Albert C. Goodyear

Middle-Range Theory in Archaeology: A Critical Review of Origins and Applications

The concept of middle-range theory, arising over three decades ago in sociology, is reviewed. The concept was proposed as an approach to theorizing, urging consolidation of high-order theories with low-order empirical studies. The critical elements in such hierarchies are theories of a middle-range of abstraction. However, most current conceptions of “middle-range theory” in archaeology are far more narrowly conceived. Derived primarily from Binfords work, they continue the New Archaeologys attempt to develop a materialist epistemology for archaeology. In this view, principles of site formation processes are nearly synonymous with “middle-range theory.” The dangers to theory-building of this approach are outlined. Examples of middle-range theory that expand our capacity for explanation of cultural behavior are presented.

Chronological Position of the Dalton Horizon in the Southeastern United States

The chronological placement of the Dalton horizon in the southeastern United States has traditionally been between 10,000 and 8,000 B.P. (8000-6000 B.C.). A review of previous dating approaches questions the basis for that assignment and casts serious doubts about the validity of alleged associations between Dalton remains and C-14 dates in caves and shelters. The significance of two Dalton-associated C-14 dates from the alluvial terrace of the Rodgers Shelter site is discussed in regard to their age and contexts. Excavations of Dalton open sites during the 1970s revealed pure Dalton assemblages with no side-notched and corner-notched points present. Radiocarbon dates spanning the period from 9,500 to 9,000 B.P. for side-notched and corner-notched points indicate that the Dalton point had ceased to be made by that time. It is argued that the interval from 10,500 to 9,900 B.P. (8500-7900 B.C.) is the correct temporal position of the Dalton horizon. The importance of correctly estimating the age and duration of the Dalton adaptation is emphasized, particularly for relating technological and settlement strategies to the paleoenvironmental changes of the early Holocene.

Tool Kit Entropy and Bipolar Reduction: A Study of Interassemblage Lithic Variability among Paleo-Indian Sites in the Northeastern United States

Bipolar flaking as a means of reducing lithic raw material is known to have occurred since the time of the Lower Palaeolithic. As a strategy for working small bits of raw material, it is probable that it has a variety of important selective contexts. Assemblages from northeastern United States Paleo-Indian sites are used to test the hypothesis that bipolar artifacts in these systems represent a method of extending the utility of a transported, highly curated lithic toolkit through recycling. It is shown that what have been called pièces esquillées among these sites are in all probability cores for the derivation of small flakes. This is demonstrated by citing ethnoarcheological and technological data and by a spatial-statistical analysis of the distribution of “pièces esquillées” at the Debert site. The methodological problems related to the accurate functional identification of artifacts are explored and their impacts on archaeological arguments are also discussed. Also discussed are the difficulties in interpreting site activities on the basis of inter site differences in tool frequencies and proportions where assemblages have been affected by lithic recycling. Last, the theoretical significance of recycling through bipolar reduction is outlined as a strategy for solving the raw material and tool replacement problems as conditioned by Paleo-Indian settlement and technological systems.

Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago

Significance We present detailed geochemical and morphological analyses of nearly 700 spherules from 18 sites in support of a major cosmic impact at the onset of the Younger Dryas episode (12.8 ka). The impact distributed ∼10 million tonnes of melted spherules over 50 million square kilometers on four continents. Origins of the spherules by volcanism, anthropogenesis, authigenesis, lightning, and meteoritic ablation are rejected on geochemical and morphological grounds. The spherules closely resemble known impact materials derived from surficial sediments melted at temperatures >2,200 °C. The spherules correlate with abundances of associated melt-glass, nanodiamonds, carbon spherules, aciniform carbon, charcoal, and iridium. Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world’s premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event.

ARCHAEOLOGY OF THE PLEISTOCENE–HOLOCENE TRANSITION IN EASTERN NORTH AMERICA

The most recently investigated significant sites dating to the Late Pleistocene and Early Holocene in eastern North America are reviewed, with special attention devoted to sites in the north, extending from the Great Lakes area east to the New England–Canadian Maritimes region. In archaeological terms, these sites date to the time of the Paleoindian to Archaic transition. Despite the problems of Late Pleistocene–Early Holocene 14C ‘plateaus’, chronological advances have occurred through the recent reporting of several, often stratified, 14C or geoarchaeologically dated sites. These sites also provide some insight into subsistence practices and the environmental context of the occupations and, particularly, for the earliest dating occupations in the north. Several trends in stone tool technology are also becoming well-documented, such as a shift from more formalized to more expedient core reduction strategies, an increasing reliance on more coarse-grained rocks, and the appearance of ground stone tools. Nonetheless, at the present time it is extremely difficult to characterize and understand the environmental coping strategies of the human occupants of the time because of (1) poor control of environmental and cultural variability in time and space; (2) limited numbers of known sites; and (3) a paucity of subsistence remains.

