Non-destructive chemical characterization of ceramic sherds from Shipwreck 31CR314 and Brunswick Town, North Carolina

The purpose of this study was to chemically and texturally characterize ceramic oil jar sherds from North Carolina Shipwreck 31CR314 and to explore the utility of environmental scanning electron microscopy/X-ray energy dispersive spectrometry (SEM/EDS) for that purpose. The oil jar sherds, widely dispersed about Shipwreck 31CR314, are morphologically similar to each other, which suggests they could be from a single jar, but with so few joins this could not be concluded with certainty. Therefore, an aim of this study was to investigate whether chemical or textural characterization of the sherds might reveal unique attributes that could distinguish individual jars; results of characterization perhaps could give information on their origin and possibly site formation processes, such as whether environmental forces could have scattered sherds of a single jar during and after sinking of the ship. Previous studies have indicated this shipwreck is likely the remnants of the Queen Anne's Revenge, flagship of the pirate Blackbeard. Sherds from this shipwreck were compared with similar oil jar sherds excavated from a land site, Brunswick Town, North Carolina, to explore the use of composition and texture as hallmarks. The chemical components of the artifacts were determined by SEM/EDS. This method of analysis is valuable for archaeological research because it is rapid and non-destructive to the ceramic artifacts. Both groups of lead-glazed coarse red earthenware sherds were texturally similar except for the glazed sides of all 31CR314 sherds that exhibited small tracks of unique crescent-shaped marks. These marks may be due to manufacturing effects and immersion in seawater, and the marks may serve as hallmarks for individual jars or potentially individual manufacturers. The sherds were generally similar in composition, but the two groups exhibited distinct differences. Brunswick Town sherds consistently contained more phosphate on unglazed sides, an average 1.46 wt.% P₂O₅, and also contained trace elements not detected in the Shipwreck 31CR314 sherds. These distinct differences could be due to different manufacturing origins for Shipwreck 31CR314 and Brunswick Town ceramics but also could reflect their subjection to different environments during use and loss prior to archaeological recovery.     

Seventeenth-century Pottery from Ash,Surrey

Abstract

About 2,000 sherds, mainly in white fabric, were found on a site at Ash which was one of several producing similar wares on the West Surrey and Hampshire borders. Some of the sherds were medieval, but the remainder were 17th century and are analysed in an attempt to assess the forms and characteristics of the post-medieval pottery made at Ash. Documentary evidence discloses the presence of potters in Ash in the 17th and 18th centuries, although there is no direct link with the site, and also indicates possible sources for the potters’ clay.     

A new method for identifying sherd refits: A case study from the Neolithic of Northumbria,U.K.

Abstract

Here we present a flexible, quantitative methodology for refitting handmade ceramics. Rather than analyzing the physical joins between sherds, we assess the likelihood that non-adjoining sherds of similar appearance are from the same vessel. The customary disregard of non-adjoining sherds in refitting experiments prompts us to address this issue. Using the Neolithic ceramic assemblage from Thirlings (Northumberland, U.K.) as a case study, we test several scoring systems for assessing the probability of two sherds pertaining to the same vessel. The utility of this approach is supported by the comparison of a set of percentage scores statistically verified using Spearman’s rank correlation coefficient. We conclude with a discussion of the contribution of the new method to post-excavation ceramic analyses, and its applicability to other assemblages.     

The correlation of surface and subsurface artifacts: A test case from Late and Terminal Classic Popola,Yucatan, Mexico

Abstract

Surface collections are commonly used by archaeologists to sample artifact assemblages, but the correlation of surface and subsurface artifacts is not fully understood. Cultural, taphonomic, and research-design factors that can affect the relationship of surface and subsurface deposits are reviewed and the correlation of surface and subsurface deposits is tested statistically with data from the site of Popola, Yucatan, Mexico, a Late and Terminal Classic period (a.d. 600–1100) village in the northern Maya lowlands. This study suggests that surface artifact density is not correlated with subsurface artifact density. Large-scale surface collections can characterize the overall assemblage of a site, but not any small area in particular. In shallow bioturbated soils there is no significant variation between surface and subsurface assemblages at any depth. Surface artifacts may be used to identify the presence of subsurface artifacts, but should not be used to suggest their absence.     

