scholarly journals 14C Dating of Carbonate Mortars from Polish and Israeli Sites

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 857-866 ◽  
Author(s):  
Danuta Nawrocka ◽  
Justyna Czernik ◽  
Tomasz Goslar
Keyword(s):  
Radiocarbon Dating ◽  
Size Fraction ◽  
Acid Leaching ◽  
Building Construction ◽  
14C Dating ◽  
Preliminary Processing ◽  
Small Scales ◽  
Quartz Aggregates ◽  
Leaching Reaction ◽  
Good Agreement

The presented research involves the analysis and radiocarbon dating of 2 different groups of carbonate mortars, from Kraków, Poland and Hippos, Israel. Differences in composition of the mortars are reflected in different rates of their acid leaching. The Israeli mortars contain carbonate-basaltic aggregates, which may cause overestimation of 14C age. Preliminary processing of these samples (choice of selected grain-size fraction and collection of CO2 released during the first phase of the acid-leaching reaction), enabled us to obtain good agreement between the 14C dates and the age derived from historical contexts. A similar method of preliminary processing was applied to the carbonate mortars of the Medieval building in Kraków. The Polish samples represent carbonate mortars with some admixture of quartz aggregates, suggesting that they would be an ideal material for 14C dating. However, these samples contained white lumps of carbonates, the structure of which differed from that of the binder. These admixtures, possibly related to the hydrological conditions at the site and to the character of the ingredients, appeared modern, and if not removed prior to acid leaching, they could cause underestimation of the age of samples. The 14C dates of the mortars from the walls of the Small Scales building in Kraków are the first obtained for this object, and their sequence does not contradict archaeological indications on several phases of the building construction.

scholarly journals Foraminiferous Limestone in 14C Dating of Mortar

Radiocarbon ◽  
2009 ◽  
Vol 51 (3) ◽  
pp. 987-993 ◽  
Author(s):  
Tomasz Goslar ◽  
Danuta Nawrocka ◽  
Justyna Czernik
Keyword(s):  
Grain Size ◽  
Reaction Rate ◽  
Preparation Method ◽  
Acid Leaching ◽  
Historical Sources ◽  
14C Dating ◽  
Time Intervals ◽  
Size Fractions ◽  
Leaching Reaction ◽  
Grain Size Fractions

Mortar as a mixture of binder and aggregate can be reliably dated with radiocarbon if the applied preparation method allows one to eliminate unburnt carbonate fragments, bearing 14C-depleted carbon and causing overestimation of 14C age. To avoid these problems, separation of specific grain-size fractions of mortar and 14C analysis of the CO2 portions collected in different time intervals of the acid-leaching reaction is usually helpful. In the present paper, we demonstrate that the rate of the leaching reaction of mortars with dense carbonate aggregate differs from that of mortars with crumbled limestone and scattered shells (e.g. of foraminifera). Verification of the obtained 14C dates against historical sources shows that for mortars rich in foraminiferous limestone, a reaction rate-based chemical elimination of “dead carbon” may appear impossible.

scholarly journals Investigation of a cold-based ice apron on a high-mountain permafrost rock wall using ice texture analysis and micro-14C dating: a case study of the Triangle du Tacul ice apron (Mont Blanc massif, France)

2021 ◽  
pp. 1-8
Author(s):  
Grégoire Guillet ◽  
Susanne Preunkert ◽  
Ludovic Ravanel ◽  
Maurine Montagnat ◽  
Ronny Friedrich
Keyword(s):  
Radiocarbon Dating ◽  
Boundary Migration ◽  
Ice Core ◽  
Ice Cores ◽  
Shear Plane ◽  
High Mountain ◽  
14C Dating ◽  
Rock Wall ◽  
Major Mechanism ◽  
Mont Blanc Massif

Abstract The current paper studies the dynamics and age of the Triangle du Tacul (TDT) ice apron, a massive ice volume lying on a steep high-mountain rock wall in the French side of the Mont-Blanc massif at an altitude close to 3640 m a.s.l. Three 60 cm long ice cores were drilled to bedrock (i.e. the rock wall) in 2018 and 2019 at the TDT ice apron. Texture (microstructure and lattice-preferred orientation, LPO) analyses were performed on one core. The two remaining cores were used for radiocarbon dating of the particulate organic carbon fraction (three samples in total). Microstructure and LPO do not substantially vary with along the axis of the ice core. Throughout the core, irregularly shaped grains, associated with strain-induced grain boundary migration and strong single maximum LPO, were observed. Measurements indicate that at the TDT ice deforms under a low strain-rate simple shear regime, with a shear plane parallel to the surface slope of the ice apron. Dynamic recrystallization stands out as the major mechanism for grain growth. Micro-radiocarbon dating indicates that the TDT ice becomes older with depth perpendicular to the ice surface. We observed ice ages older than 600 year BP and at the base of the lowest 30 cm older than 3000 years.

