ALBERT

Description / Table of Contents: The Antarctic fur seal Arctocephalus gezella has increased in numbers at Heard Island since the Australian National Antarctic Research Expeditions (ANARE) station was established in 1947. Increases have also been recorded at other breeding sites in the South Atlantic and South Indian Oceans this century, particulary at South Georgia. In the 1987-88 summer, fur seals at Heard Island were counted in several age and sex categories. The aims of the project were to determine the location of pupping sites, the extent of the pupping season and the size of the population, and to record the changes in numbers of animals ashore during the summer. Maps of the colonies and main haul-out areas, together with descriptions of census areas and tabulations of counts, provide a basis fr future comparison.

Description / Table of Contents: INTRODUCTION Over the past 18 years the author and several colleagues have developed a mathematical model designed to predict the propagation characteristics of acoustic waves in marine sediments. The model is based on the classical work of Maurice Biot who developed a comprehensive theory for the mechanics of porous, deformable media in a series of papers spanning the time period from 1941 to 1973. Since our objective was to develop a practical working model that could be used as a guide in planning and interpreting experimental work, we began with the simplest possible form of the model and added various complexities only as they were needed to explain new variations in the data that were obtained. Thus the number of material parameters that had to be measured or assumed at any stage in the development of the model was kept to a minimum. Since the first version of the model was introduced in 1970, we have published over twenty technical papers covering various stages of its development and many papers have been published by colleagues who have utilized our work in various ways. This monograph is an attempt to summarize the development and use of the model to date. Acoustic waves in ocean sediments may be considered as a limiting case in the more general category of mechanical waves that can propagate in fluid-saturated porous media. The general problem of wave motion in this kind of material has been studied extensively over the past thirty years by engineers, geophysicists and acousticians for a variety of reasons. In some cases, interest is focused on low-frequency waves of rather large amplitude, such as those that arise near the source of an earthquake or near a building housing heavy, vibrating machinery. At other times, the main interest is in waves of low frequency and amplitude that have traversed long distances through the sediment. In still another category, high-frequency waves that are able to resolve thin layering and other fine structural details are of interest in studying near-bottom sediments. Thus the full spread of frequency and amplitude has been studied for geological materials ranging from soft, unconsolidated sediments to rock. Because of the almost limitless combinations of different types of sediment, stratification and structure, accurate mathematical description of the wave field produced by a particular source can be constructed only if accurate descriptions of the acoustic properties of individual components can be specified. These properties depend on the geological history of the sediment deposit, on the frequency content of the wave field and on a number of other factors that depend on the environment in situ. A survey of the literature suggests that there are a number of parameters that play principal roles in controlling the dynamic response of saturated sediments...

Description / Table of Contents: M. A. Cooper and G. D. Williams: Introduction / Geological Society, London, Special Publications, 44:vii, doi:10.1144/GSL.SP.1989.044.01.01 --- Modelling and Theoretical Concepts --- G. D. Williams, C. M. Powell, and M. A. Cooper: Geometry and kinematics of inversion tectonics / Geological Society, London, Special Publications, 44:3-15, doi:10.1144/GSL.SP.1989.044.01.02 --- A. B. Hayward and R. H. Graham: Some geometrical characteristics of inversion / Geological Society, London, Special Publications, 44:17-39, doi:10.1144/GSL.SP.1989.044.01.03 --- K. R. McClay: Analogue models of inversion tectonics / Geological Society, London, Special Publications, 