Studying the Cannons of Punta Santa Anna,Spain: In Situ Conservation,Promoting Public Access,and Monitoring Iron Corrosion

The 2001 UNESCO convention for the Protection of Underwater Cultural Heritage (UCH) encourages and supports projects that would make accessible to the general public underwater cultural sites. Since 2010 the Catalonian Federation of the World Underwater Federation (FECDAS), have been developing outreach activities with the objective of promoting the protection of the UCH among recreational scuba divers. The purpose of this paper is to introduce one such project, the Punta Santa Anna in Blanes, Spain. This project has three objectives: the promotion of UCH to the general public, the in situ protection of this underwater archaeological site, and a case study on iron corrosion processes. FECDAS/CMAS will create an underwater archaeological park where recreational scuba divers will be able to visit some purposely selected archaeological iron cannons. To expose UCH to the general public will potentially affect the integrity of these artefacts. This risks potential damage and so, with the objective of minimizing potential threats, a series of protective measures and a systematic monitoring programme have been planned. The programme is designed to study the relationship between the underwater environment and the artefacts. The aim is to acquire a better understanding of the corrosion processes of iron objects present in marine underwater sites.     

Discovery of Iron Grapnel Anchors in Early Modern Ryukyu and Management of Underwater Cultural Heritage in Okinawa,Japan

The Yarabuoki underwater site contains seven iron grapnel anchors and Early Modern Okinawan ceramic jars and is dated to the 16th–19th centuries. The site lies at a depth of 12–32 m off the western coast of Ishigaki Island in Okinawa, Japan. Based on underwater archaeological and broadband multibeam surveys, as well as historical research of the artefacts and Early Modern Ryukyuan shipping, we discuss the possible anchor and vessel types in Ryukyu and Eastern Asia in Early Modern times. We also discuss the efficacy of low‐cost ROV for assisting surveys in shallow‐water environments and the value of educational programmes for promoting the management and conservation of underwater cultural heritage.     

Evaluation of Fe isotope values as a provenance tool for chert artefacts from the north-eastern United States

Iron (Fe) isotope compositions of prehistoric stone tools and geological sources were compared to evaluate the robustness of this isotopic fingerprinting technique. Artefacts and source materials were collected from the Hatch site in central Pennsylvania, United States, where both veined chert (Bald Eagle chert) and stone tools coexist within several metres. Yellow artefacts (δ⁵⁶Fe = 0.38 ± 0.1, n = 7) and source materials (δ⁵⁶Fe = 0.42 ± 0.1, n = 8) isotopically matched within error. The source values also overlap yellow chert samples from three other Bald Eagle chert locations in the area. These values are different from six other chert locations in the north-eastern United States. These data suggest that the Fe isotope composition of chert artefacts reflect distinct geological sources. To enhance the mechanical characteristics of the stone tools, the chert experienced heat treatment, which induced a phase shift of the Fe oxide mineral goethite to hematite. This phase shift changes the colour of the chert to red. The red chert artefacts and source material also have overlapping Fe isotope values, but are 0.2‰ higher than the initial yellow chert. Experimental work where cherts were heated with different clays shows that Fe exchange with site soils induces the +0.2 fractionation. These data demonstrate that predictable Fe isotope fractionation occurs during heating, resulting in isotopically distinct artefacts.     

87Sr/86Sr: a New Discriminant for Provenancing Neolithic Porcellanite Artifacts from Ireland

