Shallow site archaeology: Artifact dispersal,stratigraphy, and radiocarbon dating at the Barger Gulch locality B Folsom Site,Middle Park,Colorado

Shallowly buried archaeological sites are particularly susceptible to surface and subsurface disturbance processes. Yet, because cultural deposition often operates on short time scales relative to geologic deposition, vertical artifact distributions can be used to clarify questions of site formation. In particular, patterns in artifact distributions that cannot be explained by occupation histories must be explained by natural processes that have affected sites. Buried only 10–50 cm beneath the ground surface for 10,450 ¹⁴C yr, the Folsom component at Barger Gulch Locality B (Middle Park, Colorado) exhibits many signs of post‐depositional disturbance. Through examination of variation in the vertical distribution of the artifact assemblage, we are able to establish that only a Folsom component is present. Using vertical artifact distributions, stratigraphy, and radiocarbon dating, we are able to reconstruct the series of events that have impacted the site. The Folsom occupation (˜10,450 ¹⁴C yr B.P.) was likely initially buried in a late‐Pleistocene eolian silt loam. Erosion brought the artifacts to rest on a deflation surface at some time prior to 9400 ¹⁴C yr B.P. A mollic epipedon formed in sediments that accumulated between 9400 and 7000 ¹⁴C yr B.P. Some time after 5200 ¹⁴C yr B.P., this soil was partially truncated, and artifacts that had previously dispersed upward created a secondary lag at its upper contact. This surface was buried again and artifact dispersal continued. © 2005 Wiley Periodicals, Inc.     

Geoarchaeological investigations at the upper Paleolithic site of Kamihoronai‐Moi,Hokkaido, Japan

In order to better understand modern human behavioral variability in Hokkaido, Japan, we consider the geoarchaeology of the Kamihoronai‐Moi site in terms of its geochronology, stratigraphy, depositional environments, and post‐depositional disturbances. A Paleolithic component is stratigraphically situated between the Eniwa‐a (15,000–17,000 ¹⁴C yr B.P.) and the Tarumae‐d (8000–9000 ¹⁴C yr B.P.) tephras. Moreover, six AMS ¹⁴C ages on charcoal from a Pleistocene‐aged hearth feature are between 14,400 and 14,800 ¹⁴C yr B.P. Quantitative examinations of patterns in artifact distributions show a low degree of vertical and horizontal displacement of chipped‐stone artifacts, suggesting that post‐depositional movement of the cultural material was insufficient to disrupt the original pattern of artifact distribution. © 2009 Wiley Periodicals, Inc.     

Beyond stratigraphic noise: Unraveling the evolution of stratified assemblages in faunalturbated sites

This study explores the stratigraphic evolution of archaeological assemblages in faunalturbated sites. These sites are sometimes described as having limited archaeological value because of varying degrees of occupation mixing. It is argued here that the vertical distribution of assemblages is predictable in faunalturbated contexts. Understanding this vertical evolution may lead to a better assessment of the archaeological potential of a cultural sequence. In faunalturbated soils, the stratigraphic evolution of the assemblages is largely dictated by faunal activity. Tunneling by small animals tend to “sink” cultural remains through the deposits. Although objects sink at a relatively fast pace near the surface, the process slows down as the objects reach the bottom of the biomantle where the sediments are more compact. This process affects the shape of the artifact vertical distribution. The analysis of a multicomponent site from southern Québec is used to model how assemblages may evolve temporally in faunalturbated settings. At Station 3‐avant, the stratigraphic distribution of the cultural remains appears to evolve from an upward‐skewed distribution to a bottom‐skewed distribution through time. This evolution is interpreted to result from the fact that objects are often too large and/or heavy to be moved upward by the pedofauna. In situations in which this stage of stratigraphic evolution is not yet reached, enough information about temporal successions may be retained for the site to be useful for investigating diachronic change. This may prove invaluable in regions in which faunalturbated sequences are common. © 2006 Wiley Periodicals, Inc.     

