A STATISTICAL APPROACH TO THE CALIBRATION OF FLOATING TREE-RING CHRONOLOGIES USING RADIOCARBON DATES

The bristlecone pine tree-ring calibration of radiocarbon dates, while necessitating changes of up to 700 years in Holocene chronology before 1000 b.c. , offers possibilities of very accurate dating when ¹⁴C determinations from floating tree-ring chronologies are utilized. A statistical approach assuming linear regression is developed and used to position the floating tree-ring chronologies at Swiss neolithic sites, using radiocarbon dates published by Ferguson, Huber and Suess and by Suess. The statistical method gives objective estimated dates with estimates of error related, in a consistent and explicit manner, to the inherent inaccuracies of the radiocarbon dates. Most of the method may readily be tested by standard statistical procedures. For the particular cases considered the assumptions of linearity and parallelism are investigated, and the precision of the estimated dates is comparable with that claimed by Suess and his co-workers. A precise calibration is thus possible without utilizing the short-term fluctuations in the Suess calibration curve. The analysis, while avoiding some assumptions of Suess and his collaborators, offers an explicit procedure for establishing controlled teleconnections with the Ferguson dendrochronology, and supports their emphasis on the importance of radiocarbon dates from floating tree-ring sequences for the construction of precise prehistoric chronologies.     

THE CHRONOLOGY OF MONKS MOUND

Abstract

Monks Mound is the largest single Native American construction in North America. The mound sits at the center of the Cahokia site, and interpretations of its construction and use are fundamental for understanding how Mississippian peoples created mounds and landscapes. In the past, researchers speculated that Monks Mound was both one of the oldest and longest-lived monuments at Cahokia. Using a Bayesian computer model that incorporates both archaeological information and radiocarbon dates, I argue the mound is younger and was built more rapidly than previously thought. The mound likely was built in two very rapid efforts spanning fewer than twenty years. This analysis shows Cahokian society could mobilize vast quantities of labor for short periods, which may have inhibited institutionalized, transgenerational sociopolitical hierarchies.     

TEMPORAL HYGIENE: PROBLEMS IN CULTURAL CHRONOLOGY OF THE LATE PREHISTORIC PERIOD OF THE MIDDLE OHIO RIVER VALLEY

Abstract

Radiocarbon dates are an independent source of data for constructing temporal relationships. Too often dates are shoehorned by preconceptions and hobbled by casual sample selection, reporting, and interpretation. Several authors have established quality-control criteria for evaluating and cleansing regional radiocarbon databases. Recent applications of such temporal hygiene practices in paleoecology and archaeology have resulted in significant reinterpretations of the sequence, timing, and tempo of change. Further, a new appreciation is often gained of the extent of synchronic variability. I apply a minimal hygienic protocol based on three criteria: material dated, method of age estimation, and when the sample was run. I illustrate both the value of and the need for such analyses by cleaning up a small sample of dates (N = 125) from 11 Fort Ancient sites. The single largest problem for determining occupation timing is the use of wood samples. Nearly 80 percent of the assays are unacceptable for use in reconstructing occupation history, except to frame the maximal age of occupation. The modifications to the timing and duration of occupation for these 11 sites significantly undermine the logical inferential structure of current reconstructions of change and difference in the middle Ohio River valley.     

Radiocarbon Dating and the George C. Davis Site,Texas

Abstract

Seventy-nine radiocarbon samples were assayed from the George C. Davis Site, a prehistoric Caddoan settlement in the central portion of east Texas. Statistical analysis of the dates convincingly establishes the age of the site as extending from about 780 A.C. to 1260 A.C. and enables us to place the cultural remains into three temporal periods. These dates also provide specific and useful examples for improving the application of radiocarbon dating to archaeological problems.     

Excavations at Rio Claro,Northeast Honduras: Preliminary Report

Abstract

During the summer of 1975, preliminary survey, mapping, and excavations were conducted at the H-CN-12:Rio Claro site, a sizeable Pre-Hispanic village settlement in the Department of ColónNE Honduras, Central America. Artifactual remains and chronometric determinations indicate that the settlement was inhabited during the Cocal Period (ca. 1000-1530 A.C.). This report describes the location and layout of H-CN-12:Rio Claro, principal excavations, the first regional radiocarbon dates for the Cocal Period, and some of the artifacts and significant findings of the second season of fieldwork in this little-studied region of the Americas. The possibility is raised that the site is the ethnohistorical chiefdom center Papayeca.     

RADIOCARBON TRENDS AND THE EAST TEXAS CADDO TRADITION (CA. A.D. 800–1680)

Abstract

Through the employment of radiocarbon (¹⁴C) dates as data, we use the date combination process to refine site-specific summed probability distributions for 555 dates from Caddo sites (n = 19) in East Texas with 10 or more ¹⁴C dates. Summed probability distributions are then contrasted across river basins and natural regions with the remainder of the East Texas Caddo Radiocarbon Database (n = 338 dates from 132 other Caddo sites), highlighting the temporal and spatial character of Caddo archaeological sites throughout East Texas.     

