Plow Zone Research Articles

Diagenesis in freshwater mussel shell and its implications for provenance determination – Evidence from the Kinlock Site, 22SU526 (Yazoo Basin, Mississippi, U.S.A.)

Freshwater shells from archaeological contexts hold the potential to allow sourcing of shell-tempered ceramics on the basis of their chemical composition. This application, however, requires understanding chemical interaction of shell with the burial environment. Here, we use material recovered at Kinlock (22SU526), a Late Woodland - to Mississippian-period site located in the Yazoo Basin, Mississippi, U.S.A. as a case study to evaluate the presence and impact of diagenesis on Unionid shells. Twenty whole shells recovered from the plow zone and the sub-plow zone are analyzed using a combination of thin sections, Scanning Electron Microscopy, and Inductively Coupled Plasma-Mass Spectrometry. Results show that, contrary to what might be expected, shells from the sub-plow zone are more affected by diagenesis than samples from the plow zone. The chemistry of the shells from the sub-plow zone is affected by modern human contaminants (fertilizers) within a perched water table, and is no longer representative of the original composition of these samples, compromising their use in provenance research. Shells from within the plow zone are less affected by contamination, making them potentially more useful to generate background data for provenance studies.

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Old finds in new plough soils – Excavations of infield Stone Age sites in Southeastern Norway. This paper discusses the results of field archaeology in southeast Norway in the last ten years and concludes that infield Stone Age sites are rarely excavated in this region. Although the reasons are complex, this can partly be explained by the emphasis given to other types of sites and subjects, and is also related to the lack of a disciplinary tradition of survey and excavation of plough zone sites.The article also examines the value of infield Stone Age sites and presents and evaluates some of the methods used in recent excavations of plough soil settlements. Although some of these sites can provide new information about settlement patterns and the Stone Age economy, there are also sites that are of less interest. An important conclusion is that more focus should be given to the more productive sites both by applying new methods of survey and by excavations.

The roles of macro‐ and micro‐scale geophysical investigations to guide and monitor excavations at a Middle Woodland site in northern Georgia, USA

AbstractGeophysical investigations have become standard in archaeological practice to map sites and help select location for excavation, but the application of these techniques in real time during excavation to help anticipate feature location and maximize recovery has not been developed. This paper presents results from both traditional geophysics and new approaches to using these methods during excavations at Rice Farm (9DW276), a Middle Woodland site located in a broad floodplain adjacent to the Etowah River in north Georgia. Ground penetrating radar (GPR) at the surface was effective in recording reflection events indicative of archaeological features, such as hearths, posts and possibly ditches. Magnetometry was helpful, but less effective due to heavy plough zone scarring and noise from modern metallic debris. High‐frequency handheld GPR was helpful in monitoring excavations in real time and assisted excavators in anticipating the locations of both large and small diameter features. Excavation of geophysical anomalies exposed important features for the interpretation of this newly documented site.

Milling Force Prediction Model for Five-Axis Machining of Freeform Surface Considering Mesoscopic Size Effect

Abstract The core parts with the characteristic of freeform surface are widely used in the major equipment of various fields. Cutting force is the most important physical quantity in the five-axis CNC machining process of core parts. Not only in micro-milling, but also in macro-milling, there is also an obvious size effect, especially in medium- and high-speed milling, which is frequently ignored. In this paper, the milling force prediction model for five-axis machining of a freeform surface with a ball-end mill considering the mesoscopic size effect is established. Based on the characteristics of cutting thickness in macro-milling, a new dislocation density correction form is proposed, and a new experiment is designed to identify the dislocation density correction coefficient. Therefore, the shear stress calculated in this paper not only reflects the cutting dynamic mechanical characteristics but also considers the mesoscopic size effect. A linear function is proposed to describe the relationship between friction coefficient and cutting speed, cutter rake angle, and cutting thickness. Considering cutter run-out, the micro-element cutting force in the shear zone and plough zone are analyzed. The cutting geometry contact between the freeform surface and the ball-end mill is analyzed analytically by the space limitation method. Finally, the total milling force is obtained by summing all the force vectors of cutting edge micro-elements within the in-cut cutting edge. In the five-axis machining experiment of freeform surface, the theoretically predicted results of milling forces are in good agreement with the measured results in trend and amplitude.