Stone artifact scatters in western NSW,Australia: Geomorphic controls on artifact size and distribution

Surface scatters of Aboriginal stone artifacts have been exposed in many parts of inland Australia by accelerated erosion that followed the introduction of pastoralism by European settlers in the 19th century. This paper reports on a set of techniques developed to investigate and quantify the effects of these post‐discard disturbance processes in Sturt National Park in northwest NSW, Australia. Backwards, stepwise, linear regression showed the influence of geomorphic parameters such as slope gradient, elevation, landform, and contemporary surface processes on artifact distribution, with artifact maximum dimension as the dependent variable. The results indicate that, even at low gradients, artifact size and slope angle are significantly related, but that the variance in maximum dimension explained by gradient is very low. Similar results were found for the other geomorphic variables. We conclude that artifact movement by surface wash across these surfaces is unlikely to significantly affect artifact distribution. While vertically conflated surface scatters do not preserve “living floors” in a short‐term, functional sense, their apparent horizontal integrity allows investigation of the long‐term use of place by hunter‐gatherer people in the past. Insofar as assemblage integrity is important for assessing site significance in the heritage management industry, our methods provide a means for assessing the degree to which a site has been damaged by water flow. © 2001 John Wiley & Sons, Inc.     

Comparison of sedimentation and occupation histories inside and outside rock shelters,Keep‐River region,northwestern Australia

This paper compares archaeological evidence of Aboriginal occupation inside rock shelters and outside in adjacent sand sheets, focusing on two locations in the Keep‐River region, northwestern Australia. Luminescence and radiocarbon dating reveal that occupation sequences inside rock shelters are generally younger ( < 10,000 yr B.P.) than outside ( < 18,000 yr B.P.). Differences in occupation chronology and artifact assemblages inside and outside rock shelters result from depositional and postdepositional processes and shifts in site function. An increase in regional sedimentation rate from 10 cm/ka ^{− 1} in the Pleistocene to 20 cm/ka ^{− 1} in the Holocene may account for late buildup of sediments within rock shelters, increased artifact accumulation, and reduced postdepositional disturbance in some settings. More intense use of rock shelters in the Late Holocene is indicated from a change in hunting technology and greater production of rock art. The results indicate that some cultural interpretations might be flawed unless archaeological evidence from rock‐shelter and open‐site excavations is integrated. © 2006 Wiley Periodicals, Inc.     

Building cultural chronology in Eastern Washington: The influence of geochronology,index fossils,and radiocarbon dating

Until the early 1950s, it was believed that the archaeological record of eastern Washington state did not exceed 4000 years. That belief changed in the middle 1950s after discovery of the Lind Coulee site (45GR97), originally dated to the Holocene on the basis of geochronological data and subsequently dated via radiocarbon to 8700 B.P. Geochronology and geoarchaeology provided temporal control and resulted in archaeological time being measured discontinuously as stratigraphically associated sets of artifacts were stacked one upon the other. Percentage stratigraphy and frequency seriation played no role in the measurement of time or the construction of cultural chronologies. Local cultural chronologies originally constructed on the basis of chronostratigraphic marker horizons were not significantly altered in the 1960s and 1970s because few radiocarbon ages were run and the chronological validity of the ages was questioned. The increased intensity of cultural resource management in the 1980s witnessed a marked increased in the production of radiocarbon ages, but extant cultural chronologies have not been significantly altered in structure or appearance. © 2000 John Wiley & Sons, Inc.     

Redistribution of archaeological assemblages in plowzones

Archaeological surface surveys have located open‐air sites on cropland in the Sierra de Atapuerca (Burgos, Spain). To what degree agricultural disturbances have impacted archaeological site integrity is poorly defined and may greatly affect interpretations of prehistoric land use. This paper presents the results of three experiments concerned with the effects of tillage on artifact distribution, focusing specifically on lateral and vertical artifact displacement. We demonstrate highly variable horizontal displacement of artifacts by plowing and overall downward movement of lithic materials within the soil. This results in an expansion of site boundaries and reduction of surface artifact density, yielding a biased and unrepresentative picture of past human activity. More experimental studies are needed to better define agricultural disturbances to surface archaeological assemblages. © 2008 Wiley Periodicals, Inc.     