44:41-59, doi:10.1144/GSL.SP.1989.044.01.04 --- Inversion in the Alps and Alpine Foreland --- P. A. Ziegler: Geodynamic model for Alpine intra-plate compressional deformation in Western and Central Europe / Geological Society, London, Special Publications, 44:63-85, doi:10.1144/GSL.SP.1989.044.01.05 --- P. C. de Graciansky, G. Dardeau, M. Lemoine, and P. Tricart: The inverted margin of the French Alps and foreland basin inversion / Geological Society, London, Special Publications, 44:87-104, doi:10.1144/GSL.SP.1989.044.01.06 --- R. W. H. Butler: The influence of pre-existing basin structure on thrust system evolution in the Western Alps / Geological Society, London, Special Publications, 44:105-122, doi:10.1144/GSL.SP.1989.044.01.07 --- I. R. Simpson, M. Gravestock, D. Ham, H. Leach, and S. D. Thompson: Notes and cross-sections illustrating inversion tectonics in the Wessex Basin / Geological Society, London, Special Publications, 44:123-129, doi:10.1144/GSL.SP.1989.044.01.08 --- D. G. Roberts: Basin inversion in and around the British Isles / Geological Society, London, Special Publications, 44:131-150, doi:10.1144/GSL.SP.1989.044.01.09 --- Inversion on the European Continental Shelf --- J. A. Cartwright: The kinematics of inversion in the Danish Central Graben / Geological Society, London, Special Publications, 44:153-175, doi:10.1144/GSL.SP.1989.044.01.10 --- T. J. Chapman: The Permian to Cretaceous structural evolution of the Western Approaches Basin (Melville sub-basin), UK / Geological Society, London, Special Publications, 44:177-200, doi:10.1144/GSL.SP.1989.044.01.11 --- M. E. Badley, J. D. Price, and L. C. Backshall: Inversion, reactivated faults and related structures: seismic examples from the southern North Sea / Geological Society, London, Special Publications, 44:201-219, doi:10.1144/GSL.SP.1989.044.01.12 --- Inversion in Other Geological Environments --- C. M. Powell and G. D. Williams: The Lewis Thrust/Rocky Mountain trench fault system in Northwest Montana, USA: an example of negative inversion tectonics? / Geological Society, London, Special Publications, 44:223-234, doi:10.1144/GSL.SP.1989.044.01.13 --- K. R. McClay, M. W. Insley, and R. Anderton: Inversion of the Kechika Trough, Northeastern British Columbia, Canada / Geological Society, London, Special Publications, 44:235-257, doi:10.1144/GSL.SP.1989.044.01.14 --- C. K. Morley: Basin inversion in the Osen-Røa thrust sheet, Southern Norway / Geological Society, London, Special Publications, 44:259-273, doi:10.1144/GSL.SP.1989.044.01.15 --- M. P. Coward, M. A. Enfield, and M. W. Fischer: Devonian basins of Northern Scotland: extension and inversion related to Late Caledonian — Variscan tectonics / Geological Society, London, Special Publications, 44:275-308, doi:10.1144/GSL.SP.1989.044.01.16 --- M. C. Daly, J. Chorowicz, and J. D. Fairhead: Rift basin evolution in Africa: the influence of reactivated steep basement shear zones / Geological Society, London, Special Publications, 44:309-334, doi:10.1144/GSL.SP.1989.044.01.17 --- M. A. Cooper, G. D. Williams, P. C. de Graciansky, R. W. Murphy, T. Needham, D. de Paor, R. Stoneley, S. P. Todd, J. P. Turner, and P. A. Ziegler: Inversion tectonics — a discussion / Geological Society, London, Special Publications, 44:335-347, doi:10.1144/GSL.SP.1989.044.01.18 --- Abstracts --- I. W. D. Dalziel: Inversion of circum-Pacific marginal basins / Geological Society, London, Special Publications, 44:351, doi:10.1144/GSL.SP.1989.044.01.19 --- J. F. Dewey: Kinematics and dynamics of basin inversion / Geological Society, London, Special Publications, 44:352, doi:10.1144/GSL.SP.1989.044.01.20 --- A. Gibbs and A. Beach: Extensional tectonics in a convergent intra-plate setting: linked inversions on oblique and frontal ramps / Geological Society, London, Special Publications, 44:353, doi:10.1144/GSL.SP.1989.044.01.21 --- R. Gillcrist, M. P. Coward, B. Trudgill, A. Pecher, and J. L. Mugnier: Structural inversion in the external French Alps / Geological Society, London, Special Publications, 44:354, doi:10.1144/GSL.SP.1989.044.01.22 --- N. J. Kusznir and G. D. Williams: Geometric, thermal and isostatic constraints on basin inversion / Geological Society, London, Special Publications, 44:355, doi:10.1144/GSL.SP.1989.044.01.23 --- B. van Hoorn: Structural evolution, timing and tectonic style of the Sole Pit inversion / Geological Society, London, Special Publications, 44:356, doi:10.1144/GSL.SP.1989.044.01.24