New Radiocarbon Dates from Franchthi Cave: A Preliminary Note Regarding Collection of Samples by Means of Flotation

Abstract

Franchthi Cave is an important prehistoric site in southern Greece. Six years of excavation have revealed a sequence beginning in later Upper Palaeolithic and continuing to near the end of the Greek Neolithic, i.e. some 17,000 (radiocarbon) years of essentially continuous human occupation. The purpose of the following is to make public 11 new dates from this sequence and, at the same time, to suggest that there is no significant difference between the results of samples collected for radiocarbon dating by flotation and those secured by conventional trench-collection.     

New radiometric dates for precolumbian (2000–700 b.p.) earthworks in western Amazonia,Brazil

Abstract

In this paper we present new data on the precolumbian geometric ditched enclosures identified in Acre State, western Amazonia, Brazil. Remote sensing and ground survey have revealed 281 earthworks, located mainly on the edges of high plateaus overlooking the river valleys drained by the southeastern tributaries of the Upper Purus River. Excavations have shown that the few existing cultural materials are concentrated on the slopes and in the bottoms of the ditches, as well as on small mounds that were likely remains of houses, whereas the central, flat enclosed areas lack major archaeological features. New radiocarbon dates place the initial stage of earthwork construction as early as ca. 2000 b.p. We suggest that the building of these geometric earthworks may have been a regionally shared phenomenon, especially among the Arawak and the Tacana peoples, who used them for special gatherings, religious activities, and, in some cases, as village sites.     

EARLY VILLAGE LIFE IN SOUTHEASTERN INDIANA: RECENT FIELD INVESTIGATIONS AT THE GUARD SITE (12D29)

Abstract

Investigations at the Guard site (12D29), located in Dearborn County, Indiana, have provided evidence pertaining to the development of early Fort Ancient villages. Recent geophysical survey and excavations alongside many new radiocarbon dates have allowed for improved understanding of household architecture and intrasite variability. Although some scholars have hypothesized that Middle Fort Ancient villages developed out of small early Fort Ancient hamlets, the Guard site provides explicit evidence for villages early in the Fort Ancient sequence. Guard also contains key Mississippian indicators for interaction, particularly wall-trench architecture and a Ramey knife. These findings demand that we reconceptualize the inception of Fort Ancient villages.     

A NEW DATE FOR THE NEANDERTHALS FROM EL SIDRÓN CAVE (ASTURIAS,NORTHERN SPAIN)*

Torres et al. (2010 ) published a series of radiocarbon, AAR, ESR and OSL dates from the site of El Sidrón, northern Spain, which is notable for the discovery of the partial remains of 12 Neanderthals. Whilst the non‐radiocarbon methods suggested an age beyond 32 600–46 300 years, direct radiocarbon dates on the human fossils were inconsistent, ranging between 10 000 and 50 000 bp . This study uses the ultrafiltration pre‐treatment protocol to obtain a date of 48 400 ± 3200 bp (OxA‐21 776) on a bone fragment and confirm the antiquity of the Neanderthal assemblage. Moreover, it demonstrates the comparability of the ultrafiltration and ninhydrin bone radiocarbon pre‐treatment protocols, and highlights the need for appropriate screening methods where valuable collections with poor biomolecular preservation are sampled for collagen extraction.     

A Late Pleistocene Occupation on the Southern Coast of Oregon

Abstract

Geoarchaeological research on the southern coast of Oregon brought to light archaeological evidence of early human occupation in the late Pleistocene. Indian Sands (35CU67) lies on a highly eroded deflated headland on the Oregon coast where previous surveys had found and dated surficial cultural materials as early as 8250 b.p. (uncalibrated radiocarbon years). Prior to excavation of Indian Sands, sediment and stratigraphic analysis, along with radiocarbon and thermoluminescence dates, established the existence of late Pleistocene deposits. The excavations confirmed the presence of buried cultural deposits containing lithic artifacts, charcoal, and fire-cracked rock. Dispersed charcoal from the floor of an artifactbearing level was dated to 10,430 b.p., more than 2000 ^l4C years older than any other Oregon coastal site.     