Integrating surface and subsurface reconnaissance data in the study of stratigraphically complex sites: Blagotin,Serbia

This article demonstrates the application of multiple reconnaissance methods as an efficient means of localizing desired data sets (e.g., artifact concentrations and architectural features) in stratigraphically complex sites. Excavations at Blagotin, Serbia, are presented as an example. Blagotin is a multioccupation site with vertically superimposed and laterally displaced cultural deposits. The application of a battery of survey techniques and the integration of the results enabled the author to define periods of occupation (Early Neolithic, Eneolithic, Early Iron Age), distinguish temporal variations, and predict the nature and distribution of subsurface archaeological remains. Ultimately, the Early Neolithic occupation is shown to consist of a small settlement with a large central pit‐house surrounded by a ring of smaller pit houses. This interpretation of the intra‐settlement spatial organization, made possible through the application of a multiple survey technique, differs from those previously offered for these types of sites. © 2000 John Wiley & Sons, Inc.     

Multiple approaches to formation processes: The Pine Spring Site,southwest Wyoming

Excavations in 1964 at the Pine Spring site in southwest Wyoming concluded that the site contains three cultural occupation levels; the earliest allegedly dates to the terminal Pleistocene and is associated with megafauna. However, excavations in 1998 and 2000, and analysis of the stratigraphy, AMS dates, micromorphology, and artifact carbonate isotopes, along with debitage refitting, density, orientation, inclination, burning, and trample damage, could not replicate the 1964 findings. A hiatus in deposition accounts for the highest density of artifacts, and the three original occupations are palimpsests. There is no unequivocal association between evidence of human activity and megafaunal remains. © 2006 Wiley Periodicals, Inc.     

Single‐Grain Luminescence Dating of Sediment Surrounding a Possible Late Pleistocene Artifact from the Wenas Creek Mammoth Site,Pacific Northwest,USA

Excavations at the Wenas Creek Mammoth Site yielded mammoth, bison, and two possible artifacts in a single colluvial stratum, with radiocarbon bone dates ∼17 ka. Eight infrared‐stimulated luminescence (IRSL) samples were collected to establish general ages of site strata, returning multi‐grain estimates consistent with stratigraphic integrity and the radiocarbon dates. Four additional IRSL samples were collected to estimate the depositional age of one artifact found in place. These produced a pooled total of 94 single‐grain estimates from near the artifact, 80% averaging 16.8 ± 0.9 ka, and 20% averaging 5.1 ± 0.5 ka. These results could be interpreted to demonstrate pre‐Clovis age artifact deposition consistent with the bone dates, or a mid to late Holocene intrusion into older deposits, possibly by bioturbation. The single‐grain IRSL dates do not provide proof of pre‐Clovis presence beyond reasonable doubt at this site, but do show that this technique is valuable in assessing the stratigraphic integrity needed for any such claim.     

Distinguishing bioturbation and trampling using pottery sherd measures,Tell Fendi,Jordan

In the Levant, the blind mole‐rat (Spalax ehrenbergi) is responsible for much disturbance at archaeological sites, but its potential destructiveness is often ignored when cultural remains are interpreted. The effects of mole‐rat burrowing on artifact distributions were evaluated through a study of mole‐hill contents and by doing a vertical particle‐size analysis of ceramic materials drawn from Tell Fendi, a Late Chalcolithic (6600–5500 B.P.) site in the Jordan Valley. While the general effects of animal burrowing are predictable to some degree, stratigraphic units affected by burrowing may not be immediately obvious to the archaeologist. The problem of identification is compounded because other disturbance processes produce similar effects. This study proposes a method for identifying bioturbation layers and for distinguishing these layers from both trampled surfaces and in situ contexts by means of pottery sherd measures. © 2000 John Wiley & Sons, Inc.     

