1. bookVolume 47 (2020): Issue 1 (January 2020)
Journal Details
License
Format
Journal
eISSN
1897-1695
First Published
04 Jul 2007
Publication timeframe
1 time per year
Languages
English
access type Open Access

14C Dating of mortar from ruins of an early medieval church Hohenrätien GR, Switzerland

Published Online: 31 Dec 2020
Volume & Issue: Volume 47 (2020) - Issue 1 (January 2020)
Page range: 118 - 123
Received: 16 Dec 2019
Accepted: 29 May 2020
Journal Details
License
Format
Journal
eISSN
1897-1695
First Published
04 Jul 2007
Publication timeframe
1 time per year
Languages
English
Abstract

Numerous ruins around the world lack the radiometric dating due to the scarcity of organic carbon. Here, we present results of radiocarbon dating of mortar samples from an early Medieval church Hohenrätien GR, Switzerland, which was dated to the early 6th century, based on typology. The method of dating mortars, which is currently applied at the ETH laboratory, involves sieving the crushed mortar, selection of grain size 45−63 μm and sequential dissolution resulting in four fractions of CO2 collected in a 3-second interval each. Two mortar samples, which were analyzed using sequential dissolution and one by dating a bulk of lime lump, resulted in a combined radiocarbon age of 1551±21 BP translating to the calendar age of 427−559 AD.

Keywords

Introduction

A considerable share of tangible cultural heritage consists of ruins and buildings. Some of them are monumental and of historical interest, some of them of local interest or remaining to be discovered. Often such objects lack a chronologic frame, and the method that would provide a time for buildings is not a straightforward radiometric dating. For millennia mortar was the prevailing one among other materials used in constructions until the early 1st half of the 20th century. Following the industrial revolution and expansion of new technologies, the traditional mortar has been replaced by cement. This industrial product, although developed using experience gained over millennia, is rather useless for radiocarbon dating as it contains old carbon additions, resulting in ages as high as tens of thousands of years.

Mortars, except for hydraulic, pozzolana and cocciopesto (Ringbom et al., 2011), can be more suitable for radiocarbon dating. The mechanism of binding CO2 from the atmosphere shown by the slacked carbonate oxide (carbonate hydroxide) is a perfect analog to the photosynthetic path of building carbon into organic matter. Early on, radiocarbon researchers tried to apply this method to dating archeological and historical monuments. The first results were encouraging (Labeyrie and Delibrias, 1964) but followed by less successful attempts (Stuiver et al., 1965). The main challenge in the preparation of mortars is the separation of old carbon, which might be included in the binder due to incomplete burning. Contamination can also be added together with aggregates such as sand and gravel. Although other complications of 14C signal in mortars can occur, such as delayed hardening, fire damage, or formation of new carbonates, the old carbon is the prevailing problem. Therefore, the first attempt is to achieve the most reliable 14C ages focused on the removal of geological carbonate. The observed difference between the reactivity of the binder, which dissolves faster, and the limestone has been used to separate the contaminant.

A ‘revolution’ has only been brought about by the application of the AMS method (Nelson et al., 1977).

The minimal quantities of carbon needed for the AMS 14C analyses open an opportunity for measurements of multiple dissolution fractions. Developed independently by two teams (Heinemeier et al., 1997), the method has been modified and adopted by few laboratories. Also, a little different approach has been proposed by Nawrocka et al. (2005) and Marzaioli et al. (2011). As well, this method underwent various modifications and, at some stage, has been combined with sequential dissolution (Michalska and Czernik, 2015).

The reliability of the radiocarbon ages of mortar has been debated ever since the first disappointing results of Stuiver et al. (1965) have been published. A considerable effort has been made by the mortar 14C dating community to establish the procedure and protocols as well as quality control (Ringbom et al., 2014). The results of MODIS inter-comparison exercise (Hajdas et al., 2017 and Hayen et al., 2017) have shown that some of the mortars cannot be dated by 14C method and that the understanding of mortar geochemical characteristics is a key to understating these problematic results (Michalska et al., 2017). Here, we present results of radiocarbon dating of a monument, which has been dated only by typology.