Research on Parameter Optimization of Micro-Milling Al7075 Based on Edge-Size-Effect.

In the process of micro-milling, the appearance of the edge-size-effect of micro-milling tools cannot be ignored when the cutting parameters are smaller than the cutting edge arc radius (r0) of the micro-milling tool or close to it, and it could easily lead to low cutting efficiency and poor surface quality of the micro-slot. Through micro-milling experiments on Al7075-T6 materials, the change of milling force in the plough zone and shear zone during micro-milling was studied, and the minimum cutting thickness (hmin) range was determined to be 0.2r0–0.4r0 based on r0 of the micro-milling tool. Subsequently, the effect of fz/r0 (fz denotes feed rate per tooth) on the top burr formation of the micro-slot, the surface roughness (Ra) of the micro-slot bottom, and the milling force was studied, and a size-effect band of micro milling was established to determine the strong size-effect zone, transition size-effect zone, and the weak size-effect zone. Finally, two different fz/r0 in the strong size-effect zone and the weak size-effect zone are compared, which proves that the main purpose of the cutting parameters optimization of micro-milling is to avoid cutting parameters locating in the strong edge-size-effect zone. The above conclusions provide a theoretical basis for the selection of micro-milling cutting parameters, and an important reference in improving the surface quality of micro-milling.

Exploring socioeconomic relationships from surface survey ceramics: New methodologies from Bronze-Age Benta Valley, Hungary

A Phase II survey team collected samples of ceramics from the Benta Valley in the western Carpathian Basin of Hungary to identify secondary (rural) sites, determine their extent and density, and investigate everyday economic and social routines. By comparing ceramic attributes such as function, decoration, and exterior finish, the authors argue that studies of ceramics from plow zone contexts can address nuanced questions of social and economic behavior played out on the landscape beyond what can be investigated in traditional excavations, which are principally focused on tell centers. The efficient, low-cost survey demonstrates the potential of plow zone archaeology in studies of socioeconomic relations within settlement systems. This micro-regional approach and the methods involved can be employed on other survey projects in Hungary and beyond, as rescue excavations across the region are becoming standard practice.

Spatial and temporal variation of resource allocation in an arable soil drives community structure and biomass of nematodes and their role in the micro-food web

The assemblages of organisms residing at different soil horizons are important drivers for carbon and nutrient cycle in arable systems, yet knowledge on food web dynamics below the plough zone is sparse. The present study investigated the effects of management practice on the nematode community structure and biomass in the top soil, rooted zone below plough layer, and root free deeper soil in two successive vegetation periods. Resource quality was manipulated by crop plant (maize and wheat) and organic amendment (with/without maize litter), to differently fuel the major soil carbon pathways based on roots, bacteria and fungi. Nematode assemblages were used as model to determine changes in the structure, function and carbon allocation of the soil micro-food web.The biomass of nematode families as well as the fungal to bacterial feeder ratio F/(F+B) assigned a predominance of the bacterial carbon channel in the arable soil. The differences in spatial and temporal availability of major plant resources, i.e. litter (recalcitrant substrate) and rhizodeposits (labile carbon), separated the nematode fauna into meta-communities along the depth profile. The seasonal pattern in population density, and the positive effects of litter amendment predominantly in the top soil, indicated low migration between these patches during crop growth. However, mass-flow as resource subsidy for communities at depth takes place under fallow during winter. Crop type was most important for carbon allocation, with wheat generally resulting in a greater biomass build-up of nematodes. The biomass distribution of trophic groups differed with depth, pointing to a strong bottom-up effect in the root channel, whereas predation likely was the primary regulating force in the fungal channel. Overall, combining nematode community composition with biomass revealed spatially separated micro-food web assemblages, differing in structure and carbon allocation. Thereby transport processes cross community boundaries, linking top soil and subsoil, notably in periods without a crop.