Phytolith analysis of an archaeological site (longshan period) in Zhumadian City,Henan Province,China: Paleoenvironmental and cultural implications

With phytolith analysis of an archaeological site (Longshan Culture Period, 4800-4000 B. P.) in Zhumadian City of Henan Province, environmental and cultural information have been obtained. Phytolith assemblages both from the site and from a nearby ancient lake deposit of the same period indicate a warm and wet climate. Since this area is in an environment outside the natural distribution of wild rice, abundant “scooped” bilobate and special glume epidermal phytoliths found in all of the cultural layers and two samples of the lake deposits suggest that rice was cultivated in this region by the local people. © 1994 John Wiley & Sons, Inc.     

郑州织机洞遗址MIS 3阶段古人类活动的环境背景

MIS3阶段,即深海氧同位素第3阶段,是末次冰期中气候比较温暖湿润的时期。大量的考古调查资料表明,这个阶段也是末次冰期中人类活动最活跃的时期,当时不仅人类遗址的数量明显增多,而且石制品也较前也有较大的进步和发展。人类活动与气候环境之间的耦合关系似乎暗示着两者之间存在着某种内在的联系,适宜的气候环境可能是导致人类活动活跃的重要原因。河南郑州织机洞遗址是我国北方重要的旧石器文化中-晚期洞穴遗址,包括上、中、下3个文化层,其中,下文化层距今5.0～3.5万年,属MIS3阶段。本文试以织机洞遗址下文化层为主要研究对象,结合洞外黄土-古土壤剖面的研究,就我国中原地区MIS3阶段人类活动的环境背景做一初步的分析。分析结果表明,在这一阶段,中原地区属于暖温带草原-森林草原环境,气候比较温暖湿润,适宜于人类生活。其中,距今5.0万年前后的MIS3阶段早期,是MIS3阶段中气候最为适宜的时期,也是人类活动最为活跃的时期,当时生长有落叶阔叶树的暖温带森林草原环境,为MIS3阶段旧石器文化的繁荣和发展提供了重要的环境背景。     

Changing patterns in the late Pleistocene/early Holocene prehistory of Southern Africa as seen from the Nelson Bay Cave Stone artifact sequence

The dating of the Stone Age sequence in southern Africa has been considerably revised over the last decade, and one of the anomalies which has resulted is that the Middle Stone Age, now dated to beyond 30,000 B.P., does not immediately precede the Later Stone Age sensu stricto. The excavation and analysis of occupation horizons dating between the most recent Middle Stone Age assemblages and the Holocene is therefore of particular interest. Nelson Bay Cave, situated on the southern coast of South Africa, contains deposits which partly fill the “gap” between the Middle and Later Stone Ages, and the occupation horizons dating between about 18,000 and 5000 years ago are described in this paper. Changes in the habitat in the vicinity of the site caused by sea-level and vegetation changes coincident with the amelioration of temperatures at the end of the Pleistocene are clearly marked in the faunal remains at the site. Largely correlated with the faunal changes (which includes the introduction of marine resources to the cave at about 12,000 B.P.) are changes in the stone artifact assemblages. Three industries are recognized in the sequence: the Robberg, characterized by microbladelets produced from bladelet cores and a few small scrapers and backed tools; the Albany, characterized by large scrapers and an absence of backed tools; and the Wilton, characterized by a variety of Formal Tools including relatively large numbers of small scrapers and backed tools. These changes in artifact-manufacturing traditions are interpreted as signaling adjustments to changing environmental conditions. An explanation for these adjustments is not sought in a simple cause-and-effect relationship between the environment and the cultural response; artifact changes are seen instead as the result of a twofold process, with the environment acting as an external stimulus to change, and the direction of the artifact change governed by the selection of a range of possibilities offered by the technology of the Later Stone Age sensu lato that was widespread in subequatorial Africa during the last 20,000 years.     

The Pleistocene hominid site of Ternifine, Algeria: New results on the environment, age, and human industries

A new multidisciplinary research program, started in 1981, provided new data on the stratigraphy, fauna, and human industries, as well as the first results on paleomagnetism and sedimentology, for the Ternifine site in Algeria, which yielded the earliest hominid remains known in North Africa. The fossils were deposited in a swamp or lake surrounded by a very open, dry environment. The lake was fed by artesian springs that raised the underlying Miocene sands. Although nothing suggests a camp or butchery site, we discovered the first undisputable bone artifact in this site, the earliest known in this part of Africa. According to paleontological data, 700,000 yr B.P. is a likely age for the Ternifine deposits, which is consistent with the paleomagnetic results.     