Evaluating the Reliability of Fluoride Dating at Two Prehistoric Mound Sites in Mississippi

Abstract

Ion-selective electrode fluoride dating is used to address chronological problems at two mound sites located in Mississippi. At the Mississippian period (A.D. 900–1520) Lyon's Bluff site, 220K520, the fluoride content of deer and human bone is compared with radiocarbon dates and stratigraphic levels to evaluate the reliability of the fluoride dating method for understanding relative burial chronology. At a second site, Pocahontas Mound A (22HI500), fluoride content of deer bone is used to corroborate radiocarbon dates and to establish the proper chronology of levels associated with two distinct occupations (Archaic and Coles Creek/Plaquemine) identified in a large midden area. Fluoride analysis also is used to date a second midden area at this site. For Lyon's Bluff; fluoride dates did not correspond with accelerator mass spectrometry (AMS)-dated burials and midden strata. In contrast, fluoride dating proved very useful in determining chronological placement of midden levels and dating other areas at Pocahontas Mound A. Sample age, site location, soil, and bone preservation are considered as possible causes for the negative results at Lyon's Bluff.     

CONFIRMATION OF AN ARCHAIC PERIOD MOUND IN SOUTHWEST MISSISSIPPI

Abstract

Site 22LI504 is a predominantly Archaic period site in Lincoln County, Mississippi. One of its primary elements of interest is a single conical mound from which small-diameter cores revealed evidence of advanced pedogenesis. A radiocarbon sample from one soil core produced a date suggesting that the mound was Archaic in age (Fulmer 2001); however, it was unclear whether the sample came from within the mound or an underlying midden. In the spring of 2006, we excavated a 1-x-1-m unit in the mound to investigate this question. Diagnostic lithic artifacts, an advanced state of soil horizonation, and a lack of ceramics indicate that the mound is of Archaic period construction, with as many as five construction stages and artifact-rich features. We describe the soil profiles, features, and artifacts recovered from the mound, with comparisons to excavation units in an adjacent Archaic midden to show that there is no clear evidence for the mound being a functionally specific locus. We also present radiocarbon dates that indicate the earthwork is over 5,000 years old. These results are evaluated within the broader context of Archaic mound building, focusing in particular on environmental parameters underlying bet-hedging behavior.     

Recent Research on the Upper Palaeolithic Phase in India

Abstract

Recent discoveries of artifactual assemblages based on blade-tool technology, occurring in post-Middle Palaeolithic and pre-Mesolithic contexts in different parts of India, are filling the gap in the Indian Stone Age sequence. These lithic industries, along with the bone tools obtained from the Kurnool caves, the faunal associations at some sites, and the available radiocarbon dates, are now seen beyond doubt to represent the Upper Palaeolithic period.     

Metal Working in the Northern Lowveld,South Africa A.D. 1000–1890

Abstract

The Iron Age archaeology of the northern Lowveld of South Africa is notable for the abundance of mining, metal working, and salt production sites recorded in the region. We report the results of scientific studies of the metallurgical remains recovered from 1965 to 1978 by Nikolaas J. van der Merwe, David Killick, and colleagues in various campaigns of survey and excavation in the Phalaborwa region, a major center of precolonial metallurgy. Both iron and copper ores occur in a carbonatite complex at Phalaborwa and were smelted in low-shaft furnaces of two different designs. Two radiocarbon dates of ca. 1000 b.p. are available for the mines themselves, which have now been completely destroyed. All other radiocarbon dates for the archaeological sequence at Phalaborwa fall in two groups, the first from the 10th to 13th centuries A.D., the second from the 17th through the 20th centuries A.D. Both iron and copper were smelted in both periods; tin-bronze and brass appeared towards the end of the earlier period.     

Radiocarbon Dating and the Historical Archaeology of Korea: An Alternative Interpretation of Hongryeonbong Fortress II in the Three Kingdoms Period,Central Korea

Relying heavily upon historical records to build archaeological chronologies, many Korean historical archaeologists question the utility of radiocarbon dating. To challenge this tendency, we test a model based on historical records by analyzing radiocarbon dates. We dated two bulk samples from Hongryeonbong Fortress II, Seoul, South Korea, which is known historically to have been occupied between a.d. 500 and 551. By dividing bulk samples into smaller aliquots, we dated 40 subsamples and statistically estimated consensus dates. The consensus dates do not support expectations of the historical model, as they do not lie within the temporal range provided by historical records. We propose an alternative model that explains both the radiocarbon dates and the historical records. It is suggested that radiocarbon dating can be successfully applied to the reconstruction of historical periods and is a way of mitigating possible biases of models based solely on historical records.     

