Neutron activation analysis of fine grey pottery from Conimbriga,Santa Olaia and Tavarede,Portugal

The concentrations of two major elements and thirteen trace elements in 73 selected sherds of fine grey ware from the Iron Age and Roman period, excavated at Conimbriga, Santa Olaia and Tavarede, Portugal, were determined by instrumental neutron activation analysis. These concentrations were used to calculate distance matrices which were then subjected to cluster analysis employing SAHN and k-means methods, as well as to principal components analysis, to group the sherds according to the overall similarity of their compositional characteristics. The results showed that equivalent groupings appeared regardless of the taxonomic method used. Two major clusters were recognized corresponding to two different sites, namely Conimbriga and Santa Olaia, suggesting that the ceramics from these sites were made locally. No significant differences in compositional patterns were observed between iron age and roman sherds from Conimbriga.     

Living on the Edge? Transformation of a Marginal Pleistocene Landscape Into a Settlement Area in the Northeastern Part of the Netherlands

ABSTRACT

This paper will examine settlement location during the Iron Age in the northeast part of the Netherlands, an area shaped by Pleistocene geology. In recent years, a number of Late Iron Age/Early Roman settlements situated on the low lying slopes of sand ridges and nearby stream ridges revealed traces of an earlier Iron Age occupation. Palynological data revealed that this part of the landscape was used by humans before it was transformed into an area of settlement. An analysis of excavation data from two key sites at Denekamp-De Borchert and Groningen-Helpermaar, as well as other known sites, lead to the conclusion that the transformation of ‘peripheral landscapes’ into permanent settlement locations was preceded by a phase of arable cultivation which left no trace of permanent habitation. It is also suggested that the impact of human behaviour on the natural landscape in the Early and Middle Iron Age was much bigger than previously anticipated. When excavating this type of settlement areas dating to the Late Iron Age, archaeologists must be aware that only of a small group of archaeological features exist. The proposed model for the choice of settlement location may be more widespread, because of similarities in landscape between the study area presented here and other landscapes in Northwest-Europe (e.g. parts of Germany and Denmark).     

Characterization of a Historical Cannonball from the Fortress of San Juan De Ulúa Exposed to a Marine Environment

Metallurgical analyses and chemical characterizations were carried out on historical cannonballs from the Fortress of San Juan de Ulúa, Veracruz, México. Cannonballs dating from the 18th and 19th centuries share metallurgical characteristics similar to those of material coming from a shipment of ammunition found in the wreck of a sunken French ship from the battle of Trafalgar. The analyses show that the base material is grey cast iron with a carbon equivalent of 4.94 and a ferritic–perlitic matrix, in which the high phosphorus content has led to the formation of iron phosphide compounds in conjunction with a homogeneous distribution of carbon graphite flakes of Type C. In addition, corrosion products from samples revealed the presence of various crystalline iron compounds (X‐ray diffraction), mostly highly chlorinated iron compounds identified as akaganeite. X‐ray fluorescence identified various characteristics of the corrosion products as a function of the sampling depth. FT–IR spectroscopy revealed that the main difference between the corrosion products (internal and external) is determined by the number of organic species. Differential scanning calorimetry corroborated that these corrosion products are thermally stable compounds at elevated temperatures.     

A Box Containing Carpenter's Accessories from The Akko 1 Shipwreck,Israel: Archaeometallurgical Analysis of Surviving Ironwork

The Akko 1 shipwreck was an Egyptian armed vessel, built at the beginning of the 19th century. A wooden saw handle and a box containing iron nails and two split pins were discovered towards the stern. Given their function, location and context, these were part of the ship's carpenter's tools and accessories. A methodology was developed for conducting systematic metallurgical analysis in order to understand the manufacturing process of the surviving ironwork items, as well as to enlarge our knowledge regarding ironworking technologies during the early 19th century. Such methodology may assist in the future understanding of the technological evolution of similar wrought‐iron objects. The results demonstrated that the artefacts have a wrought‐iron heterogeneous microstructure and were manufactured by hot‐working prior to surface hardening by pack carburization.     

3D Digital Survey of Iron Tie-Rods in Masonry Buildings: Cross-Sections Analysis and Error Estimation

Ancient iron tie-rods are handcrafted elements with large geometric irregularities, due to production techniques (they are shaped by hammering and linked by hot-forging) and corrosion processes. In common practice, their cross section (that is one of the main parameter to assess their strength) is manually measured on site with a manual caliber. By analyzing a set of detailed three-dimensional (3D) digital surveys of real ancient tie-rods, this study provide an evaluation of the errors made by in-situ manual geometric measurements. In particular, it shows that, in some cases, manual on-site survey is sufficiently reliable and has errors that fall below 10%. Moreover, it shows that when tie-rods have high corrosion levels in hidden zones (typically those close or within the retaining walls) the on-site survey of visible parts only may produce far greater errors that exceed 100%, leading to a strong overestimation of the cross-section of the tie. The ongoing study is a first step toward the definition of correction coefficients to be applied to the on-site manual measurements of ancient tie-rods, with the final aim to improve the reliability of structural analyses.     

Historical Use of Metal Tie-Rods in the Italian Territory: Treatises,Essays, and Manuals through Four Centuries of History

The use of metal tie-rods in buildings is documented and visible in many Italian areas since the 15th century. This article refers to the study of treatises, manuals and essays from the 15th to the early 20th century, mainly in the Italian context with some exceptions of certain foreign texts that, due to their diffusion and importance, have greatly influenced the technical literature on the subject. Technology is an expression of the social, economic, cultural, political and juridical events of a country and, as such, is deeply linked to the times and territories in which it develops. However, it is also closely linked to the laws of nature and to forms of communication, therefore it is useful to compare, underlining the analogies and differences, the knowledge and the ways of the productive and technical process in a long-term analysis.     

