From 2014 to 2020, we compiled radiocarbon ages from the lower 48 states, creating a database of more than 100,000 archaeological, geological, and paleontological ages that will be freely available to researchers through the Canadian Archaeological Radiocarbon Database. Here, we discuss the process used to compile ages, general characteristics of the database, and lessons learned from this exercise in “big data” compilation.

Seeman, Morris, and Summers misrepresent or misunderstand the arguments we have made, as well as their own previous work. Here, we correct these inaccuracies. We also reiterate our support for hypothesis-driven and evidence-based research.

This study examines small-scale household ceramic production at the site of Xaltocan, Mexico, to understand the organization of household ceramic production prior to the development of the Aztec Empire. We examine utilitarian vessels and serving wares from an Early Postclassic (a.d. 900–1200) domestic context using neutron activation analysis (NAA). We also examine archaeological evidence for ceramic manufacture. The NAA data reveal that similar raw materials and paste recipes were used for both utilitarian and decorated wares, suggesting that households produced both plain and decorated pottery. We conclude that ceramic production was an intermittent activity that took place alongside other crafts and agriculture. By looking at ceramics within their contexts of use and production, we consider the practices and choices made by individual social units, which is crucial to interpreting broader Early Postclassic economic systems and the ways in which commoners influenced these systems.

Stone was a critical resource for prehistoric hunter-gatherers. Archaeologists, therefore, have long argued that these groups would actively have sought out stone of ‘high quality’. Although the defining of quality can be a complicated endeavour, researchers in recent years have suggested that stone with fewer impurities would be preferred for tool production, as it can be worked and used in a more controllable way. The present study shows that prehistoric hunter-gatherers at the Holocene site of Welling, in Ohio, USA, continuously selected the ‘purest’ stone for over 9000 years.

The Abbott Farm National Historic Landmark is one of the more significant Woodland-period sites in the Northeast. Numerous Hopewellian cultural traits (copper artifacts, cremated burials, exotic cherts, and mica) have been identified at the site. Numerous potential geological sources for the mica artifacts exist in the Mid-Atlantic region. We explore two analytical methods to evaluate the most likely geological sources of the mica artifacts. Source and artifact specimens were analyzed using pXRF as well as neutron activation. Our pXRF data are suggestive, but show high analytical uncertainty. We make several recommendations relevant to future attempts that would use this kind of instrument to study sheet mica. Our neutron activation results are promising and suggest that geochemical sourcing of mica has much potential. Results of both assays suggest that most of the artifact specimens recovered from Abbott Farm share a similar chemistry, and this composition is very similar to mica from southeastern Pennsylvania. A cut-and-drilled pendant exhibits a chemical makeup distinctly different from all other artifacts and source specimens evaluated here. Although our results are preliminary, the application of modern analytical methods to extant archaeological collections has the potential to provide significant new information.

Ronald Mason’s hypothesis from the 1960s that the southeastern United States possesses greater Paleoindian projectile-point diversity than other regions is regularly cited, and often assumed to be true, but in fact has never been quantitatively tested. Even if valid, however, the evolutionary meaning of this diversity is contested. Point diversity is often linked to Clovis “origins,” but point diversity could also arise from group fissioning and drift, admixture, adaptation, or multiple founding events, among other possibilities. Before archaeologists can even begin to discuss these scenarios, it is paramount to ensure that what we think we know is representative of reality. To this end, we tested Mason’s hypothesis for the first time, using a sample of 1,056 Paleoindian points from eastern North America arui employing paradigmatic classification and rigorous statistical tools used in the quantification of ecological biodiversity. Our first set of analyses, which compared the Southeast to the Northeast, showed that the Southeast did indeed possess significantly greater point-class richness. Although this result was consistent with Mason’s hypothesis, our second set of analyses, which compared the Upper Southeast to the Lower Southeast and the Northeast showed that in terms of point-class richness the Upper Southeast > Lower Southeast > Northeast. Given current chronometrie evidence, we suggest that this latter result is consistent with the suggestion that the area of the Ohio, Cumberland, and Tennessee River valleys, as well as the mid-Atlantic coastal plain, were possible initial and secondary “staging areas” for colonizing Paleoindian foragers moving from western to eastern North America.

