OxCal is a widely used software package for the calibration of radiocarbon dates and the statistical analysis of 14 C and other chronological information. The program aims to make statistical methods easily available to researchers and students working in a range of different disciplines. This paper will look at the recent and planned developments of the package. The recent additions to the statistical methods are primarily aimed at providing more robust models, in particular through model averaging for deposition models and through different multiphase models. The paper will look at how these new models have been implemented and explore the implications for researchers who might benefit from their use. In addition, a new approach to the evaluation of marine reservoir offsets will be presented. As the quantity and complexity of chronological data increase, it is also important to have efficient methods for the visualization of such extensive data sets and methods for the presentation of spatial and geographical data embedded within planned future versions of OxCal will also be discussed. DOI:  10.2458/azu_js_rc.55.16215

/pdf/recent-and-planned-developments-of-the-program-oxcal-29g75lvsgt.pdf

Recent and Planned Developments of the Program OxCal

The 15 archipelagos of East Polynesia, including New Zealand, Hawaii, and Rapa Nui, were the last habitable places on earth colonized by prehistoric humans. The timing and pattern of this colonization event has been poorly resolved, with chronologies varying by >1000 y, precluding understanding of cultural change and ecological impacts on these pristine ecosystems. In a meta-analysis of 1,434 radiocarbon dates from the region, reliable short-lived samples reveal that the colonization of East Polynesia occurred in two distinct phases: earliest in the Society Islands A.D. ∼1025–1120, four centuries later than previously assumed; then after 70–265 y, dispersal continued in one major pulse to all remaining islands A.D. ∼1190–1290. We show that previously supported longer chronologies have relied upon radiocarbon-dated materials with large sources of error, making them unsuitable for precise dating of recent events. Our empirically based and dramatically shortened chronology for the colonization of East Polynesia resolves longstanding paradoxes and offers a robust explanation for the remarkable uniformity of East Polynesian culture, human biology, and language. Models of human colonization, ecological change and historical linguistics for the region now require substantial revision.

http://www.hilites.org.uk/wp-content/uploads/PNAS-2011-Wilmshurst-1815-20.pdf

High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia

Historical collapse of ancient states poses intriguing social-ecological questions, as well as potential applications to global change and contemporary strategies for sustainability. Five Old World case studies are developed to identify interactive inputs, triggers, and feedbacks in devolution. Collapse is multicausal and rarely abrupt. Political simplification undermines traditional structures of authority to favor militarization, whereas disintegration is preconditioned or triggered by acute stress (insecurity, environmental or economic crises, famine), with breakdown accompanied or followed by demographic decline. Undue attention to stressors risks underestimating the intricate interplay of environmental, political, and sociocultural resilience in limiting the damages of collapse or in facilitating reconstruction. The conceptual model emphasizes resilience, as well as the historical roles of leaders, elites, and ideology. However, a historical model cannot simply be applied to contemporary problems of sustainability without adjustment for cumulative information and increasing possibilities for popular participation. Between the 14th and 18th centuries, Western Europe responded to environmental crises by innovation and intensification; such modernization was decentralized, protracted, flexible, and broadly based. Much of the current alarmist literature that claims to draw from historical experience is poorly focused, simplistic, and unhelpful. It fails to appreciate that resilience and readaptation depend on identified options, improved understanding, cultural solidarity, enlightened leadership, and opportunities for participation and fresh ideas.

https://www.pnas.org/content/pnas/109/10/3632.full.pdf

Collapse, environment, and society

Historical collapse of ancient states or civilizations has raised new awareness about its possible relevance to current issues of sustainability, in the context of global change. This Special Feature examines 12 case studies of societies under stress, of which seven suffered severe transformation. Outcomes were complex and unpredictable. Five others overcame breakdown through environmental, political, or socio-cultural resilience, which deserves as much attention as the identification of stressors. Response to environmental crises of the last millennium varied greatly according to place and time but drew from traditional knowledge to evaluate new information or experiment with increasing flexibility, even if modernization or intensification were decentralized and protracted. Longer-term diachronic experience offers insight into how societies have dealt with acute stress, a more instructive perspective for the future than is offered by apocalyptic scenarios.