Transitions in cast iron technology of the nomads in Mongolia

Metallurgical study of seven cast iron artifacts recovered from sites of the former Xiongnu (BC 3rd to AD 1st), Turk (AD 6th to 8th), Khitan (AD 10th to 12th), and Mongolian empires (AD 12th to 15th) shows that the earlier Xiongnu and Turk artifacts were made of cast iron alloys of near eutectic composition. The later Khitan and Mongol objects had greatly reduced carbon content in the range of ultrahigh carbon steel rather than cast iron, and contained more than 0.5 mass % silicon as an alloying element. Inclusions high in sulfur, phosphorus or silicon are also present. These differences suggest that Mongolia experienced a technical transition a few centuries before the establishment of the Mongolian empire, which is in agreement with some written accounts. The microstructures of the cast iron artifacts are compared with the related archaeological and documentary evidence. The results suggest that the use of fossil coal in smelting and the state policy of controlling iron production were the major factors responsible for the transition.     

A 15th‐Century Wreck of an Ordnance‐Carrying Ship from Atlit North Bay,Israel

In 1977, a shipwreck assemblage was discovered off Atlit, Israel. Finds included three iron anchors, a large bombard, four swivel guns, stone and lead shot, and bronze helmets. The bronze bombard (2210 kg, 3.247 m long) contained a wooden wad and remnants of what may have been gunpowder. The swivel guns (each 185 kg) were bronze, with swivels and the tillers of iron. Twenty (or 21) bronze helmets were recovered. The findings provide rare evidence for the mounting of heavy ordnance on the bow of a galley or ship in the 15th century.     

“长江口二号”沉船出水青花瓷中的污染物研究

位于长江入海口的“长江口二号”清代沉船是中国目前发现的保存最为完整的古代木制沉船之一，已于2022年11月完成整体打捞。在进行水下考古调查时，沉船出水的部分青花瓷出现的病害现象引起了考古工作者的关注，特别是裂纹中黑色污染物及表面铁锈状污染物对文物的外观产生了很大影响。本工作选取了三件具有典型被污染特征的青花瓷标本作为代表，使用能量色散X射线荧光分析(EDXRF)、光学显微镜(OM)、X射线衍射分析(XRD)、拉曼光谱分析(Raman)和扫描电子显微镜-能谱分析(SEM-EDS)等方法，对污染物进行了研究，探讨了其形成原因以及环境的影响作用，并对其潜在危害进行了分析。研究表明，污染物主要以方解石、菱铁矿等碳酸盐以及铁的氧化物、氢氧化物和硫化物为主。长期处于河口淤泥中的还原性环境是导致菱铁矿和亚稳的铁硫化物形成的原因，船体中铁质构件腐蚀对局部环境的污染是重要的影响因素，这也反映出被污染的青花瓷所处位置和环境的特殊性。出水的部分青花瓷釉中裂纹的形态表明其形成是由物理撞击造成，而釉中硅灰石晶体的选择性腐蚀会导致腐蚀坑的形成，裂纹和腐蚀坑均为外部污染物进入釉层内部提供了通道，导致瓷器劣化。出水后...     

Monitoring fluid chemistry in iron oxide–copper–gold‐related metasomatic processes,eastern Mt Isa Block,Australia

Most researchers in the Proterozoic eastern Mt Isa Block, NW Queensland, Australia, favour magmatic fluid and salt sources for sodic‐(calcic) alteration and iron oxide–copper–gold mineralization. Here we compare spatial, mineralogic and stable isotope data from regional alteration assemblages with magmatic and magmatic‐hydrothermal interface rocks in order to track chemical and isotopic variations in fluid composition away from inferred fluid sources. Tightly clustered δ¹⁸O values for magnetite, quartz, feldspar and actinolite for igneous‐hosted samples reflect high temperature equilibration in the magmatic‐hydrothermal environment. In contrast, these minerals record predominantly higher δ¹⁸O values in regional alteration and Cu–Au mineralization. This dichotomy reflects partial equilibration with isotopically heavier wallrocks and slightly lower temperatures. Increases in Si concentrations of metasomatic amphiboles relative to igneous amphiboles in part reflect cooling of metasomatic fluids away from igneous rocks. Variations in X_Mg for metasomatic amphiboles indicate local wallrock controls on amphibole chemistry, while variations in X_Cl/X_OH ratios for amphiboles (at constant X_Mg) indicate variable aH₂O/aHCl ratios for metasomatic fluids. Biotite geochemistry also reflects cooling and both increases and decreases in aH₂O/aHCl for fluids away from plutonic rocks. Decreased aH₂O/aHCl ratios for metasomatic fluids reflect in part scavenging of chlorine out of meta‐evaporite sequences, although this process requires already saline fluids. Local increases in aH₂O/aHCl ratios, as well as local decreases in δ¹⁸O values for some minerals (most notably haematite and epithermal‐textured quartz), may indicate ingress of low salinity, low δ¹⁸O fluids of possible meteoric origin late in the hydrothermal history of the region. Taken together, our observations are most consistent with predominantly magmatic sources for metasomatic fluids in the eastern Mt Isa Block, but record chemical and isotopic variations along fluid flow paths that may be important in explaining some of the diversity in alteration and mineralization styles in the district.