scholarly journals Successful AMS 14C Dating of Non-Hydraulic Lime Mortars from the Medieval Churches of the Åland Islands, Finland

Radiocarbon ◽  
2010 ◽  
Vol 52 (1) ◽  
pp. 171-204 ◽  
Author(s):  
Jan Heinemeier ◽  
Åsa Ringbom ◽  
Alf Lindroos ◽  
Árný E Sveinbjörnsdóttir
Keyword(s):  
Direct Contact ◽  
Radiocarbon Dating ◽  
14C Dating ◽  
Hydraulic Lime ◽  
Ams Radiocarbon Dating ◽  
Lime Mortars ◽  
Ams Dating ◽  
Chemical Testing ◽  
Shed Light ◽  
Ams 14C Dating

Fifteen years of research on accelerator mass spectrometry (AMS) radiocarbon dating of non-hydraulic mortar has now led to the establishment of a chronology for the medieval stone churches of the Åland Islands (Finland), where no contemporary written records could shed light on the first building phases. In contrast to other material for dating, well-preserved mortar is abundantly available from every building stage.We have gathered experience from AMS dating of 150 Åland mortar samples. Approximately half of them have age control from dendrochronology or from 14C analysis of wooden fragments in direct contact with the mortar. Of the samples with age control, 95% of the results agree with the age of the wood. The age control from dendrochronology, petrologic microscopy, chemical testing of the mortars, and mathematical modeling of their behavior during dissolution in acid have helped us to define criteria of reliability to interpret the 14C results when mortar dating is the only possibility to constrain the buildings in time. With these criteria, 80% of all samples reached conclusive results, and we have thus far been able to establish the chronology of 12 out of the 14 churches and chapels, while 2 still require complementary analyses.

The Strange Case of the Ankhpakhered Mummy: Results of AMS 14C Dating

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1403-1408
Author(s):  
G Quarta ◽  
S Malgora ◽  
M D'Elia ◽  
V Gaballo ◽  
E Braione ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fourier Transform ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
14C Dating ◽  
Egyptian Mummy ◽  
Ams Radiocarbon Dating ◽  
Ancient Egyptian ◽  
The University ◽  
Ams 14C Dating

The ancient Egyptian mummy discovered in the wooden coffin of Ankhpakhered, priest of the god Min, has been studied at CEDAD (Centre for Dating and Diagnostics) at the University of Salento, Italy. The CT scan, performed by the multidisciplinary team of the Mummy Project of Milan, highlighted unusual features of the mummy, suggesting a reuse of the sarcophagus. Furthermore, specimens were taken via endoscopy for accelerator mass spectrometry (AMS) radiocarbon dating and Fourier transform infrared (FTIR) analyses, which have been carried out at CEDAD.

scholarly journals A Simple Method to Separate Pollen for AMS Radiocarbon Dating and its Application to Lacustrine and Marine Sediments

Radiocarbon ◽  
1999 ◽  
Vol 41 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Scott A Mensing ◽  
John R Southon
Keyword(s):  
Mass Spectrometry ◽  
Lake Sediments ◽  
Marine Sediments ◽  
Radiocarbon Dating ◽  
Minimal Cost ◽  
Simple Method ◽  
Ams Radiocarbon Dating ◽  
Sediment Reworking ◽  
Scientific Equipment ◽  
Ams Dating

We present a simple method for manually separating pollen concentrates for radiocarbon accelerator mass spectrometry (AMS) dating using a mouth pipetting system. The required equipment is readily available from scientific equipment supply houses at minimal cost. Pollen samples from lake sediments required about 4 h of hand picking, whereas samples from marine sediments required about 8 h labor. Pollen dates from marine sediments were much older than expected. We are attempting to resolve whether this is due to contamination of the pollen or the presence of significant quantities of old reworked pollen. Pollen dates from lake sediments associated with Mazama Ash were consistent with other published ages; however, replicate dates on pollen samples from above the ash were consistently older than the surrounding sediment. Our results suggest that caution must be used when interpreting pollen dates if the potential for sediment reworking is present.

scholarly journals Identification, Extraction, and Preparation of Reliable Lime Samples for 14C Dating of Plasters and Mortars with the “Pure Lime Lumps” Technique

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 933-942 ◽  
Author(s):  
Giovanni L A Pesce ◽  
Richard J Ball ◽  
Gianluca Quarta ◽  
Lucio Calcagnile
Keyword(s):  
Case Studies ◽  
Radiocarbon Dating ◽  
Historic Sites ◽  
14C Dating ◽  
Relative Simplicity ◽  
Lime Mortars ◽  
The Matrix ◽  
The 1960S ◽  
Selection Of ◽  
Contamination Problem

