 yr.

scholarly journals The Integration of Radiocarbon Dating in Archaeology

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 639-644 ◽  
Author(s):  
H T Waterbolk
Keyword(s):  
Radiocarbon Dating ◽  
The Other ◽  
New Method ◽  
Time Range ◽  
Traditional Methods ◽  
Radiocarbon Dates ◽  
Fully Integrated ◽  
Expected Time ◽  
The Past

In the past 30 years many hundreds of archaeologic samples have been dated by radiocarbon laboratories. Yet, one cannot say that 14C dating is fully integrated into archaeology. For many archaeologists, a 14C date is an outside expertise, for which they are grateful, when it provides the answer to an otherwise insoluble chronologic problem and when it falls within the expected time range. But if a 14C date contradicts other chronologic evidence, they often find the ‘solution’ inexplicable. Some archaeologists are so impressed by the new method, that they neglect the other evidence; others simply reject problematic 14C dates as archaeologically unacceptable. Frequently, excavation reports are provided with an appendix listing the relevant 14C dates with little or no discussion of their implication. It is rare, indeed, to see in archaeologic reports a careful weighing of the various types of chronologic evidence. Yet, this is precisely what the archaeologist is accustomed to do with the evidence from his traditional methods for building up a chronology: typology and stratigraphy. Why should he not be able to include radiocarbon dates in the same way in his considerations?

Spatiotemporal Changes of Riverbed and Surrounding Environment in Yongding River (Beijing section) in the Past 40 Years

2020 ◽  
Vol 64 (4) ◽  
pp. 40407-1-40407-13 ◽  
Author(s):  
Ran Pang ◽  
He Huang ◽  
Tri Dev Acharya
Keyword(s):  
Economic Development ◽  
Water Conservation ◽  
Human Activities ◽  
Urban Areas ◽  
Water Volume ◽  
Cropland Area ◽  
The Past ◽  
Surrounding Environment ◽  
Spatiotemporal Changes ◽  
Yongding River

Abstract Yongding River is one of the five major river systems in Beijing. It is located to the west of Beijing. It has influenced culture along its basin. The river supports both rural and urban areas. Furthermore, it influences economic development, water conservation, and the natural environment. However, during the past few decades, due to the combined effect of increasing population and economic activities, a series of changes have led to problems such as the reduction in water volume and the exposure of the riverbed. In this study, remote sensing images were used to derive land cover maps and compare spatiotemporal changes during the past 40 years. As a result, the following data were found: forest changed least; cropland area increased to a large extent; bareland area was reduced by a maximum of 63%; surface water area in the study area was lower from 1989 to 1999 because of the excessive use of water in human activities, but it increased by 92% from 2010 to 2018 as awareness about protecting the environment arose; there was a small increase in the built-up area, but this was more planned. These results reveal that water conservancy construction, agroforestry activities, and increasing urbanization have a great impact on the surrounding environment of the Yongding River (Beijing section). This study discusses in detail how the current situation can be attributed to of human activities, policies, economic development, and ecological conservation Furthermore, it suggests improvement by strengthening the governance of the riverbed and the riverside. These results and discussion can be a reference and provide decision support for the management of southwest Beijing or similar river basins in peri-urban areas.

Children’s Lives and Deaths in Merovingian Gaul

2020 ◽  
pp. 185-213
Author(s):  
Émilie Perez
Keyword(s):  
Social Identity ◽  
Age Groups ◽  
New Method ◽  
Recent Analysis ◽  
Age And Gender ◽  
The Past ◽  
And Gender ◽  
Grave Goods

The role of children in Merovingian society has long been downplayed, and the study of their graves and bones has long been neglected. However, during the past fifteen years, archaeologists have shown growing interest in the place of children in Merovingian society. Nonetheless, this research has not been without challenges linked to the nature of the biological and material remains. Recent analysis of 315 children’s graves from four Merovingian cemeteries in northern Gaul (sixth to seventh centuries) allows us to understand the modalities of burial ritual for children. A new method for classifying children into social age groups shows that the type, quality, quantity, and diversity of grave goods were directly correlated with the age of the deceased. They increased from the age of eight and particularly around the time of puberty. This study discusses the role of age and gender in the construction and expression of social identity during childhood in the Merovingian period.

The Future of the Planetary Trust in a Kaleidoscopic World

2021 ◽  
pp. 1-8
Author(s):  
Edith Brown Weiss
Keyword(s):  
Artificial Intelligence ◽  
Natural Resource ◽  
Human Activities ◽  
New Technologies ◽  
Future Generations ◽  
Nuclear War ◽  
Human Environment ◽  
The Past ◽  
Resource Degradation ◽  
Shared Goal

Today, it is evident that we are part of a planetary trust. Conserving our planet represents a public good, global as well as local. The threats to future generations resulting from human activities make applying the normative framework of a planetary trust even more urgent than in the past decades. Initially, the planetary trust focused primarily on threats to the natural system of our human environment such as pollution and natural resource degradation, and on threats to cultural heritage. Now, we face a higher threat of nuclear war, cyber wars, and threats from gene drivers that can cause inheritable changes to genes, potential threats from other new technologies such as artificial intelligence, and possible pandemics. In this context, it is proposed that in the kaleidoscopic world, we must engage all the actors to cooperate with the shared goal of caring for and maintaining planet Earth in trust for present and future generations.

scholarly journals A New Radiocarbon Pretreatment Method for Molluscan Shell Using Density Fractionation of Carbonates in Bromoform