https://www.pnas.org/content/pnas/109/10/3628.full.pdf

Critical perspectives on historical collapse

Explanations for the Late Bronze Age crisis and collapse in the eastern Mediterranean are legion: migrations, predations by external forces, political struggles within dominant polities or system collapse among them, inequalities between centers and peripheries, climatic change and natural disasters, disease/plague. There has never been any overarching explanation to account for all the changes within and beyond the eastern Mediterranean, some of which occurred at different times from the mid to late 13th throughout the 12th centuries B.C.E. The ambiguity of the evidence—material, textual, climatic, chronological—and the differing contexts involved across the central-eastern Mediterranean make it difficult to disentangle background noise from boundary conditions and to distinguish cause from effect. Can we identify the protagonists of the crisis and related events? How useful are recent explanations that focus on climate and/or chronology in providing a better understanding of the crisis? This article reviews the current state of the archaeological and historical evidence and considers the coherence of climatic explanations and overprecise chronologies in attempting to place the “crisis” in context. There is no final solution: the human-induced Late Bronze Age “collapse” presents multiple material, social, and cultural realities that demand continuing, and collaborative, archaeological, historical, and scientific attention and interpretation. This article is available as open access on (AJA Online).

https://www.jstor.org/stable/10.3764/aja.120.1.0099

Crisis in Context: The End of the Late Bronze Age in the Eastern Mediterranean

The historical chronologies for dynastic Egypt are based on reign lengths inferred from written and archaeological evidence. These floating chronologies are linked to the absolute calendar by a few ancient astronomical observations, which remain a source of debate. We used 211 radiocarbon measurements made on samples from short-lived plants, together with a Bayesian model incorporating historical information on reign lengths, to produce a chronology for dynastic Egypt. A small offset (19 radiocarbon years older) in radiocarbon levels in the Nile Valley is probably a growing-season effect. Our radiocarbon data indicate that the New Kingdom started between 1570 and 1544 B.C.E., and the reign of Djoser in the Old Kingdom started between 2691 and 2625 B.C.E.; both cases are earlier than some previous historical estimates.

http://img2.timg.co.il/forums/1_143488617.pdf

Radiocarbon-Based Chronology for Dynastic Egypt

Amenemhet II and the Sea: Maritime Aspects of the Mit Rahina (Memphis) Inscription

The discovery of L. clymenum at the Middle Bronze IIA settlement at Tel Nami, Israel is reported. Archaeobotanical evidence is presented in order to show the Aegean origin and demonstrate the peculiarities of this exotic food crop. The archaeological context of the discovery and its implications indicate that maritime contacts existed between the Aegean and the southern Levant during the first quarter of the second millennium B.C.

Import of an Aegean Food Plant to a Middle Bronze IIA Coastal Site in Israel

Correlating and Combining Egyptian Historical and Southern Levantine Radiocarbon Chronologies at Middle Bronze Age IIa Tel Ifshar, Israel

Thirteen Middle Bronze Age IIa and four Late Bronze Age IIb (ca. 1950-1750 B.C. and thirteenth century, B.C., respectively)pieces of charcoal or water logged wood were found in the recent excavations of Tel Nami, a small port on the coast near Mount Carmel, Israel. These includedCedrus libani (cedar of Lebanon) (three samples), and local tree species that still grow today in the vicinity of the site—Pinus halepensis (Aleppo pine) (one sample),Olea europaea (olive tree) (five samples),Quercus calliprinos (kermes oak) (three samples),Quercus ithaburensis (Mt. Tabor oak) (four samples), andQuercus sp. (one sample). The discovery of Cedrus libani in a Middle Bronze Age IIa port is one of the earliest published examples of cedar wood from Israel. Together with other artifactual evidence for maritime trade from Tel Nami, this find suggests that a maritime trade in cedar wood existed along the Levantine coast.

Ezra S. Marcus

Papers

Radiocarbon-Based Chronology for Dynastic Egypt

Amenemhet II and the Sea: Maritime Aspects of the Mit Rahina (Memphis) Inscription

Import of an Aegean Food Plant to a Middle Bronze IIA Coastal Site in Israel

Correlating and Combining Egyptian Historical and Southern Levantine Radiocarbon Chronologies at Middle Bronze Age IIa Tel Ifshar, Israel

Wood remains from Tel Nami, a middle bronze IIa and late bronze IIb port, local exploitation of trees and levantine cedar trade