Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1?C3%/year) of N-mineralization rates. The end-member values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e.g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization.     

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest,Part 1: The Southern Colorado Plateau and Rio Grande Regions

Maize is the New World’s preeminent grain crop and it provided the economic basis for human culture in many regions within the Americas. To flourish, maize needs water, sunlight (heat), and nutrients (e.g., nitrogen). In this paper, climate and soil chemistry data are used to evaluate the potential for dryland (rain-on-field) agriculture in the semiarid southeastern Colorado Plateau and Rio Grande regions. Processes that impact maize agriculture such as nitrogen mineralization, infiltration of precipitation, bare soil evaporation, and transpiration are discussed and evaluated. Most of the study area, excepting high-elevation regions, receives sufficient solar radiation to grow maize. The salinities of subsurface soils in the central San Juan Basin are very high and their nitrogen concentrations are very low. In addition, soils of the central San Juan Basin are characterized by pH values that exceed 8.0, which limit the availability of both nitrogen and phosphorous. In general, the San Juan Basin, including Chaco Canyon, is the least promising part of the study area in terms of dryland farming. Calculations of field life, using values of organic nitrogen for the upper 50 cm of soil in the study area, indicate that most of the study area could not support a 10-bushel/acre crop of maize. The concepts, methods, and calculations used to quantify maize productivity in this study are applicable to maize cultivation in other environmental settings across the Americas.     

Chronology and Cultural Activity in Johnson Canyon Cliff Dwellings: Interpretations from Tree-Ring Data

Abstract

Archaeological tree-ring samples were collected during the summer of 1974 from nine cliff dwellings in the tributaries of Johnson Canyon on the Ute Mountain Indian Reservation in SW Colorado. The cliff dwellings belong to the Mesa Verde branch of the Anasazi cultural tradition and on the basis of ceramics and architecture could be assigned to the McElmo phase (1050-1150 A.C.) and the Mesa Verde phase (1150-1300 A.C.). Of a total of 461 tree-ring samples, 352 could be dated. These dates and other observations made during the analysis are applied toward refinement of the dating of the sites as well as to interpretations about utilization of timber resources, environment, and demography. Two clusters of cutting dates consistently occur in most of the sites indicating two periods of construction activity, one in the middle 1100s and the other in the early 1200s. The existing architecture at these sites dates to the early 1200s while the earlier structures have apparently been dismantled and their materials reused. These data suggest an occupation of the area beginning in the 1140s, followed by an abandonment by the 1160s. The area was reoccupied in the early 1200s for only 30 to 40 years before final abandonment.     

Possible sources of archaeological maize found in Chaco Canyon and Aztec Ruin,New Mexico

Maize played a major role in Chaco's interaction with outlying communities in the southern Colorado Plateau. This paper seeks to determine where archaeological corn cobs brought to Chaco Canyon were grown. Strontium-isotope and trace-metal ratios of 180 soil-water and 18 surface-water sites in the Southern Colorado Plateau have revealed possible source areas for some of 37 archaeological corn cobs from Chaco Canyon and 10 archaeological corn cobs from Aztec Ruin, New Mexico. The most probable source areas for cobs that predate the middle-12th-century drought include several Upper Rio Chaco sites (not including Chaco Canyon). There are many potential source areas for cobs that date to the late A.D. 1100s and early 1200s, all of which lie in the eastern part of the study area. Some Athapascan-age cobs have potential source areas in the Totah, Lobo Mesa, and Dinetah regions. One Gallo Cliff Dwelling cob has a strontium-isotope ratio that exceeds all measured soil-water values. Field sites for this cob may exist in association with Paleozoic and Precambrian rocks found 80–90 km from Chaco Canyon. Potential source areas for most Aztec Ruin cobs (many of which were found in rooms dating to the first half of the 13th-century) appear to be associated with a loess deposit that blankets the Mesa Verde and McElmo Dome regions.     