Antrim porcellanite (thermally metamorphosed Tertiary laterite) was the most common raw material used in the production of stone implements during the Neolithic in Ireland and was worked at two localities in North Antrim: Tievebulliagh, near Cushendall and Brockley on Rathlin Island.Attempts have been made to provenance material from these two known sources, the most successful to date being the use of geochemical data (Sr and Yppm). Here we present a new geochemical discriminant—Sr isotopic data—which reveal that Tievebulliagh and Brockley porcellanites are distinctive. Present-day⁸⁷Sr/⁸⁶Sr ratios form two discrete groupings ranging from 0·705894±25–0·706443±24 at Tievebulliagh and 0·704088±27–0·704587±25 at Brockley. A coherent relationship between⁸⁷Sr/⁸⁶Sr and Sr (ppm) reiterates the use of Sr content as a discriminant and illustrates the geochemical variability of Sr between these two sources.Although this is a destructive technique,⁸⁷Sr/⁸⁶Sr represents the best discriminant to date for Antrim porcellanites and will enable definitive provenancing of porcellanite artifacts from Ireland with important archaeological implications.     

Application of veratraldehyde as a temporary consolidant for relics at underwater cultural heritage sites

Because it is often difficult to preserve fragile relics in situ at underwater cultural heritage sites, it is sometimes necessary for relics to be extracted and moved to a controlled environment on land for protection and study. This paper discusses the feasibility of using the volatile organic compound veratraldehyde as a temporary consolidant for underwater fragile relics extraction. The results show that different materials (iron, tile, sand, wood) under water can be bonded together and extracted when using veratraldehyde. The fact that veratraldehyde is difficult to spread on the surface of underwater objects is a problem that can be solved by adding a layer of strong hydrophobic polypropylene (PP) fibres onto the object, serving as a ‘package' for the relics. Under laboratory conditions, we used veratraldehyde and PP fibres to extract broken tiles from underwater sand onto an exhibition stand. The broken tiles, in both condition and distribution, were safely and completely retained as the veratraldehyde was slowly removed by the soaking process. This work fills a gap in knowledge about temporary consolidant materials in underwater archaeology, and provides a new method for extracting underwater fragile cultural relics without damaging them.     

The Effect of Accelerated Alteration on the Discrimination between Baltic and Romanian Amber

Ten geological samples (five from each source—Romanian amber and Baltic amber) in duplicate for five different media (air, water, saline, acid and basic) were subjected to thermal alteration at 80 ± 2°C for 12 weeks, in the dark. The samples were analysed before and after the accelerated alteration experiment by Fourier transform infrared spectroscopy, both in transmittance and reflectance mode, and the acquired spectra were statistically processed by multivariate data analysis, mainly using principal component analysis. The results of the experiment are useful in giving a better picture of how to discriminate between archaeological amber artefacts.     

FINGERPRINTING OF ROMAN MINTS USING LASER‐ABLATION MC–ICP–MS LEAD ISOTOPE ANALYSIS*

In this paper we present data to demonstrate the applicability of laser‐ablation MC–ICP–MS isotope analysis to archaeological artefacts, in this case Roman silver coins. The technique requires no chemical preparation, does minimal damage to the sample and yields external reproducibility that is better than conventional TIMS analysis; ²⁰⁷Pb/²⁰⁶Pb =±0.015% 2σ in comparison with ²⁰⁷Pb/²⁰⁶Pb =±0.04% 2σ, respectively. We show that Pb isotope compositions give isotope fingerprints to mints despite the likely reworking of the metal during coin production.     

The Shipwrecks of Xlendi Bay,Gozo, Malta

Xlendi Bay, Gozo, Malta, is a rich underwater site. It was discovered in 1961 by British Navy divers on a training mission. Since then, a significant number of artefacts has been retrieved but not well studied. This paper summarizes a recent detailed study of the archaeological material and describes five amphora types that have not yet been identified. It also takes deep‐water surveys that have recently been conducted by various teams into consideration.     