Site and material

The site of Hohenrätien (GR) is located on a rock rising 250 m above the Viamala Valley (Fig. 1a) overseeing the roads of the San Bernardino and the Splügen Pass, which connect the Swiss Valley of Hinterreihn with the Italian Valle San Giacomo and Chiavenna (Fig. 1b).

Fig 1a

Map of Switzerland and the location of the castle of Hohenrätien (GR) − Sils im Domleschg.

Fig 1b

The castle of Hohenrätien (GR) − Sils im Domleschg.

The transit from Northern Italy to the Rhine Valleys appreciated since the Bronze and the Iron Age, was also used by the Romans. In the medieval ages, the strategic location was chosen for the construction of the castle, which in years 1996−1997 was a subject of archeological prospections and investigations. Moreover, in 1999, the owner of the castle discovered additional remains of older construction. The archeological excavations 2001−2004 documented an early Christian church (Gairhos and Janosa, 2011). The latter phases of constructions of the whole monument could be dated by dendrochronology, and a wiggle-matching of 14C dated tree rings to 1180−1210 AD (Gairhos et al., 2005). However, the earlier phases could only be dated by typology; therefore, the radiocarbon dating of mortar is one possibility to provide a numeric date on the monument.

The location of the three mortar samples collected from the remains of construction A (Bau A) is shown in Fig. 2.

Fig 2

Location of the mortar samples analyzed in this study (Figure modified from (Gairhos and Janosa 2011)).

Methods

Preparation of mortar for radiocarbon dating followed the protocol developed so far at ETH Laboratory (Hajdas et al., 2017 and Hajdas et al., 2020). The principle of the method is a separation of suitable grain size and discrimination between anthropogenic and geogenic carbonate by a different dissolution time. Two samples (Nos. 891 and 894) were prepared using the method of sequential dissolution, which targets the fast-dissolving component of the binder. In the case of sample No. 891, two different grain size fractions: 45−63 μm and 32−63 μm were analyzed

The sample No.891 has been prepared using an old protocol, and as modifications has been implemented, new standard fraction 45−63 μm was re-done. Sample No. 894 was submitted later and prepared using the new standard procedure only.

; in the case of sample No. 894, only fraction of 45−63 μm was used. For sequential dissolution, sub-samples containing ca. 50 mg of powder were placed in one of the chambers of the special dual-chamber-glass vessel. The second chamber was filled with 10 ml of concentrated phosphoric acid (85% H3PO4). The vessel was then closed and evacuated at room temperature before pouring of acid to the chamber, which contained mortar. This process was timed, and freezing of purified (passing through a water trap) CO2 in LN was performed in sequence: four consecutive fractions were collected after each 3-second interval. The carbon content of each collected fraction was measured, and 10−100 μg of C was trapped in a 4-mm tube to be flame-sealed for analysis using Gas Ion Source (GIS) AMS facility at ETHZ (Ruff et al., 2010). The third sample of mortar (No. 897) contained visible lime lump (LL), which was used without sieving (the bulk of LL). This sample was sufficiently large; therefore, it was dissolved and graphitized to be measured using the MICADAS at ETH Zurich (Synal et al., 2007). Solid- and gas-formed samples were analyzed together with the corresponding size of standard (Oxa2) and background samples (C-1, IAEA).