scholarly journals Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

2016 ◽  
Vol 13 (5) ◽  
pp. 1537-1552 ◽  
Author(s):  
Marta Petrillo ◽  
Paolo Cherubini ◽  
Giulia Fravolini ◽  
Marco Marchetti ◽  
Judith Ascher-Jenull ◽  
...  
Keyword(s):  
Picea Abies ◽  
Decay Rate ◽  
Norway Spruce ◽  
Matrix Model ◽  
Rate Constants ◽  
Radiocarbon Dating ◽  
Time Lag ◽  
Larix Decidua ◽  
European Larch ◽  
14C Dating

Abstract. Due to the large size (e.g. sections of tree trunks) and highly heterogeneous spatial distribution of deadwood, the timescales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the chronosequence approach and the five-decay class system that is based on a macromorphological assessment. For the decay classes 1–3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) radiocarbon dating was used. In addition, density, cellulose, and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model, a regression approach, and the stage-based matrix model. In the decay classes 1–3, the ages of the CWD were similar and varied between 1 and 54 years for spruce and 3 and 40 years for larch, with no significant differences between the classes; classes 1–3 are therefore not indicative of deadwood age. This seems to be due to a time lag between the death of a standing tree and its contact with the soil. We found distinct tree-species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were estimated to be in the range 0.018 to 0.022 y−1 for spruce and to about 0.012 y−1 for larch. Snapshot sampling (chronosequences) may overestimate the age and mean residence time of CWD. No sampling bias was, however, detectable using the stage-based matrix model. Cellulose and lignin time trends could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 years for spruce and 50 years for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD. Consequently, the decay of Picea abies and Larix decidua is very low. Several uncertainties, however, remain: 14C dating of CWD from decay classes 4 and 5 and having a pre-bomb age is often difficult (large age range due to methodological constraints) and fall rates of both European larch and Norway spruce are missing.

scholarly journals Historic Lime-Mortar 14C Dating of Santa María La Real (Zarautz, Northern Spain): Extraction of Suitable Grain Size for Reliable 14C Dating

Radiocarbon ◽  
2012 ◽  
Vol 54 (01) ◽  
pp. 23-36
Author(s):  
Luis Angel Ortega ◽  
Maria Cruz Zuluaga ◽  
Ainhoa Alonso-Olazabal ◽  
Xabier Murelaga ◽  
Maite Insausti ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Fraction ◽  
Northern Spain ◽  
14C Dating ◽  
Lime Mortar ◽  
Parish Church ◽  
Slaked Lime ◽  
Lime Mortars ◽  
Santa Maria ◽  
Detrital Carbonate

This paper describes a method for effective separation of the pure binder fraction of lime mortars for reliable radiocarbon dating. The methodology allows removal of the detrital carbonate fraction and the unburnt limestone particles, obtaining particles of under 1 μm. The extracted fraction ensured that all carbonate has been generated by slaked lime carbonation. Consequently, the measured carbon corresponds to atmospheric carbon. The proposed method allows to obtain pure datable binder, simplifying considerably the performance of radiometric measurements because dating other grain-size fraction is unnecessary. In order to prove the effectiveness of binder refining, the extraction method has been applied to 5 lime mortars of different archaeological periods from the perimeter walls of Santa María la Real parish church (Zarautz, northern Spain).

14C Dating of Historical Buildings in Japan

Radiocarbon ◽  
2014 ◽  
Vol 56 (02) ◽  
pp. 691-697 ◽  
Author(s):  
Nanae Nakao ◽  
Minoru Sakamoto ◽  
Mineo Imamura
Keyword(s):  
Research Method ◽  
Radiocarbon Dating ◽  
Historical Buildings ◽  
14C Dating ◽  
History Of ◽  
Dating Method ◽  
Japanese Architecture