In Situ Preservation of Wetland Heritage: Hydrological and Chemical Change in the Burial Environment of the Somerset Levels,UK

Abstract

In situ preservation is a core strategy for the conservation and management of waterlogged remains at wetland sites. Inorganic and organic remains can, however, quickly become degraded, or lost entirely, as a result of chemical or hydrological changes. Monitoring is therefore crucial in identifying baseline data for a site, the extent of spatial and or temporal variability, and in evaluating the potential impacts of these variables on current and future in situ preservation potential.

Since August 2009, monthly monitoring has taken place at the internationally important Iron Age site of Glastonbury Lake Village in the Somerset Levels, UK. A spatial, stratigraphic, and analytical approach to the analysis of sediment horizons and monitoring of groundwater chemistry, redox potential, water table depth and soil moisture (using TDR) was used to characterize the site.

Significant spatial and temporal variability has been identified, with results from water-table monitoring and some initial chemical analysis from Glastonbury presented here. It appears that during dry periods parts of this site are at risk from desiccation. Analysis of the chemical data, in addition to integrating the results from the other parameters, is ongoing, with the aim of clarifying the risk to the entire site.     

The Definition of Ancient Manured Zones by Means of Extensive Sherd-Sampling Techniques

Abstract

Thin carpets of worn and abraded sherds frequently occur over many square kilometers of ground around archaeological sites in the Middle East. Sherd scatters around three sites in Iran, Oman, and Syria are described. It is suggested that the artifacts arrive as a result of transport of compost or manure incorporating urban refuse from the city to the nearby fields. The sherd scatters occupy a zone of between 3 and 6 km. radius around the sites, and this belt, it is suggested, corresponds to the inner zone of intensive cultivation. The data presented give some empirical support to concepts of site-catchment analysis and also suggest that the use of manure in agriculture can be traced back to at least the 3rd millennium B.C.     

Defining the provenance of red slipped pottery from Texas and Oklahoma by petrographic methods

Ceramics are among the most important artifacts that archaeologists use to reconstruct patterns of prehistoric trade and exchange. Petrographic analysis of ceramic thin-sections, in addition to providing detailed technological data, enables the identification of sand-tempering agents. These raw materials are potentially important evidence for ceramic provenance, assuming that such common materials themselves would not have been traded. Here we apply methods developed by sedimentary petrographers to the problem of determining the provenance of Red Slipped sherds from late Prehistoric (c. AD 1000–1400) sites in the Caddoan area and contemporaneous Plains Village sites. Modal frequencies of different kinds of quartz, feldspars and lithic grains are used to construct several triangular graphs that reveal compositional patterns indicative of provenance. Sherds from the Plains Village sites exhibit higher frequencies of lithic grains, feldspars and polycrystalline quartz relative to the sherds from sites in eastern Texas and eastern Oklahoma. While anomalous sherds were identified, the longstanding assumption that Red Slipped sherds in Plains Village contexts were traded from the Caddoan area is not supported by these data. These methods have strong application potentials for other, geologically diverse portions of North America.     

A Qualitative Approach for Assessment of the Burial Environment by Interpreting Soil Characteristics; A Necessity for Archaeological Monitoring

Abstract

Modern-day archaeological monitoring is often hampered by lack of money, lack of time, inadequate measuring equipment, and lack of insight in the conservation potential of a site.

Although in modern archaeological excavations soil characteristics are noted (colour, texture, groundwater level, and sometimes mineralogy), these characteristics are mainly used for the interpretation of a site. However, by looking to these characteristics from a conservational view eventually combined with the conservation status of the archaeological objects, much can be learned about the burial environment. This is essential for optimizing archaeological monitoring.

