THE WRITING'S IN THE WALL: A REVIEW OF NEW PRELIMINARY APPLICATIONS OF ELECTRICAL RESISTIVITY TOMOGRAPHY WITHIN ARCHAEOLOGY

Natural processes are known to cause significant damage to archaeological monuments. In fact, the key to understanding the decay of building materials is the internal movement of water through the mineral matrix, which influences the distribution of chemical, physical and biological deterioration processes. Electrical resistivity tomography (ERT) was traditionally used as a surveying tool within archaeology, but a new high‐resolution technique that accurately traces the movement of moisture in building materials could provide a vital tool for understanding the decay of many archaeological monuments. This paper considers current progress, the shift of ERT from soil to rock research and the impact that this development could have on future conservation, using Hertford College (Oxford) and Neolithic rock art (Golden Gate Reserve, South Africa) as case studies.     

ALTERATION PROCESSES OF POTTERY IN LAGOON‐LIKE ENVIRONMENTS

Post‐depositional processes in pottery can give rise to chemical and mineralogical alterations, the extent of which is closely related not only to the microstructure and composition of the potsherds, but also to the chemical–physical conditions of the burial environment. The present paper describes the characterization of post‐depositional alterations and identification of processes involving pottery buried in lagoon‐like environments. A set of various types of Roman transport amphorae and African Red Slip ware (ARS), collected from two archaeological sites characterized by a lagoon‐like depositional environment and showing evident changes in the original colours, was analysed by a combination of microstructural, mineralogical and microchemical approaches. The formation of pyrite after hematite, jarosite after pyrite and microstructural substitution features are interpreted here in terms of the chemico‐physical conditions of the burial environment and their evolution in time.     

Survey of the Outline of an Early Roman Marching-camp in Germany by Rammner's Current Line Pertubation Method

The outline of the first discovered early Roman Marching-camp north of the Limes in Germany (Dorlar, State of Hessen) was determined by electrical resistivity sounding. The camp was inhabited sometime between 11 and 15 and used as base to conquer Dünsberg, a keltic-germanic oppidum. Rammner's Current Line Pertubation Method (CLP) detected soil disturbances caused by ancient Roman construction. The CLP-Method was used to measure the perturbation of a current due to inhomogeneities in the ground. Data processing made it possible to determine the outline of the Roman marching-camp with an accuracy of ±0·15 m. The electrical soundings were confirmed by selected excavations.     

Endurance in the Canyon: Assessing preservation at a multi-component site on the Southern High Plains,USA

Abstract

Preservation decisions often have to be made regarding the long-term status of deeply buried sites. However, the opportunity to evaluate these decisions practically, decades later, is rare. The Nash site, on the Southern High Plains of the USA, is one site where reinvestigation has permitted the assessment of a well-stratified site after an intervening period of thirty years during which it was impacted by dredging and impoundment. The current condition of the site has generated challenges in both recovery and conservation of material. Renewed fieldwork at the Nash site highlights the need to evaluate preservation options while critically considering the effects of geomorphic, taphonomic, and cultural processes.