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1301-1311 ◽  
Author(s):  
Christopher M Russo ◽  
Jennifer A Tripp ◽  
Katerina Douka ◽  
Thomas F G Higham
Keyword(s):  
Radiocarbon Dating ◽  
Separation Technique ◽  
Archaeological Sites ◽  
Density Fractionation ◽  
Pretreatment Method ◽  
Density Separation ◽  
Molluscan Shell ◽  
Archaeological Artifacts ◽  
Organic Remains

Coastal archaeological sites that lack organic remains for radiocarbon dating are often abundant sources of molluscan shells. As a substitute for materials such as bone and charcoal, shells can be analyzed with 14C dating to determine a site's age. Despite their being convenient, non-mobile archaeological artifacts, molluscan shells are plagued by several issues, including carbonate remodeling, in which aragonite in shells is converted to calcite as predicted by thermodynamics. We present here a carbonate density separation technique that addresses the issue of carbonate remodeling. Using a density fractionation with bromoform, aragonite concentrations are enriched in shells that have undergone significant remodeling. The technique has been applied to archaeological shells and has returned dates that are younger than those previously determined for the same shells.

SUITABILITY OF ACID-SOLUBLE AND ACID-INSOLUBLE LEATHER FRACTIONS IN RADIOCARBON DATING

Radiocarbon ◽  
2020 ◽  
pp. 1-8
Author(s):  
Alyssa M Tate ◽  
Brittany Hundman ◽  
Jonathan Heile
Keyword(s):  
Radiocarbon Dating ◽  
Insoluble Fraction ◽  
Economic Life ◽  
Chemical Pretreatment ◽  
Acid Base ◽  
The Past ◽  
Acid Soluble Collagen ◽  
Method Of Production ◽  
Insight Into

ABSTRACT Leather has been produced by a variety of methods throughout human history, providing researchers unique insight into multiple facets of social and economic life in the past. Archaeologically recovered leather is often fragile and poorly preserved, leading to the use of various conservation and restoration efforts that may include the application of fats, oils, or waxes. Such additives introduce exogenous carbon to the leather, contaminating the specimen. These contaminants, in addition to those accumulated during interment, must be removed through chemical pretreatment prior to radiocarbon (14C) dating to ensure accurate dating. DirectAMS utilizes organic solvents, acid-base-acid (ABA) and gelatinization for all leather samples. Collagen yield from leather samples is variable due to the method of production and the quality of preservation. However, evaluating the acid-soluble collagen fraction, when available, provides the most accurate 14C dates for leather samples. In instances where gelatinization does not yield sufficient material, the resulting acid-insoluble fraction may be dated. Here we examine the effectiveness of the combined organic solvent and ABA pretreatment with gelatinization for leather samples, as well as the suitability of the acid-insoluble fraction for 14C dating.

A new method to constrain soil development time using both OSL and radiocarbon dating

Geoderma ◽  
2016 ◽  
Vol 261 ◽  
pp. 93-100 ◽  
Author(s):  
Xiaodong Miao ◽  
Hong Wang ◽  
Paul R. Hanson ◽  
Joseph A. Mason ◽  
Xiaodong Liu
Keyword(s):  
Radiocarbon Dating ◽  
Development Time ◽  
Soil Development ◽  
New Method

scholarly journals Radiocarbon Dating of Calcined Bones: Where Does the Carbon Come from?

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 601-611 ◽  
Author(s):  
A Zazzo ◽  
J-F Saliège ◽  
A Person ◽  
H Boucher
Keyword(s):  
Radiocarbon Dating ◽  
Tooth Enamel ◽  
Skeletal Remains ◽  
Archaeological Sites ◽  
Carbonate Content ◽  
The Past ◽  
Mineral Fraction ◽  
Different Temperatures ◽  
C Value ◽  
Paleodietary Reconstruction

Over the past decade, radiocarbon dating of the carbonate contained in the mineral fraction of calcined bones has emerged as a viable alternative to dating skeletal remains in situations where collagen is no longer present. However, anomalously low δ13C values have been reported for calcined bones, suggesting that the mineral fraction of bone is altered. Therefore, exchange with other sources of carbon during heating cannot be excluded. Here, we report new results from analyses on cremated bones found in archaeological sites in Africa and the Near East, as well as the results of several experiments aiming at improving our understanding of the fate of mineral and organic carbon of bone during heating. Heating of modern bone was carried out at different temperatures, for different durations, and under natural and controlled conditions, and the evolution of several parameters (weight, color, %C, %N, δ13C value, carbonate content, crystallinity indexes measured by XRD and FTIR) was monitored. Results from archaeological sites confirm that calcined bones are unreliable for paleoenvironmental and paleodietary reconstruction using stable isotopes. Experimental results suggest that the carbon remaining in bone after cremation likely comes from the original inorganic pool, highly fractionated due to rapid recrystallization. Therefore, its reliability for 14C dating should be seen as close to that of tooth enamel, due to crystallographic properties of calcined bones.

scholarly journals The creative work of Sergey Paradzhanov as an event of Postmodernism

2009 ◽  
Vol 1 (1) ◽  
pp. 124-132
Author(s):  
Anna Georgievna Lukashova
Keyword(s):  
20Th Century ◽  
New Method ◽  
Past Century ◽  
Creative Work ◽  
The Past

In this article a new method of analysis of S. Paradzhanov's creative work is suggested: the works of Paradzhanov-artist and Paradzhanov-director are examined as a united paradigm, which gives an opportunity to present the phenomenon of his art in the context of art culture of the 20th century in the most adequate way, and deine the connection of the aesthetics of his work and the basic tendencies of the past century.

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