Gas breakthrough experiments on fine-grained sedimentary rocks

The capillary sealing efficiency of fine‐grained sedimentary rocks has been investigated by gas breakthrough experiments on fully water saturated claystones and siltstones (Boom Clay from Belgium, Opalinus Clay from Switzerland and Tertiary mudstone from offshore Norway) of different lithological compositions. Sand contents of the samples were consistently below 12%, major clay minerals were illite and smectite. Porosities determined by mercury injection lay between 10 and 30% while specific surface areas determined by nitrogen adsorption (BET method) ranged from 20 to 48 m² g ^{? 1}. Total organic carbon contents were below 2%. Prior to the gas breakthrough experiments the absolute (single phase) permeability (k_abs) of the samples was determined by steady state flow tests with water or NaCl brine. The k_abs values ranged between 3 and 550 nDarcy (3 × 10^?21 and 5.5 × 10^?19 m²). The maximum effective permeability to the gas‐phase (k_eff) measured after gas breakthrough on initially water‐saturated samples extended from 0.01 nDarcy (1 × 10^?23 m²) up to 1100 nDarcy (1.1 × 10^?18 m²). The residual differential pressures after re‐imbibition of the water phase, referred to as the ‘minimum capillary displacement pressures’ (P_d), ranged from 0.06 to 6.7 MPa. During the re‐imbibition process the effective permeability to the gas phase decreases with decreasing differential pressure. The recorded permeability/pressure data were used to derive the pore size distribution (mostly between 8 and 60 nm) and the transport porosity of the conducting pore system (10^‐5–10^‐2%). Correlations could be established between (i) absolute permeability coefficients and the maximum effective permeability coefficients and (ii) effective or absolute permeability coefficients and capillary sealing efficiency. No correlation was found between the capillary displacement pressures determined from gas breakthrough experiments and those derived theoretically by mercury injection.     

Big Game and Small Prey: Paleolithic and Epipaleolithic Economy from Valencia (Spain)

This study analyzes the faunal assemblages corresponding to the Middle and Upper Paleolithic and the Early Epipaleolithic for the central Spanish Mediterranean Region dated from between 135,000 and 9,000 B.P. To interpret these data, we employ a zooarchaeological and paleoeconomic perspective. Human large and small game hunting systems are analyzed through the identification of the origins of faunal assemblages, bone breackage patterns, and prey selection patterns. Our study shows that hunting systems changed significantly through time, which may be related to the characteristics of the Mediterranean ecosystem and, above all, to cultural changes.     

The Effect of State Economic Development Incentives on Employment Growth of Establishments

This paper examines the effects of state economic development incentives on the growth of 366 Ohio manufacturing and nonmanufacturing establishments that launched major expansions between 1993 and 1995. Growth is measured as the actual employment change that occurred in these establishments and as the employment growth announced when expansions were launched. Empirical findings indicate that incentives have very little (or even a negative) effect on actual growth and they have a substantial positive effect on announced growth. Findings also suggest that establishments that received incentives overestimated their announced employment targets more than establishments that did not receive incentives.     

Transmission electron microscopy (TEM) applied to ancient pottery

A comparative study of ancient pottery has been carried out, which utilized X‐ray diffraction, optics and scanning and transmission electron microscopy (SEM and TEM). Samples came from three prehistoric sites in northern Spain (La Rioja). Transmission electron microscope techniques, which use intact ion‐milled samples, allow minerals and glass to be imaged in situ, providing data on textures, crystal structures and composition. TEM provided detailed characterization of both source‐characteristic raw materials and products of the firing process, and revealed the range of intermediate phases, most of which had sizes beyond that of resolution by SEM. More importantly, TEM provided definition of the reaction processes, from starting materials through glass and new crystalline phases, providing data on both temperature and duration of firing.     

Morphological taphonomic transformations of fossil bones in continental environments,and repercussions on their chemical composition

The aim of this paper is to provide a summary of structural or surface modifications of vertebrate bone remains in continental palaeoenvironments that may have repercussions on their chemical composition. Both before and after burial, a different set of physical, chemical and biological agencies may produce modifications of the bone morphological structure and/or bone chemical composition. Several of these morphological modifications are diagnostic of particular agents, which otherwise may not be noticed or identified in a fossil association. In order to understand diagenesis, those events that occurred before final burial have to be considered, as they may strongly modify the bone morphological structure and influence post–burial changes.     

Bear dentine aspartic acid racemization analysis: a proxy for the dating of Pleistocene cave infills

A high correlation between chronometric determinations based on aspartic acid racemization ratios and radioactive dating methods is described from samples of cave bear (Ursus deningeri and Ursus spelaeus) dentine. For samples from a very restrictive environment, as deep cave bear sites are (in view of their highly stable geochemical and thermal history), an age calculation algorithm was obtained. It has been found that there is a very close relationship between collagen preservation, from total aspartic acid in the > 3500 D fraction, and the amino acid racemization.     

The Politics of Caring for the Poor: Anglican Responses in 1890s Tasmania

Relieving poverty amongst skilled but unemployed workers during the Tasmanian economic collapse in the 1890s challenged both a conservative government's policy of avoiding public debt by initiating minimal relief and the limited financial and human resources of voluntary philanthropic agencies, the Anglican Church amongst them, whom the Tasmanian governments expected to carry the burden of delivering relief to those deemed to deserve it. With labour organisations too weak to lead, and amidst the silence of church leaders, it fell to individuals like the Reverend Archibald Turnbull to articulate a Christian socialist critique of government policies and values and to advocate the desperate plight of the poor. In this context, this study examines how contemporary government and Anglican Church leaders responded to Turnbull's political and pastoral initiatives in Hobart in 1893–96.     

Book reviews

STRENGTHENING THE FRAMEWORK OF PEACE. A Study of Current Proposals for amending, developing, or replacing present International Institutions for the Maintenance of Peace. By Alan de Rusett. (London and New York, Royal Institute of International Affairs, 1950. xiii +225 pp.)

VOTING AND THE HANDLING OF DISPUTES IN THE SECURITY COUNCIL. By Eduardo Jiménez de Aréchaga. Carnegie Endowment, N.Y., 1950. This is a lawyer's study of the operations of the Security Council. The author, a Uruguayan, was an officer in the U.N. Secretariat for some time and is now Under Secretary of Foreign Relations in Uruguay.

IMMIGRATION. By W. D. Borrie, 1949. Sydney and London, Angus and Robertson, pp. 105 + viii.

THE BRITISH COMMONWEALTH SINCE 1815. By C. H. Currey. 2 vols. Sydney, Angus & Robertson, 1950–51. Vol. I, pp. viii +471; Vol. II, pp. viii +287.

DEFENCE IN THE COLD WAR. By a Chatham House Study Group. London: R.I.I.A. 1950, pp. viii +123.

ASPECTS OF AMERICAN GOVERNMENT. A Symposium edited by Sidney Bailey. London: The Hansard Society. 1950.