Identifying activity areas in archaeological soils from a colonial Virginia house lot using phytolith analysis and soil chemistry

Environmental archaeology methods can uncover both house lot organization and economic adaptation practices when applied systematically in conjunction with traditional archaeological research. This is the first study to employ both phytolith analysis and soil chemistry to interpret activity areas on an archaeological site. The patterning in the phytolith and soil chemistry analyses from the site of Rich Neck Plantation, Williamsburg, Virginia, reveals a set of six activity areas in and around the 17th century house lot, demonstrating a degree of economic diversification generally attributed only to 18th century colonial economic and social transformations.     

Rapid phytolith extraction for analysis of phytolith concentrations and assemblages during an excavation: an application at Tell es-Safi/Gath,Israel

A rapid phytolith extraction procedure is described, that allows phytolith concentrations and morphotype assemblages to be analyzed within hours. This procedure enables the results of these analyses to be used during an archaeological excavation, in order to better understand how plants were used. The new procedure was tested using a standard phytolith extract and two experimental phytolith-sediment blends and found to be both accurate and precise. The reliability of partial slide counting was evaluated and found to be as accurate and precise as existing phytolith quantification methods. The new extraction and counting procedures were applied to an archaeological site, Tell es-Safi/Gath, Israel. The results demonstrate how information on phytolith concentrations in sediments that are available from one day to the next, can be used during an excavation to more effectively document the local features of interest and obtain better information.     

Extended depth of focus image for phytolith analysis

This paper proposes a new phytolith analysis method by extended depth of focus technology. The extended depth of focus image is sharp throughout by the image processing of a series of photos, while each acquisition of the original photo will be compromised and show certain parts of the specimen in and out of focus. Consequently, the extended depth of focus image is suitable for computer-assisted morphometrics analysis. Meanwhile, the extended depth of focus image can be used for three-dimensional reconstruction images. Experiments on rice husk multi-cell panel show that the three-dimensional reconstruction image method can reconstruct multiple double-peaked phytoliths at one time. We also measure the parameters of multiple double-peaked phytoliths from the reconstructed three-dimension image. Comparative experiments show that the reconstructed three-dimensional image is precise enough for rice identification. Based on the above experiments, we recommend the extended depth of focus method as a promising tool in phytolith research.     

Investigating crop processing using phytolith analysis: the example of rice and millets

The application of crop processing models to macro-botanical assemblages has traditionally been used to interpret past husbandry practices and organisation of labour involved in crop-processing. Phytoliths offer an alternative method of analysis because they are durable in most environments, regardless of whether plant parts are charred, and the identification of plant types and plant parts allows them to be used in much the same way as macro-botanical remains. Indeed macro-remains and phytoliths are complementary datasets for examining the input of plant parts, such as crop-processing waste, into archaeological deposits. We outline crop-processing models in relation to macro-remains and then develop the framework for their application to archaeological phytolith assemblages. Rice and millet processing models are explored in relation to patterns expected in both macro-remains and phytoliths. The utility of these models is demonstrated with archaeological evidence from the site of Mahagara, an early farming site in North-Central India. The results indicate a way to employ phytoliths in archaeology which complements the fragmentary evidence available from plant macroremains.     

Use of space in a Neolithic village in Greece (Makri): phytolith analysis and comparison of phytolith assemblages from an ethnographic setting in the same area

Phytolith analyses were conducted in a Pottery Neolithic village (Makri) of Northern Greece in order to reconstruct aspects of past human activities as a function of both space and time. The analyses of phytolith assemblages were based on a reference collection of modern plant phytoliths (Tsartsidou et al., 2007), as well as an ethnographic study in an agropastoral community (Sarakini) in the same area that showed that many phytolith assemblages are characteristic of the activities carried out in different locations within and around the village (Tsartsidou et al., 2008). The same approach was used for studying the phytolith assemblages in the Neolithic village of Makri, namely measuring phytolith concentrations, diversities of phytolith assemblages relative to control samples collected from samples outside the village and detailed analysis of various phytolith morphotypes. At Makri samples from floors and various constructions (i.e. pit, platforms) were analysed, as well as sediments from an open area inside the village. The results show that Neolithic Makri was a society with a mixed agricultural and pastoral economy. Wheat and barley were cultivated for food and fodder and free-range animals were raised in a village inhabited year round. Indoor areas were not clearly differentiated from outdoor areas inside the village. The phytolith assemblages in only one series of floors produced at a specific location over an extended period of time reflected the use of that space for cereal storage or food processing. The phytolith assemblages from all the other floors examined did not reflect the local activities, but rather the constructional materials used for producing the floors.     