Radiocarbon dating was first applied to historic lime mortars during the 1960s. However, despite the relative simplicity of the technique in principle, a number of subsequent studies have highlighted important aspects that should be considered. One of the most significant of these challenges arises from sample contamination by carbonaceous substances such as incompletely burnt limestone and aggregates of fossil origin containing “dead” 14C. More recent studies have shown that in the majority of old lime-based mixtures the contamination problem can be avoided through selection of pure lime lumps. These particular types of lumps are believed to originate from areas where the lime is incompletely mixed with the aggregate. It has been demonstrated that even a single lime lump can provide sufficient material for a 14C date of the mortar from which the lump was taken (Pesce et al. 2009). This paper describes the practical challenges associated with location, extraction, and preparation of 4 lime lumps extracted from 2 new sites for 14C dating. These include distinguishing the lime lumps from other lumps present in the matrix and the removal of material surrounding the lime lump. The coherence of 14C dating with other archaeological information on the chronology of historic sites is highlighted through case studies.

scholarly journals Correcting for Contamination in AMS 14C Dating

Radiocarbon ◽  
2002 ◽  
Vol 44 (2) ◽  
pp. 591-595 ◽  
Author(s):  
Ken Mueller ◽  
Paul Muzikar
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Chemical Processing ◽  
14C Dating ◽  
Two Stage ◽  
Carbon Contamination ◽  
Ams 14C Dating

When using accelerator mass spectrometry (AMS) for radiocarbon dating, it is important to correct for carbon contamination that is added to the sample and the standard during chemical processing. We derive an equation for making this correction that generalizes previous work in several ways. We treat the case in which contaminating carbon is added during both the combustion step and graphitization step. Taking this two-stage contamination process into account is particularly important when only a fraction of the CO2 produced in the combustion is graphitized. We also allow for the fact that the 13C fractions of the sample, the standard, and the contaminants may be different.

scholarly journals A Pretreatment Procedure for the AMS Radiocarbon Dating of Sub-Fossil Insect Remains

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 147-154 ◽  
Author(s):  
J A Tripp ◽  
T F G Higham ◽  
R E M Hedges
Keyword(s):  
Mass Spectrometry ◽  
Radiocarbon Dating ◽  
The Other ◽  
Roman Britain ◽  
Ams Radiocarbon Dating ◽  
Maillard Reactions ◽  
Fossil Insect ◽  
Ams Dating ◽  
Acid Wash ◽  
Ams Dates

Two pretreatment methods for accelerator mass spectrometry (AMS) dating of insect remains were explored. One method involves a simple acid wash that removes carbonate, while the other is based on the industrial purification of chitin and results in isolation of polymeric chitosan. No contamination is observed from Maillard reactions during the deacetylation reaction used to isolate the chitosan. The methods were tested on Coleoptera samples from two Roman Britain sites. Our results demonstrate that both methods produce acceptable AMS dates that correspond well to the expected age of the deposits from which they came.

scholarly journals Mortar Dating Using AMS 14C and Sequential Dissolution: Examples from Medieval, Non-Hydraulic Lime Mortars from the Åland Islands, SW Finland

Radiocarbon ◽  
2007 ◽  
Vol 49 (1) ◽  
pp. 47-67 ◽  
Author(s):  
Alf Lindroos ◽  
Jan Heinemeier ◽  
Åsa Ringbom ◽  
Mats Braskén ◽  
Ámy Sveinbjörnsdóttir
Keyword(s):  
Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Pressure Curve ◽  
Direct Relation ◽  
Hydraulic Lime ◽  
Carbonate Formation ◽  
Lime Mortars ◽  
Dating Method ◽  
Total Dissolution

Non-hydraulic mortars contain datable binder carbonate with a direct relation to the time when it was used in a building, but they also contain contaminants that disturb radiocarbon dating attempts. The most relevant contaminants either have a geological provenance and age or they can be related to delayed carbonate formation or devitrification and recrystallization of the mortar. We studied the mortars using cathodoluminescence (CL), mass spectrometry (MS), and accelerator mass spectrometry (AMS) in order to identify, characterize, and date different generations of carbonates. The parameters—dissolution rate, 13C/12C and 18O/16O ratios, and 14C age—were measured or calculated from experiments where the mortars were dissolved in phosphoric acid and each successive CO2 increment was collected, analyzed, and dated. Consequently, mortar dating comprises a CL characterization of the sample and a CO2 evolution pressure curve, a 14C age, and stable isotope profiles from at least 5 successive dissolution increments representing nearly total dissolution. The data is used for modeling the interfering effects of the different carbonates on the binder carbonate age. The models help us to interpret the 14C age profiles and identify CO2 increments that are as uncontaminated as possible. The dating method was implemented on medieval and younger mortars from churches in the Åland Archipelago between Finland and Sweden. The results are used to develop the method for a more general and international use.

