Chloride ion concentrations during the compression of rocks to extract pore water

Pore water needs to be extracted from rocks with low permeabilities to allow the major ion concentrations in the pore water to be estimated. Compressing a rock is the most widely used method of extracting the pore water. However, ion concentrations have been found to change during compression in previous studies, and the mechanisms involved in such ion concentration changes have not yet been fully assessed. In this study, two natural rocks and four artificially prepared samples were compressed, and changes in the chloride ion (Cl^?) concentrations as the compression pressure increased were investigated. Mechanisms that could have caused the changes observed were then assessed. The Cl^? concentrations in squeezed water decreased as the pressure increased if the sample contained a significant amount of smectite. The strong dependence of Cl^? concentration on the amount of smectite indicated that smectite played an important role in decreasing the Cl^? concentration. The dilution of the pore water with interlayer water from the smectite appeared to be the dominant mechanism involved in the decrease in Cl^? concentration found in a Kunigel‐V1 sample, because dilution of the pore water with interlayer water quantitatively explained the decrease in the Cl^? concentration. The filter effect caused by the anion exclusion effect did not appear to be a dominant mechanisms in our case. However, Cl^? concentration decrease found in natural rocks could not be fully explained by dilution with interlayer water, so other mechanisms must be involved the phenomenon in natural rocks.     

Preliminary neutron diffraction study of two fenestrated axes from the ‘Enot Shuni' Bronze Age cemetery (Israel)

Neutron diffraction (ND) analyses of ancient metals show that this method is capable of detecting differences in the inner composition and microstructure of ancient metal objects. Here, ND measurements were conducted on two ‘eye shaped’ axes from the end of the 3rd-beginning of the 2nd millennium BC. The objects were excavated from the ancient cemetery of ‘Enot Shuni' Israel; one is made of bronze and the other of silver. Both artefacts are rare finds, with the silver axe unique in the archaeology of Israel, and therefore had to be analysed locally. For that purpose, a newly assembled diffractometer (KARL) at the IRR-1 of the Nuclear Research Centre (Soreq, Israel) was used. ND measurement on the bronze axe revealed the existence of an α-phase with a range of Cu/Sn ratios (Cu–Sn solid solutions) and some amount of a δ-phase (intermetallic compound of Cu and Sn). The silver axe ND pattern shows the existence of an α-phase (Ag–Cu solid solution) and some amount of copper metal. Our ND data are discussed in comparison with XRF surface measurements and thermal neutron radiography. The results are shedding more light on the in-depth material composition profile, as well as on the objects’ structural and compositional affinities, and help to better understand the production processes and assist in conservation decisions.     

Iron and bronze production in Iron Age IIA Philistia: new evidence from Tell es-Safi/Gath, Israel

A metallurgically-oriented excavation in Area A at Tell es-Safi/Gath yielded evidence for iron and bronze production dating to the early Iron Age IIA. Two pit-like features, which differed considerably from one another in colour, texture and content, were excavated. Evidence shows that each feature represents a different in situ activity related to iron production, inferred by the presence of hammerscales, slag prills and slag. An upturned crucible was found on top of one of the features. Analysis of the crucible slag showed that it was used for bronze metallurgy. Tuyères, both round and square in cross-section, were found in and around the two features. The presence of the two industries together presents a unique opportunity to explore the relationship between copper and iron working. This is especially important against the background of the scarcity of evidence for iron production in the Levant during the early phases of the Iron Age.     

Sediments exposed to high temperatures: reconstructing pyrotechnological processes in Late Bronze and Iron Age Strata at Tel Dor (Israel)

Many of the sediments analysed from Tel Dor (Israel) show structural alterations indicating that they were exposed to high temperatures. This observation is consistent with the abundant evidence for use of pyrotechnology from the earliest exposed Middle Bronze Age strata through the Roman period. Such structurally altered sediments may well represent one of the more widespread and durable records of pyrotechnology, and as such could be invaluable for reconstructing past human activities. The specific aims of this research are therefore to develop the means for identifying local sediments that were altered by different pyrotechnological activities and to elucidate the varying circumstances whereby sediments were exposed to high temperatures in a Late Bronze and Iron Age 1 section.     

Metalworking at Hazor: A Long‐Term Perspective

The temporal and spatial distribution of metal production remains from Hazor was used in this study to sketch the development of metalworking (bronze, iron and silver) at this important site. The remains attest to a long sequence of metalworking at Hazor, from the Middle Bronze Age through to the Iron Age, and significantly highlight the transition from bronze to iron production and the mode of bronze production after the transition had been completed.     

IIR Compensation in Real-Time Hybrid Simulation using Shake Tables with Complex Control-Structure-Interaction

This article considers the use of actuator compensation in real-time hybrid simulation (RTHS) containing experimental substructures with complex control-structure-interaction (CSI). The existence of CSI in shake table testing is derived using theoretical relations. An infinite-impulse-response (IIR) compensator is developed to compensate for the shake table time delay as well as the effects of CSI. The efficacy of the IIR compensator is verified through numerical and experimental investigations of substructure shake table testing completed at Johns Hopkins University. IIR compensation is not limited to substructure shake table testing, and the concept is applicable to any RTHS that suffers from complex CSI.     

Can argillaceous formations isolate nuclear waste? Insights from isotopic,noble gas,and geochemical profiles

There is considerable interest in the use of thick argillaceous geologic formations to contain nuclear waste. Here, we show that diffusion can be the controlling transport process in these formations and diffusional time scales for δ¹⁸O and δ²H in water, dissolved He, and Cl transport in shale‐dominated aquitards are typically over 10⁶ years, well exceeding the regulatory requirements for isolation in most countries. Our scientific understanding of diffusive solute transport processes through argillaceous formations would benefit from the application of additional isotopic tracers (e.g., using new ⁴He sampling technology), multidimensional diffusive‐dispersive modeling of groundwater flow and diffusive‐dispersive solute transport over long geologic time scales, and an improved understanding of spatial heterogeneity as well as time‐dependent changes in the subsurface conditions and properties of argillaceous formations in response to events such as glaciation. Based on our current isotopic and geochemical understanding of transport, we argue that argillaceous formations can provide favorable long‐term conditions for isolating nuclear wastes.     

An integrated approach to reconstructing primary activities from pit deposits: iron smithing and other activities at Tel Dor under Neo-Assyrian domination

Secondary pit deposits in historical occupations of Near Eastern mounds are usually regarded as uninteresting and are seldom analyzed. We used an integrated approach to study all the artifacts as well as the sediments in a pit at Tel Dor, on Israel's Carmel coast, dating to the 7th c. BCE – a period when the site served as an Assyrian administrative center. This pit was unusually large, had a peculiar ceramic assemblage, and many macroscopic metallurgical wastes. A detailed excavation and analysis revealed that the pit served intermittently as a waste disposal site for an iron smithy and for pottery that was presumably involved in maritime trading. On two occasions the area was also used for animal penning. Despite the obvious importance of the iron industry to the Neo-Assyrian Empire, actual workshops are rare in its archaeological record. Hence the new information regarding an Iron Age iron smithy in the southern Levant contributes to the study of this industry, and also to the history of Dor in this period.