Radiocarbon Chronometry of Site QJ-280, Quebrada Jaguay,a Terminal Pleistocene to Early Holocene Fishing Site in Southern Peru

Excavations in 1970, 1996, and 1999 at Site QJ-280, Quebrada Jaguay, in southern Peru, yielded enough dateable terrestrial plant material to establish an extensive radiocarbon chronology for the site. QJ-280 is one of oldest well-dated fishing sites in the Americas: it was occupied from the terminal Pleistocene to the mid-Holocene (about 13,000–8,300 calibrated years BP) based on 42 terrestrial radiocarbon dates, encompassing the Jaguay and Machas Phases of the local archaeological sequence. In addition to the terrestrial dates, radiocarbon measurements on valves of two marine surf clam (Mesodesma donacium) individuals from a single, well-dated mid-Holocene Manos Phase archaeological context have provided insight into marine upwelling conditions during the occupation of Quebrada Jaguay. The marine reservoir age varied between 130 and 730 ¹⁴C years during the brief lives of the two clams (up to 5 years each), and varied by up to 530 ¹⁴C years within an individual valve, suggesting strong and variable deep marine upwelling; conditions broadly similar to those that exist in coastal Peru today. These rapid variations in marine radiocarbon age suggest that marine radiocarbon dates from environments with variable upwelling could be skewed by up to hundreds of years.     

A REASSESSMENT OF THE CHRONOLOGY OF MOUND A AT TOQUA

Abstract

The Toqua site (40MR6) is one of the most thoroughly excavated Late Mississippian mound sites in East Tennessee. The site has been a focal point of research on late prehistory in southern Appalachia, but there are issues surrounding its chronological placement. The radiometric dates obtained for the site in the 1970s and the archaeomagnetic dates reported in 1999 have large standard deviations. These dates are too imprecise to be useful for a temporal placement of the site that is clear enough for current discussions of the development of Mississippian culture. A newly obtained Accelerator Mass Spectrometry (AMS) date from the large platform mound (Mound A) allows a reevaluation of the occupation sequence of the Toqua site. This date provides an anchor for a refined chronology for Mound A. In addition to the new AMS date, this refined chronology is based on complementary lines of evidence, including architectural evidence, mortuary practices, pottery traditions, and shell gorget styles.     

Chronological Reconstruction of Natfieh Tombs,Northern Jordan

Abstract

This research radiocarbon dates human teeth and bones sampled from seven tombs from the archaeological site of Natfieh, Northern Jordan. The small number of artifact fragments uncovered, looting and disruption of the tombs in antiquity and/or recent times, and the continuity between the Greek and Roman burial traditions and similarity in tomb architecture impede determining accurate dates and chronology of the tombs. This research aims to ascertain the archaeological dates and the chronological sequence of the tombs and the artifacts uncovered. Results show that the probable earliest use of these tombs was between 90 BC and AD 20, and their probable latest use was from AD 126–236. Most probably, at Natfieh new tombs spread northward and carving the tombs started in the lower rock layers and later in the upper layers.     

Palaeoenvironmental and chronological investigations of the Magdalenian sites of Goyet Cave and Trou de Chaleux (Belgium), via stable isotope and radiocarbon analyses of horse skeletal remains

Trou de Chaleux and Goyet are caves situated less than 30 km apart in Belgium that contain stratified Magdalenian artefacts and butchered faunal remains. Published radiocarbon dates suggest that both sites were contemporaneously occupied during to the Late-glacial interstadial. It has previously been suggested that the Trou de Chaleux Late-glacial faunal remains might be slightly older than those at Goyet Cave, and that Trou de Chaleux has two phases of occupation during the Late-glacial interstadial. However, the limited number of radiocarbon dates currently available makes it impossible to determine whether the sites are truly contemporaneous, and the assessment of their absolute chronologies is complicated by a plateau in the calibration curve. In this paper, bone collagen δ¹³C and δ¹⁵N signatures of horse bones from the two sites are used to reconstruct local palaeoenvironments. We hypothesise that if occupations at the two sites were contemporaneous, the horse collagen δ¹³C and δ¹⁵N isotope signatures from both sites will be similar, since comparable carbon and nitrogen isotopic values would reflect similar diets, ecologies and environments. To provide clear dating parameters, new AMS radiocarbon determinations are also presented. Results show that horse collagen δ¹³C and δ¹⁵N isotope signatures at the two sites are different, indicating that the populations were not subject to similar diets, ecologies and environments. The new radiocarbon dates confirm that the horse bones from Trou de Chaleux date to the Late-glacial interstadial, but they also show that in Goyet Cave Horizons 1 and 2, older horse remains dating to ca. 32?000–27?000 ¹⁴C yr BP are mixed with Late-glacial horse remains. The δ¹⁵N values of the Goyet Cave horse bones radiocarbon dated to the Pleniglacial are substantially higher than those that have Late-glacial radiocarbon dates. Therefore, we now hypothesise that the majority of the horse bones isotopically analysed from Goyet Cave Horizon 1 are Pleniglacial in age. Statistical analysis of the radiocarbon dates indicates that the Late-glacial occupation at the two sites was contemporaneous, and that while there may appear to be two phases of occupation at Trou de Chaleux, this may be an artefact of the radiocarbon calibration curve.