The Woodland Period Component at the Wolfshead Site (41SA117), San Augustine County, Texas

The Wolfshead site (41SA117) was excavated by the Texas Archeological Salvage Project at The University of Texas in the fall and winter of 1960 prior to the inundation of the site by the waters of Lake Sam Rayburn in the Angelina River basin in East Texas. The site was located on a sandy terrace and covered ca. 1 acre in size; the sandy deposits were a maximum of ca. 60 cm in thickness below an historic plow zone. The excavations were in the northern and southern parts of the site, and indicated that the Wolfshead site had an extensive Late Paleoindian–Early Archaic San Patrice culture occupation dating ca. 10,500–9800 years B.P., as well as a Woodland period (ca. 2500–1150 years B.P.) occupation in both site areas. The latter occupation is a component of the inland and deep East Texas Mossy Grove culture defined by Story. This component is recognized by the occurrence of sandy paste Goose Creek Plain ceramic vessel sherds, contracting stem dart points (in the earlier part of the Woodland period), and various stemmed arrow points (after ca. A.D. 700 in the Woodland period).

Late Paleoindian–Early Archaic Dart Points from the Wolfshead Site (41SA117) in the Angelina River Basin in East Texas

The Wolfshead site (41SA117) was excavated by the Texas Archeological Salvage Project at The University of Texas in 1960 prior to the inundation of the site by the waters of Lake Sam Rayburn in the Angelina River basin in East Texas. The site was located on a sandy terrace and covered ca. 1 acre in size; the sandy deposits were a maximum of ca. 60 cm in thickness below an historic plow zone. The excavations in the northern and southern parts of the site indicated that the Wolfshead site had an extensive Late Paleoindian–Early Archaic San Patrice culture occupation estimated to date between ca. 10,500–9800 years B.P. based on the radiocarbon dating of archaeological deposits with San Patrice points in sites in the Woodland and Southern Plains in south central North America. San Patrice components cluster “in the eastern half of Texas, where prairies and woodlands would have predominated." The component at the Wolfshead site is marked by a number of distinctive dart points, as discussed in the next section, as well as scraping tools, and Albany scrapers. The Albany scrapers were made on local petrified wood, while the unifacial side and end scrapers were manufactured on both petrified wood and pebble cherts.

Temporal and seasonal variations of As, Cd and Pb atmospheric deposition flux in the vicinity of lead smelters in Jiyuan, China

Atmospheric deposition from non-ferrous mining and smelting is one of the dominant sources of heavy metal pollution in soil. Jiyuan City in Henan Province, China produces about 900 000 tonnes of lead annually. Heavy metal soil contamination and elevated blood lead levels (BLLs) of local children in Jiyuan have been reported. This work investigated As, Cd and Pb deposition fluxes over 17 consecutive months at collection sites about 1000 m from a major lead smelter in Jiyuan. Mean As, Cd and Pb deposition fluxes were 17.2, 3.45 and 88.8 mg/m2/(30 d), respectively, lower values occurred from July to September during the traditional rainy season. Decreasing deposition fluxes of Cd and Pb were observed during the 17 month period, while As increased in the same period. Deposition fluxes of As, Cd and Pb of the sites near the smelter were 22.6, 29.2 and 29.4 times of those of a clean background site (0.762, 0.118 and 3.03 mg/m2/(30 d), respectively) far away from the smelter. Annually, the deposition enriches agricultural soil (0–20 cm plow zone) at the sampling sites with 0.805, 0.161 and 4.16 mg/kg As, Cd and Pb, respectively.

