Condition reporting and monitoring of archaeological sites: The use of large-scale vertical aerial photographs in New Zealand

Abstract

Large-scale aerial photographs (approximately 1:2000 to 1:10000 scale on the negative) have a number of virtues for condition reporting. The same site can be photographed at intervals so that rate of change can be measured. The record is objective and it gives sufficient detail to observe not only patterns but also the details of condition in such matters as past repairs, sheep tracking or the existence and state of repair of fences. In addition, photographic prints provide a ready basis for annotation. They are the primary record of condition and may highlight and focus the needs for conservation intervention. Archiving of photographs makes possible future study in the light of new research interests. Monitoring using photographs taken at regular intervals is also recommended.     

Phosphatic mineralization of seeds from archaeological sites

Recent investigations of botanical material from archaeological sites have provided seeds and plant remains exhibiting a crystalline or semi-crystalline appearance. X-ray diffraction and partial chemical analysis have revealed that the particular plant materials had been replaced by calcium phosphate. Using systematic sampling and retrieval techniques a significant body of data has been accumulated. Most mineralized botanical evidence has been recovered from faecal deposits, in particular cess pits and garderobes, and has provided an important source of information about aspects of diet of past populations.     

The design of effective and efficient trial trenching strategies for discovering archaeological sites

This paper reports a study on the effectivity and efficiency of trial trenching strategies for site discovery within the context of Dutch archaeological heritage management. It discusses the principles of site discovery by means of trial trenching, and suggests the optimal strategies for trial trenching survey, based on the results of simulations. Effective and efficient strategies for discovering different groups of archaeological sites are given, according to their presumed size, shape and feature density. The recommended strategies will be included in the Quality Norm for Dutch archaeology.     

The economic importance of plant resources represented on archaeological sites

Techniques for estimating the economic importance of plants represented on archaeological sites have usually assumed that plant samples were random in composition. The effects of crop-processing activities and other factors upon the composition of each sample have frequently been overlooked, or their importance minimized. This article proposes an alternative approach and suggests that the economic value of a prehistoric plant resource can be ascertained by considering its context within crop-processing activities. It is argued that the merits of this technique are that it provides a more accurate means, first, of distinguishing between actual and potential plant resources, and secondly, of evaluating their importance.     

Structured light scanning for high-resolution documentation of in situ archaeological finds

Archaeologists strive to document the process of excavation and discovery as completely as possible. Over the past several decades archaeologists have incorporated a growing number of computerized techniques for documenting archaeological finds. Scanning is one such technique. There are a number of technologies that now allow archaeologists to scan structures, excavation surfaces and in situ artifacts to create high-resolution, 3D data sets. We report here on a trial application of one of these, a structured-light scanner, to create 3D representations of excavated surfaces and associated artifacts at two Middle Paleolithic sites in southwest France. In each instance, surfaces of approximately 2.5 m² were scanned in approximately 1 day. The resulting data sets are very good representations of the originals in terms of colors and spatial details, and as such provided an important piece of archaeological documentation. To use this equipment successfully in the field, however, required solving a number of logistical issues, and the amount of time required to learn to use this equipment was significant. Once these issues are addressed, this technology is appropriate for documenting extraordinary, unique finds where time and costs are offset by the importance of good documentation.     

The ethics of displaying human remains from British archaeological sites

Abstract

The 1998 exhibition London Bodies at the Museum of London provided an opportunity to review the ethical issues relating to the excavation, study and display of human remains in modern Britain. It is suggested that for most Britons the display of human skeletal material is not considered a problem, but that archaeologists would do well to ensure that their practices are in line with the views and beliefs of the society in which they work.     

New methods for the identification of evidence for bitting on horse remains from archaeological sites

This article describes alterations to equid lower second premolars and diastemata from a series of known life history equids and a number of archaeological horse specimens from the British Iron Age. Two new methods for recording bit wear are proposed involving the analysis of the extent and morphology of enamel/dentine exposure on the anterior edge of LP2s and analysis of the extent of new bone formation and bone loss to the diastema of the mandible. It is suggested that when a bit is used on a horse it acts more frequently on the anterior margin of the LP2 than has previously been thought and that repeated contact between the bit and the LP2s and diastemata results in recognisable damage to these areas of the mouth.     

Teeth of juvenile woodchucks as seasonal indicators on archaeological sites

The woodchuck, Marmota monax, a burrowing scuirid of eastern North America, was a common food animal of prehistoric peoples. Since the species has a single, brief birthing period all juveniles are at a comparable stage of development at a given time. Widths of the continuously growing incisors, development of the cheek teeth and alveoli, and loss of deciduous teeth have been determined from a sample with known dates of collection. These data are compared to juvenile woodchuck remains from an archaeological site to determine season of kill.     

Optically stimulated luminescence dating of Southern High Plains archaeological sites

The Southern High Plains of North America is rich in archaeological sites, but many are not well constrained chronologically, owing to a lack of material for radiocarbon dating. A program of optically stimulated luminescence (OSL) dating, applying mainly single-grain analyses, was therefore initiated. Many samples have independent age estimates from radiocarbon to check the OSL results, but OSL age estimates are also provided for those sites that otherwise lack secure chronological control. Sediment samples for OSL were obtained primarily from Paleoindian and Archaic localities, though include deposits of more recent age. Through the analysis of single grains, equivalent dose—the numerator of the age equation—is evaluated independently on numerous grains. The distribution of these values is relatively broad for some samples, and this is attributed to post-depositional mixing. Mixing is also evident in some samples with more narrow distributions. Selecting portions of the mixed distributions for age determination allows more accurate dating for some samples, but the nature of the distributions limits the resolution on others, conclusions that cannot be as easily drawn from multi-grain analysis. Where independent age control is available, most OSL results broadly conform; however, some samples show discrepancies that are not readily explained, but may relate to association or dose rate problems. This underscores the desirability of obtaining where possible suites of chronological evidence.     