Degradation processes result from the change of reactive phases in the soil or the site. Reactive phases are soil components such as organic matter, sulfides, iron(hydr)oxides and carbonates (chalk, shells), and, if present, components in the ground or interstitial water such as hydrogen ions and sulphate. The presence of these phases can easily be established by the archaeologist or soil scientist in the field. We propose a simple field-based method for assessing degradation processes essential for in situ preservation and monitoring.     

The Altars of Zeus and Hera on Mt. Arachnaion in the Argeia,Greece

Abstract

Pausanias (ii.25.10), who traveled extensively in Greece in the 2nd century A.C., mentioned the existence of two altars of Zeus and Hera on Mount Arachnaion above the village of Lessa in the Argeia of the Greek Peloponessos. Two travellers in the early 19th century climbed to the saddle between the two peaks of the mountain and saw there a quadrangular enclosure wall of polygonal masonry on a low hill which they assumed to be the site of these altars. Since then this identification has been accepted by most scholars, including J. G. Frazer. Since most altars of Zeus are found on or near the top of the mountains, I climbed the mountain to check this attribution.

A section of a crude polygonal retaining wall exists on the hill but no traces of the altars were found. Obsidian bladelets and sherds found on the surface suggest that the wall might mark the location of a farmstead or small settlement dating as early as the Bronze Age. On the summit of the western peak of the mountain two low foundations of rubble masonry and three concentrations of sherds and burnt animal bone fragments in a blackish-brown soil matrix were discovered. One of the foundations must represent the ruins of the chapel of Hagios Elias known once to have stood on the summit. The sherd concentrations, which date from the mid-8th century B.C. through at least the 6th century B.C., must represent remains associated with the altars of Zeus and Hera.     

Reburial in the context of development: Approaches to reburial in the English planning process

Abstract

Rescue archaeology in England is now firmly embedded in the planning process, following the introduction by the UK government of Planning Policy Guidance Note 16 in 1990 (PPG 16; Departmentof the Environment. Planning Policy Guidance Note 16 — Archaeology and Planning. HMSO, London (1990)). The basic premise of PPG 16 is a strong preference for in situ preservation of nationally important archaeological remains. This often includes reburial of archaeology prior to construction activity, once it has been exposed in test-pitting (‘evaluations’) or full excavation. Reburial strategies are often prepared by civil engineers and there appears to be an overemphasis on consideration of the potential physical impacts on the archaeology. These strategies usually include the use of geotextiles and sand, or other graded material, chosen for its particular particle size/shape characteristics. A greater awareness of the chemical and physical characteristics of a burial environment is now required to ensure that reburial is effective. Archaeologists and conservators are beginning to consider both the natural and, increasingly, the ‘man-made’ (industrial, domestic and agricultural) changes to the soil chemistry of an archaeological site. More use needs to be made of the potential information ‘locked up’ in the artefactual material retrieved from evaluations and excavation nearby. An assessment of the degree of preservation of material should be an integral component for the design of a reburial strategy.     

Quantification and Visualization of In Situ Degradation at the World Heritage Site Bryggen in Bergen,Norway

Abstract

Environmental monitoring at the World Heritage Site of Bryggen in Bergen, Norway, has shown damaging settling rates caused by degradation of underlying archaeological deposits. Measurements of piezometric head, oxygen, and soil moisture content, as well as chemical analyses of water and soil samples are key elements of the environmental monitoring.

Groundwater monitoring and geochemical analyses reveal a complex and dynamic flow through the natural and anthropogenic stratigraphy. The preservation conditions within the organic archaeological deposits are strongly correlated with oxygen and soil moisture content, that are controlled by the groundwater flow conditions at the site. To quantify decay rates, it is thus essential to understand the wider hydrogeological context of the site. This paper presents recent advancements in quantifying decay rates in the saturated zone at Bryggen. The paper also shows that 3D geo-archaeological modelling can contribute to preservation management by visually combining results of geological, archaeological, geochemical, and hydrological investigations. This opens up for improved multidisciplinary understanding of preservation potential, thereby contributing to an improved protection of archaeological deposits in situ.     

