Volcanic climate forcing, extreme cold and the Neolithic Transition in the northern US Southwest

The impacts on global climate of the AD 536 and 541 volcanic eruptions are well attested in palaeoclimatic datasets and in Eurasian historical records. Their effects on farmers in the arid uplands of western North America, however, remain poorly understood. The authors investigate whether extreme cold caused by these eruptions influenced the scale, scope and timing of the Neolithic Transition in the northern US Southwest. Archaeological tree-ring and radiocarbon dates, along with settlement survey data suggest that extreme cooling generated the physical and social space that enabled early farmers to transition from kin-focused socio-economic strategies to increasingly complex and widely shared forms of social organisation that served as foundational elements of burgeoning Ancestral Pueblo societies.

Using the ArcGIS Collector Mobile App for Settlement Survey Data Collection in Armenia

Recent years have seen the rapid adoption of digital site recording strategies following the proliferation of GPS-enabled mobile devices and data collection apps. Much of the emerging literature on digital—or paperless—archaeology, however, has focused on excavation contexts, with fewer discussions of mobile-GIS solutions on archaeological survey. This article discusses the design and implementation of a site survey workflow based on Esri's ArcGIS Collector mobile app in the context of Project ArAGATS's Kasakh Valley Archaeology Survey in northwestern Armenia. The Collector app provides a simple, map-centric user interface that allows surveyors with little-to-no GIS experience to record site locations, enter attribute data on customized digital forms, and attach photographs. With a network connection, the Collector app instantly uploads site information as GIS data to the project geodatabase and refreshes the data across surveyors’ mobile devices. Although the Collector app lacks certain GIS features and requires an institutional Esri license, we found that the native integration with our project GIS and broad access to visualization and recording tools in the app made in-field decision-making and interpretation more collaborative and inclusive across the survey team.

The Izapa Kingdom's Capital: Formative Period Settlement Patterns, Population, and Dating Low-Relief Stelae

This article presents new settlement survey data from the Izapa center of southern Mesoamerica, a site long known for its corpus of low-relief stelae. These data, which track the changing distribution of population from 1000 BC–AD 100, indicate that the city's population peaked at 5,725 inhabitants. Izapa was the capital of a regional kingdom with more than 40 lower-order monumental centers and a territory that covered at least 450 sq. km. Recent AMS dates confirm the apogee of the kingdom at 300–100 BC, and volcanological reconstruction suggests that a Tacaná volcano eruption corresponds with archaeological evidence of political and demographic disruptions to the kingdom. Patterns at Izapa are contextualized in terms of Inomata and colleagues’ (2014) call for redating Kaminaljuyu, placing the erection of stelae there to after 100 BC, as well as Love's (2018) and Mendelsohn's (2018) responses in this journal. Izapa was an integrated kingdom from 700–100 BC, and “Izapa-style” sculptures were a novel medium of political communication introduced after the polity had been functioning without them for centuries. If Inomata and colleagues' (2014) proposal is correct that low-relief stelae were erected only after 100 BC at other centers in southern Mesoamerica, this was centuries after the practice was established at Izapa.

Questioning Postclassic Continuity at Baking Pot, Belize, Using Direct AMS 14C Dating of Human Burials

Archaeologists working in the Belize Valley have argued for the persistence of Maya populations from the Classic (AD 300–900) through Postclassic (AD 900–1500) periods since Gordon Willey's groundbreaking settlement survey and excavation work in the 1950s. This is contrary to the trajectory recorded in some parts of the Maya region where there is clear evidence for political disruption and population decline at the end of the Classic period. The argument for continuous Classic to Postclassic occupation in the Belize Valley remains ambiguous due to researchers' reliance on relative ceramic chronologies. This article reports the results of direct accelerator mass spectrometry (AMS) radiocarbon dating of human skeletons (n = 12) from the important center of Baking Pot, Belize, which is thought to provide some of the best ceramic evidence for continuity in the valley. The AMS dates show a long span of mortuary activity between the Middle Preclassic and Late Classic periods (405 cal BC to cal AD 770), with a hiatus in activity during the Early Postclassic (cal AD 900–1200) and subsequent activity in the Late Postclassic (cal AD 1280–1420). These results are not consistent with the idea that Baking Pot was occupied continuously from the Classic through Postclassic periods. This work highlights the need for additional AMS 14C work at Baking Pot and elsewhere to establish absolute chronologies for evaluating the political and demographic collapse of Classic Maya regional centers.