Ammonite-based correlations in the Cenomanian-lower Turonian of north-west Europe, central Tunisia and the Western Interior (North America)

The biochronology of Cenomanian-early Turonian ammonite faunas from three key stratotype areas (north-west Europe, central Tunisia and the Western Interior of North America) has been analysed and revised by utilizing the unitary association method. This review is prompted by the huge amount of biostratigraphic data published during recent decades and by a taxonomic homogenisation of the ammonite faunas from these key areas. The Cenomanian and lower Turonian of Tunisia comprise twenty-four Unitary Association zones and the middle Cenomanian-lower Turonian of the Western Interior Basin twenty-three such zones. The unitary association method means a two-fold increase in resolution of these ammonite zonations compared to the standard, empirical schemes. Central Tunisia and the Western Interior are correlated with north-west Europe by constructing a zonation including all taxa common to these areas. These correlations highlight the variable completeness and resolution of the faunal record through space and time, and reveal a significant number of diachronous taxa between the three areas. These correlations enable the designation of a new global marker for the middle/upper Cenomanian boundary, which is characterised by the disappearance of the genera Turrilites, Acanthoceras and Cunningtoniceras and by the appearance of Eucalycoceras, Pseudocalycoceras and Euomphaloceras. The only synchronous datum known is the last occurrence of Turrilites acutus, which may thus be used as a marker for the middle/upper Cenomanian boundary, provided that it does not turn out to be diachronous in the light of any new data.     

Radial velocities in the open cluster IC 2391

We have determined radial velocities for 31 stars in the field of the open cluster IC 2391, and derived the percentage of probable radial-velocity variables. We improved the orbit of one previously known spectroscopic binary, and confirmed the existence of two double-line binaries. We discussed with such data the membership to the cluster, the average cluster radial velocity and compared the incidence of short-period binaries among the Main-Sequence members of IC 2391 with the incidence for other clusters with similar average axial rotation of its members.Member of the Carrera del Investigador Científico del Consejo Nacional de Investigaciones Científicas y Técnicas de la República ArgentinaVisiting Astronomer, Cerro Tololo Inter-American Observatory, operated by AURA, Inc. under contract with the National Science Foundation.     

Growing folds and sedimentation of the Gosau Group, Muttekopf, Northern Calcareous Alps, Austria

Analysis of the three-dimensional geometry of Upper Cretaceous clastics in the Muttekopf area (Northern Calcareous Alps, Austria) indicate fold and fault structures active during deposition. Coniacian continental to neritic sedimentation (Lower Gosau Subgroup) was contemporaneous with displacements on NW-trending faults and minor folding along NE-trending axes. From the Santonian onwards (sedimentation of the deep-marine Upper Gosau Subgroup) the NW-trending faults were sealed and large folds with WSW-trending axes developed. The direction of contraction changed to N-S after the end of Gosau deposition in the Danian (Paleocene). Synorogenic sedimentation patterns indicate continuous contraction from the Coniacian to the Late Maastrichtian/?Danian. Therefore, large-scale extension as observed in the central part of the Eastern Alps cannot be documented in the western parts of the Northern Calcareous Alps. A combination of subduction tectonic erosion for the frontal parts and gravitational adjustment of an unstable orogen after nappe stacking for the internal parts possibly accounts for the different development of Gosau basins in the frontal and trailing regions of the Austroalpine wedge.     

Addressing Social and Community Planning Issues with Spatial Information

In Australia today, there is still relatively limited use being made of spatial information systems (SIS). Nevertheless, the technology and methodology is developing rapidly. What is already available has the capacity to assist in the process of making social service provision and community planning more people oriented, more effective and more equitable in its outcomes. Recognising the need for a sound social science context, this paper demonstrates, using a range of examples especially geared towards rural and regional Australia, the work of the National Key Centre for Social Applications of Geographical Information Systems.     

EUREKA industrial R&D projects for an improved environment

International collaboration is increasingly necessary in the field of environmental protection in relation to industrial research and development. The EUREKA initiative, launched in 1985, aims to increase industrial productivity and competitiveness in Europe by encouraging cross-border high technology research and development. The programme encompasses a number of ‘umbrella’ projects—EUROMAR, EUROCARE, EUROENVIRON, EUROTRAC and ENVINET. Each of these is designed to generate and support research and development projects. The paper gives examples of the projects and discusses the value of such large-scale international collaboration.     

On the electrojet in South America

Summary The diurnal variation in the horizontal component (H) of south american stations under and close to the electrojet were plotted during the I.G.Y. Thus a dilatation towards the south of the electrojet in the western part of South America was inferred.