Physico-chemical Properties of Disturbed Plastic Film House Soils under Cucumber and Grape Cultivation as Affected by Artificial Accumulation History

This study was carried out to investigate the effects of profile disturbance with different artificial accumulation history on physico-chemical properties of soil under plastic film house. The investigations included soil profile description using soil column cylinder auger F10cm x h110cm, in situ and laboratory measurements of soil properties at five sites each at the cucumber (Site Ic ~ Vc) and grape (Site Ig ~ Vg) plastic film houses with artificial soil accumulation. The sites except sites Ic, IVc, IVg and Vg, belong to ex-paddy area. The types of accumulates around root zone included sandy loam soil for 3 sites, loam soil for 1 site, saprolite for 2 sites, and multi-layer with different accumulates for 3 sites. Especially, Site IIg has mixed plow zone (Ap horizon) with original soil and saprolite, whereas disturbed soil layers of the other sites are composed of only external accumulates. The soil depth disturbed by artificial accumulation ranged from 20 cm, for Site IIg, to whole measured depth of 110 cm, for Site IVc, Vc, and Site IVg. Elapsed time from artificially accumulation to investigation time ranged from 3 months, Site IIc, to more than 20 years, Site Vg, paddy-soil covering over well-drained upland soil during land leveling in 1980s. Disturbed top layer in all sites except Site Vg had no structure, indicating low structural stability. In situ infiltration rate had no correlation with texture or organic matter content, but highest value with highest variability in Site IIIc, the shortest elapsed time since sandy loam soil accumulation. Relatively low infiltration rate was observed in sites accumulated by saprolite with coarse texture, presumably because its low structural stability in the way of weathering process could result in relatively high compaction in agro-machine work or irrigation. In all cucumber sites, there were water-transport limited zone with very low permeable or impermeability within 50 cm under soil surface, but Site IIg, IIIg, and Vg, with relatively weak disturbance or structured soil, were the reverse. We observed the big change in texture and re-increase of organic matter content, available phosphate, and exchangeable cations between disturbed layer and original soil layer. This study, therefore, suggest that the accumulation of coarse material such as saprolite for cultivating cash crop under plastic film house might not improve soil drainage and structural stability, inversely showing weaker disturbance of original soil profile with higher drainage.

The T. M. Joslin Site (41VN3) in the Sabine River Basin, Van Zandt County, Texas

The T. M. Joslin site (41VN3) is a multi-component prehistoric site that was investigated by the University of Texas (UT) in September 1940 as Works Progress Administration (WPA) Project No. 15409. The excavations began immediately after the UT WPA crew had finished work at the nearby Yarbrough site (41VN6). The site is on a sandy knoll on Caney Creek, a northward-flowing tributary of the Sabine River in the Post Oak Savannah of East Texas. Supervised by William A. Duffen of UT, a crew of 16 local laborers excavated a 100 x 100 ft. block (30.5 x 30.5 m) on the knoll between September 12-30, 1940. The local labor began their excavations with shovels at the southern end of the block, and moved north at the completion of each 10 ft. row, working from the completed vertical face of the previous row. The archaeological deposits were described by Duffen as a shallow midden overlying a red clay subsoil; the subsoil was reached between 1.0-1.3 ft. bs (ca. 30-41 cm bs) and the upper plow zone extended from 0-13 cm bs. No cultural features were identified in the WPA excavations, but a very large Canton Incised jar was reconstructed from a large sherd concentration encountered at ca. 25 cm bs. A. T. Jackson, who had first visited the site in the Spring of 1930, before he began to work at UT, had discovered in a “test hole” portions of a large ceramic bowl (36 cm in diameter) and a large water bottle, presumably from a Caddo burial feature, but he did not further explore the feature. About 15 m away he found remnants of a dog burial. It is not known where these finds were in relationship to the WPA excavations.

