Equations of state for basin geofluids: algorithm review and intercomparison for brines

Physical properties of formation waters in sedimentary basins can vary by more than 25% for density and by one order of magnitude for viscosity. Density differences may enhance or retard flow driven by other mechanisms and can initiate buoyancy‐driven flow. For a given driving force, the flow rate and injectivity depend on viscosity and permeability. Thus, variations in the density and viscosity of formation waters may have or had a significant effect on the flow pattern in a sedimentary basin, with consequences for various basin processes. Therefore, it is critical to correctly estimate water properties at formation conditions for proper representation and interpretation of present flow systems, and for numerical simulations of basin evolution, hydrocarbon migration, ore genesis, and fate of injected fluids in sedimentary basins. Algorithms published over the years to calculate water density and viscosity as a function of temperature, pressure and salinity are based on empirical fitting of laboratory‐measured properties of predominantly NaCl solutions, but also field brines. A review and comparison of various algorithms are presented here, both in terms of applicability range and estimates of density and viscosity. The paucity of measured formation‐water properties at in situ conditions hinders a definitive conclusion regarding the validity of any of these algorithms. However, the comparison indicates the versatility of the various algorithms in various ranges of conditions found in sedimentary basins. The applicability of these algorithms to the density of formation waters in the Alberta Basin is also examined using a high‐quality database of 4854 water analyses. Consideration is also given to the percentage of cations that are heavier than Na in the waters.     

Frontiers of Individuality: Embodiment and Relationships in Cultural Context

Book reviewed in this article:
Margaret S. Archer, Being Human: The Problem of Agency     

Frontiers of Contact: Bioarchaeology of Spanish Florida

The arrival of Europeans in the New World had profound and long-lasting results for the native peoples. The record for the impact of this fundamental change in culture, society, and biology of Native Americans is well documented historically. This paper reviews the biological impact of the arrival of Europeans on native populations via the study of pre- and postcontact skeletal remains in Spanish Florida, the region today represented by coastal Georgia and northern Florida. The postcontact skeletal series, mostly drawn from Roman Catholic mission sites, are among the most comprehensive in the Americas, providing a compelling picture of adaptation and stress in this setting. Study of paleopathology, dental and skeletal indicators of physiological stress, stable isotope (carbon and nitrogen) analysis, tooth microwear, and skeletal morphology (cross-sectional geometry) reveals major alterations in quality of life and lifestyle. The bioarchaeological record indicates a general deterioration in health, declining dietary diversity and nutritional quality, and increasing workload in the contact period. The impact of contact in Spanish Florida appears to have been more dramatic in comparison with other regions, which likely reflects the different nature of contact relations in this setting versus other areas (e.g., New England, New France). The bioarchaeological record represents an important information source for understanding the dynamics of biocultural change resulting from colonization and conquest.     

Environment and Modernity in Transitional China: Frontiers of Ecological Modernization

The process of institutionalizing environmental interests and considerations in Western (especially, but not only, European) industrialized societies has been reflected and theorized upon by social scientists, many of whom have adopted the ‘ecological modernization’ framework. One of the key questions on the research agenda of ecological modernization is its appropriateness for developing or industrializing countries in other parts of the world. This contribution analyses to what extent environmental reforms in contemporary China can be interpreted as ecological modernization. It focuses on the similarities and differences between Chinese and European modes or styles of ecological modernization with respect to the role of state institutions, market dynamics, civil society pressure and international integration.     

Agricultural Origins and Frontiers in South Asia: A Working Synthesis

The accumulation of recent data from archaeobotany, archaeozoology and Neolithic excavations from across South Asia warrants a new overview of early agriculture in the subcontinent. This paper attempts a synthesis of these data while recommending further systematic work and methodological developments. The evidence for origins and dispersals of important crops and livestock from Southwest Asia into South Asia is reviewed. In addition evidence for indigenous plant and animal domestication in India is presented. Evidence for probable indigenous agricultural developments in Gujarat, the Middle Ganges, Eastern India, and Southern India are reviewed. An attempt is made to highlight regions of important frontiers of interaction between early farmers and hunter-gatherers. The current evidence suggests that the Neolithic trajectories in different parts of South Asia differ from each other. Indigenous centers of plant domestication in India also differ from the often discussed trajectory of Southwest Asia, while suggesting some similarities with agricultural origins in Africa and Eastern North America as well as secondary agricultural developments on the peripheries of Eurasia. An erratum to this article can be found at     

Guest editorial

Abstract

The Asse Salt Mine near Brunswick in the Federal Republic of Germany has since 1965 been used to develop and to test suitable techniques for the safe disposal of radioactive wastes. Test disposal of low-level wastes started in 1967. During this large-scale experiment about 141 000 200-litre drums of low-level wastes were successfully disposed of until November 1978. Starting in 1972 techniques for the disposal of intermediate-level wastes were successfully demonstrated over a five-year period by disposing of 1298 200-litredrums. As a result of these tests and the accompanying research and development programmes, especially for the disposal of high-level wastes, one can now conclude that reliable techniques exist for the disposal of radioactive wastes at a full-scale industrial repository. This was planned within a German Entsorgungszentrum.     

National Frontiers,Great World Frontiers,and the Shadow of Frederick Jackson Turner

WILLIAM H. MCNEILL. The Great Frontier: Freedom and Hierarchy in Modern Times. Princeton, N.J.: Princeton University Press, 1983. Pp. 79. $13.95 (US).