COMPARISON OF THERMAL DECOMPOSITION AND SEQUENTIAL DISSOLUTION—TWO SAMPLE PREPARATION METHODS FOR RADIOCARBON DATING OF LIME MORTARS

Author:

Daugbjerg Thomas SchrøderORCID,Lindroos AlfORCID,Hajdas IrkaORCID,Ringbom ÅsaORCID,Olsen JesperORCID

Abstract

ABSTRACTDating lime mortar samples using the radiocarbon (14C) method can be difficult. This is because the contamination is similar to the primary dating material (CaCO3) and consequently difficult to remove. Mortar can also have late-in-formation pyrogenic carbonate from interactions with the environment after the initial hardening phase, such as recrystallization, fire damage or delayed hardening. When 14C dating a system of primary dating material, contamination and late-in-formation pyrogenic carbonate, one approach is multi-fraction dating with conclusiveness criteria. If a sample has sufficient contamination or late-in-formation pyrogenic carbonate, the criteria evaluate the result inconclusive. To improve inconclusive results from such samples, this study investigates sample preparation by thermal decomposition. Here samples that were inconclusively dated by the authors’ traditional method, sequential dissolution with 85% phosphoric acid, are investigated further. This study finds that CO2 thermally decomposed at low temperatures contains some late-in-formation pyrogenic carbonate. By rejecting CO2 decomposed at low temperatures, Kastelholm castle and Kimito church in Finland are conclusively and accurately dated. Furthermore, a preheating method removes some late-in-formation carbonate, but not enough for a conclusive result. Finally, thermal decomposition finds difficulty in discerning binder carbonate from limestone and marble contamination.

Publisher

Cambridge University Press (CUP)

Subject

General Earth and Planetary Sciences,Archeology

Reference58 articles.

1. Methodological Aspect of Mortars Dating (Poznań, Poland, MODIS)

2. Dating of Old Mortars by the Carbon-14 Method

3. The Influence of Contaminating (Fossil) Carbonate and the Variations of δ13C in Mortar Dating

4. Capello, R-MD , Galán, MB. 1995. El anfiteatro de Augusta Emerita: rasgos arquitectónicos y problemática urbanística y cronológica, en el anfiteatro en la Hispania romana; Mérida, 26–28 de Noviembre de 1992. p. 247–264.

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3