广州榄园岭遗址先民祭祀遗迹的炭屑和植硅体分析

祭祀是先民生活的重要组成部分之一。尽管贵族祭祀活动的研究较多,但平民祭祀遗迹却由于发现较少而难以深入分析。广州榄园岭遗址春秋时期墓葬群中发现了越文化中常见的碎物祭祀坑。本研究对若干墓葬和相关祭祀坑中的填土开展了炭屑和植硅体分析。结果表明,先民在祭祀坑中有意燃烧过植物类祭品;用作祭品的植物种类较杂,包含扇型、棒型、方型或刺球型等植硅体。结合其他遗址中出现的类似现象,榄园岭先民的祭祀活动,应是在因地制宜、就地取材的基础上,吸收了苗蛮文化的因素,同时影响了其他地区。这一发现为探索先秦古人的祭祀行为提供了丰富信息;此外,炭屑和植硅体分析为确定祭祀遗迹提供了新的研究范式。     

The phytolith archaeological record: strengths and weaknesses evaluated based on a quantitative modern reference collection from Greece

The phytolith record from archaeological strata is a powerful tool for reconstructing aspects of past human behaviour and ecology. Considerable insights into the problems and potentials of this record can be obtained by studying phytoliths in modern plants. We prepared a phytolith reference collection of modern plants mostly from northern Greece that includes quantitative information on phytolith concentrations (number of phytoliths per gram dry organic material) and morphological assemblages. Here we analyse this reference collection with the aim of evaluating the strengths and weaknesses of the archaeological phytolith record. The reference collection comprises 62 different plant taxa. Of them, 28 are trees, 1 conifer, 10 shrubs and 1 herb, 3 domesticated annual legumes and 19 monocotyledons. We demonstrate quantitatively the extent to which woody species, legumes and fruits of dicots contribute only small amounts of phytoliths to the sediments per unit tissue dry weight, while leaves of trees and shrubs produce significant amounts of phytoliths and grasses are prolific phytolith producers. We compare the data of this reference collection with a similar reference collection from another Mediterranean ecosystem (Israel). The comparison indicates that some aspects of phytolith production are probably genetically controlled, whereas others are environmentally controlled. We note that despite the fact that woody species produce few phytoliths per gram of tissue, their record can be most informative when taking into account other properties of the sediments. We also note that jigsaw puzzle-shaped phytoliths normally form in plants that grow in humid conditions, but may form in arid environments when the plants are irrigated. This study clearly shows the extent to which some plants can be under-represented and others over-represented in the phytolith record. Knowing the extent of this bias can greatly improve our interpretation of the phytolith record.     

Late Holocene Neotropical agricultural landscapes: phytolith and stable carbon isotope analysis of raised fields from French Guianan coastal savannahs

This paper summarizes phytolith analyses from four pre-Columbian agricultural raised-field sites of the coastal savannahs of French Guiana—Savane Grand Macoua, Piliwa, Bois Diable and K-VIII—and carbon isotope analyses from the first-named site. The combined phytolith and ¹³C isotope analyses evidence the transformation of the landscape from a relatively homogeneous wetland vegetation comprised of a mixture of C4 and C3 plants (the latter including Cyperaceae and other herbaceous monocots such as Marantaceae and Heliconia, Oryzoideae grasses, and other plants typical of frequently flooded areas) to the construction of raised fields that were dominated by C4 plants (maize and other Panicoideae grasses). Our analysis proves the utility of phytoliths for tracing the agricultural history of landscapes, showing that, as in other parts of the Central and South American lowlands, maize (Zea mays) was one important crop cultivated in raised fields. We also estimated the productivity of raised-field agriculture, showing that in combination with other subsistence activities, it certainly had the capacity to sustain sizeable populations.     

Differentiating banana phytoliths: wild and edible Musa acuminata and Musa balbisiana

Recent reports indicate that phytoliths may provide direct archaeological evidence of banana cultivation. However, archaeologists may, in many places, recover phytoliths generated by banana plants with quite different historical backgrounds. Hence the need for a differentiation among phytoliths produced by specific banana groups. The present paper discusses the morphometric distinction between phytoliths produced by the constitutive diploid species Musa acuminata and Musa balbisiana. Our study suggests that domestication of the banana, which was initiated at the diploid M. acuminata level, does not appear to have influenced phytolith morphometry.     