Optical and thermoluminescence dating of Middle Stone Age and Kintampo bearing sediments at Birimi,a multi-component archaeological site in Ghana

We report the first luminescence ages for the archeological and geological sediments forming the substrate of the Birimi archaeological site in the Northern Region of Ghana. The site's significance rests on the fact that it contains a rich collection of artifact assemblages representative of three distinct cultures, and that, on the basis of artifact typology, the earliest assemblage is diagnostic of the Middle Stone Age (MSA). In situ occurrences of MSA artifacts are found at over 1 m below today's surface. They are overlain by a ceramic-rich complex of a sedentary or semi-sendentary Later Stone Age culture known as the Kintampo. The western half of the site is dominated by the industrial remains of Iron Age smelting activity.Elemental, mineralogical, and sedimentological analysis of the cultural and sub-cultural sedimentary horizons at the site revealed at least three distinct lithostratigraphic units. The quartz sediments are derived from the sandstone of the Gambaga escarpment, mass wasted and accreted fluvially at a rate of 3.2 cm/ka, forming a wide terrace at Birimi. Silts and finer fractions derive from windblown dust, likely from White Volta River and granitic sources to the north. Soil forming processes and wide fluctuations in moisture have progressively reduced the sediments at depth to the resistant quartz and kaolinite, with rich iron oxide coatings, and created two ironstone horizons composed of goethite-cemented quartz nodules.Multiple aliquot green-light stimulated optical ages for 125–150 μm quartz grains yielded ages of 23.6±2.9 and 40.8±11.8 ka for the MSA-bearing sediments, and 58.4±15.3 ka for the base of the terrace. Radiocarbon ages on charcoal from Kintampo-bearing units are 3.36–3.83 ka cal BP, and are supported by thermoluminescence (TL) ages on pottery sherds and burnt house daub fragments of this cultural complex. A 0.4 ka age on sediment from the site's surface confirms that the quartz zeroes well when exposed to natural light. Sediments bearing the Kintampo artifacts, however, yielded ages of 7.8–16.9 ka. These ages were obtained on sediments from large pits, some over 50 cm deep, and they deviate only slightly from the ages expected for naturally aggraded sediments at these depths. We conclude, therefore, that extensive digging of pits by the Kintampo dwellers was followed by rapid refilling, and that the bulk mobilization of the matrix did not permit the sedimentary quartz grains to experience any appreciable zeroing at that time.     

Paleoeskimo site taphonomy: An assessment of the integrity of the Tayara site,Qikirtaq Island,Nunavik, Canada

A detailed taphonomic study was undertaken at the Tayara site in order to determine the impact of natural processes such as surface water flow on spatial patterning and site formation. The study focused on Paleoeskimo level II, which contains many lithics and significant faunal remains. Level II integrity was assessed through spatial analysis and by examining the size distribution of lithic artifacts and bone orientation. Experimental knapping aimed at replicating Paleoeskimo lithic technology was used to assess the possible size sorting of lithics. The study indicates that artifact burial by water‐laid sediments did not result in a selective impoverishment in small‐sized lithics. Statistically significant lithic concentrations and associations suggest that spatial distribution was not significantly modified by site formation processes. However, slight post‐depositional changes were presumably induced by water flows in the form of statistically significant horizontal bone reorientations. These occurred when gently flowing water inundated bone accumulations without inducing significant washing or sorting of smaller lithic debris. The spatial integrity evaluation of the level II assemblage reveals a low degree of spatial disturbance and disorganization of the material (i.e., limited entropy), which is likely related to low‐energy hydraulic forces and rapid burial soon after Paleoeskimo occupation. The grouping and deposition of much of the occupation debris is likely the result of Paleoeskimo activities (e.g., knapping and butchering), and the lithics and fauna specimens are probably at or very near their original location. These results show the behavioral significance of the grouping and deposition of debris in Tayara's level II. © 2009 Wiley Periodicals, Inc.     

