Prof Christopher Ramsey: Publications

Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean wood sculpture

Journal of Archaeological Science (2012)

Authors:

J Ostapkowicz, C Bronk Ramsey, F Brock, T Higham, AC Wiedenhoeft, E Ribechini, JJ Lucejko, S Wilson

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Paired Dating of Pith and Outer Edge (Terminus) Samples from Pre-Hispanic Caribbean Wooden Sculptures

Radiocarbon Cambridge University Press (CUP) 54:3-4 (2012) 677-688

Authors:

Fiona Brock, Joanna Ostapkowicz, Christopher Bronk Ramsey, Alex Wiedenhoeft, Caroline Cartwright

Abstract:

Radiocarbon dating of historical and archaeological wood can be complicated, sometimes involving issues of “inbuilt” age in slow-growing woods, and/or the possibility of reuse or long delays between felling and use of the wood. Terminus dates can be provided by dating the sapwood, or the outermost edge of heartwood, while a date from the pith can give an indication of the first years of growth. A sequence of samples from specific points within the bole can be used to determine the growth rate of the tree. Such a combined dating strategy is particularly useful in cross-referencing dates from a single piece, better placing it in its chronological context. This paper reports paired or multiple dates from 11 wooden sculptures dated as part of the Pre-Hispanic Caribbean Sculptural Arts in Wood project, which studied 66 wooden artifacts attributed to the pre-colonial Taíno, the indigenous peoples of the Caribbean's Greater Antilles. The calibrated ages of the pieces published here range from ∼AD 700–1500, indicating that the Taíno were producing elaborate sculptures much earlier than previously thought. The paired or multiple dates from these carvings confirmed the accuracy of the results, and were also used to construct a growth rate model of what was expected to be a slow-growing species (Guaiacum sp.). This model demonstrates that the boles used to create the sculptures grew on average 1 cm every 6–13 yr.

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Rapid coupling between ice volume and polar temperature over the past 150,000 years

Nature (2012)

Authors:

KM Grant, EJ Rohling, M Bar-Matthews, A Ayalon, M Medina-Elizalde, CB Ramsey, C Satow, AP Roberts

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Reliability of Nitrogen Content (%N) and Carbon:Nitrogen Atomic Ratios (C:N) as Indicators of Collagen Preservation Suitable for Radiocarbon Dating

Radiocarbon Cambridge University Press (CUP) 54:3-4 (2012) 879-886

Authors:

Fiona Brock, Rachel Wood, Thomas FG Higham, Peter Ditchfield, Alex Bayliss, Christopher Bronk Ramsey

Abstract:

A recent study into prescreening techniques to identify bones suitable for radiocarbon dating from sites known for poor or variable preservation (Brock et al. 2007, 2010a) found that the percent nitrogen (%N) content of whole bone powder was the most reliable indicator of collagen preservation. Measurement of %N is rapid, requires little preparation or material, and is relatively cheap. The technique reduces the risk of needlessly sampling valuable archaeological objects, as well as saving time and money on their unsuccessful pretreatment prior to dating. This method of prescreening is now regularly used at the Oxford Radiocarbon Accelerator Unit (ORAU). In the original study, linear regression analysis of data from 100 bones from 12 Holocene sites across southern England showed that when 0.76% N was chosen as a threshold, 84% of bones were successfully identified as containing sufficient (i.e. >1%) or insufficient (i.e. <1%) collagen for dating. However, it has been observed that for older, Pleistocene bones the failure rate may be higher, possibly due to the presence of more degraded, short-chain proteins that pass through the ultrafilters used in pretreatment, resulting in lower yields. Here, we present linear regression analysis of data from nearly 600 human and animal bones, antlers, and teeth, from a wide range of contexts and ages, to determine whether the 0.76% threshold identified in the previous study is still applicable. The potential of carbon:nitrogen atomic weight ratios (C:N) of whole bone to predict collagen preservation is also discussed.

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The Chronology of Tell El-Daba: A Crucial Meeting Point of¹⁴C Dating, Archaeology, and Egyptology in the 2nd Millennium BC

Radiocarbon Cambridge University Press (CUP) 54:3-4 (2012) 407-422

Authors:

Walter Kutschera, Manfred Bietak, Eva Maria Wild, Christopher Bronk Ramsey, Michael Dee, Robin Golser, Karin Kopetzky, Peter Stadler, Peter Steier, Ursula Thanheiser, Franz Weninger

Abstract:

Radiocarbon dating at the Tell el-Daba site in the Nile Delta has created an enigma for many years. Despite great efforts, the difference of about 120 yr between the chronology based on14C dates and the one based on archaeological evidence linked to the Egyptian historical chronology has not been solved. In order to foster open discussions on this discrepancy, we present here the results of 4014C accelerator mass spectrometry (AMS) measurements on short-lived plant material assigned to 14 different phases of the Tell el-Daba excavation, spanning 600 yr (about 2000–1400 BC). On the one hand, the recently established agreement between14C dates and dynastic Egypt (Bronk Ramsey et al. 2010) makes it unlikely that the problem lies in the14C dates and/or the Egyptian historical chronology. On the other hand, the extensive archaeological evidence from Tell el-Daba linked to many different cultures in the eastern Mediterranean and to the Egyptian historical chronology provides strong evidence for an absolute chronology shifted by about 120 yr with respect to the14C dates.

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Prof Christopher Ramsey

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Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean wood sculpture

Authors:

Paired Dating of Pith and Outer Edge (Terminus) Samples from Pre-Hispanic Caribbean Wooden Sculptures

Authors:

Abstract:

Rapid coupling between ice volume and polar temperature over the past 150,000 years

Authors:

Reliability of Nitrogen Content (%N) and Carbon:Nitrogen Atomic Ratios (C:N) as Indicators of Collagen Preservation Suitable for Radiocarbon Dating

Authors:

Abstract:

The Chronology of Tell El-Daba: A Crucial Meeting Point of¹⁴C Dating, Archaeology, and Egyptology in the 2nd Millennium BC

Authors:

Abstract:

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Prof Christopher Ramsey

Research theme

Sub department

Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean wood sculpture

Authors:

Paired Dating of Pith and Outer Edge (Terminus) Samples from Pre-Hispanic Caribbean Wooden Sculptures

Authors:

Abstract:

Rapid coupling between ice volume and polar temperature over the past 150,000 years

Authors:

Reliability of Nitrogen Content (%N) and Carbon:Nitrogen Atomic Ratios (C:N) as Indicators of Collagen Preservation Suitable for Radiocarbon Dating

Authors:

Abstract:

The Chronology of Tell El-Daba: A Crucial Meeting Point of14C Dating, Archaeology, and Egyptology in the 2nd Millennium BC

Authors:

Abstract:

The Chronology of Tell El-Daba: A Crucial Meeting Point of¹⁴C Dating, Archaeology, and Egyptology in the 2nd Millennium BC