Oxygen isotopes in cellulose identify source water for archaeological maize in the American Southwest

Maize (Zea mays) was a primary food crop for aboriginal societies of the arid American Southwest. Water used for maize production in these arid zones could have come from precipitation and runoff during the summer monsoon, from perennial streams and springs, or from stored soil water fed by snowmelt. The oxygen stable isotope ratio (δ¹⁸O) of summer and winter precipitation on the Colorado Plateau naturally differ by more than 10‰ providing a powerful tool for distinguishing winter- from summer-derived water sources used in cultivation of maize. We investigated whether variation in δ¹⁸O of potential source waters is preserved in the δ¹⁸O of cellulose (δ¹⁸O_cellulose) of maize cobs by growing four aboriginal and one modern maize variety in pots irrigated with water of known δ¹⁸O composition. The δ¹⁸O_cellulose values of cobs ranged from 26.8 to 36.4‰ (averaged within varieties) and were highly correlated with δ¹⁸O values of the source irrigation water (−15.8 to −8.2‰). Cob δ¹⁸O_cellulose from five archaeological sites on the Colorado Plateau in southeastern Utah ranged from 27.3 to 34.6‰, closely matching the range of values observed in experimental plants. A δ¹⁸O_cellulose model developed originally for tree rings was parameterized and applied to the archaeological maize cobs. The model indicated that monsoonal precipitation accounted for 0–20% of the moisture for archaeological cob samples from a site adjacent to a perennial stream and 43–98% for samples from an upland site, more distant from a perennial water source. These results reveal the potential for using δ¹⁸O_cellulose to investigate prehistoric irrigation practices and source water used for maize production in the American Southwest.     

Sensitivity of bulk sedimentary stable carbon isotopes to prehistoric forest clearance and maize agriculture

The stable carbon isotope compositions (δ¹³C) of tropical lake sediments and soils have been used to reconstruct the occurrence of prehistoric maize cultivation and its relative importance through time. This study assesses some of the possible variables affecting the response of lake sediment bulk organic carbon isotope (δ¹³C_TOC) values to variations in the scale of prehistoric maize cultivation and the potential of this proxy to yield quantitative estimates of the scale of prehistoric maize agriculture in small tropical watersheds. High resolution analyses of δ¹³C_TOC values, maize pollen concentrations, and mineral influx were conducted on sediments deposited during a ∼220 year period of prehistoric maize agriculture in the watershed of Laguna Castilla, a small lake in the mid-elevations of the Cordillera Central, Dominican Republic. Close correspondence between δ¹³C_TOC values and maize pollen concentrations in the Laguna Castilla sediment record indicates a close relationship between the isotopic values and the scale of prehistoric maize cultivation. Correlations between the δ¹³C_TOC signature and mineral influx indicate that the isotope record is also sensitive to variations in allochthonous carbon delivery. This study establishes that sedimentary δ¹³C_TOC values can provide a highly sensitive proxy of the spatial scale of prehistoric maize agriculture in small tropical watersheds, but emphasizes the need for a better understanding of sediment dynamics and carbon cycling in anthropogenically modified landscapes before this proxy can be widely employed in diverse archaeological settings.     

Paleodietary implications from stable carbon isotope analysis of experimental cooking residues

The regional timing of maize introduction in eastern North America is a long-standing topic of archaeological interest. Most recently, Morton and Schwarcz [2004. Paleodietary implications from stable isotopic analysis of residues on prehistoric Ontario ceramics. Journal of Archaeological Science 31, 503–517] investigated the timing of maize introduction in Ontario through isotope analysis of charred cooking residues adhering to the interior of prehistoric ceramic containers. They interpret their results to suggest maize was incorporated into diets after A.D. 600. We assess their approach and conclusions with stable carbon isotope assays on three sets of experimental cooking residues, evaluating the variable combustion of carbon fractions, contributions of fats and carbohydrates, and the contribution of total carbon. We also undertake multiple resource modeling of two part food mixes with green maize and maize flour. Our results suggest that systematic under representation of maize can result depending on residue composition and that some prior knowledge of C3 plant and animal contents is necessary to interpret stable carbon isotope values on cooking residues. We question the independent use of stable carbon isotope analysis of charred cooking residues as a viable technique for extracting paleodietary information.     