Reconstructing late Holocene palaeoenvironments in Bangladesh: phytolith analysis of archaeological soils from Somapura Mahavihara site in the Paharpur area,Badalgacchi Upazila,Naogaon District,Bangladesh

Palaeoenvironmental reconstruction based on phytolith analysis of late Holocene-aged soils in and around the Somapura Mahavihara archaeological monastery site in the Paharpur area, Badalgacchi Upazila of Naogaon District in northwestern Bangladesh was undertaken. Results indicate five climate zones marked by alternatively cool and temperate events. The phytolith assemblages of Zones 1, 3 and 5 are clearly characterized by a higher proportion of Pooideae phytoliths. The climate indices for these zones are all greater than 50, indicating cooler climatic conditions. In contrast, the phytolith assemblages of Zones 2 and 4 are typified by a higher proportion of Panicoideae phytoliths; their climate indices are 42 and 44, respectively, indicating the presence of a warmer, more temperate climate. In general, the dominance of grasses over broad- leaved trees throughout the sequences suggests that generally cool to temperate and dry conditions with some cyclical variability persisted around Paharpur and the surrounding region throughout the Pala Dynasty from AD 730 to 1080. The question of whether these shifts in vegetation might be linked with El Niño Southern Oscillation events, and whether these might in turn have cultural responses, is raised.     

Ethnoarchaeological study of phytolith assemblages from an agro-pastoral village in Northern Greece (Sarakini): development and application of a Phytolith Difference Index

Phytolith assemblages are analysed in an ethnographic agro-pastoral community in Northern Greece. A new method for analyzing the data, combined with the concentrations of phytoliths per gram sediment, helps to differentiate diverse uses of space in the village. The Phytolith Difference Index (PDI) contrasts the phytolith assemblages in sediment samples from the region around the village least affected by human activities with those in the village and its immediate surroundings. The PDI reveals that many of the samples are dominated by the input of the stalks of the domestic cereal, rye, which is used for food, animal fodder and roof thatching. The PDI also differentiates between dung from mules or donkeys with dung from free ranging cows and goats. Activity areas analysed include storage areas, stabling areas, animal enclosures, floors from living areas that were repeatedly swept, hearths and open areas between structures. The combined use of the PDI, together with phytolith concentrations and phytolith morphotype analyses, may prove to be useful for deciphering activity areas in archaeological sites of not only agro-pastoralists, but also pastoralists and hunter–gatherers.     

One,two, three phytoliths: assessing the minimum phytolith sum for archaeological studies

The number of phytolith studies has increased steadily in the last decades in palaeoecological as well as archaeological research, and phytolith analysis is currently recognised as a proper area of expertise within archaeobotany. This has led towards a strengthening in the standardisation of the different steps involved in analysis; e.g. sampling strategies, laboratory extraction or processing of plant material/soils for the creation of reference collections. In spite of this, counting procedures remain one of the areas that could be further developed. The aim of this paper is to assess representativeness of phytolith count size in archaeological samples and specifically to assess whether an increase in total number of individuals counted influences the number or distribution of morphotypes observed. Two statistical tests are performed to evaluate the representativeness of count size: phytolith sum variability analysis (PSVA) and morphotype accumulation curve (MAC). The analyses show the relationship among the number of counted phytoliths, the variability (that is, the number of different morphotypes identified) and the stabilisations of the MACs. Results allow us to support the standard count size in phytolith studies, which ranges from 250 to 300 particles. Together with a quick scan, this strategy should produce a precise and clear phytolith assemblage for archaeological studies.     

The status of phytolith analysis in the American tropics

Phytolith analysis is now sufficiently mature to provide an independent source of data in tropical paleoethnobotany and paleoecology. At the same time, ongoing studies of phytoliths from tropical plants and sediments are discovering new applications. There are, to be sure, problems in interpreting prehistoric plant use and paleoecology which cannot be addressed through phytolith analysis; some of the more important ones are listed. Through a review of recent studies in the New World tropics, this paper presents some contributions to, problems of, and prospects for phytolith analysis to inform the archaeological community about such issues as (1) the origins and dispersals of domesticated plants, (2) the development of tropical forest agriculture, (3) the uses of tropical plants in prehistory, and (4) the distribution and composition of past plant communities.     