Results and discussion

The outcome of the radiocarbon dating performed on samples from the Hohenrätien old parish church is summarized in Table 1. With the exception of one sample, radiocarbon ages of the fast fractions (1st and 2nd, i.e. 1−3 s and 4−6 s) show close 14C ages (at 2-sigma error level) for all three preparations. Slow fractions (3rd and 4th, i.e. >7 s dissolution time) are older, which shows the presence of the old (geological) component. The ages obtained on samples <100 μg using GIS have higher uncertainly than the one measurement on the lime lump, which was graphitized. The lime lump shows age, which is in agreement with the ages of the 1st fast fraction. However, due to the high uncertainty of the GIS measurements, the ages of the sequential dissolution cannot help to evaluate if the 14C age of lime lump is older than the selected 1st fraction. The three ages of the 1st fraction from the three independent preparation can be combined to 1495±41 BP (X2-Test: df=2 T=5.3 (5% 6.0)) and all the 1st fraction ages can also be combined with the age of the lime lump. The resulting age is 1551±21 BP (X2-Test: df=3 T=7.7 (5% 7.8)). Calendar ages of mortar samples were obtained for radiocarbon ages, which are considered accurate (Table 1). OxCal v4.3.2 online calibration software was used (Ramsey, 2017) with the INTCAL13 calibration data set (Reimer et al., 2013).

Results of the 14C AMS analysis of mortar samples. All the samples but lime lump (LL) were analyzed using GIS. Combined and calibrated ages were obtained using OxCal v4.3.2 (only for 14C ages evaluated as accurate).

Lab CodeSample/Fraction (μm)Dissolution time (s)14C age ±1 sigma (BP)Calibrated age (95.4% conf. level) (AD)μg C
ETH-65530891, 45−631−31534±84348−656 AD95
ETH-65530891, 45−634−61688±88NA109
ETH-65530891, 45−637−92108±102NA108
ETH-65530891, 45−6310−122621±101NA104
ETH-65530891, 32−451−31605±74257−606 AD60
ETH-65530891, 32−454−61737±83NA105
ETH-65530891, 32−457−92144±103NA88
ETH-65530891, 32−4510−122461±105NA96
ETH-69913894, 45−631−31386±64543−770 AD81
ETH-69913894, 45−634−61581±63NA99
ETH-69913894, 45−637−91664±77NA91
ETH-69913894, 45−6310−122254±76NA82
ETH-85506897, LL (lime lumps)Total dissolution1569±24422−547 AD1200

graphite

Combined891 & 894all 1−3 s1495±41430−646 ADX2-Test: df=2 T=5.3 (5% 6.0)
Combined891 & 894 & 897all 1−3 s & LL1551±21427−559 ADX2-Test: df=3 T=7.7 (5% 7.8)

Figure 3 shows all the results of the radiocarbon dating of all the samples and their evaluation. Following the procedure outlined in Hajdas et al., (2020), the radiocarbon ages of the fast-dissolving fractions: 1st: 1−3 s and 2nd: 4−6 s, have the potential of providing the accurate 14C signal for the time of binding the mortar. The slight increase in the ages of the 3rd and 4th fractions indicates the presence of the old, geological component. To establish a laboratory procedure for calculating the following is applied: only the 1st, i.e. the fastest fraction, is considered if the following fractions are not coherent. In an ideal case, if the following 2nd fractions of all three samples were in close agreement with the 1st fraction, a weighted mean can be calculated. Here, however, such combination failed the X2-Test; therefore, only 1st fractions were combined. In addition to the radiocarbon ages of the separated fast fractions of samples Nos. 891 and 894, a sample of lime lump from No. 897 was also analyzed as a whole, which showed a radiocarbon age that is in agreement with the 1st fractions of the three preparations. The calibration curve for the early medieval times 400−800 AD has a complicated nature. Moreover, the uncertainty of 14C ages obtained using GIS is higher. As a result, the calibrated ranges of the three samples were wide (Table 1, Figs. 4 and 5). The youngest of the radiocarbon ages dates the mortar to the period between 543 and 770 AD (Fig. 4). The combined calibrated age (weighted mean) of the mortar sample from the Hohenrätien church dates the mortar to 427−559 AD (Fig. 5). The typological dating of this monument points to the 5th/6th century AD (Gairhos and Janosa 2011), indicating a broad agreement of the obtained 14C chronology of mortar.