Subsistence change,landscape use,and changing site elevation at the Pleistocene–Holocene transition in the Dordogne of southwestern France

The dramatic topography of the Dordogne Valley region of southwestern France has long been recognized as an influence on prehistoric human settlement and subsistence patterns. Previous research on late Pleistocene settlement patterns in this region implies that, as cold-adapted higher-ranked resources became scarce in the lowlands, site location in the Dordogne and adjacent river valleys should shift towards higher-elevation areas during the period from 18,000 to 6500 years BP. This study employs a GIS-based analysis to evaluate the changing settlement patterns in the Dordogne region at this time. While no significant changes in elevation were found during this period, site elevation variance does appear to increase significantly between the Magdalenian and the Sauveterrian. Explanations for this finding are explored using zooarchaeological data from Moulin du Roc, one of the sites in the data set. Results suggest that the Magdalenian period in the Dordogne may not have been as resource-rich as is often assumed.     

Organic Loss in Drained Wetland Monuments: Managing the Carbon Footprint

Abstract

The recent installation of land drains at Star Carr, Yorkshire, UK, has been linked with loss of preservation quality in this important Mesolithic buried landscape, challenging the PARIS principle. Historically captured organic carbon, including organic artefacts, is being converted to soluble organic compounds and less soluble carbon gases. At the same time sulphur and nitrogen compounds are oxidized to species that are chemically destructive of artefacts and ecofacts. Two of the carbon products, CO₂ and methane, are ‘greenhouse gases’ whose environmental impact can be costed in terms of carbon equivalents, which can be set against an assessment of the gain in agricultural productivity of the land arising from drainage, at Star Carr being the improved cereal crop. Wetland studies elsewhere suggest that such decay processes could be slowed by restoring the historic soil environment, and even reversed to create carbon capture, enabling the farmer to claim carbon credits.     

Nitrogen cycling in western India as revealed by nitrogen isotopes,and the historic production of saltpetre

Saltpetre (KNO₃) manufacture was a principal monopoly industry in early Modern India when the United Kingdom governed the social and economic systems. The process represented microbial transformation of excrementitious livestock and human wastes deposited around habitats, resulting in formation of salt efflorescence at an economic scale. Low caste people collected these wastes for extraction and production of rough saltpetre under the administrative control of British India. Stable isotope composition (δ¹⁵N and δ¹⁸O) was used to trace details of the microbial transformation processes, often involving the isotopic fractionation of nitrogen and oxygen. Marked elevation in δ¹⁵N and δ¹⁸O values for nitrates in soils and deposits, relative to those of primary organic nitrogen in diets and water sources, characterizes the unique processes of historic saltpetre manufacture in British India.     

Tewa Place Names for Early Habitation Sites in the Northern Rio Grande Valley,New Mexico

Place names have the potential to aid in the investigation of regional settlement histories because they reflect the importance of specific locations in the social or cultural memories of indigenous groups. Unique place names for ancient habitation sites such as villages or hamlets, i.e., those names for which there are no cognates in other languages, suggest that those ancient villages or hamlets still retain the names given to them by their original inhabitants. Here, we present Tewa place names for habitation sites identified archaeologically in the northern Rio Grande Valley of New Mexico. The results of our study strongly suggest that the Tewa language was spoken in the northern Rio Grande Valley, specifically, within the southern Tewa Basin, as early as the Late Developmental period (a.d. 900–1200), thus challenging the currently well-accepted model postulating a Mesa Verde origin for the Tewa language and culture.     

Anthropogenic saltpetre: dual (oxygen and nitrogen) isotopic constraints to the biogeochemical processes

Saltpetre constitutes one of the major ingredients of gunpowder, which was a driving force during the political changes in late medieval to early modern times in Japan. Two types of model saltpetre mineralization are studied. One represents efflorescent saltpetre formed as the byproduct of indigo dye manufacture, whereas the second is anthropogenic, derived from relict nitre‐beds. Here, oxygen and nitrogen isotopic analysis, as expressed by δ¹⁸O and δ¹⁵N notations, is applied. The calculated δ¹⁸O values for ambient water, responsible for the microbial‐mediated oxidation of ammonium into oxygen in nitrates, tended to have higher ranges than average local meteoric waters of the relevant regions. An overall trend could be seen, showing the apparent positive nitrogen isotopic fractionation during the microbial transformation from initial organic nitrogen into nitrate product. Dual isotopic analysis for industrial nitrates provides a useful tool for investigation of the provenance of historic gunpowder. Present anthropogenic saltpetre involves positive control over temperature–moisture regimes and oxygen fugacity during formation, the process being distinctive from those prevailed in British India and other European countries.     

