Christopher Bronk Ramsey

Christopher Bronk Ramsey
University of Oxford | OX · School of Archaeology

BA, MA, DPhil (Oxon)

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540
Publications
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Publications

Publications (540)
Article
A new chronological study of the LBK in the central Polish lowlands shows that it emerged later, lasted for a shorter period, and ended sooner than has been supposed up till now. LBK communities emerged, probably in the middle of the 53 rd century cal BC, to form an enclave in the central Polish lowlands, probably as a result of colonisation from l...
Article
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The North Atlantic region experienced abrupt high-amplitude cooling at the onset of the Younger Dryas stadial. However, due to chronological uncertainties in the available terrestrial records it is unclear whether terrestrial ecosystem response to this event was instantaneous and spatially synchronous, or whether regional or time-transgressive lags...
Article
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Geomagnetic excursions represent the dynamic nature of the geodynamo. Accumulated palaeomagnetic records indicate that such excursions are dominated by dipolar-fields, but exhibit different structures. Here we report a palaeomagnetic record from the varved sediments of Lake Suigetsu, central Japan, which reveals fine structures in the Laschamp Excu...
Article
This paper summarises research on freshwater reservoir effects (FRE) in the Baikal region and their impact on the radiocarbon dating of human remains. Varying relationships are seen between human δ¹³C and δ¹⁵N values and ¹⁴C offsets in paired human-terrestrial mammal radiocarbon dates from the same graves in the different microregions of Cis-Baikal...
Article
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Yuzhniy Oleniy Ostrov in Karelia, northwest Russia, is one of the largest Early Holocene cemeteries in northern Eurasia, with 177 burials recovered in excavations in the 1930s; originally, more than 400 graves may have been present. A new radiocarbon dating programme, taking into account a correction for freshwater reservoir effects, suggests that...
Article
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Our paper about the impacts of the Laschamps Geomagnetic Excursion 42,000 years ago has provoked considerable scientific and public interest, particularly in the so-called Adams Event associated with the initial transition of the magnetic poles. Although we welcome the opportunity to discuss our new ideas, Hawks' assertions of misrepresentation are...
Article
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Our study on the exact timing and the potential climatic, environmental, and evolutionary consequences of the Laschamps Geomagnetic Excursion has generated the hypothesis that geomagnetism represents an unrecognized driver in environmental and evolutionary change. It is important for this hypothesis to be tested with new data, and encouragingly, no...
Article
Radiocarbon (14C), as a consequence of its production in the atmosphere and subsequent dispersal through the carbon cycle, is a key tracer for studying the Earth system. Knowledge of past 14C levels improves our understanding of climate processes, the Sun, the geodynamo, and the carbon cycle. Recently updated radiocarbon calibration curves (IntCal2...
Article
A considerable amount of bioarchaeological research – including AMS 14C dating and stable carbon and nitrogen isotope analyses (δ13C and δ15N) – has been undertaken on the hunter-gatherers from the area west of Lake Baikal, known as Cis-Baikal. No such work has previously been reported for the east side of the lake, Trans-Baikal. Here, we present n...
Article
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Sea-level change is thought to influence the frequencies of volcanic eruptions on glacial to interglacial timescales. However, the underlying physical processes and their importance relative to other influences (e.g. magma recharge rates), remain poorly understood. Here we compare a ~360 kyr long record of effusive and explosive eruptions from the...
Article
Despite eastern Africa being a key location in the emergence of Homo sapiens and their subsequent dispersal out of Africa, there is a paucity of long, well-dated climate records in the region to contextualize this history. To address this issue, we dated a ∼293 m long composite sediment core from Chew Bahir, south Ethiopia, using three independent...
Article
Stable oxygen isotope dendrochronology is an effective precision-dating method for fast grown, invariant (complacent) tree-rings and for trees growing in moist, temperate climatic regions where growth may not be strongly controlled by climate. The method works because trees preserve a strong common isotopic signal, from summer precipitation, and th...
Article
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Reconstructions of climatic and environmental conditions can contribute to current debates about the factors that influenced early human dispersal within and beyond Africa. Here we analyse a 200,000-year multi-proxy paleoclimate record from Chew Bahir, a tectonic lake basin in the southern Ethiopian rift. Our record reveals two modes of climate cha...
Article
Leads, lags, or synchronies in climatic events among different regions are key to understanding mechanisms of climate change, as they provide insights into the causal linkages among components of the climate system. The well-studied transition from the Lateglacial to early Holocene (ca. 16–10 ka) contains several abrupt climatic shifts, making this...
Technical Report
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The Dating the Earliest Neolithic Ceramics of Wessex project was part of a training programme in the Bayesian chronological modelling of radiocarbon dates funded by Historic England. Its original scope was to target ceramic assemblages for dating in four areas: the Middle Thames, the Avebury area, the Stonehenge area of Salisbury Plain, and an area...