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Resumen Se graficó la variación diurna en la componente horizontal (H) de estaciones sudamericanas bajo y próximas al «electrojetra, durante el A.G.I. Estas sirvieron para inferir una dilatación hacia el sur del «electrojet» en el oeste de América del Sur.

     

The Albert Formation of New Brunswick: a paleozoic lacustrine model

Recent work on the Lower Carboniferous Albert Formation of New Brunswick, Canada, has confirmed it to be mainly limnitic (lacustrine) in origin. Within its smallsized basin (ca. 4,000 sq. km.) over 1,300 m of sediment were deposited. These greyish beds are stratigraphically bounded below, above, and toward the south by terrestrial, mainly redbed, formations. Abundant organic varves in a dolomitic marlstone are present, and in places contain articulated fish skeletons. Elsewhere, symmetrical ripple-marks predominate, testifying to gentle water-current movements. The crossopterygianLatvius sp. dates basal beds, in part at least, as Upper Devonian. Ostracodes from an upper member —Euestheria sp., cf.E. lirella; Hilboldtina sp.,Carbonita sp., cf.C. subula — are from the Carboniferous. It is concluded that the Albert Formation was deposited in a tropical or sub-tropical environment, probably in an east-trending rift valley or fault-block basin, over a period of several hundred thousand years, and terminating with evaporitic deposits, at least a part of which were non-marine in origin.     

Feintektonische Untersuchungen an Schlechten und Klüften in Steinkohlenflözen des Ruhrgebietes

Zusammenfassung Im Bereich des Gelsenkirchener Sattels und der Emscher Mulde wurden im Felde Neuessen der Hoesch A.G. in Altenessen feintektonische Untersuchungen angestellt mit dem Ziel, die Entstehung der Schlechten in der Kohle, insbesondere der bankschrägen t-Schlechten und der Klüfte im Nebengestein zu erklären.Auf Grund der Messungen in den Flözen der Bochumer und Essener Schichten wurden Diagramme nach SCHMIDT-SANDERs entworfen und ausgewertet. Getrennt nach steiler und flacher Lagerung worden die bankrechten - sowie die bankschrägen t-Schlechten mit ihren symmetrologischen Beziehungen genetisch gewertet. Bei der Übertragung vom Kleinbereich zur Großstruktur ließen sich Parallelen aufzeigen, die für eine einheitliche tektonische Beanspruchung des ganzen Ruhrgebietes sprechen durften.     

Ecosystem responses in the Rhine-Meuse delta during two decades after enclosure and steps toward estuary restoration

Changes in hydrology, and developments in morphology, water quality, and ecology of the Rhine-Meuse estuary after its enclosure in 1970 are analyzed on the basis of existing monitoring data. Annual averages of ammonium, nitrate plus nitrite, total phosphate, total lead, and chlorophyll-a concentrations as well as transparency of the water are presented. Abundances of some water bird species are given for the period 1970–1993, and the relative fish biomass for the period 1971–1988 is discussed. The gradual evolution led toward the dominance of bream. The area has developed toward a system with generally low natural ecological values. Ecological impacts of present sluice management are discussed and include the accumulation of contaminated sediments, disappearance of intertidal areas and nursery grounds for fish, disturbance of fish migration, and less mixing of river and seawater. Recent policy developments have brought the present management of the Haringvliet sluices back in to discussion. A recent policy document has presented several management alternatives, including partial and complete reopening of the sluices to permit saltwater intrusion. Three management options are compared in terms of costs and ecological benefits. It is concluded that a complete reopening, and thus a partial restoration of the estuarine characteristics, is most beneficial for the ecosystems of the area itselt, for the upstream Rhine and Meuse rivers, and for the adjacent North Sea, but costs amount to about 600 million US $.     

Environmental destruction as a counterinsurgency strategy in the Kurdistan region of Turkey

We examine environmental aspects of the conflict between the Turkish state and the insurgent Kurdistan Workers Party (Partiya Karkerên Kurdistan or PKK). Since the early 1990s, several civil society groups have claimed that the Turkish army burned forests and destroyed other livelihood resources in the Kurdistan region of Turkey as it evacuated settlements. We report the results of a case study of destruction in Tunceli, eastern Turkey, undertaken in order to evaluate support for such claims. We demonstrate the use of geospatial techniques in case-specific approaches to the study of armed conflict. Through the analysis of satellite images, we verified eyewitness reports and confirmed that substantial burnings did indeed take place in the study area between 1991 and 1994. We argue that this destruction was not irrational or wanton, but that it was part of a strategy used by the Turkish army in the early 1990s that aimed at actively transforming the war environment.