Radiocarbon re-dating of contact-era Iroquoian history in northeastern North America

The Monongahela tradition in "real time": Bayesian analysis of radiocarbon dates

Despite advances in techniques, methods, and theory, northeastern North American archaeologists continue to use early to mid-twentieth century culture historical taxa as units of analysis and narrative. There is a distinct need to move away from this archaeological practice to enable fuller understandings of past human lives. One tool that enables such a move is Bayesian analysis of radiocarbon dates, which provides a means of constructing continuous chronologies. A large dataset of radiocarbon dates for late prehistoric (ca AD 900/1000–1650) sites in the lower upper Ohio River basin in southwestern Pennsylvania and adjacent portions of Maryland, Ohio, and West Virginia is used here as an example. The results allow a preliminary assessment of how the settlement plans of contemporaneous villages varied considerably, reflecting decisions of the village occupants how to structure built environments to meet their needs.

Second Intermediate Period date for the Thera (Santorini) eruption and historical implications

The historical relevance of the Thera (Santorini) volcanic eruption is unclear because of major dating uncertainty. Long placed ~1500 BCE and during the Egyptian New Kingdom (starts ~1565–1540 BCE) by archaeologists, ¹⁴C pointed to dates ≥50–100 years earlier during the preceding Second Intermediate Period. Several decades of debate have followed with no clear resolution of the problem—despite wide recognition that this uncertainty undermines an ability to synchronize the civilizations of the eastern Mediterranean in the mid-second millennium BCE and write wider history. Recent work permits substantial progress. Volcanic CO₂ was often blamed for the discrepancy. However, comparison of ¹⁴C dates directly associated with the eruption from contemporary Aegean contexts—both on and remote from Thera—can now remove this caveat. In turn, using Bayesian analysis, a revised and substantially refined date range for the Thera eruption can be determined, both through the integration of the large ¹⁴C dataset relevant to the Thera eruption with the local stratigraphic sequence on Thera immediately prior to the eruption, and in conjunction with the wider stratigraphically-defined Aegean archaeological sequence from before to after the eruption. This enables a robust high-resolution dating for the eruption ~1606–1589 BCE (68.3% probability), ~1609–1560 BCE (95.4% probability). This dating clarifies long-disputed synchronizations between Aegean and East Mediterranean cultures, placing the eruption during the earlier and very different Second Intermediate Period with its Canaanite-Levantine dominated world-system. This gives an importantly altered cultural and historical context for the New Palace Period on Crete and the contemporary Shaft Grave era in southern Greece. In addition, the revised dating, and a current absence of southern Aegean chronological data placed soon afterwards, highlights a period of likely devastating regional eruption impact in the earlier-mid 16^th century BCE southern Aegean.

Resolving Indigenous village occupations and social history across the long century of European permanent settlement in Northeastern North America: The Mohawk River Valley ~1450-1635 CE

The timeframe of Indigenous settlements in Northeast North America in the 15th-17th centuries CE has until very recently been largely described in terms of European material culture and history. An independent chronology was usually absent. Radiocarbon dating has recently begun to change this conventional model radically. The challenge, if an alternative, independent timeframe and history is to be created, is to articulate a high-resolution chronology appropriate and comparable with the lived histories of the Indigenous village settlements of the period. Improving substantially on previous initial work, we report here high-resolution defined chronologies for the three most extensively excavated and iconic ancestral Kanien'kehá꞉ka (Mohawk) village sites in New York (Smith-Pagerie, Klock and Garoga), and a fourth early historic Indigenous site, Brigg's Run, and re-assess the wider chronology of the Mohawk River Valley in the mid-15th to earlier 17th centuries. This new chronology confirms initial suggestions from radiocarbon that a wholesale reappraisal of past assumptions is necessary, since our dates conflict completely with past dates and the previously presumed temporal order of these three iconic sites. In turn, a wider reassessment of northeastern North American early history and re-interpretation of Atlantic connectivities in the later 15th through early 17th centuries is required. Our new closely defined date ranges are achieved employing detailed archival analysis of excavation records to establish the contextual history for radiocarbon-dated samples from each site, tree-ring defined short time series from wood charcoal samples fitted against the radiocarbon calibration curve ('wiggle-matching'), and Bayesian chronological modelling for each of the individual sites integrating all available prior knowledge and radiocarbon dating probabilities. We define (our preferred model) most likely (68.3% highest posterior density) village occupation ranges for Smith-Pagerie of ~1478-1498, Klock of ~1499-1521, Garoga of ~1550-1582, and Brigg's Run of ~1619-1632.