Northeastern North America has produced an incredible number of late Pleistocene faunal remains; however, many of these were discovered and excavated prior to the development of radiocarbon dating. Moreover, many of the 14C dates that do exist for such specimens were assayed prior to the development of purified collagen extraction methods, were performed on botanical remains of unspecified association with the faunal remains, or were accepted without concerns of young-carbon contamination from museum preservatives. Here, we present a set of high-precision accelerator mass spectrometry (AMS) dates obtained on Pleistocene faunal specimens from Connecticut, New Jersey, and Pennsylvania. Our data contain both newly discovered specimens and specimens that have resided in museum collections for over a century.

Recently, advocates of an “older -than- Clovis” occupation of eastern North America have suggested that bi-pointed leaf-shaped lanceolate stone bifaces provide definitive evidence of human culture on the eastern seaboard prior to the Late Glacial Maximum. This argument hinges on two suppositions : first, that points of this form are exceedingly rare in the East and second, that all known occurrences of these point forms are from landforms or depositionaI environments dating to some time before the late Pleistocene. Neither of these suppositions is supported by the archaeological record. Bi-pointed leaf shaped blades have been recoveredfrom throughout the Middle Atlantic and Northeast, where they have been repeatedly dated, either radiometrically or by association with diagnostic artifacts, to between the Late Archaic and the Early Woodland. Statistical analysis of supposed “older-than-Clovis” leaf-shaped blades demonstrates that there are no significant differences in morphology between them and unequivocally Middle Holocene leaf-shaped blades. Until such time as evidence demonstrates otherwise, there is no reason to accept that these leaf-shaped bifaces are diagnostic of a Pleistocene, much less pre-Late Glacial Maximum, occupation in eastern North America.

The comments of Stanford and Bradley (above) do not address our criticisms and obfuscate the topic at hand with irrelevant data (e.g. the south-to-north movement of fluted points through the Ice Free Corridor), nonexistent data (e.g. ‘under the water’ or ‘destroyed sites’), and questionable data (e.g. Meadowcroft and Cactus Hill are by no means widely accepted, nor are Stanford and Bradley's ‘eight LGM sites’ in the mid-Atlantic region). Before touching on some of these points, we direct the reader to several recent articles (e.g. Morrow 2014; Raff & Bolnick 2014) that provide new evidence or arguments inconsistent with a trans-Atlantic migration, including the fact that DNA from the Clovis Anzick child (Montana) shows no European ancestry (Rasmussen et al. 2014). Although Stanford and Bradley describe their Solutrean ‘solution’ (Stanford & Bradley 1999) to the Pleistocene colonisation of North America as ‘testable’, their position is that the idea is correct until falsified. They propose that their colleagues have yet to provide sufficient ‘critiques’ or ‘challenges’ to discount it (see also Collins 2012; Collins et al. 2013). Yet they are the ones proposing a hypothesis inconsistent with overwhelming multidisciplinary evidence, and they ignore results of tests that do not support their claims.

Across Atlantic ice: the origin of America's Clovis culture (Stanford & Bradley 2012) is the latest iteration of a controversial proposal that North America was first colonised by people from Europe rather than from East Asia, as most researchers accept. The authors, Dennis Stanford and Bruce Bradley, argue that Solutrean groups from southern France and the Iberian Peninsula used watercraft to make their way across the North Atlantic and into North America during the Last Glacial Maximum (LGM). According to Stanford and Bradley, this 6000km journey was facilitated by a continuous ice shelf that provided fresh water and a food supply. Across Atlantic ice has received a number of positive reviews. Shea (2012: 294), for example, suggests that it is “an excellent example of hypothesis-building in the best tradition of processual archaeology. It challenges American archaeology in a way that will require serious research by its opponents”. Runnels (2012) is equally enthusiastic.

Archaeologists have suggested that various methods of surface texturing, specifically those resulting in alternating ridges and grooves, affect the gripability of a ceramic vessel. Various methods of vessel texturing were applied to ceramic test tiles and evaluated using a tribometer outfitted with a malleable skinlike substrate. Nontextured (smoothed) ceramic tiles were similarly evaluated. Tiles were evaluated under both dry and wet conditions. Coefficients of static friction suggest that, under wet and dry conditions, smoothed surfaces generate less friction than textured surfaces and that not all textured surfaces produce the same amount of friction. Results indicate that vessel-wall texturing may be an adaptation for increased vessel longevity. Explanations of the development and use of textured pottery must now consider gripability along with a variety of factors related to vessel performance.