Neanderthal use of plants and past vegetation reconstruction at the Middle Paleolithic site of Abrigo de la Quebrada (Chelva,Valencia, Spain)

Despite phytoliths having been used to understand past human use of plants and palaeoenvironment in Middle Paleolithic sites, little is known on this aspect in the well-documented central region of Mediterranean Iberia. This paper presents the first phytolith and mineralogical study conducted at Abrigo de la Quebrada (Chelva, Valencia). Forty-one samples were analyzed through phytoliths and Fourier transform infrared spectroscopy (FTIR) from different areas, stratigraphic levels, and archeological contexts (hearth, hearth-related, and non-hearth-related sediments) of the shelter. The results obtained point towards a different pattern of preservation in the site depending firstly on the stratigraphy and secondly on the area where the samples were collected. Postdepositional processes that may have chemically affected phytolith preservation are discussed. Grasses are the main plant component identified in all the samples while woody plants are scarce. The abundance of grasses in the non-hearth-related sediments might be related, at least partially, to the dispersion of ashes from hearths, as indicated by the FTIR results. The results are indicative of an occupation of the site during the spring-autumn season. At this time, the area would be dominated by a semi-open environment with supramediterranean vegetation.     

Microarchaeology of a collective burial: cova des Pas (Minorca)

FTIR and phytolith analyses have been used to understand the exceptional preservation of the organic remains at the burial cave of Cova des Pas (Minorca), and to obtain high-resolution data of the plant remains present in the sediments. The presence of sodium nitrate and gypsum suggests a relatively dry environment that has enabled the preservation of the organic material, and contributed to the natural mummification. The dry conditions also favored phytolith preservation. Grass inflorescence phytoliths are abundant all over the site suggesting that phytolith accumulations might have an anthropogenic origin and are related to the burial ritual.     

Husbandry practices and livestock dung at the Numidian site of Althiburos (el Médéina,Kef Governorate,northern Tunisia): the phytolith and spherulite evidence

Recent excavations at Althiburos, northern Tunisia, have shown the existence of permanent pre-roman occupations in the central area of the urban settlement. Significantly, the site has been found to contain one of the most complete Numidian sequences, spanning from the Early Numidian (at least from the 10th–9th century BC) to its final stage. Research at the site addresses questions related to the identification of settlement patterns at this time.The combined study of phytoliths and spherulites recovered from well defined archeological contexts at the site have provided new data for identifying husbandry activities carried out by the ancient Numidian populations. The results show that there is abundant evidence for both cooking and processing cereals, primarily from common or bread wheat (Triticum aestivum). Also significantly, was the abundance of faecal spherulites in certain areas of the site, indicative of dung accumulation. The correlation between large amounts of spherulites and rich phytolith sediments in specific contexts, suggested that grasses were brought to the site or consumed offsite and deposited onsite as livestock dung or dung-products. The identification of dung accumulations in the site raises questions about the diversity of economic practices developed by Protohistoric communities in northern Africa. Future research questions regarding such dung rich layers will also be examined.     

Paleoenvironment and plant cultivation on terraces at La Quemada,Zacatecas, Mexico: the pollen,phytolith and diatom evidence

This paper reports the results of pollen, phytolith and diatom analyses conducted on a series of soil samples collected from a large, possibly communal, system of terraces associated with La Quemada in the Malpaso Valley, Zacatecas, Mexico. These analyses rendered data related to both paleoenvironmental and plant cultivation in the area. Preliminary pollen analyses of soil sediments suggest Agave sp. and Opuntia spp. cultivation played an important role on the terraces. The phytolith analyses recovered abundant, well preserved grass phytoliths, including Zea mays. The composition of the grass community suggests that paleoenvironmental conditions in this area were warm and dry, similar to those of today. The presence of three fresh water diatom taxa and sponge spicules in several archaeological soil samples suggests the possibility that water was carried to the terraces for irrigation from the nearby Rio Malpaso on a regular basis.     