A NOVEL APPROACH TO STUDIES OF PREHISTORIC EXPLOITATION OF STONE TOOL MATERIALS USING MATERIAL COMPOSITION,SURFACE MORPHOLOGY,MICROSTRUCTURE AND MECHANICAL PROPERTIES*

For a comprehensive understanding of material exploitation in prehistory, we applied advanced analytical methods to Japanese prehistoric stone tool materials. Compositions, surface morphologies, microstructures and mechanical properties of the primary lithic materials were analysed. As a result of the tests on actual Palaeolithic artefacts, preferential material selection was observed based on composition, structure and other physical properties of the materials. Homogeneous materials composed of a single type of mineral—α‐quartz—were intentionally selected for Palaeolithic tools regardless of the type of rock. These materials unexceptionally present higher hardness and strength. Moreover, materials composed of extremely fine crystal grains of ~0.1 µm in size with highest hardness and strength were selectively used for sharp‐edged blades. These results lead us to the conclusion that quantitative and objective analyses will give us precise information on prehistoric materials, which will enable us to make an analytical approach to the comprehension of prehistoric exploitation of stone materials. This could eventually complement the traditional interpretation of material exploitation based on conventional petrological classifications.     

The Odyssey Case: press,public opinion and future policy

The Odyssey Case refers to the dispute between Odyssey Marine Exploration Inc. (OME) and the Kingdom of Spain in the US courts to determine the ownership of more than 500,000 coins, as well as other artefacts, that OME recovered from a wreck‐site it had code‐named Black Swan. However, the process was much more than a dispute over the coins. It reflected many of the components involved in the protection of underwater archaeological heritage, especially when economic and political interests are at stake. Written from the perspective of an archaeologist working for the regional authority responsible for developing archaeological policy, this paper tries to assess the case's impact on future policy development.     

Satellite image analysis of changes in glacier cover in Canada's northern Mackenzie Mountain Range (1987–2017)

The state of a group of glaciers in the northern Mackenzie Mountains across the Yukon‐Northwest Territories border was investigated over a period of three decades, using Landsat TM and OLI imagery from 1987, 1994, 1999, 2004, 2013, and 2017 to examine changes in glacier extents. A thresholded red/shortwave infrared band ratio image was used to delineate glacier boundaries. The total area of 74 glaciers in the study area decreased from 52.78 ± 1.32 km² in 1987 to 24.89 ± 0.62 km² in 2017, a loss of 27.89 ± 1.39 km² or 52.8 ± 2.6%, with a mean rate of reduction of 1.8% · a^?1. Smaller glaciers experienced larger relative changes in area. In this study, the rates of reduction are high compared to decreases reported for other glaciers in the region in the late 20^th century. Based on linear extrapolation of the trend in values of total glacier area, it is predicted—subject to uncertainties in how glaciers diminish in size and eventually disappear—that the study area could be free of visible glacier cover within three decades.     

Ceremonial objects or household items? Non‐destructive μ‐XRD2 and μ‐XRF studies on three Neolithic hematite axes from Qatar

Three small stone axes were collected by the joint Qatari‐German South Qatar Survey Project (SQSP) at two places close to the eastern and western coast of Qatar in autumn 2012. Associated with settlement remains, flint artefacts and pieces of ?Ubaid pottery, the implements have been dated to the fifth millennium BCE. Non‐destructive μ‐XRD² and μ‐XRF analyses could, for the first time, prove the use of hematite as the raw material for the manufacture of these tools in Arabia. The absence of major hematite sources in the region and the special characteristics of hematite — a unique metallic shine of polished pieces and the blood‐red colour that appears during the manufacturing process — suggest the highly symbolic character of these objects.     

Some Aspects of the Bioerosion of Stone Artefact Found Underwater: Significant Case Studies

Abstract

Within the framework of the project Restoring Underwater started in 2001, the ISCR Marine Biology sector with the ISCR Underwater Archaeology Operation Unit has begun a study of the deterioration of stone artefacts exposed to marine environments (Torre Astura – Nettuno; Baiae – Naples). These studies have allowed to better understanding the factor of degradation by biological, mineralogical, and petrographic analyses and to develop measures for the protection in situ of cultural heritage. Based on what was recorded, usually the bioerosion presents various degrees of gravity: limited and sporadic damage or very serious alterations. Depending on their chemical composition, the artefacts proved to be particularly susceptible to the action of corrosion exercised by perforating animal and plant organisms.

