To date or not to date? A comparison of different ¹⁴C pretreatment methods applied to archeological marine shells from Vale Boi (Portugal)

TY - JOUR

T1 - To date or not to date? A comparison of different 14C pretreatment methods applied to archeological marine shells from Vale Boi (Portugal)

AU - Paleček, Dragana

AU - Falini, Giuseppe

AU - Wacker, Lukas

AU - Mannino, Marcello A.

AU - Bicho, Nuno

AU - Cascalheira, João

AU - Rombolà, Alessandro G.

AU - Fabbri, Daniele

AU - Talamo, Sahra

N1 - Publisher Copyright: © The Author(s), 2024. Published by Cambridge University Press on behalf of University of Arizona.

PY - 2024/8/1

Y1 - 2024/8/1

N2 - Mollusk shells are often found in archeological sites, given their great preservation potential and high value as a multipurpose resource, and they can often be the only available materials useful for radiocarbon (14C) dating. However, dates obtained from shells are often regarded as less reliable compared to those from bones, wood, or charcoals due to different factors (e.g., Isotope fractionation, reservoir effects etc.). The standard acid etching pretreatment for mollusk shells is the most used in many 14C laboratories, although another protocol known as CarDS (Carbonate Density Separation) was introduced just over a decade ago. We compare these two methods with two newly proposed methods for intracellular organic matrix extraction. We applied all four methods to samples selected from different archeological layers of the well-known Upper Paleolithic site of Vale Boi, rich in mollusk specimens throughout the stratigraphic sequence. Here we compare our results to previous dates to determine which of these pretreatment methods results in the most reliable 14C dates. Based on the results of this study, all four methods gave inconsistent ages compared to previous dates and the stratigraphic attribution.

AB - Mollusk shells are often found in archeological sites, given their great preservation potential and high value as a multipurpose resource, and they can often be the only available materials useful for radiocarbon (14C) dating. However, dates obtained from shells are often regarded as less reliable compared to those from bones, wood, or charcoals due to different factors (e.g., Isotope fractionation, reservoir effects etc.). The standard acid etching pretreatment for mollusk shells is the most used in many 14C laboratories, although another protocol known as CarDS (Carbonate Density Separation) was introduced just over a decade ago. We compare these two methods with two newly proposed methods for intracellular organic matrix extraction. We applied all four methods to samples selected from different archeological layers of the well-known Upper Paleolithic site of Vale Boi, rich in mollusk specimens throughout the stratigraphic sequence. Here we compare our results to previous dates to determine which of these pretreatment methods results in the most reliable 14C dates. Based on the results of this study, all four methods gave inconsistent ages compared to previous dates and the stratigraphic attribution.

KW - chemical analysis

KW - mollusk shells

KW - Paleolithic

KW - pretreatment

KW - radiocarbon AMS dating

UR - http://www.scopus.com/inward/record.url?scp=85208985413&partnerID=8YFLogxK

U2 - 10.1017/RDC.2024.80

DO - 10.1017/RDC.2024.80

M3 - Journal article

AN - SCOPUS:85208985413

SN - 0033-8222

VL - 66

SP - 699

EP - 720

JO - Radiocarbon

JF - Radiocarbon

IS - 4

ER -