Evaluating artifact burial by eolian versus bioturbation processes,South Carolina Sandhills,USA

Artifacts are commonly buried by approximately 50 cm of sediment at prehistoric archeological sites (early Archaic through Mississippian) on uplands of the Sandhills of the upper Coastal Plain of the southeastern United States. Bioturbation, eolian sedimentation, and colluviation are the primary processes that can explain artifact burial because of the upland position of the sites in an erosional landscape setting. Colluvial sedimentation is discounted at most of the sites because they occur on interstream divides and upper hillslope positions. Thus, the focus is on eolian sedimentation versus bioturbation as burial agents. Six sites in the midst of the Sandhills region along the corridor of South Carolina Highway 151 in Chesterfield County provide the data. The Sandhills consist primarily of Cretaceous and Tertiary marine, fluvial, and eolian sediments that are highly dissected and overlie crystalline rocks in the deep subsurface. Two of the sites are on high fluvial terrace remnants that predate 12 ka and serve as controls where bioturbation is the only reasonable burial process. Hillslope positions of the sites are on erosional elements of the landscape (crests, shoulder slopes, and upper backslopes) where sediment transfer operates (colluvial and overland flow), but where deposition is minimal. The sites occur on very sandy soils having a texture of loamy sand to sand. In some instances, a fine textured cover sand, which is about 1.5 m thick, overlies a clayey subsoil or Bt horizon. This cover sand has been interpreted by some as an eolian sand sheet that buries a second parent material and paleosol, but standard particle size and heavy mineral data indicate that it is simply a thick E horizon over a Bt horizon. Standard particle size fractionation at whole phi intervals, and particle size analysis of the heavy mineral fraction, indicate that eolian sedimentation is unlikely at five of the six sites. Heavy minerals were analyzed with respect to the sedimentological principle of hydraulic equivalence, which provides clear separation of eolian versus water-laid sediment. Results of particle size analysis suggest that the cover sands are water-laid (probably fluvial) at five of the six sites, which favors the bioturbation process of artifact burial. Heavy mineral analysis corroborates the standard particle size data, indicating that only one site, 38CT16, possibly is composed of eolian sediment. Soil profile development suggests that the age of the sediment at site 38CT16 probably is older than 12 ka and was in place prior to human occupation. Therefore, possible eolian sedimentation at that site is not relevant to artifact burial, which also suggests bioturbation is the primary process of artifact burial. Additional evidence favoring bioturbation as a vigorous artifact burial process in the Sandhills comes from the two sites on high elevation sandy fluvial terraces (38CT34, 38CT17) where artifacts are also buried. At these terraced sites bioturbation is the only possible burial process. Overall results suggest that bioturbation best explains the occurrence of buried artifacts and that eolian sedimentation processes are not readily apparent, and are not required, in explaining artifact burial. © 1998 John Wiley & Sons, Inc.     

Desert Pavement Disturbance and Artifact Taphonomy: A Case Study from the Eastern Libyan Plateau,Egypt

Accretionary desert pavements on the eastern Libyan Plateau of central Egypt support a rich Middle and Upper Paleolithic artifact assemblage exhibiting intensive blank production and minimal tool production. These assemblages appear to be in primary context with numerous examples of lithic refits showing on‐site lithic production. However, the smallest (length ≤2.5 cm) archaeological fragments are recovered at a much lower rate on this desert pavement surface than expected given comparable data from lithic assemblages in cave and shelter contexts in France. Excavation of archaeological contexts on the Libyan Plateau reveals the loss of small artifact fragments into the subsurface due to aeolian accumulation of silts, whereas geomorphic examination of desert pavement surfaces suggests a potential for relatively isolated bioturbation as a source of lateral and vertical disturbance of desert pavement surfaces over small areas. Archaeologists should be aware of the potential for long‐term assemblage stability as well as small artifact burial in surficial desert pavement contexts.