Fig 3

Radiocarbon ages of the three samples obtained after sequential dissolution in 3-second intervals. The first fraction was the collection of CO2 after the first 3 seconds and the consecutive fractions were collected in 3-second intervals (x-axis shows dissolution fractions: 1=1st fraction 1−3 s; 2= 2nd fraction 4−6 s; 3= 3rd fraction 7−9 s; 4=4th fraction 10−12 s). The red square marks the age of the lime lump.

Fig 4

Calibrated radiocarbon ages of the fast fraction (1st) and the lime lump (LL).

Fig 5

Combined (weighted mean) radiocarbon age of 1st fraction and the lime lump, calibrated using OxCal 4.3.2 and INTCAL13 data set.

Conclusions

Radiocarbon dating of the mortar provides the potential to date archeological and historic buildings. The early church at the Hohenrätien is an excellent example of the potential for the numeric dating method to be applied to mortar. The resulting radiocarbon ages of the three samples date the monument to the period between 257 and 770 AD. The wide range of calendar ages is due to the nature of the calibration curve and the age plateau between 420 and 530 AD. Nevertheless, the combined age of the fast component of the mortar and a single lime lump results in an age of 427−559 AD, confirming the typological dating. In summary, this study adds information about the reliability in using the 1st, i.e. the fastest dissolution fraction. Given the complexity of mortars, building a collection of well-dated sites with consistent mortar ages based on 1st fraction should be the goal of mortar dating projects.

Fig 1a

Map of Switzerland and the location of the castle of Hohenrätien (GR) − Sils im Domleschg.
Map of Switzerland and the location of the castle of Hohenrätien (GR) − Sils im Domleschg.

Fig 1b

The castle of Hohenrätien (GR) − Sils im Domleschg.
The castle of Hohenrätien (GR) − Sils im Domleschg.

Fig 2

Location of the mortar samples analyzed in this study (Figure modified from (Gairhos and Janosa 2011)).
Location of the mortar samples analyzed in this study (Figure modified from (Gairhos and Janosa 2011)).

Fig 3

Radiocarbon ages of the three samples obtained after sequential dissolution in 3-second intervals. The first fraction was the collection of CO2 after the first 3 seconds and the consecutive fractions were collected in 3-second intervals (x-axis shows dissolution fractions: 1=1st fraction 1−3 s; 2= 2nd fraction 4−6 s; 3= 3rd fraction 7−9 s; 4=4th fraction 10−12 s). The red square marks the age of the lime lump.
Radiocarbon ages of the three samples obtained after sequential dissolution in 3-second intervals. The first fraction was the collection of CO2 after the first 3 seconds and the consecutive fractions were collected in 3-second intervals (x-axis shows dissolution fractions: 1=1st fraction 1−3 s; 2= 2nd fraction 4−6 s; 3= 3rd fraction 7−9 s; 4=4th fraction 10−12 s). The red square marks the age of the lime lump.

Fig 4

Calibrated radiocarbon ages of the fast fraction (1st) and the lime lump (LL).
Calibrated radiocarbon ages of the fast fraction (1st) and the lime lump (LL).

Fig 5

Combined (weighted mean) radiocarbon age of 1st fraction and the lime lump, calibrated using OxCal 4.3.2 and INTCAL13 data set.
Combined (weighted mean) radiocarbon age of 1st fraction and the lime lump, calibrated using OxCal 4.3.2 and INTCAL13 data set.

Results of the 14C AMS analysis of mortar samples. All the samples but lime lump (LL) were analyzed using GIS. Combined and calibrated ages were obtained using OxCal v4.3.2 (only for 14C ages evaluated as accurate).