Beyond megadrought and collapse in the Northern Levant: The chronology of Tell Tayinat and two historical inflection episodes, around 4.2ka BP, and following 3.2ka BP

There has been considerable focus on the main, expansionary, and inter-regionally linked or 'globalising' periods in Old World pre- and proto-history, with a focus on identifying, analyzing and dating collapse at the close of these pivotal periods. The end of the Early Bronze Age in the late third millennium BCE and a subsequent 'intermediate' or transitional period before the Middle Bronze Age (~2200-1900 BCE), and the end of the Late Bronze Age in the late second millennium BCE and the ensuing period of transformation during the Early Iron Age (~1200-900 BCE), are key examples. Among other issues, climate change is regularly invoked as a cause or factor in both cases. Recent considerations of "collapse" have emphasized the unpredictability and variability of responses during such periods of reorganization and transformation. Yet, a gap in scholarly attention remains in documenting the responses observed at important sites during these 'transformative' periods in the Old World region. Tell Tayinat in southeastern Turkey, as a major archaeological site occupied during these two major 'in between' periods of transformation, offers a unique case for comparing and contrasting differing responses to change. To enable scholarly assessment of associations between the local trajectory of the site and broader regional narratives, an essential preliminary need is a secure, resolved timeframe for the site. Here we report a large set of radiocarbon data and incorporate the stratigraphic sequence using Bayesian chronological modelling to create a refined timeframe for Tell Tayinat and a secure basis for analysis of the site with respect to its broader regional context and climate history.

Using Maize δ15N values to assess soil fertility in fifteenth- and sixteenth-century ad Iroquoian agricultural fields

Native Americans developed agronomic practices throughout the Western Hemisphere adapted to regional climate, edaphic conditions, and the extent of dependence on agriculture for subsistence. These included the mounding or "corn hill" system in northeastern North America. Iroquoian language speakers of present-day New York, USA, and Ontario and Québec, Canada were among those who used this system. While well-known, there has been little archaeological documentation of the system. As a result, there is scant archaeological evidence on how Iroquoian farmers maintained soil fertility in their often-extensive agricultural fields. Using δ15N values obtained on fifteenth- and sixteenth-century AD maize kernels from archaeological sites in New York and Ontario, adjusted to take into account changes that result from charring as determined through experiments, we demonstrate that Iroquoian farmers were successful at maintaining nitrogen in their agricultural fields. These results add to our archaeological knowledge of Iroquoian agronomic practices. Our results also indicate the potential value of obtaining δ15N values on archaeological maize in the investigation of Native American agronomic practices.

Radiocarbon, Bayesian chronological modeling and early European metal circulation in the sixteenth-century AD Mohawk River Valley, USA

European metal artifacts in assemblages from sites predating the physical presence of Europeans in Northern Iroquoia in present-day New York, USA and southern Ontario, Canada have been used as chronological markers for the mid-sixteenth century AD. In the Mohawk River Valley of New York, European metal artifacts at sites pre-dating the physical presence of Europeans have been used by archaeologists as a terminus post quem (TPQ) of 1525 to 1550 in regional chronologies. This has been done under the assumption that these metals did not begin to circulate until after sustained European presence on the northern Atlantic coast beginning in 1517. Here we use Bayesian chronological modeling of a large set of radiocarbon dates to refine our understanding of early European metal circulation in the Mohawk River Valley. Our results indicate that European iron and cuprous metals arrived earlier than previously thought, by the beginning of the sixteenth century, and cannot be used as TPQs. Together with recent Bayesian chronological analyses of radiocarbon dates from several sites in southern Ontario, these results add to our evolving understanding of intra-regional variation in Northern Iroquoia of sixteenth-century AD circulation and adoption of European goods.

Freshwater reservoir offsets on radiocarbon-dated dog bone from the headwaters of the St. Lawrence River, USA

Isotopic analysis of dog (Canis lupus familiaris) bone recovered from archaeological sites as proxies for human bone is becoming common in North America. Chronological placement of the dogs is often determined through radiocarbon dating of dog bone. The Great Lakes, their tributaries, and nearby lakes and streams were important fisheries for Native Americans prior to and after sustained European presence in the region. Carbon entering the food web in freshwater systems is often not in full isotopic equilibrium with the atmosphere, giving rise to spuriously old radiocarbon ages in fish, other aquatic organisms, and their consumers. These freshwater reservoir offsets (FROs) have been noted on human and dog bone in several areas of the world. Here we report the results of multi-tracer Bayesian dietary modeling using δ¹⁵N and δ¹³C values on dog bone collagen from mid-fifteenth to mid-sixteenth-century Iroquoian village sites at the headwaters of the St. Lawrence River, New York, USA. Results indicate that fish was an important component of dog diets. A comparison of radiocarbon dates on dog bone with dates on deer bone or maize from the same sites indicate FROs ranging from 97 ± 24 to 220 ± 39 ¹⁴Cyr with a weighted mean of 132 ± 8 ¹⁴Cyr. These results suggest that dog bone should not be used for radiocarbon dating in the absence of modeling to determine fish consumption and that previously reported radiocarbon dates on human bone from the larger region are likely to have FROs given the known importance of fish in regional human diets.