Ceramics Technology at Late Classic K’axob,Belize

Abstract

Excavation of a Late Classic Maya platform at K’axob, Belize, has revealed a suite of pit features and associated artifacts that are strongly suggestive of pottery production. Interpretation of the features as remnants of pit kilns used to fire pottery is bolstered by comparanda from the Andean region. Archaeometric and experimental replication studies also support the interpretation of this locale as one of pottery fabrication. Findings discussed include features identified as kilns, raw material suitable for temper, lumps of fired clay, ground stone, and expedient clay-working tools made of recycled pottery sherds. This research contributes to knowledge of the organization of Maya pottery production by providing the most comprehensive information presented to date on the technology of ancient Maya pottery fabrication and firing.     

Mineral weathering in forest soils and its relevance to the preservation of the buried archaeological resource

There is more woodland in Britain now than for many centuries and considering many international climate change mitigation policies, woodland cover, both in Britain and internationally, is being promoted. However, neither the management of existing woodlands nor their expansion should be at the expense of important archaeological evidence. Due to the large number of known archaeological sites, the large areas of land with uninvestigated archaeological potential and the expanding woodland cover, suitable mitigation strategies need to be developed to allow preservation in situ of important sites. An understanding of how woodland soils and the buried archaeological resource interact is, therefore, essential. This paper utilises ongoing environmental research into the mineral weathering rates in forest soils and considers its application to artefact preservation. The study concludes that soil water pH, its movement, and the saturation of dissolved ions in the soil solution are major factors determining both mineral and artefact longevity. A simple guide to artefact longevity based on these properties is proposed and a geochemical model for predicting loss is tested. These tools could be applied to any soil or individual horizon irrespective of land-use.     

Forensic Ar/Ar dating: a provenance study of Middle Stone Age obsidian artifacts from Ethiopia

Obsidian sourcing based on geochemistry is widely applied to reconstruct commerce patterns and dissemination of early hominid groups. Due to problems concerning potential intra-source variability or homogeneity of a geological source over large areas, parameters additional to this classical approach are desirable. Here we present the first ⁴⁰Ar/³⁹Ar investigation of Middle Stone Age (MSA) obsidian artifacts (i.e. debitage pieces) for this purpose, as well as of potential geological obsidian sources from Ethiopia. With the present pilot study we demonstrate that ⁴⁰Ar/³⁹Ar geochronology represents a reliable and powerful tool for archaeological provenance studies complementary to the geochemical approach and more recently applied techniques like fission track counting or Mössbauer spectroscopy. Two independent sets of debitage and potential source rock samples were dated by the ⁴⁰Ar/³⁹Ar method. Debitage pieces from the Kulkuletti excavation site and obsidian samples from the nearby obsidian outcrop Worja (central Ethiopia) exhibit basically identical age ranges as well as similar Ca/K and Cl/K ratios, supporting the debitage/source rock relationship previously inferred on geochemical grounds. A second small set of geochemically characterized debitage samples from the Porc Epic cave and potential source rocks from an obsidian outcrop at Kone (Eastern Ethiopia) however have different ⁴⁰Ar/³⁹Ar ages and Ca/K and Cl/K ratios. These results contradict the previous conclusion about a debitage/source rock relationship of the Porc Epic and Kone samples made on the basis of geochemistry [A. Negash, M.S. Shackley, Archaeometry 48 (2006) 1]. Additional sampling at the Kone outcrop as well as of other obsidian occurrences in the greater area is needed to unambiguously pinpoint the origin of these obsidian tools.     

Pollen Extraction for Arid-land Sediments

Abstract

Critical examination of traditional extraction procedures employed to recover pollen from a variety of archeological contexts demonstrated the inadequacy of many such techniques. Particularly in arid zones, where pollen preservation is notoriously poor, inappropriate laboratory analysis acts to distort grains further. A satisfactory methodology for pollen samples recovered from areas subjected to such deteriorating effects as oxidation and weathering is essential for archeologists attempting to reconstruct prehistoric environments. A new extraction methodology harmless to pollen grains, yielding excellent pollen counts and preservation from archeological soils was, therefore, experimentally developed for arid-land sediments.     