Lab CodeSample/Fraction (μm)Dissolution time (s)14C age ±1 sigma (BP)Calibrated age (95.4% conf. level) (AD)μg C
ETH-65530891, 45−631−31534±84348−656 AD95
ETH-65530891, 45−634−61688±88NA109
ETH-65530891, 45−637−92108±102NA108
ETH-65530891, 45−6310−122621±101NA104
ETH-65530891, 32−451−31605±74257−606 AD60
ETH-65530891, 32−454−61737±83NA105
ETH-65530891, 32−457−92144±103NA88
ETH-65530891, 32−4510−122461±105NA96
ETH-69913894, 45−631−31386±64543−770 AD81
ETH-69913894, 45−634−61581±63NA99
ETH-69913894, 45−637−91664±77NA91
ETH-69913894, 45−6310−122254±76NA82
ETH-85506897, LL (lime lumps)Total dissolution1569±24422−547 AD1200

graphite

Combined891 & 894all 1−3 s1495±41430−646 ADX2-Test: df=2 T=5.3 (5% 6.0)
Combined891 & 894 & 897all 1−3 s & LL1551±21427−559 ADX2-Test: df=3 T=7.7 (5% 7.8)

Gairhos S, and Janosa M, 2011. Eine spätantike Kirchenanlage mit Baptisterium auf Hohenrätien bei Sils im Domleschg/Graubünden. Jahresbericht des Archäologischen Dienstes Graubünden 63-100.GairhosSandJanosaM2011Eine spätantike Kirchenanlage mit Baptisterium auf Hohenrätien bei Sils im Domleschg/GraubündenJahresbericht des Archäologischen Dienstes Graubünden63-100Search in Google Scholar

Gairhos S, Janosa M, and Seifert M, 2005. Neue Erkenntnisse zur Burganlage Hohenrätien, Sils i. D. Jahresbericht des Archäologischen Dienstes Graubünden 64-74.GairhosSJanosaMandSeifertM2005Neue Erkenntnisse zur Burganlage Hohenrätien, Sils iD. Jahresbericht des Archäologischen Dienstes Graubünden64-74Search in Google Scholar

Hajdas I, Lindroos A, Heinemeier J, Ringbom A, Marzaioli F, Terrasi F, Passariello I, Capano M, Artioli G, Addis A, Secco M, Michalska D, Czernik J, Goslar T, Hayen R, Van Strydonck M, Fontaine L, Boudin M, Maspero F, Panzeri L, Galli A, Urbanova P, and Guibert P, 2017. Preparation and Dating of Mortar Samples-Mortar Dating Inter-Comparison Study (Modis). Radiocarbon 59: 1845-1858, DOI:10.1017/RDC.2017.112.HajdasILindroosAHeinemeierJRingbomAMarzaioliFTerrasiFPassarielloICapanoMArtioliGAddisASeccoMMichalskaDCzernikJGoslarTHayenRVanStrydonck MFontaineLBoudinMMasperoFPanzeriLGalliAUrbanovaPandGuibertP2017Preparation and Dating of Mortar Samples-Mortar Dating Inter-Comparison Study (Modis)Radiocarbon591845185810.1017/RDC.2017.112Open DOISearch in Google Scholar

Hajdas I, Maurer M, and Röttig MB, submitted. Development of 14C dating of mortars at ETH Zurich. Radiocarbon 62: 591-600, DOI:10.1017/RDC.2020.40.HajdasIMaurerMandRöttigMBsubmitted. Development of 14C dating of mortars at ETH ZurichRadiocarbon6259160010.1017/RDC.2020.40Open DOISearch in Google Scholar