Article
Analyses of radiocarbon dates (all corrected for the freshwater reservoir effect) and associated stable isotope values obtained from the skeletal remains of ~650 individuals provide many new insights about Middle Holocene hunter–gatherers (HGs) of the Cis-Baikal region, Eastern Siberia. The new radiocarbon evidence clarifies the culture history of...
Article
Hunter-gatherer archaeology typically focusses on the details of subsistence strategies and material culture and, in the case of cemeteries, on various aspects of mortuary practices, beliefs, and social differentiation. This paper aims to look rather at patterns of change over time and space in how past hunter-gatherer cemeteries were used from Lat...
Article
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Geological archives record multiple reversals of Earth’s magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion [41 to 42 thousand years ago (ka)]. We use ancient New Ze...
Article
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Supplementary Material for 'A global environmental crisis 42,000 years ago' Geological archives record multiple reversals of Earth’s magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the...
Article
The limestone islands of the Bahamian archipelago provide a challenging environment for human settlement, one that was not taken up until after AD 700. The analysis of human skeletal remains offers new insights into how this challenge was met. A substantial program of AMS ¹⁴C dating on pre-Columbian humans (n = 66) provides a robust chronological f...
Article
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The Glastonbury Lake Village in Somerset, UK, is made up of 90 mounds comprising 40 roundhouses. Excavations between 1892 and 1907 revealed Iron Age structural and material remains unparalleled in Western Europe. The settlement's exact chronology, however, has remained uncertain. Here, the authors present a programme of radiocarbon and dendro-chron...
Article
Several scientific expeditions surveyed the ocean during the 19th century, gathering a wealth of interdisciplinary data as well as samples of different kinds. The latter are currently held by museums worldwide, and are the subject of study in different sciences, offering a unique opportunity to access information which is not readily available else...
Article
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This paper, presents formally modelled date estimates for the sequence of Lengyel funerary pottery in western Hungary, eastern Austria and south-west Slovakia. It is an extension of the dating and modelling already carried out by the project, The Times of Their Lives (ToTL), on the major Lengyel aggregation, including burials, at Alsónyék-Bátaszék...
Chapter
Chronological modelling of radiocarbon dates from Stonehenge
Article
Radiocarbon dating and Bayesian chronological modelling have provided precise new dating for the henge monument of Mount Pleasant in Dorset, excavated in 1970-1. A total of 59 radiocarbon dates are now available for the site and modelling of these has provided a revised sequence for the henge enclosure and its various constituent parts: the timber...
Article
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The new IntCal20 radiocarbon record continues decades of successful practice by employing one calibration curve as an approximation for different regions across the hemisphere. Here we investigate three radiocarbon time-series of archaeological and historical importance from the Mediterranean-Anatolian region, which indicate, or may include, offset...
Article
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To create a reliable radiocarbon calibration curve, one needs not only high-quality data but also a robust statistical methodology. The unique aspects of much of the calibration data provide considerable modeling challenges and require a made-to-measure approach to curve construction that accurately represents and adapts to these individualities, b...
Article
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The concentration of radiocarbon ( ¹⁴ C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their ¹⁴ C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the i...
Technical Report
Full-text available
Analysis was undertaken on samples from the roof and ceiling structures of the hall and cross-wing resulting in the construction of three site sequences: GRLNSQ01 contains 34 oak samples and spans the period AD 1268–1440; GRLNSQ02 contains 13 oak samples and spans the period AD 1412–1579; GRLNSQ03 contains six elm samples but remains undated. In th...
Conference Paper
The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 11 m) relative to present day. LIG sea level...
Article
Full-text available
We test a recent prediction that stable carbon isotope ratios from UK oaks will display age-trends of more than 4‰ per century by measuring >5400 carbon isotope ratios from the late-wood alpha-cellulose of individual rings from 18 modern oak trees and 50 building timbers spanning the 9th–21st centuries. After a very short (c.5 years) juvenile phase...
Article
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Connecting calendar ages to radiocarbon ( ¹⁴ C) ages, i.e. constructing a calibration curve, requires ¹⁴ C samples that represent, or are closely connected to, atmospheric ¹⁴ C values and that can also be independently dated. In addition to these data, there is information that can serve as independent tests of the calibration curve. For example, i...
Article
The Lake Baikal region of southern Siberia has a rich mortuary record that has provided the most comprehensive isotopic database for palaeodietary studies of north-temperate hunter-gatherers in the world, permitting more detailed reconstructions and finer-grained research questions than are usually possible. Building on previous work, this study co...
Article
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Oxygen isotope ratios from oak tree rings are used to extend the May–August precipitation totals of the England and Wales precipitation series back to 1201 ce. The agreement between instrumental and reconstructed values is unusually strong, with more than half of the variance explained and standard verification tests passed. The stability of this r...
Technical Report
Full-text available
Tree-ring analysis was undertaken on samples taken from the coach house/stables range, the castle tower, and the castle annexe resulting in the construction of a single site sequence representing two tiebeams from the tower. This site sequence could not be conclusively dated through dendrochronology alone but tentative dating obtained has now been...