Geoarchaeology in an urban context: The uses of space in a Phoenician monumental building at Tel Dor (Israel)

Interpretation of past urban societies in the Near East, whose settlements are known mostly as tell sites, is largely based on macro-stratigraphy and on the association of architecture with macroscopic artifacts. Analyses of sediments, common in prehistoric sites, are rare in tell sites. Here we show the results of a detailed geoarchaeological study of the micro-stratigraphy of a sedimentary sequence associated with early Iron Age Phoenician monumental architecture. The study involves mineralogical, micromorphological and phytolith analyses and provides new insights into the stratigraphic sequence and the use of architectural spaces. The sedimentary sequence examined comprises alternating layers of gray ‘fill’ deposits and white ‘floors’. We show that ‘floors’ made from local calcareous sandstone in the lower part of the sedimentary sequence were heated and are thus in effect ‘plaster floors’. A concentration of micro-laminated, trampled fish remains above the most elaborate of these plaster ‘floors’ indicates activities related to fish processing. Fine white layers in the upper part of the sedimentary sequence that were considered as plaster based on macroscopic examination are in fact composed almost entirely of opaline grass phytoliths. The phytoliths appear in an undulating micro-laminated structure and are associated with dung spherulites and phosphate nodules, thus probably reflecting livestock penning. The formation of ‘phytolith floors’ involves extensive volume reduction due to the degradation of the organic material and this may result in ‘floor’ subsidence, a phenomenon that is often observed in archaeological sites. Most ‘fill’ deposits include macroscopic and microscopic remains of wood ash, bones, phytoliths, charcoal, ceramics, plaster and mollusk shells, reflecting the debris produced from household activities. This study shows how a combination of macro-stratigraphy with microscopic and mineralogical analyses of the sediments within architectural spaces can provide information on the varying ways in which the space was used through time, and also contributes to solving macro-stratigraphic problems.     

Phytoliths and microcharcoal at Jinluojia archeological site in middle reaches of Yangtze River indicative of paleoclimate and human activity during the last 3000 years

A variety of phytoliths, together with prolific microcharcoal particles, sponge spicules and diatoms were extracted and identified in four cultural layers from an archeological site at Jinluojia, Macheng, Hubei Province, Central China. The warmth (Iw) and aridity (Iph) indices calculated from grass phytoliths reveal warm and wet periods during the West Zhou, early East Zhou, Tang and Song Dynasties whilst cool and dry periods occurred during the late East Zhou, Ming and Qing Dynasties. The paleoclimate conditions reconstructed on the basis of grass phytoliths extracted from archeological sediments are in agreement with those from natural sediments in the Middle Yangtze region. In contrast, the woody phytoliths show a positive correlation with microcharcoal particles, suggesting an anthropogenic contribution to the woody phytoliths from the use of woody plants for fuel during cooking and heating. Two episodes of the enhanced abundance of woody phytoliths and microcharcoal particles were found to occur at East Zhou Dynasty and from Ming and Qing Dynasties to the Present, proposed to be a consequence of the population expansion and/or the frequent wars.     

Identification of pastoral sites using stable nitrogen and carbon isotopes from bulk sediment samples: a case study in modern and archaeological pastoral settlements in Kenya

The identification of pastoral sites in the East African archaeological record is problematic. Recently, a method for the identification of degraded livestock enclosure sediments had been developed that takes into account the geoarchaeological indicators of micromorphology, phytolith concentrations and the mineral assemblages. This suite of indicators may not always be present in degraded livestock enclosure sediments. This study presents an additional indicator by which degraded livestock enclosure sediments may be identified, namely the isotopic composition of organic nitrogen measured on bulk sediment samples. We studied a highly controlled ethnoarchaeological sequence of abandoned Maasai livestock enclosure sediments sampled in Rombo area, southern Kenya. The results were compared to archaeological sediments from the Elmenteitan Pastoral Neolithic site of Sugenya, southwestern Kenya, radiocarbon dated to ca. 2000 BP (uncalibrated). The sediments from both sites were studied using all four types of analyses, i.e., micromorphology, mineralogy, phytolith concentrations, and stable carbon and nitrogen isotopic compositions on bulk sediment samples. The results show that in abandoned livestock enclosure sediments of known ages a significant enrichment in the heavy nitrogen isotope (¹⁵N) occurs, and that carbon isotopic compositions may be useful for differentiating cattle from caprine enclosures following their dietary preferences (i.e., grazers vs. browsers). A similar pattern of ¹⁵N enrichment is observed in sediments sampled within the site of Sugenya while sediments sampled outside the site's perimeter are generally depleted in ¹⁵N. The micromorphological, mineralogical and phytolith analyses support the conclusion that the sediments from within the site of Sugenya represent degraded livestock enclosure sediments. The carbon isotopic composition from the degraded dung deposits strongly suggests that livestock kept at Sugenya were cattle. Overall, this study presents new empirical data that can be used for the identification of livestock enclosures, and shows that the isotopic signatures and geoarchaeological indicators can preserve for at least two millennia.