Hayen R, Van Strydonck M, Fontaine L, Boudin M, Lindroos A, Heinemeier J, Ringbom A, Michalska D, Hajdas I, Hueglin S, Marzaioli F, Terrasi F, Passariello I, Capano M, Maspero F, Panzeri L, Galli A, Artioli G, Addis A, Secco M, Boaretto E, Moreau C, Guibert P, Urbanova P, Czernik J, Goslar T, and Caroselli M, 2017. Mortar Dating Methodology: Assessing Recurrent Issues and Needs for Further Research. Radiocarbon 59: 1859-1871, DOI:10.1017/RDC.2017.129.HayenRVanStrydonck MFontaineLBoudinMLindroosAHeinemeierJRingbomAMichalskaDHajdasIHueglinSMarzaioliFTerrasiFPassarielloICapanoMMasperoFPanzeriLGalliAArtioliGAddisASeccoMBoarettoEMoreauCGuibertPUrbanovaPCzernikJGoslarTandCaroselliM2017Mortar Dating Methodology: Assessing Recurrent Issues and Needs for Further ResearchRadiocarbon591859187110.1017/RDC.2017.129Open DOISearch in Google Scholar

Heinemeier J, Jungner H, Lindroos A, Ringbom A, von Konow T, Rud N, and Sveinbjornsdottir A, 1997. AMS C-14 dating of lime mortar. In: Edgren T, ed. Proceedings of the VII Nordic Conference on the Application of Scientific Methods in Archaeology. Iskos: 214-215.HeinemeierJJungnerHLindroosARingbomAvon KonowTRudNandSveinbjornsdottirA1997AMS C-14 dating of lime mortar. In: Edgren T, ed. Proceedings of the VII Nordic Conference on the Application of Scientific Methods in ArchaeologyIskos21421510.1016/S0168-583X(96)00705-7Search in Google Scholar

Labeyrie J, and Delibrias G, 1964. Dating of old mortars by the carbon-14 method. Nature 201, DOI: 10.1038/201742b0.LabeyrieJandDelibriasG1964Dating of old mortars by the carbon-14 methodNature20110.1038/201742b0Open DOISearch in Google Scholar

Marzaioli F, Lubritto C, Nonni S, Passariello I, Capano M, and Terrasi F, 2011. Mortar Radiocarbon Dating: Preliminary Accuracy Evaluation of a Novel Methodology. Analytical Chemistry 83: 2038-2045, DOI: 10.1021/ac1027462.MarzaioliFLubrittoCNonniSPassarielloICapanoMandTerrasiF2011Mortar Radiocarbon Dating: Preliminary Accuracy Evaluation of a Novel MethodologyAnalytical Chemistry832038204510.1021/ac102746221338118Open DOISearch in Google Scholar

Michalska D, and Czernik J, 2015. Carbonates in leaching reactions in context of 14C dating. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 361: 431-439, DOI: 10.1016/j.nimb.2015.08.033.MichalskaDandCzernikJ2015Carbonates in leaching reactions in context of 14C datingNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms36143143910.1016/j.nimb.2015.08.033Open DOISearch in Google Scholar

Michalska D, Czernik J, and Goslar T, 2017. Methodological aspect of mortars dating (Poznań, Poland, MODIS). Radiocarbon 59: 1891-1906, DOI: 10.1017/RDC.2017.12.MichalskaDCzernikJandGoslarT2017Methodological aspect of mortars dating (Poznań, Poland, MODIS)Radiocarbon591891190610.1017/RDC.2017.12Open DOISearch in Google Scholar

Nawrocka D, Michniewicz J, Pawlyta J, and Pazdur A, 2005. Application of radiocarbon method for dating of lime mortars. Geochronometria 24: 109-115.NawrockaDMichniewiczJPawlytaJandPazdurA2005Application of radiocarbon method for dating of lime mortarsGeochronometria24109115Search in Google Scholar

Nelson DE, Korteling RG, and Stott WR, 1977. Carbon-14: direct detection at natural concentrations. Science 198: 507-508, DOI: 10.1126/science.198.4316.507.NelsonDEKortelingRGandStottWR1977Carbon-14: direct detection at natural concentrationsScience19850750810.1126/science.198.4316.50717842138Open DOISearch in Google Scholar

Ramsey C. 2017. OxCal 4.2. 4. Electronic document.RamseyC.2017OxCal 4.24. Electronic documentSearch in Google Scholar