Mapping plow zone soil magnetism to delineate disturbed archaeological site boundaries

This paper presents the results of a magnetic susceptibility survey at Ocmulgee National Monument, a large archaeological site located in central Georgia. Ocmulgee consists of numerous bluffs, each subjected to plowing and erosion. Archaeological remains preserved differentially better on some bluffs, while remains on other bluffs have been obliterated. Magnetic susceptibility readings were recorded in the plow zone on Mound X Ridge, an area of the site that is significantly disturbed. Although the archaeological site is no longer intact, superparamagnetic micro-particles from daub, ceramics, or charcoal have been mixed from 100 years of plowing and remain in the plow zone. The goal of the project was to delineate the northern boundary of this activity area. Thirty posthole tests were excavated and the presence or absence of artifacts from each posthole test was recorded. Magnetic susceptibility values were also recorded in the plow zone following excavation of each test. The positive correlation of high susceptibility values with presence of artifacts indicates this method is useful for mapping disturbed site boundaries of plowed archaeological sites. This method is quicker than more traditional invasive testing and does not further disturb archaeological remains if posthole tests are not excavated below the plow zone.

Temporal variation in surface and subsoil abundance and function of the soil microbial community in an arable soil

Many studies of the microbial ecology of agricultural ecosystems focus on surface soils, whereas the impacts of management practice and season on soil microbial community composition and function below the plough zone are largely neglected. Deep soils have a high potential to store carbon; therefore any management driven stimulation or repression of microorganisms in subsoil could impact biogeochemical cycling in agricultural sites. The aim of this study was to understand whether soil management affects microbial communities in the topsoil (0–10 cm), rooted zone beneath the plough layer (40–50 cm), and the unrooted zone (60–70 cm). In a field experiment with different crops [wheat (Triticum aestivum L.) and maize (Zea mays L.)] and agricultural management strategies (litter amendment) we analysed microbial biomass as phospholipid fatty acids (PLFAs) and enzyme activities involved in the C-cycle (β-glucosidase, N-acetyl-β-d-glucosaminidase, β-xylosidase, phenol- and peroxidase) across a depth transect over a period of two years. Wheat cultivation resulted in higher bacterial and fungal biomass as well as higher enzyme activities at most sampling dates in comparison to maize cultivated plots, and this effect was visible to 50 cm depth. Litter application increased bacterial and fungal biomass as well as hydrolytic enzyme activities but effects were apparent only in the topsoil. In winter high microbial biomass and enzyme activities were measured in all soil layers, possibly due to increased mobilization and translocation of organic matter into deeper soil. Hydrolytic enzyme activities decreased with depth, whereas oxidative enzyme activities showed no decrease or even an increase with depth. This could have been due to differing sorption mechanisms of hydrolytic and oxidative enzymes. Specific enzyme activities (enzyme activity per microbial biomass) were higher in the deeper layers and possible reasons are discussed.

Late Woodland-Emergent Mississippian Occupation and Plant Use at the AE Harmon Site (11MS136)

AbstractThe 2002 Southern Illinois University Edwardsville field school was conducted at the AE Harmon site (11MS136), located on the bluff above the American Bottom in Edwardsville, Illinois. Artifacts recovered from the plow zone indicate that the site was occupied from the Archaic through Mississippian periods. Sub-plow zone excavations revealed a prehistoric house structure and six pit features. The style of the structure, as well as artifacts recovered from the structure and several associated pits, indicate occupation during the Late Woodland and Emergent Mississippian periods. Prehistoric activities at the site included manufacture, use, and maintenance of lithic artifacts, as well as ceramic manufacture. Subsistence remains show that native cultigens, maize, nuts, wild plants, fish, and venison were consumed. The sample of plant remains reported here adds to the Late Woodland-Emergent Mississippian paleoethnobotanical database for the American Bottom, most notably for the Late Woodland Sponemann p...