Dietary patterns during the late prehistoric/historic period in Cikobia island (Fiji): insights from stable isotopes and dental pathologies

The dietary patterns of eight adults and one child interred in the Korotuku burial mound (Cikobia, northern Fiji), dated from the late prehistoric/historic period (around AD 1850), have been investigated using carbon and nitrogen stable isotope signatures and dental and oral pathologies. Bone collagen isotopic compositions showed that (1) males and females had similar diets in terms of terrestrial C₃ resources and marine fish components and proportions; (2) the proportion of marine fish comprised around 25% of the protein fraction of the diet, and the proportion of vegetal food was high; and (3) one canid that was also studied had a different diet, probably rich in shellfish. Oral and dental examinations of the humans evidenced (1) a low level of dental macrowear, (2) a high rate of carious lesions—interproximal and cervical—of about 15%, and (3) a low amount of abscessing, as well as the presence of alveolar bone recession and calculus in most of the adults. This evidence suggests a diet relying mainly on vegetal food with very limited shellfish consumption. When viewed in the light of ethnohistoric information, this pattern suggests a particular sociocultural behaviour, including food selection, since the analyses of the canid remains indicate that more diversified food resources were available than those consumed by the humans. Overall observations suggest that the deceased in the Korotuku burial mound might be members of an elite living on the island, thus pointing to possible social stratification in the late prehistoric/historic Cikobia community.     

Recent Developments in the Archaeology of Southwestern China

Archaeology of ancient China’s periphery has traditionally been examined through the historiographic lens of Chinese textual sources. Social developments in the periphery are often explained in relation to accounts of migration from “core” regions of China. Setting conventional paradigms and textual sources aside, this article examines prehistoric developments in southwestern China in conjunction with broader trends in Southeast Asia. This comparative approach reveals that the development of bronze metallurgy in southwestern China parallels trends observed among Neolithic communities in Southeast Asia. Using recent data and a reassessment of radiocarbon dates for the Bronze Age, I propose that sociopolitical complexity emerged in southwestern China as part of a multiregional phenomenon that had its beginning with the formalization of trade networks during the Neolithic period.     

Prehistoric land use and hydrology: a multi-scalar spatial analysis in central Arizona

Human land-use strategies involving the management of rainfall and runoff to promote crop production are found throughout the world. This paper presents a functional assessment using hydrological modeling with modern high-resolution LiDAR datasets and contextual archaeological site data to study prehistoric agriculture. The focus is on rock alignments created by the Hohokam culture in the semi-arid environment of the US Southwest. By incorporating a multi-scalar GIS study for terrain analysis at a regional, community, and site scale, the complex interactions between the prehistoric sites, features and the environment are revealed. The results of these analyses on digital elevation models (DEMs) gave insight to the past functionality of such agricultural features within the cultivated landscapes. The results included:1) The agricultural features were suitably placed for the collection of rainfall and runoff.2) The features were reducing the volume of water flowing through the area to prevent flooding and crop destruction and promoting soil infiltration.This shows the complexity and innovation of prehistoric societies living in marginal environments and how their adaptation to such environments was necessary to sustain their populations.     

Land Tenure, Archaeology, and the Ancestral Pueblo Social Landscape

Archaeology relies upon evidence of past human modification of the natural landscape in order to infer past human social dynamics on the site, local, and regional levels. Given the inferential linkages between past landscape use and social relationships, archaeology can benefit from an approach that more explicitly delineates relationships between systems of land use and land tenure, the social means through which people define and assert land use rights. This research outlines a set of methods for modeling prehistoric land tenure systems and developing a middle range theory of land tenure relationships that may assist archaeologists in their investigations of prehistoric resource access systems. Land tenure systems are complex risk-buffering strategies that are conditioned by the labor invested in food production, the size of groups holding direct access to productive lands and resources, and the temporal duration of land access rights. The role of these variables is supported by cross-cultural data from a worldwide sample of food-producing societies. The land tenure model is applied to data from the prehistoric Southwest to help explain local and regional changes in food production, settlement size, and community organization in southwest Colorado between 900 and 1300 A.D.     

