Late Iron Age Ballast-Quarries at Hengistbury Head, Dorset

During excavations at Hengistbury Head between 1979 and 1984 certain Late Iron Age features, described as 'quarry hollows' and 'scoops', were discovered along the shoreline. They are the result of gravel extraction, which, it is argued, was carried out in order to supply ballast for ships plying their trade across the English Channel during the first half of the first century BC. Accordingly, these features represent the first on-shore archaeological evidence for the provision of ballast in antiquity.     

A horned member of the labyrinthodont super-family Brachyopoidea from the Early Triassic of Queensland

A horned, short-skulled labyrinthodont amphibian from the Arcadia Formation of the Rewan Group near Bluff, Queensland, is placed in the family Chigutisauridae of the superfamily Brachyopoidea. This is the first occurrence of this family outside Argentina. The material, consisting of two skulls and three mandibles is described as Keratobrachyops australis gen. et sp. nov., and used as a basis for an examination of the relationship between the families Brachyopidae and Chigutisauridae.     

Representing Structural Change in U.S. Migration Patterns

This paper focuses on the identification of three sets of relationships exhibited by a time series of age-specific national migration rates and multiregional transition probability matrices: the relationship across time for the same age group, as defined by period (temporal) transformation coefficients or matrices; the relationships across age at a particular moment in time, as defined by age transformation coefficients or matrices; and the relationships across time and age, as defined by cohort transformation coefficients or matrices. Given any two of these relationships one can solve for the third. This feature of age-period-cohort relationships has a practical application in the development of improved methods for representing structural change in migration patterns over time and for indirectly estimating migration patterns using inadequate data.