Sclerochronological analysis of archaeological mollusc assemblages: methods,applications and future prospects

Accreting skeletal tissues found in bone, teeth, otoliths and molluscan shell act as sensitive recorders of local environmental and climatic conditions. Owing to their robust nature, ubiquity and abundance in the archaeological record as well as the potential for high-resolution data acquisition, the accreting skeletal tissues of archaeological molluscs are increasingly employed as palaeoenvironmental proxies. Researchers have chiefly utilised such proxies to extend instrumental records of environmental conditions through palaeoenvironmental reconstruction and explore the impact of environmental and climatic change on human populations. However, the use of environmental proxies from the archaeological record can be hampered by a number of methodological challenges including inadequate sampling strategies, appropriate calibration, the use of inappropriate proxies and the broad extrapolation of localised results. This paper reviews the use of molluscan shell from archaeological contexts as palaeoenvironmental proxies. We focus on the application of sclerochronology—a suite of high-resolution physical and geochemical data recovery methods widely used in conjunction with molluscan shell. This paper presents an overview of the potential of these techniques in approaching more nuanced understandings of human-environment interactions and how they can be more successfully incorporated into archaeological research.     

Hydrogeology of the Krafla geothermal system,northeast Iceland

The Krafla geothermal system is located in Iceland's northeastern neovolcanic zone, within the Krafla central volcanic complex. Geothermal fluids are superheated steam closest to the magma heat source, two‐phase at higher depths, and sub‐boiling at the shallowest depths. Hydrogen isotope ratios of geothermal fluids range from ?87‰, equivalent to local meteoric water, to ?94‰. These fluids are enriched in ¹⁸O relative to the global meteoric line by +0.5–3.2‰. Calculated vapor fractions of the fluids are 0.0–0.5 wt% (~0–16% by volume) in the northwestern portion of the geothermal system and increase towards the southeast, up to 5.4 wt% (~57% by volume). Hydrothermal epidote sampled from 900 to 2500 m depth has δD values from ?127 to ?108‰, and δ¹⁸O from ?13.0 to ?9.6‰. Fluids in equilibrium with epidote have isotope compositions similar to those calculated for the vapor phase of two‐phase aquifer fluids. We interpret the large range in δD_EPIDOTE and δ¹⁸O_EPIDOTE across the system and within individual wells (up to 7‰ and 3.3‰, respectively) to result from variable mixing of shallow sub‐boiling groundwater with condensates of vapor rising from a deeper two‐phase reservoir. The data suggest that meteoric waters derived from a single source in the northwest are separated into the shallow sub‐boiling reservoir, and deeper two‐phase reservoir. Interaction between these reservoirs occurs by channelized vertical flow of vapor along fractures, and input of magmatic volatiles further alters fluid chemistry in some wells. Isotopic compositions of hydrothermal epidote reflect local equilibrium with fluids formed by mixtures of shallow water, deep vapor condensates, and magmatic volatiles, whose ionic strength is subsequently derived from dissolution of basalt host rock. This study illustrates the benefits of combining phase segregation effects in two‐phase systems during analysis of wellhead fluid data with stable isotope values of hydrous alteration minerals when evaluating the complex hydrogeology of volcano‐hosted geothermal systems.     

Britishness or Englishness? The Historical Problem of National Identity in Britain

Abstract. The dominant ‘modernisation’ perspective on the nature of nations and national identities characterises these phenomena as purely modern artefacts which function as sociological cement for complex industrial societies. In opposition, Anthony D. Smith has elaborated an ‘ethno-symbolist’ framework which posits the possibility of pre-modern antecedents to modern national identities. According to Smith, modern states which have been able to establish their official cultures on the ethnicity of a demographically dominant and cohesive ethnic core are likely to be more stable than states that are divided by the rival histories and traditions of competing ethno-national communities. This paper evaluates Smith's ethno-symbolist thesis by applying his work on the relationship between states and ethnic cores to the historical example of Britain. What is Britishness? Is it just a transnational state patriotism, or is it a secondary form of national identity constructed largely in English terms?