Mapping the possible occurrence of archaeological sites by Bayesian inference

Regional archaeological prospections are often done by field walking, where the location of the sampled fields is often determined by factors like feared disturbance or recent plowing. The resulting data configuration can be suboptimal for spatial prediction of the archaeological potential by geostatistical methods like kriging. As an alternative, we propose a Bayesian method to map the possible occurrence of archaeological finds and compare this to indicator regression kriging. Three types of predictive models were implemented in the Bayesian context following deductive, inductive and mixed approaches to use auxiliary geographical information in the mapping. After prediction of a validation set, it was concluded that the mixed approach gave the best results in terms of map quality, and that the kriging method performed poorly. Usage of data on the presence and the absence of archaeological finds is to be preferred above usage of presence data only. Furthermore, a method is presented that filters those parts of a predictive map that are not strongly supported by evidence.     

Methods for assessing stormwater management at archaeological sites: Copan Ruins case study

Archaeological sites may be discovered by fortuitous soil erosion, but their protection requires deliberative stormwater management plans and estimates of runoff volumes. This paper uses the Maya site of Copan, Honduras to demonstrate widely applicable methods to estimate runoff, including use of satellite rainfall data processed by single parameter models. Our analysis compares present day estimates of runoff and erosion with those of two historic periods, 900 A.D during peak Maya occupation of the Great Plaza, and 1800 A.D. prior to excavation when the site was mostly forest covered. For each period, the watershed area, soil, land cover, and rainfall data were used with a single parameter Curve Number model to estimate the runoff volume for annual to decadal storms. The maximum runoff depth and erosive potential in conveyance channels was then computed with the HEC-RAS model. The models did not predict runoff would occur for the forested period of 1800 A.D., but predicted that runoff for 900 and post-1800 A.D was large enough to cause the erosion observed in the drainage channel today. Our results provide runoff magnitudes that demonstrate the need for Copan Maya designed stormwater removal infrastructure described in earlier archaeological analysis. The need for stormwater removal was also designed into the wet Maya site of Palenque, while stormwater capture and storage was designed into the Maya sites of Tikal, a drier site due to local drainage characteristics and water availability. Methods used in stormwater runoff analysis can empower communities and managers to develop scientifically and culturally appropriate non-structural management methods to conserve archaeological sites.     

Potential of satellite based sensors for studying distribution of archaeological sites along palaeo channels: Harappan sites a case study

A large number of remote sensing based studies have shown evidence of a prominent river system, which has become buried under sand cover of Thar Desert sometime during late Holocene. This major river has been identified as Sarasvati, a legendary river mentioned in ancient Indian texts. This region is rich with archaeological sites of Harappan civilization (2500–500 BC). The present study has utilised digital image processing and enhancements techniques on multisensor satellite data followed by field investigations to reconfirm known traces and detect hitherto unknown traces of palaeochannels of Sarasvati river through parts of Indus alluvial plain in Thar desert. Potentials of IRS-P4 OCM (Primarily an Ocean Color Sensor, with eight narrow spectral channels, high radiometric resolution of 12 bits and large swath of 1420 m) could be exploited for the first time to detect hitherto unknown traces of palaeochannels of Sarasvati river through sand dune topography of Thar desert in parts of Western Rajasthan in India and adjoining parts of Pakistan by applying Principal Component Analysis technique. Pattern of palaochannels indicate westward migration of the Sarasvati river in parts of Indus alluvial plain. Database of more than 1000 archaeological sites compiled from various published sources, prepared in GIS environment could be utilised to understand their relationship with identified courses of the Sarasvati palaeochannels. Through this study it was found that there is a large spread of Mature Harappan (2200–1700 BC) sites along the palaeochannel of the Sarasvati and its tributaries in north-west India, but late Harappan (1700–1500 BC) sites are limited to further west in adjoining regions of Pakistan indicating that the shift of cluster of settlements have followed the pattern of river migration towards west. Digital terrain modelling by superimposing archaeological sites on SRTM DEM along with draped satellite data (Resourcesat-1 AWiFS and IRS-1D LISS-III) has helped in identifying geomorphological guides for archaeological investigations such as presence of relict natural levees seen as raised mounds and coincidence of known archaeological sites over them. It is suggested that other relict natural levees or raised mounds adjoining the identified palaochannel courses may be taken up for further archaeological exploration.     

Absence of premolar teeth from ruminant mandibles found at archaeological sites

Three bovine and three ovine mandibles are described in each of which the second permanent premolar tooth was absent. In one of the bovine jaws an absence of the fifth cusp of the third molar was also noted. A review of tooth absence in wild and domestic bovidae is presented and suggestions are made as to the reason for absence.     

A system for classification and description of the horn cores of cattle from archaeological sites

A system is proposed for the classification and sexing of the horn cores of cattle recovered from archaeological sites. The cores are first divided into four groups depending on their length. The terms “small”, “short”, “medium” and “long horned” are given to these groups but bear no relation to the names used for modern breeds of cattle. After differentiation according to length, the sex of the core is designated by visual appraisal of the shape, curvature and angle of attachment of the cores to the frontal bones. It is not claimed that the sex of individual horn cores can always be established but from the sample of 80 cores that we tested by statistical analysis (presented in an appendix) it was evident that the categories based on length and assessment of sex did separate out as expected.