scholarly journals AMS 14C Dating of the Cremated Human Bones and Funeral Fuel of the Western Balts. In Theory and in Practice

2019 ◽  
Vol 20 ◽  
pp. 40-74
Author(s):  
Roman Shiroukhov
Keyword(s):  
Static Analysis ◽  
Radiocarbon Dating ◽  
Baltic Region ◽  
14C Dating ◽  
Human Bones ◽  
Dating Method ◽  
Ams 14C Dating

The article is dedicated to the application of AMS 14C dating method of cremated bones and samples of related charcoal, which is rather new for the East Baltic region. The data of 3 Western Balts cemeteries from Lithuania are analysed. Results of radiocarbon dating are compared to the estimated typological chronology of the artefacts. The OxCal simulation is applied in order to obtain the most probable dates. The study lays the foundation for further spatial and static analysis of selected data.

Unexpected Problems in AMS 14C Dating of Fen Peat

Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Minna Väliranta ◽  
Markku Oinonen ◽  
Heikki Seppä ◽  
Sanna Korkonen ◽  
Sari Juutinen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Time Window ◽  
Plant Macrofossils ◽  
Carbon Accumulation ◽  
14C Dating ◽  
Plant Macrofossil ◽  
Peat Core ◽  
Ams Dating ◽  
Ams 14C Dating

Four fen peat sequences in northern Finland were dated by the accelerator mass spectrometry (AMS) radiocarbon method in order to study past peatland dynamics and carbon accumulation patterns. Initially, plant macrofossils were used for dating. However, the dates were severely disordered, with marked inversions in all sequences. In one 140-cm peat core, for example, all ages fell within a ∼1000-yr time window. Following these unreliable results, a few bulk peat samples were dated to help assess if any of the plant macrofossil-derived dates were reliable. Bulk dates did not help to solve the problem. This study evaluates the possible sources of error but is unable to single out one clear cause. It is probable that many factors related to the fen environment, such as flooding and root intrusion, may have contributed to the errors. Peat plant macrofossils and bulk peat samples are considered to be reliable dating materials, but the examples given herein highlight the difficulties that can be associated with AMS dating of peat samples.

scholarly journals 14C Mortar Dating: The Case of the Medieval Shayzar Citadel, Syria

Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 514-525 ◽  
Author(s):  
Sara Nonni ◽  
Fabio Marzaioli ◽  
Michele Secco ◽  
Isabella Passariello ◽  
Manuela Capano ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Good Accuracy ◽  
Time Constraints ◽  
X Ray ◽  
Ams Radiocarbon Dating ◽  
Lime Mortars ◽  
Biasing Effects ◽  
Centrifugation Protocol

This paper reports the results from applying the Cryo2SoniC (Cryobreaking, Sonication, Centrifugation) protocol to some lime mortars sampled from the citadel of Shayzar (Syria). The overall aims of this project are 1) to use the properties offered by high-precision accelerator mass spectrometry (AMS) radiocarbon dating for the evaluation of absolute chronology with its typical robust time constraints (i.e. 25 14C yr), and 2) to apply the dating directly to the citadel structures in order to prevent possible biasing effects potentially affecting indirect 14C dating on organic materials found at the study site. The analyses presented in this paper have been mainly performed as a preliminary check of the Cryo2SoniC methodology in order to assess its applicability to this study site by comparing observed mortar results with archaeological expectations about the citadel development phasing and charcoals found encased in mortars. Petrographic and mineralogical thin-section analyses by optical microscopy (TSOM), X-ray powder diffraction (XRD), and scanning electron microscopy plus energy dispersive spectroscopy (SEM/EDS) investigations were carried out for characterization of the mortar samples to verify the occurrence of some features, related to their production technology, which may introduce dating offsets. The resulting 14C calibrated ages were in agreement with the archaeological expectations based on type and stratigraphic site reconstructions, in situ inscriptions, and written sources. Such results showed also a general (with 1 exception) statistical agreement among the charcoals and the analyzed mortars simultaneously, confirming the archaeological expectations for the Shayzar citadel. Results presented in this paper indicate good accuracy for the applied procedure for chronology reconstruction and highlight the capability of Cryo2SoniC to further characterize the Shayzar site.

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