From pedologic indications to archaeological reconstruction: deciphering land use in the Islamic period in the Baida district (north-western Sicily)

The aim of this work was to detect imprints on soil properties from former Islamic land use (9th to 11th century) using a multi-method, soil-chemical approach. Four soil profiles (with buried horizons) found in the vicinities of former Islamic settlements in Sicily were analysed for phosphorus (total, organic and inorganic), nitrogen (total, NO₃⁻ and NH₄⁺), carbon compounds (δ¹³C, lipids, polycyclic aromatic hydrocarbons (PAH) and functional groups), physical and chemical C-fractions and the state of soil weathering. Two soil profiles contained ceramic sherds from the Islamic period. Inorganic nitrogen forms, phosphorous and the PAH content indicated strong impacts from traditional agriculture and/or burning. Radiocarbon dating of soil organic carbon (SOC) fractions from buried horizons showed that distinct changes must have occurred during the Islamic epoch. The isotopic composition of SOC indicated that land use was probably different in earlier times. C₄ plant cultivation was expected but surprisingly lipid analyses did not confirm this. A high amount of aliphates and low C/N ratio indicated a good, long-term SOC stabilisation under the native conditions combined with Islamic land use. The irrigation of the soils probably increased the production of weakly-crystalline Fe forms that helped to stabilise SOC.     

Paleolithic occupations of the Göllü Dağ, Central Anatolia,Turkey

Abstract

Systematic archaeological surface reconnaissance of the Göllü Da? volcanic complex from 2007 to 2012 documented more than 230 findspots with Paleolithic artifacts, ranging from isolated finds to extensive and dense scatters of artifacts. Most of the activities represented relate to exploitation of the rich obsidian resources in the region. Paleolithic artifacts are attributed mainly to the Middle Paleolithic based on the presence of Levallois technology but there is a substantial Lower Paleolithic component represented by handaxes and other large bifacial tools. Upper and Epipaleolithic sites and artifacts are scarce or absent in the survey sample. The distributions of handaxes and Levallois elements differ substantially, reflecting differences in site preservation and exposure as well as organization of prehistoric activities. Multiple variants of Levallois are represented but centripetal preferential and unipolar flake production dominate. The frequent co-occurrence of different Levallois forms suggests flexible reduction strategies. Distributions of different classes of artifact across the survey area indicate that the Middle Paleolithic occupations of Göllü Da? were not entirely oriented toward workshop activities.     

CONFIRMATION OF AN ARCHAIC PERIOD MOUND IN SOUTHWEST MISSISSIPPI

Abstract

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

Questioning Craft Production at Angel Mounds Analysis of the 2006–2009 Angel Mounds Field-Schools

Abstract

Seventy years of archaeological investigations at the site of Angel Mounds (12VG1) have led to a broad overall understanding of the cultural practices of the Mississippian people in southwest Indiana nearly 1,000 years ago, but have also raised ever expanding new questions. Recent field-school excavations at Angel Mounds, sponsored by the Glenn A. Black Laboratory (GBL) at Indiana University, explored magnetic anomalies in a previously unexcavated area at Angel Mounds. Analyses of features and artifacts encountered during the excavations at Unit A (the “Potter's House”), including large amounts of Mississippi Plain pottery and craft-production objects, inspired new questions on the organization of craft production at Angel Mounds and other Mississippian archaeological sites. In this article, I test whether a structure at Unit A may have been a craftproduction workshop by reviewing data archaeologists traditionally associate with workshops and examining the standardization of pottery found at the location. Preliminary results demonstrate the variability of Mississippi Plain pottery, even within single locations, and also show the potential analytical utility of such variability for testing important issues in the archaeology of Mississippian societies, including supposed elite-control over craft production and intrasite social organizations.