Independent evaluation of conflicting microspherule results from different investigations of the Younger Dryas impact hypothesis

Firestone et al. sampled sedimentary sequences at many sites across North America, Europe, and Asia [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 106:16016–16021]. In sediments dated to the Younger Dryas onset or Boundary (YDB) approximately 12,900 calendar years ago, Firestone et al. reported discovery of markers, including nanodiamonds, aciniform soot, high-temperature melt-glass, and magnetic microspherules attributed to cosmic impacts/airbursts. The microspherules were explained as either cosmic material ablation or terrestrial ejecta from a hypothesized North American impact that initiated the abrupt Younger Dryas cooling, contributed to megafaunal extinctions, and triggered human cultural shifts and population declines. A number of independent groups have confirmed the presence of YDB spherules, but two have not. One of them [Surovell TA, et al. (2009) Proc Natl Acad Sci USA 104:18155–18158] collected and analyzed samples from seven YDB sites, purportedly using the same protocol as Firestone et al., but did not find a single spherule in YDB sediments at two previously reported sites. To examine this discrepancy, we conducted an independent blind investigation of two sites common to both studies, and a third site investigated only by Surovell et al. We found abundant YDB microspherules at all three widely separated sites consistent with the results of Firestone et al. and conclude that the analytical protocol employed by Surovell et al. deviated significantly from that of Firestone et al. Morphological and geochemical analyses of YDB spherules suggest they are not cosmic, volcanic, authigenic, or anthropogenic in origin. Instead, they appear to have formed from abrupt melting and quenching of terrestrial materials.

Bayesian chronological analyses consistent with synchronous age of 12,835-12,735 Cal B.P. for Younger Dryas boundary on four continents.

Significance A cosmic impact event at ∼12,800 Cal B.P. formed the Younger Dryas boundary (YDB) layer, containing peak abundances in multiple, high-temperature, impact-related proxies, including spherules, melt glass, and nanodiamonds. Bayesian statistical analyses of 354 dates from 23 sedimentary sequences over four continents established a modeled YDB age range of 12,835 Cal B.P. to 12,735 Cal B.P., supporting synchroneity of the YDB layer at high probability (95%). This range overlaps that of a platinum peak recorded in the Greenland Ice Sheet and of the onset of the Younger Dryas climate episode in six key records, suggesting a causal connection between the impact event and the Younger Dryas. Due to its rarity and distinctive characteristics, the YDB layer is proposed as a widespread correlation datum. The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature minerals and melt glass, nanodiamonds, carbon spherules, aciniform carbon, platinum, and osmium. Bayesian chronological modeling was applied to 354 dates from 23 stratigraphic sections in 12 countries on four continents to establish a modeled YDB age range for this event of 12,835–12,735 Cal B.P. at 95% probability. This range overlaps that of a peak in extraterrestrial platinum in the Greenland Ice Sheet and of the earliest age of the Younger Dryas climate episode in six proxy records, suggesting a causal connection between the YDB impact event and the Younger Dryas. Two statistical tests indicate that both modeled and unmodeled ages in the 30 records are consistent with synchronous deposition of the YDB layer within the limits of dating uncertainty (∼100 y). The widespread distribution of the YDB layer suggests that it may serve as a datum layer.

Nanodiamond-Rich Layer across Three Continents Consistent with Major Cosmic Impact at 12,800 Cal BP

A major cosmic-impact event has been proposed at the onset of the Younger Dryas (YD) cooling episode at ≈12,800 ± 150 years before present, forming the YD Boundary (YDB) layer, distributed over >50 million km2 on four continents. In 24 dated stratigraphic sections in 10 countries of the Northern Hemisphere, the YDB layer contains a clearly defined abundance peak in nanodiamonds (NDs), a major cosmic-impact proxy. Observed ND polytypes include cubic diamonds, lonsdaleite-like crystals, and diamond-like carbon nanoparticles, called n-diamond and i-carbon. The ND abundances in bulk YDB sediments ranged up to ≈500 ppb (mean: 200 ppb) and that in carbon spherules up to ≈3700 ppb (mean: ≈750 ppb); 138 of 205 sediment samples (67%) contained no detectable NDs. Isotopic evidence indicates that YDB NDs were produced from terrestrial carbon, as with other impact diamonds, and were not derived from the impactor itself. The YDB layer is also marked by abundance peaks in other impact-related proxies, including cosmic-impact spherules, carbon spherules (some containing NDs), iridium, osmium, platinum, charcoal, aciniform carbon (soot), and high-temperature melt-glass. This contribution reviews the debate about the presence, abundance, and origin of the concentration peak in YDB NDs. We describe an updated protocol for the extraction and concentration of NDs from sediment, carbon spherules, and ice, and we describe the basis for identification and classification of YDB ND polytypes, using nine analytical approaches. The large body of evidence now obtained about YDB NDs is strongly consistent with an origin by cosmic impact at ≈12,800 cal BP and is inconsistent with formation of YDB NDs by natural terrestrial processes, including wildfires, anthropogenesis, and/or influx of cosmic dust.

Southeastern data inconsistent with Paleoindian demographic reconstruction

Buchanan et al.s (1) statistical evaluation of radiocarbon dates as a demographic proxy depends on accurate and complete datasets. However, their database is incomplete for the Southeast, where 181 radiocarbon dates from Paleoindian and Early Archaic deposits are now available (2). Only a fraction of these are included in their …

The Pleistocene—Holocene Transition in the Eastern United States

We define the eastern United States for the purposes of this chapter as being bordered by the Laurentide Ice Sheet on the north, the ancestral Gulf of Mexico on the south, the Atlantic Ocean on the east, and the Western Plains on the west. These borders enclose most of the area between the latitudes 25–50°N and longitudes 65–90°W a region of ecological diversity and complexity even today.