Maize Agriculture Evolution in the Eastern Woodlands of North America: A Darwinian Perspective

David Rindos' coevolution theory remains the most comprehensive application of Darwinian theory to issues of prehistoric agriculture evolution. While his theory has drawn attention, there has been a lack of subsequent development of the application of Darwinian theory to prehistoric agricultural evolution. Combining Sewall Wright's shifting balance theory of evolution with aspects of Rindos' coevolution theory provides important new insights into the processes of crop transmission between regions. Using these theories, a model is developed for the adoption and subsequent evolution of maize agriculture in the Eastern Woodlands of North America.     

Stable carbon- and nitrogen-isotope ratios and electron spin resonance (ESR) g-values of charred bones: changes with heating and a critical evaluation of the utility of g-values for reconstructing thermal history and original isotope ratios

Changes in the stable carbon and nitrogen isotope ratios of modern bone samples heated to a variety of times and temperatures were used to determine the effect of heating on isotope ratios and the retention of organic matter in charred bones. For organic extracts produced by slow demineralization in weak acid, δ¹³C values were unchanged, while δ¹⁵N values increased by up to 5‰ and were primarily determined by heating temperature. Changes in the electron spin resonance (ESR) g-value of whole bone and organic extracts were also measured. For organic extracts from charred bones, the g-value was well-correlated with δ¹⁵N and temperature, suggesting that g-values could be used to estimate the charring temperature and original δ¹⁵N values of charred bones. Thus, g-values from demineralized extracts could be very useful in forensic investigations where it would important to reconstruct the thermal history of burned bones. Isotope ratios and g-values of demineralized extracts from four prehistoric components at three sites that produced cremated human bone were used to test whether the same approach can be applied to archaeological materials. While carbon isotope ratios of the prehistoric samples were similar to those of uncharred specimens, nitrogen isotope ratios were increased and the g-value corrections for nitrogen isotope ratios were not effective.     

Advanced design of Chinese traditional materials for the conservation of historic stone buildings

The conservation of historic stone buildings and sculptures is recently receiving growing attention and becoming a focus of research because of rapid changes in weather conditions (pollution, acid rain, etc.). Presently, techniques for stone conservation primarily involve the use of organic coating treatments, but their side effects have been recognized. In contrast, some traditional materials used in historic stone buildings function well for thousands of years. In this paper, we report our research on the reasons why traditional protective materials can provide an unexpected long-term protection. First, calcium carbonate was prepared according to a formula for making Chinese traditional consolidating materials, and its structure and morphology were examined by different instruments. Second, the reinforcing effectiveness of the prepared CaCO₃ powders was tested and analyzed by investigating its surface characteristics. The experimental results reveal that a biocontrolled process occurs, in which an organic template can induce the precipitation of a mineral structure, which in turn results in a great improvement in the conservation of the historic stone buildings protected by these traditional protective materials. This provides a contribution toward the development of new researches on biocontrolled processes and on some protective materials with excellent performance through biocontrolled synthesis.     

Reassessing the northern limit of maize consumption in North America: stable isotope,plant microfossil,and trace element content of carbonized food residue

In combination, the analysis of carbonized food residue for stable C and N isotopes, elemental composition, and plant microfossils (phytoliths and starch granules) offers a powerful tool for understanding patterns of prehistoric maize (Zea mays) consumption in small-scale societies. Using this approach, we conclude that maize was more widely consumed in North America than previously suspected. Between ∼AD 700 and 1600, despite little or no archaeological evidence of gardening, corn was a widespread component of diet on the eastern Canadian prairies. This pattern, furthermore, extended into the adjacent boreal forest at about the same time. However, carbon (δ¹³C) and nitrogen (δ¹⁵N) values on food residue samples vary widely, suggesting significant overall dietary differences from one region to the next. Analysis of a subset of residue samples for elemental composition (using ICP-OES [inductively coupled plasma–optical emission spectrometry]) may help identify broad trends in the provenience of foods consumed at these sites.