Technical Report
Full-text available
Tree-ring analysis of samples taken from 15 Flemingate, Beverley, resulted in the construction of two site sequences: BEVGSQ01, a site sequence of 92 rings containing four samples, and BEVGSQ02, a 177-ring site sequence from two samples. Neither of these nor any of the ungrouped individual series could be securely dated using tree-ring analysis. Tr...
Technical Report
Full-text available
Tree-ring analysis of samples taken from The Guildhall resulted in the construction of four site sequences: BEVJSQ01, a site sequence of 197 rings containing four samples, BEVJSQ02, an 82-ring site sequence also containing four samples, and BEVJSQ03 and BEVJSQ04, site sequences of 84 rings and 63 rings respectively each of which contained two sampl...
Technical Report
Full-text available
Forty samples from the nave, south aisle, and porch of this church were subject to tree-ring dating; three of these also underwent radiocarbon and wiggle-match analysis. Three nave timbers were dendrochronologically dated to AD 1581--1606 and two to c AD 1616. A further nine timbers from this roof have now been dated by radiocarbon wiggle-matching...
Article
Full-text available
The curves recommended for calibrating radiocarbon ( ¹⁴ C) dates into absolute dates have been updated. For calibrating atmospheric samples from the Northern Hemisphere, the new curve is called IntCal20. This is accompanied by associated curves SHCal20 for the Southern Hemisphere, and Marine20 for marine samples. In this “companion article” we disc...
Article
Full-text available
A new isotopic method for dating oak and non-oak (elm) timbers is applied to samples from the portcullis windlass mechanism in the Byward Tower, Tower of London. This structure was previously sampled for ring width dendrochronology but failed to date. Successful application of the stable oxygen isotope dating method returns a felling date of winter...
Article
Terrestrial plant macrofossils from the sedimentary record of Lake Suigetsu, Japan, provide the only quasi-continuous direct atmospheric record of radiocarbon ( ¹⁴ C) covering the last 50 ka cal BP (Bronk Ramsey et al. 2012). Since then, new high precision data have become available on U-Th dated speleothems from Hulu Cave China, covering the same...
Article
Full-text available
In much of Europe, the advent of low-input cereal farming regimes between c.ad 800 and 1200 enabled landowners—lords—to amass wealth by greatly expanding the amount of land under cultivation and exploiting the labour of others. Scientific analysis of plant remains and animal bones from archaeological contexts is generating the first direct evidence...
Article
Full-text available
The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level...
Article
Full-text available
We thank Helama and Matskovsky (2019, https://doi.org/10.1177/0959683616652709) for their interest in our work. They argue that we should use Regional Curve Standardization (RCS) to identify trends in our oxygen isotope series and to detrend them prior to climate reconstruction. We disagree.
Article
The recent development of an oxygen isotope (δ¹⁸O) master chronology for south central England (1200–2000 AD) has successfully demonstrated reliable cross-dating between the master chronology and undated samples from vernacular and high-status buildings. The method is well suited to complacent, wide-ringed samples, which are commonplace throughout...
Technical Report
Full-text available
Sixteen timbers from worked wood and a tree stump excavated from Glastonbury Lake Village were submitted for tree-ring dating, Five oak samples, that had originally be excavated by Bulleid and Grey in 1896-7 but been reburied, were deemed suitable for analysis. Two sets of two samples (GLV 206 and 214, and GLV 207 and 213) crossmatched against each...
Article
Full-text available
We report the application of oxygen isotope dendrochronology to date a high-status and remarkably unaltered late medieval hall house on the eastern border of South Wales. The oak timbers have either short and complacent ring series, or very strong growth disturbance, and none were suitable for ring-width dendrochronology. By using stable oxygen iso...
Article
Full-text available
Bayesian chronological modelling of radiocarbon dates from the Brochtorff Circle at Xagħra, Gozo, Malta (achieved through the ToTL and FRAGSUS projects), provides a more precise chronology for the sequence of development and use of a cave complex. Artefacts show that the site was in use from the Żebbuġ period of the late 5th/early 4th millennium ca...
Article
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Ring‐width dendrochronology, based on matching patterns of ring width variability, works best when trees are growing under significant environmental (climatic) stress. In the UK, and elsewhere in the temperate mid‐latitudes, trees generally experience low stress, so dating is more difficult and often fails. Oxygen isotopes in tree rings passively r...
Article
Full-text available
The potential for age‐related trends in the stable oxygen isotope ratios of latewood alpha cellulose was investigated in samples of living oak trees and historic building timbers from the UK. When the series are examined individually, it is clear that the strongest trends in individual trees and timbers reflect concurrent trends in climate. Nonclim...
Article
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Little synthesis of evidence for Middle Neolithic food and farming in Wiltshire, particularly in and around the Stonehenge World Heritage Site (WHS) has been possible, until now, due to a paucity of assemblages. The excavation of a cluster of five Middle Neolithic pits and an inhumation burial at West Amesbury Farm (WAF) has prompted a review of ou...