The radiocarbon dating method was applied to the study of Japanese traditional wooden buildings. The traditional Japanese architecture studied includes the Main Hall of Banna-ji Temple (Buddhist building), Sekisui-in of Kozan-ji Temple (noble house), Hakogi-ke house (farmhouse), and Kawai-ke house (townhouse).14C dating proved useful as a research method to better understand the history of these buildings and Japanese architecture as a whole.

scholarly journals 14C Dating Compared to Art Historical Dating of Roman and Coptic Textiles from Egypt

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 231-244 ◽  
Author(s):  
Mark Van Strydonck ◽  
Antoine De Moor ◽  
Dominique Bénazeth
Keyword(s):  
Radiocarbon Dating ◽  
Interquartile Range ◽  
14C Dating ◽  
Art Historians ◽  
Representative Selection ◽  
The Individual ◽  
Selection Of ◽  
Individual Objects

A representative selection of Roman and Coptic textiles is used to compare the radiocarbon dating results with the chronology proposed by art historians. In some cases, the comparison was made on individual objects, but in other cases, groups of stylistically and/or technologically related textiles were compared. In the case of the latter, the interquartile range was calculated. The results of this comparison show that some individual samples and groups are dated older than expected, while for another group the opposite is the case. One group was matching well with the presumed period as a whole, but not on the basis of the individual pieces. The analyses showed the necessity of 14C dating to obtain a more accurate dating of Coptic textiles.

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 Data Analysis and Calibration of Radiocarbon Dating Results from the Cemetery of the Marquises of Jin

Radiocarbon ◽  
2001 ◽  
Vol 43 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Xiangyang Lu ◽  
Zhiyu Guo ◽  
Hongji Ma ◽  
Sixun Yuan ◽  
Xiaohong Wu
Keyword(s):  
Data Analysis ◽  
High Precision ◽  
Radiocarbon Dating ◽  
Careful Analysis ◽  
Historical Record ◽  
Calibration Result ◽  
Special Part ◽  
Peking University ◽  
Very High ◽  
Good Agreement

The chronology study of the cemetery of Marquises of Jin is valuable to improving the chronological table of Marquis of Jin family. It is also helpful for improving the chronological table of the Zhou Dynasty. The samples were measured at Peking University (PKUAMS). We also made an interlaboratory check with Isotrace to ensure the accuracy. By careful analysis of archaeological information, we built different models and calibrated by OxCal. The calibration results, both sampling contexts and estimations, are in very good agreement with the historical record. Because the dates of some events correspond to the special part of the curve, the calibration gets very high precision. The calibration result of tomb M93 suggests that its host is Marquis Shangshu instead of Marquis Wen.

X-ray diffraction line profile analysis of acid-resistant goethite in Western Australian nickel laterite ore

2015 ◽  
Vol 48 (3) ◽  
pp. 814-826
Author(s):  
Xiaodong Wang ◽  
Jian Li ◽  
Robbie G. McDonald ◽  
Arie van Riessen ◽  
Robert D. Hart
Keyword(s):  
Size Distribution ◽  
Size Fraction ◽  
Acid Leaching ◽  
Domain Size ◽  
Line Profile Analysis ◽  
Nickel Laterite ◽  
X Ray ◽  
Peak Broadening ◽  
Nickel Laterite Ore ◽  
Laterite Ore

The goethite peaks in synchrotron and laboratory X-ray powder diffraction (XRPD) patterns of an acid-resistant nickel laterite ore sample from a site in Western Australia exhibit a `super-Lorentzian' shape. The method for extracting the coherently scattering domain size distribution published by Leoni & Scardi [J. Appl. Cryst.(2004),37, 629–634] is adapted to fit the asymmetric goethite peak profiles, allowing the refinement of lattice parameters for multiple goethite structural models while maintaining their relationships. The anisotropic peak broadening due to the acicular shape of the goethite crystals is addressed using spherical harmonics predefined from an XRPD pattern of a synthetic goethite sample. A bimodal coherently scattering domain size distribution of goethite crystals is predicted from the goethite profile fitting and agrees with previous transmission electron microscopy findings that two goethite populations with different domain sizes and metal substitutions exist in the ore sample. The small goethite size fraction dissolved slowly during atmospheric acid leaching, while the large goethite fraction barely dissolved. Caustic pre-treatment by KOH digestion significantly enhanced the acid-leaching performance of the small goethite fraction, but had no effect on the large goethite fraction. This study demonstrates that quantitative phase analysis on designated goethite size fractions can successfully fit the super-Lorentzian shaped line profiles of natural goethite crystals with a confirmed bimodal domain size distribution.

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