Ancient tin production: Slags from the Iron Age Carvalhelhos hillfort (NW Iberian Peninsula)

Provenance and production of tin in the Ancient World has since long been a major topic of discussion among archaeologists. In Western Europe, where significant tin ore (cassiterite) deposits are known, only a few remains of ancient tin production, such as tin slags, have been detected. In the present work, elemental and microstructural analyses by WDXRF, SEM-EDS and XRD were performed on recently recognised tin slags from the Iron Age Carvalhelhos hillfort located in NW Iberia, a territory that represents the largest extension with tin mineralisation in Western Europe. Elemental and microstructural characterisation of cassiterite collected in a pilot field survey in the region of the hillfort are presented and discussed, as well as two ceramic fragments that could be part of a smelting structure and an iron slag from the settlement. Results show that the tin slags have variable but high contents in Sn, similarly to Pre-Medieval tin slags found in other Western European areas, but also high contents of Ta and Nb, which specifically distinguish them from other tin slags, such as those found in SW Britain. Tin ores from the hillfort region frequently have Ta and Nb in cassiterite solid solution or as inclusions of columbite group minerals, relating well with the Carvalhelhos tin slags. Up to present, the Carvalhelhos slags are amongst the very few ancient tin slags known in Western Europe, and their study can contribute to a better knowledge on ancient tin sources and trade routes

An Archaeometric Study

The Chalcolithic period in the Lisbon region, Portugal, is usually divided into three phases chronologically: the Early Chalcolithic, characterized by cylindrical corrugated cups, Full Chalcolithic by so-called acacia-leaf decoration, and Late Chalcolithic by Bell Beaker pottery. The aim of this research is to determine if Chalcolithic ceramic raw materials and production techniques have remained the same over time and whether the pottery is locally produced. Regarding the Lisbon region, 149 ceramic samples from four Chalcolithic settlements (Vila Nova de São Pedro, Penedo do Lexim, Espargueira and Baútas) were evaluated concerning textural, chemical and mineralogical compositions. Textural analysis was performed using optical microscopy, chemical characterization was achieved using micro-energy dispersive X-ray fluorescence spectrometry and mineralogical characterization was undertaken using X-ray powder diffraction and petrographic microscopy as main techniques. Results suggest that production techniques may have remained similar throughout all the Chalcolithic period, with firing temperatures between 700 and 800 °C. Multivariate analysis of results from chemical and mineralogical analyses suggests that multiple sources of raw materials must have been used in the manufacture of the pottery collected at the four Chalcolithic settlements.publishersversionpublishe

The role of entrepreneurial ecosystems in the SME internationalization

The Entrepreneurial Ecosystems (EE) articulate concepts from various streams of literature and are formed by multiple stakeholders and relate to different levels of analysis. Although the literature shows a growing relevance on the theme of EE, most studies reveal to be conceptual, and the existence of empirical studies with quantitative methodologies is still scarce. This study attempts to contribute to filling this gap by developing a dynamic model of EE and its impact on the small and medium-sized enterprises (SME) international performance by aggregating different levels of analysis. Based on a sample of 120 SMEs, the results suggest that macro (agents) and meso (different partners) level variables positively impact international performance. We also find that technology transfer has a negative moderating effect on the meso level relationship of EE with digital performance. Our study also contributes to a greater understanding of the Entrepreneurial Ecosystems, its internationalization and the digital performance effect.info:eu-repo/semantics/publishedVersio