This phenomenon becomes more significant in the case in which the artefacts remain exposed and in the same position for a long period of time. It is possible to confirm that the combined action of attack from clionides (sponges) and bivalves can lead, over time, to the total destruction of portions of the artefact (macroboring). As well as these more macroscopic types of damage, there was evidence of the widespread presence of microscopic bioerosion (microboring), caused by autotrophic and heterotrophic microorganisms, visible only through SEM observations, which, despite not creating large chambers, progressively undermine the resistance of the stone and facilitate the development of other biodeteriogens. This paper will be focused on the characterization of the bioerosion observed on different artefacts: the roman statues discovered underwater in the Grotta Azzurra, Capri and in the Campi Flegrei area (Naples –Italy), and the marble sarcophagi that are still on the seabed of San Pietro in Bevagna (Taranto – Italy).     

Reburial and Analyses of Archaeological Remains in the Marine Environment — Investigations into the Effects on Metals

Abstract

The treatment and long-term storage of recovered cultural material from underwater heritage sites is becoming less cost effective, and reburial of archaeological sites and the associated artefacts in the marine environment is becoming increasingly common practice in managing the submerged cultural resource. Following recent large-scale underwater archaeological excavations in Marstrand harbour, Sweden, the majority of recovered finds were reburied in defined trenches in the harbour sediment. Subsequently, the Studio of the Western Sweden Conservators in conjunction with the Bohus County Museum initiated a fifty-year research project to evaluate reburial as an appropriate method of preserving waterlogged archaeological artefacts in the long term. The research project, entitled ‘Reburial and Analyses of Archaeological Remains’, was launched in 2002 and consists of six sub-projects. The main aims of these sub-projects are to analyse the extent of deterioration of the most common material types found on underwater archaeological sites, assess the stability of packing and marking materials used in archaeological documentation, and monitor the reburial environment.

The aim of the metals sub-project is to investigate the short- to long-term corrosion behaviour of metals buried in the marine environment by examining the deterioration of reburied and exposed modern metal coupons and eventually compare these results to the analysis of actual shipwreck artefacts. The environmental monitoring sub-project is designed to complement the other sub-projects by assessing the physico-chemical changes occurring in the reburial environment over time and the effect on the deterioration of the different reburied material types. In comparing the results obtained over the past seven years from both the metals and monitoring sub-projects, it should be possible to more accurately evaluate the effectiveness of reburial as a long-term in situ preservation strategy for metallic archaeological remains.     

Reinterpreting a Textile Tradition: David McDiarmid's Ecstatic and Utopian Klub Kwilt

Abstract

Appropriating traditional American quilting patterns, and the homely communal ambience of the quilt, self-proclaimed queer artist David McDiarmid proposes in his work, Klub Kwilt (1979), an inter-racial, queer 'community' with its own uniquely appropriate community artefacts. Klub Kwilt is a shiny, reflective art work made in what was then a new synthetic material — laser-etched Mylar. The artist's intention was to materialize and affirm in this work the utopian and ecstatic impulses of the New York gay male, black and Hispanic, underground dance club, Paradise Garage. The utopian world McDiarmid evokes — in a knowing, camp embrace of the synthetic, the showy and the excessive — is one of sexual and musical ecstasy, inter-racial resonance and visual and aural opulence.     

A Critical Analysis and Philosophical Review of ‘Rapid Reburial’: the Clarence project

In 2012, Australian cultural heritage practitioners and conservation scientists collaborated on a national underwater cultural heritage (UCH) reburial project, known as the Australian Historic Shipwreck Preservation Project (AHSPP) funded by the Australian Research Council. This resulted in the excavation, documentation and reburial of the ‘at risk’ shipwreck Clarence. Following the excavation, the site and associated artefacts were reburied and subsequently covered by shade cloth and finally, with polyvinyl chloride (PVC) tarpaulins. After completion of the in situ reburial, a number of critical issues were put into sharp relief including: what constitutes the accurate identification of a site as being ‘at risk’; and the implications of ‘rapid reburial’.     