Reimer PJ, Bard E, Bayliss A, Beck JW, Blackwell PG, Ramsey CB, Brown DM, Buck CE, Edwards RL, Friedrich M, Grootes PM, Guilderson TP, Haflidason H, Hajdas I, Hatte C, Heaton TJ, Hogg AG, Hughen KA, Kaiser KF, Kromer B, Manning SW, Reimer RW, Richards DA, Scott EM, Southon JR, Turney CSM, and van der Plicht J, 2013. Selection and Treatment of Data for Radiocarbon Calibration: An Update to the International Calibration (Intcal) Criteria. Radiocarbon 55: 1923-1945, DOI: 10.2458/azu_js_ rc.55.16955.ReimerPJBardEBaylissABeckJWBlackwellPGRamseyCBBrownDMBuckCEEdwardsRLFriedrichMGrootesPMGuildersonTPHaflidasonHHajdasIHatteCHeatonTJHoggAGHughenKAKaiserKFKromerBManningSWReimerRWRichardsDAScottEMSouthonJRTurneyCSMandvan derPlicht J2013Selection and Treatment of Data for Radiocarbon Calibration: An Update to the International Calibration (Intcal) CriteriaRadiocarbon551923194510.2458/azu_js_rc.55.16955Open DOISearch in Google Scholar

Ringbom Å, Lindroos A, Heinemeier J, and Brock F, 2011. Mortar Dating and Roman Pozzolana, Results and Interpretations. In: Ringbom, A and Hohlfelder eds., Proceedings from Building Roma Aeterna, conference in Rome March 23-25 2008, Commentationes Humanarum Litterarum Societas Scientiarium Fennica: 187-208.Ringbom Å LindroosAHeinemeierJandBrockF2011Mortar Dating and Roman Pozzolana Results and InterpretationsIningbomRAand Hohlfelder edsProceedings from Building Roma Aeterna, conference in Rome March 23-25 2008, Commentationes Humanarum LitterarumSocietas Scientiarium Fennica187208Search in Google Scholar

Ringbom A, Lindroos A, Heinemeier J, and Sonck-Koota P, 2014. 19 Years of Mortar Dating: Learning from Experience. Radiocarbon 56: 619-635, DOI: 10.2458/56.17469.RingbomALindroosAHeinemeierJandSonck-KootaP201419 Years of Mortar Dating: Learning from ExperienceRadiocarbon5661963510.2458/56.17469Open DOISearch in Google Scholar

Ruff M, Szidat S, Gaggeler HW, Suter M, Synal HA, and Wacker L, 2010. Gaseous radiocarbon measurements of small samples. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms 268: 790-794, DOI: 10.1016/j.nimb.2009.10.032.RuffMSzidatSGaggelerHWSuterMSynalHAandWackerL2010Gaseous radiocarbon measurements of small samplesNuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms26879079410.1016/j.nimb.2009.10.032Open DOISearch in Google Scholar

Stuiver M, Smith C, Chatters R, and Olson E, 1965. Radiocarbon dating of ancient mortar and plaster. In: Proceedings of the 6th International Conference on Radiocarbon and Tritium Dating Washington, DC, US Department of Commerce: 338-341.StuiverMSmithCChattersRandOlsonE1965Radiocarbon dating of ancient mortar and plasterInProceedings of the 6th International Conference on Radiocarbon and Tritium DatingWashington, DCUS Department of Commerce338341Search in Google Scholar

Synal HA, Stocker M, and Suter M, 2007. MICADAS: A new compact radiocarbon AMS system. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms 259: 7-13, DOI: 10.1016/j. nimb.2007.01.138.SynalHAStockerMandSuterM2007MICADAS: A new compact radiocarbon AMS systemNuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms25971310.1016/j.nimb.2007.01.138Open DOISearch in Google Scholar

Recommended articles from Trend MD

Plan your remote conference with Sciendo