Behavior of Simetryn and Thiobencarb in the Plough Zone of Rice Fields

The behavior of simetryn and thiobencarb in flooded rice soil was investigated in a 2-year study. The concentrations of simetryn and thiobencarb were in the hundreds of μg kg−1 in the top soil layer (0–5 cm) and became significantly lower in tens of μg kg−1 in the deeper soil layers (5–10 and 10–15 cm). The half-lives of the two herbicides were also shorter (36 and 17 days for simetryn and thiobencarb, respectively) in the top soil layer, as they were most affected by environmental conditions, compared with corresponding values of 82 and 69 days in the 5–10 cm soil layer. Simetryn concentration was stable, while thiobencarb’s half-life was 165 days in the 10–15 cm layer. About 35% of the applied mass of simetryn and thiobencarb were found in the rice soil compartment.

Woodland Adaptations at the Vergennes Substation (VT-AD-1474), a Native American Site, Vergennes, Vermont

The University of Massachusetts identified, evaluated, and completed a data recovery survey in 2006 and 2007 of the Vergennes Substation site in advance of construction of an electrical substation. The excavations documented a series of lithic work areas and 1 burn episode in association with several postmolds and over 14,000 lithic artifacts. Levanna projectile points predominate the diagnostic artifacts, which also include a Meadowood perforator. The site is interpreted as representing a hunting camp with ongoing tool reworking. The project highlights the dangers of writing off a site in CRM contexts based on limited Phase I finds, as well as the amount of information that can be gathered from primarily plow zone contexts, using tight sampling procedures.

Exploring Surface Collected Data with Spatial Analysis Methods

Surface collection is commonly conducted as a first step in the investigation of many archaeological sites. Such data are often used to provide information concerning the subsurface nature of the site. In some instances, the surface collected data can provide additional information concerning the site component(s) represented at a site. In cases where intact cultural deposits are not present below the base of the plow zone, surface collected data may represent the only chance of understanding the site. In this article, we apply spatial analysis methods to surface collection data from two prehistoric sites (15Hr14 and 15FL104) in Kentucky. By combining the results of the spatial analysis with that of the lithic analysis, additional data concerning both sites are brought to light.

Evidence for Paleoindians in Wisconsin and at the Skare Site

The Skare site, situated along the Yahara River in southern Wisconsin, has produced evidence of human activity spanning from Paleoindian times to the early Euro-American settlement of Wisconsin. During recent excavations at the site, two Paleoindian artifacts, the base of a Folsom biface and a heavily reworked Dalton biface, were found below the plow zone. Inventories of Paleoindian sites and fluted biface distributions primarily documented in the surface archaeology of Wisconsin are examined to establish a regional settlement context for the Skare site and to investigate the nature of Paleoindian exploration and colonization of the state. Areas with the highest numbers of known Paleoindian sites and reported fluted bifaces correspond with resource-rich habitats, unique lithic raw material sources, and regions that have been the focus of Paleoindian research and fluted biface collecting. Clovis bifaces are found across the state, while Folsom bifaces are largely restricted to the southern half of the state. A comparison of Early and Late Paleoindian site distributions indicates that Paleoindian exploration of the state occurred relatively rapidly following the last glacial retreat.

The analysis of soil cores polluted with certain metals using the Box–Cox transformation

To define the soil properties for a given area or country including the level of pollution, soil survey and inventory programs are essential tools. Soil data transformations enable the expression of the original data on a new scale, more suitable for data analysis. In the computer-aided interactive analysis of large data files of soil characteristics containing outliers, the diagnostic plots of the exploratory data analysis (EDA) often find that the sample distribution is systematically skewed or reject sample homogeneity. Under such circumstances the original data should be transformed. The Box–Cox transformation improves sample symmetry and stabilizes spread. The logarithmic plot of a profile likelihood function enables the optimum transformation parameter to be found. Here, a proposed procedure for data transformation in univariate data analysis is illustrated on a determination of cadmium content in the plough zone of agricultural soils. A typical soil pollution survey concerns the determination of the elements Be (16 544 values available), Cd (40 317 values), Co (22 176 values), Cr (40 318 values), Hg (32 344 values), Ni (34 989 values), Pb (40 344 values), V (20 373 values) and Zn (36 123 values) in large samples.