Description / Table of Contents: A. D. Saunders and M. J. Norry: Introduction / Geological Society, London, Special Publications, 42:vii-viii, doi:10.1144/GSL.SP.1989.042.01.01 --- I. G. Gass: Magmatic processes at and near constructive plate margins as deduced from the Troodos (Cyprus) and Semail Nappe (N Oman) ophiolites / Geological Society, London, Special Publications, 42:1-15, doi:10.1144/GSL.SP.1989.042.01.02 --- Robert S. White: Asthenospheric control on magmatism in the ocean basins / Geological Society, London, Special Publications, 42:17-27, doi:10.1144/GSL.SP.1989.042.01.03 --- John G. Spray: Upper mantle segregation processes: evidence from alpine-type peridotites / Geological Society, London, Special Publications, 42:29-40, doi:10.1144/GSL.SP.1989.042.01.04 --- James H. Natland: Partial melting of a lithologically heterogeneous mantle: inferences from crystallization histories of magnesian abyssal tholeiites from the Siqueiros Fracture Zone / Geological Society, London, Special Publications, 42:41-70, doi:10.1144/GSL.SP.1989.042.01.05 --- H. J. B. Dick: Abyssal peridotites, very slow spreading ridges and ocean ridge magmatism / Geological Society, London, Special Publications, 42:71-105, doi:10.1144/GSL.SP.1989.042.01.06 --- Sherman H. Bloomer, James H. Natland, and Robert L. Fisher: Mineral relationships in gabbroic rocks from fracture zones of Indian Ocean ridges: evidence for extensive fractionation, parental diversity and boundary-layer recrystallization / Geological Society, London, Special Publications, 42:107-124, doi:10.1144/GSL.SP.1989.042.01.07 --- Don Elthon: Pressure of origin of primary mid-ocean ridge basalts / Geological Society, London, Special Publications, 42:125-136, doi:10.1144/GSL.SP.1989.042.01.08 --- Toshitsugu Fujii: Genesis of mid-ocean ridge basalts / Geological Society, London, Special Publications, 42:137-146, doi:10.1144/GSL.SP.1989.042.01.09 --- Z. A. Palacz and J. A. Wolff: Strontium, neodymium and lead isotope characteristics of the Granadilla Pumice, Tenerife: a study of the causes of strontium isotope disequilibrium in felsic pyroclastic deposits / Geological Society, London, Special Publications, 42:147-159, doi:10.1144/GSL.SP.1989.042.01.10 --- M. Storey, J. A. Wolff, M. J. Norry, and G. F. Marriner: Origin of hybrid lavas from Agua de Pau volcano, Sao Miguel, Azores / Geological Society, London, Special Publications, 42:161-180, doi:10.1144/GSL.SP.1989.042.01.11 --- G. Thompson, W. B. Bryan, and S. E. Humphris: Axial volcanism on the East Pacific Rise, 10–12°N / Geological Society, London, Special Publications, 42:181-200, doi:10.1144/GSL.SP.1989.042.01.12 --- Johann Helgason: The Fjallgardar volcanic ridge in NE Iceland: an aborted early stage plate boundary or a volcanically dormant zone? / Geological Society, London, Special Publications, 42:201-213, doi:10.1144/GSL.SP.1989.042.01.13 --- P. A. Floyd: Geochemical features of intraplate oceanic plateau basalts / Geological Society, London, Special Publications, 42:215-230, doi:10.1144/GSL.SP.1989.042.01.14 --- G. R. Davies, R. A. Cliff, M. J. Norry, and D. C. Gerlach: A combined chemical and Pb-Sr-Nd isotope study of the Azores and Cape Verde hot-spots: the geodynamic implications / Geological Society, London, Special Publications, 42:231-255, doi:10.1144/GSL.SP.1989.042.01.15 --- D. J. Chaffey, R. A. Cliff, and B. M. Wilson: Characterization of the St Helena magma source / Geological Society, London, Special Publications, 42:257-276, doi:10.1144/GSL.SP.1989.042.01.16 --- J.-L. Joron and M. Treuil: Hygromagmaphile element distributions in oceanic basalts as fingerprints of partial melting and mantle heterogeneities: a specific approach and proposal of an identification and modelling method / Geological Society, London, Special Publications, 42:277-299, doi:10.1144/GSL.SP.1989.042.01.17 --- D. E. Fisher: Evaluation of rare gas data in relation to oceanic magmas / Geological Society, London, Special Publications, 42:301-311, doi:10.1144/GSL.SP.1989.042.01.18 --- S.-s. Sun and W. F. McDonough: Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes / Geological Society, London, Special Publications, 42:313-345, doi:10.1144/GSL.SP.1989.042.01.19 --- B. J. Murton: Tectonic controls on boninite genesis / Geological Society, London, Special Publications, 42:347-377, doi:10.1144/GSL.SP.1989.042.01.20