典型环氧类粘结材料老化过程的探索性研究

环氧树脂类粘结材料目前已成为文物保护工作中常用的粘结材料。但是,在一些应用案例中经常发现环氧树脂类粘结材料有变色、脆化、剥落等老化现象。为了了解环氧类粘结材料的老化规律,摸清材料成分、配方和环境因素的影响,以通用双酚A型环氧树脂为主剂与各种典型固化剂、稀释剂、偶联剂等配制成黏结材料,模拟自然界极端环境条件,通过反复的破坏循环实验,探讨典型环氧类粘结材料的老化过程和机理。     

THE BLACK INLAY DECORATION ON A MYCENAEAN BRONZE DAGGER*

The black inlay decoration with superb marine, hunting and other scenes on Mycenaean bronze daggers and silver cups has often been referred to in the literature as niello—a mixture of sulphides of copper, silver or lead—despite the absence of any systematic analysis of these precious metal artefacts. This paper presents semi-quantitative surface analyses of an example of black inlay on a Mycenaean dagger, now in the Archaeological Museum at Patras in Greece. Using non-destructive X-ray fluorescence spectrometry, it has been established that, contrary to the traditionally-held view, the black inlay is a copper-gold alloy with some silver and possibly small amounts of tin.     

A sedimentation study of St. Ana Lake (Romania) applying the <Superscript>210</Superscript>Pb and <Superscript>137</Superscript>Cs dating methods

The biggest problem with most lakes that have no contact with other water sources and are being charged by precipitation is the massive eutrophication. The aim of this work was to determine the sedimentation rate in order to evaluate the progress of eutrophication for St. Ana Lake (Ciomad Mountain near the Băile Tuşnad in Harghita County (Romania)). The concentration of ²¹⁰Pb was determined by means of high resolution gamma spectrometry as well as derived from ²¹⁰Po activity which was measured through alpha spectrometry; values obtained are in good agreement. For the excess ²¹⁰Pb activity values between 4.0±0.5 Bq/kg and 218±20 Bq/kg have been found. As an alternative method, the ¹³⁷Cs dating method was applied as well. Calculated mass sedimentation rates are in the range of 0.06±0.01 to 0.32±0.05 g/cm² year with a mean of value of 0.15±0.02 g/cm² year. Linear sedimentation rates yielded much higher sedimentation values (between 0.5±0.1 and 7.9±0.7 cm/year with a mean of 2.4±0.6 cm/year), due to the predominant organic matter composition and the long suspension time of the sediment. This is an indication for the process of eutrophication which will probably lead to the transformation of the lake into a peat bog.     

Neolithic Adhesive from a T‐shaped Ornamental Element Excavated at Site 14 at Kowal,Kuyavia, Central Poland

We conducted an identification of a substance isolated from a T‐shaped ornamental element excavated from a Globular Amphora Culture tomb at the Kowal 14 archaeological site in Poland. ¹⁴C dating indicated 4105 ± 35 bp (POZ‐21912) and 3990 ± 50 bp (POZ‐21910). Analytical methods such as SEM–EDS, XRD and FT–IR were applied to study the origin of its structure. The results of instrumental analysis and the archaeological context indicate that the adhesive substance investigated consists mainly of calcium carbonate (calcite, 78–88%), silica dioxide (quartz), sodium aluminium silicate (albite) and potassium aluminium silicate (microcline). The material might be a man‐made, mineral adhesive, a kind of lime mortar. The object is considered as the oldest European finding of this type outside the Mediterranean Basin. It provides evidence for the use of the lime calcination process in Central Europe as early as in the Late Neolithic, for which there were—up to now—no convincing premises.