Technological, elemental and colorimetric analysis of an engraved ochre fragment from the Middle Stone Age levels of Klasies River Cave 1, South Africa

It is generally accepted that abstract and iconographic representations are reflections of symbolic material culture. Here we describe a fragmented ocherous pebble bearing a sequence of sub-parallel linear incisions. These were produced by a lithic point and may represent one of the oldest instances of a deliberate engraving. The object was recovered from Middle Stone Age II levels of Klasies River Cave 1, South Africa, and is dated to between 100,000 and 85,000 years ago. Microscopic analysis reveals that the surface of the object was ground until smooth before being engraved with a sequence of sub-parallel lines made by single and multiple strokes. X-ray fluorescence and colorimetric analysis of the object and a sample of twelve additional ochre pieces from the same level reveals that the brown colour and Manganese-rich composition renders the engraved piece distinct. This suggests that a particular type of raw material may have been selected for engraving purposes. Although the purpose of marking this object remains uncertain, its detailed analysis adds relevant information to previously published occurrences of Middle Stone Age engraved objects and contributes to clarify their distribution through time and space.     

Do municipal unions improve cost efficiency for the social function? A quasi-experimental endogenous stochastic frontier approach

Homogeneous national policies can generate heterogeneous effects on the territory. This paper aims to verify the impact of the entry of single Italian municipalities into an inter-municipal association on the unitary costs of the social services supplied to the local communities. Panel cost stochastic frontier model in the presence of endogeneity has been introduced based on two pillars: a counterfactual setting to verify the aggregation effects concerning a set of similar municipalities and the use of a cost efficiency estimation methodology which considers the endogeneity of output with respect to cost. The results of our analysis show that the effects of adopting associated forms of service delivery can be very multifaceted and diversified according to the typology and the degree of implementation of the Municipal Union itself. The analysis sheds light on the effects of municipalities' organisational choices, addressing the consolidation of small municipalities not in binary terms but also—and above all—suggesting that it is the type of union that impacts the possibility of convergence towards greater cost efficiency.     

The Environmental History of Tigray (Northern Ethiopia) in the Middle and Late Holocene: A Preliminary Outline

This paper outlines the environmental history of the Tigrean Plateau (northern Ethiopia) during the Holocene, based on the available geomorphological, palynological, archaeological, and historical evidence. At present, it seems that (1) the plateau experienced a more humid climate with a denser vegetation cover during the Early Holocene; (2) Soil erosion due to clearing vegetation began in the Middle Holocene; (3) agricultural activity was intensified in the Late Holocene, as a consequence of the rise of a state; (4) demographic pressure increased from the early first millennium BC to the mid–first millennium AD, causing soil erosion; (5) environmental degradation and demographic decline occurred in the late first millennium AD; (6) the vegetation cover was regenerated in the early second millennium AD; and (7) progressive vegetation clearance started again in the second half of the second millennium AD.Cet article trace l'histoire ambiante du Plateau Tigréen dans l'Holocène en utilisant les données géomorphologiques, palynologiques, archéologiques et historiques. Il semble que (1) dans l'Holocène ancien le plateau était caractérisé par une phase humide avec une dense végétation; (2) l'érosion causée par l'abbattage de la végétation commen¸a dans l'Holocène moyen; (3) l'activité agricole s'inténsifia à la fin de l'Holocène, par conséquence de l'essor d'un état; (4) la pression démographique augmenta de plus en plus du début du premier millénaire av. J.-Ch. à la moitié du premier millénaire ap. J.-Ch.; (5) la dégradation ambiante et la diminution démographique se vérifièrent à la fin du premier millénaire ap. J.-Ch.; (6) une régéneration de la vegetation se vérifia au début du seconde millénaire ap. J.-Ch.; et (7) l'abbatage de la végétation recommen¸a dans la seconde moitié du seconde millénaire ap. J.-Ch.     

Contact Dynamics of Masonry Block Structures Using Mathematical Programming

A simple variational formulation for contact dynamics is adopted to investigate the dynamic behavior of planar masonry block structures subjected to seismic events. The numerical model is a two-dimensional assemblage of rigid blocks interacting at potential contact points located at the vertices of the interfaces. A no-tension and associative frictional behavior with infinite compressive strength is considered for joints. The dynamic contact problem is formulated as a quadratic programming problem (QP) and an iterative procedure is implemented for time integration. Applications to analytical and numerical case studies are presented for validation. Comparisons with the experimental results of a masonry wall under free rocking motion and of a small scale panel with opening subjected to in-plane loads are also carried out to evaluate the accuracy and the computational efficiency of the formulation adopted.     

Neutron imaging study of ‘pattern-welded’ swords from the Viking Age

We present novel imaging results from a non-invasive examination of three ‘pattern-welded’ swords from the Viking Age belonging to the National Museum of Denmark, using white beam and energy resolved tomographies with neutrons. Pattern-welded blades are made by forge welding together thin strips of iron and steel that were twisted and joined in various ways, producing a decorative pattern on the surface. The study shed light on the inner structure of the composite material and manufacturing techniques of these admired examples of past technology, revealing some otherwise invisible details of their assembly methods, phase distribution and extent of the corrosion.     

Archeometric characterization of prehistoric grindstones from Milazzo Bronze Age settlement (Sicily,Italy)

The results of a petrographic and geochemical study carried out on archeological grindstones allow to provide new constraints on protohistoric commercial exchanges over the Mediterranean area. Eleven grindstones, discovered in an archeological site located in Milazzo (Messina, Sicily) and dated from the Early Bronze Age, have been investigated by geochemical and petrographic techniques. The raw materials are mainly volcanic rocks characterized by calc-alkaline and K-alkaline affinities with volcanic arc geochemical signature. Only one sample, made of basalt belonging to the Na-alkaline series, shows an intraplate signature. The comparison with the available literature data for similar rocks allowed constraining the volcanic origin of the exploited lavas. While the intraplate-type raw material came from Mt. Etna Volcano (Sicily), the arc-type volcanic rocks are mostly trachyandesites, basaltic andesites, and one rhyolite. Although most of them come from the Aeolian Arc, a provenance of some samples from the Aegean Arc cannot be excluded. This last region could represent the most probable provenance area for the rhyolite sample.     

A prehispanic Maya pit oven? Microanalysis of fired clay balls from the Puuc region,Yucatán,Mexico

Excavations of a kitchen at Escalera al Cielo in the Puuc Maya region of Yucatán, Mexico uncovered a concentration of fired clay balls (ca. 3–5 cm in diameter), in addition to other de facto domestic refuse. The kitchen pertains to an intensively excavated elite residential group that was rapidly abandoned sometime near the end of the Terminal Classic period (A.D. 800–950), resulting in floor assemblages that provide an opportunity to explore the types and distribution of daily household activities. The results of experimental replications and a suite of analyses comprising modal analysis, ceramic petrography, Fourier transform infrared spectroscopy (FTIR), and microbotanical residue analysis reveal aspects of clay preparation, firing temperatures, repeated use of the balls, firing conditions, and specific plant food or fuel residues adhering to them. We show that the fired clay balls were manufactured with local, clay-rich soil and employed by the inhabitants of Escalera al Cielo as heating elements; relatively high concentrations of microbotanical residues from edible plants adhering to them support the hypothesis that they were involved in kitchen activities related to food processing.