Towards a three-dimensional cost-effective registration of the archaeological heritage

Archaeological practice within the European context of heritage management is facing huge challenges in ways of recording and reproduction of ex-situ preserved sites. As a consequence of the Valletta-treaty, numbers of archived images and drawings of excavated structures as prime sources of past human activity, are exponentially growing. Contrarily to portable remains however, their future study and revision is biased by the two-dimensional character of the recorded data, rendering difficult their future reconstruction for new study or public dissemination. A more realistic three-dimensional (3D) way of recording and archiving should be pursued. In this paper the possibilities for 3D registration of archaeological features are examined in a computer vision-based approach using the PhotoScan software package (Agisoft LCC). It proved to be a scientific and cost-effective improvement compared to traditional documentation methods. Advantages can be found in the high accuracy and straightforwardness of the methodology. The extraction of an orthophoto or a Digital Terrain Model from the 3D model makes it feasible to integrate detailed and accurate information into the digital archaeological excavation plan. The visual character of 3D surface modeling offers enhanced output-possibilities allowing a better documentation of in-situ structures for future research and a higher public participation and awareness for the archaeological heritage.     

A laboratory cave for the study of wall degradation in rock art caves: an implementation in the Vézère area

The aim of this proposal is to present an original approach to the study and preservation of rock art caves. A multidisciplinary study of cave wall alteration will be performed to understand the impact of environmental context on the evolution of wall surfaces. The approach involves the choice of a cave with characteristics similar to painted caves in the studied area (Vézère Valley in Dordogne, France): e.g., cave wall alteration, lithology, morphology, etc. This selected cave is intended to become a laboratory cave, monitored for the acquisition of chemical, physical and biological environmental data on bedrock, air and fluids along with their characteristics. A cave without art or archaeological interest has been chosen specifically to conduct experiments, to make in situ analysis and to obtain samples. The results are to be completed by specific observations in several other caves and compiled in a database.     

Use of robust methods to determine quadratic surfaces: application to heritage

3D surveys of archaeological elements and the construction of virtual models enable us to reconstruct historical sites. They provide useful data to select specific building processes.Photogrammetry and Terrestrial Laser Scanning (TLS) are the most common techniques to obtain synthetically heritage models. These techniques provide massive data which can only be managed by replacing them by primitive shapes, thereby obtaining more simple models and the explicit geometry of the element. Statistical and robust methods are used for this substitution, thereby avoiding the common errors due to measuring. Of these methods, the most widely used are the least-median-of-squares (LMedS) and the RANSAC method.Another computation method consists in recursive processes based on evolutive-type algorithms to adjust the model to the data captured.This paper describes two surface computation methodologies to determine the modelling of a column shaft located in temple G of the archaeological park of Selinunte (Sicily).     

Oldest Australian vespertilionid (Microchiroptera) from the early Miocene of Riversleigh,Queensland

An upper molar of a small bat, here described from an early Miocene freshwater lime-stone deposit at Riversleigh, northwestern Queensland, is the oldest record in Australia of the microchiropteran family Vespertilionidae. The new taxon is referred to the cosmopolitan genus Leuconoe, but it does not appear to be closely related to the two extant Australian species of this genus.     

SLEEPING ABROAD BUT WORKING AT HOME: CROSS‐BORDER RESIDENTIAL MOBILITY BETWEEN TRANSNATIONALISM AND (RE)BORDERING

Cross‐border residential mobility (CBRM) has so far largely been approached from a transnational perspective. However, recent developments in border studies and transnationalism give rise to certain doubts. While border studies have come to include mental borders next to physical borderlands, transnationalism today refers not just to cross‐border movements but also to identities trans‐cending the national. But border studies have shown that the increased crossing of borders is not necessarily coupled with their diminished significance. CBRM is a particularly interesting phenomenon as it entails the continuous crossing of a physical border, but the question is whether it also implies the erosion of mental borders and the emergence of transnational ties. While drawing on experiences from parallel cases, my study focuses on Poles from Szczecin moving just across the boundary to Vorpommern, Germany. Some are integrating there, but their large majority appears to carry on with everyday life in Poland as before moving. This settlement has triggered considerable resentment among local Germans, who as a reaction mark the borderland discursively and physically. As my survey shows, while both groups regularly cross the physical border, many even among the cross‐border residents consider it as a necessary dividing line or prefer cooperation to be reserved to some activities. Hence, unlike longdistance migration leading either to diaspora identities or to gradual dissolution in the majority culture, CBRM appears as a specific form of international migration where the physical proximity allows such intensive links with the country of origin that transnational effects are mitigated.