Heat flow map of the European part of the U.S.S.R.

A heat flow isoline map is presented. Low and relatively constant heat flow has been observed in the old shield areas of the East European Platform (25–40 mW/m²). Increased heat flow (>50 mW/m²) has been found in the Dniepr-Donetz depression. The area south of the East European Platform is characterized by highly variable heat flow (55–100 mW/m²). Some geophysical implications are discussed.     

Mechanical aspects of sedimentary basin formation: development of integrated models for lithospheric and surface processes

Different assumptions for the thermo-mechanical properties of the lithosphere strongly affect predictions inferred from quantitative sedimentary basin modeling. Examples from various basins, selected as natural laboratories, illustrate the importance of incorporating a finite strength of the extending lithosphere in forward stratigraphic modeling of large-scale basin stratigraphy. Current models can effectively couple erosion at uplifted rift shoulders of extensional basins with the basin fill architecture of the subsiding basin compartments. Modeling of the synrift strata integrates spatial scales characteristic for subbasins, such as the Oseberg field in the North Sea, with large-scale lithospheric properties characterizing the bulk strength of extending lithosphere. Modeling of compressional basins in foreland fold-and-thrust-belt settings can effectively link lithospheric flexure with surface processes. Scales pertinent to short-term spatial and temporal variations in basin fill and basin deformation can now be addressed, allowing the quantitative investigation of consequences of different modes of thrusting for basin fill geometry and facies characteristics.     

Aquaculture intensification under land and water limitations

Two intensive aquaculture systems are described in which high yields are obtained for relatively low inputs of land area, water and supplementary feed. The one is a polyculture of a number of fish species in deep cotton irrigation reservoires (5–7 m deep) in Israel. The large volume of water in these reservoirs improves the oxygen regime and dilutes catabolites excreted by the fish. This allows the increase of fish density to 10,000–18,000 fish ha^–1. It also enables the increase of the resevoir's productivity by manuring with liberal amounts of animal wastes. Yields obtained in this system reach over 10 ton ha^–1 yr^–1 at very low feed conversion rates. The second system is practiced in Taiwan for the culture of red tilapia. Pond water is stirred mechanically by paddlewheels to create a gentle current around a central water outlet. This supplies ample oxygen and concentrates wastes in the center of the pond, from where it is removed twice daily, thus alleviating the build-up of catabolite concentration in the pond. Densities of fish amount to 215,000 to 430,000 fish ha^–1, and the yields are accordingly high reaching more than 200 ton ha^–1 yr^–1. The ecological principles involved in these systems are discussed.     

New perspectives on Mars’ crustal magnetic field

The planet Mars lacks, today, a planetary, dynamic magnetic field, but strong, intense, localized magnetic fields of lithospheric origin, one to two orders of magnitude larger than the terrestrial lithospheric field, are present. This lithospheric magnetic field is the result of magnetization processes in the presence of a magnetic dynamo and of demagnetization processes after the dynamo shutdown, such as impact or volcanoes. This crude scenario can be more accurately specified by interpreting global and local models of the current magnetic field of Mars. Some specific areas are studied, including the intensely magnetized Terra Sirenum, as well as the magnetic anomaly associated with Apollinaris Patera. Magnetic minerals could be of primary and/or secondary origin; this latter would imply an early hydration of a basaltic crust. A scenario, in which Mars experienced a major polar wander due to the Tharsis bulge, prior to the cessation of its dynamo, is proposed and discussed.     

Mantle Structure Beneath the SW Slave Craton, Canada: Constraints from Garnet Geochemistry in the Drybones Bay Kimberlite

This study describes the petrography of peridotite xenoliths,and the major and trace element geochemistry of garnets in bothxenoliths and coarse concentrate from the Drybones Bay kimberlite.The temperature and depth of equilibration of clinopyroxeneand garnet show that the mantle lithosphere beneath the SW marginof the Slave Province was at least 160 km thick at the timeof kimberlite emplacement (     

Some critical remarks on the analysis of phengite and paragonite components in muscovite by X-ray diffractometry

In the past lattice parameters b and c of muscovite s.1. from pelitic schists have been used to determine its phengite and paragonite component. A critical review of the literature and of some new data shows, however,

that a convincing statistical correlation between these physical and chemical properties does not exist

that an eventual trend-like correlation cannot be used for a quantitative analysis of phengite and/or paragonite components in muscovite.

Obviously further factors influence the lattice parameters of muscovite s.1., besides octahedral and interlayer chemistry.     

Evaluation of seismic events detection algorithms

Identification of seismic events from continuously recorded seismic data in real-time through a Digital Seismic Data Recording system is a difficult task. Despite the vast amount of research in this field, the signal processing and event parameters discrimination algorithms have not yet fully come of age. Presently, we have a wide spectrum of trigger algorithms, ranging from a very simple amplitude threshold type to the sophisticated ones based on pattern recognition approaches. Some of the other approaches use adaptive technique and neural network methods. Researchers are continuously making efforts for the development of algorithms using various techniques, which produce minimum false trigger. Some approaches have been reported which are accurate for detecting first phase of events and take minimum possible computational time. In this paper several approaches for detecting event signals in background noise are presented and their precision evaluation is discussed.     

The south-western Black Forest and the Upper Rhine Graben Main Border Fault: thermal history and hydrothermal fluid flow

The thermal history of the south-westernmost Black Forest (Germany) and the adjacent Upper Rhine Graben were constrained by a combination of apatite and zircon fission-track (FT) and microstructural analyses. After intrusion of Palaeozoic granitic plutons in the Black Forest, the thermal regime of the studied area re-equilibrated during the Late Permian and the Mesozoic, interrupted by enhanced hydrothermal activity during the Jurassic. At the eastern flank of the Upper Rhine Graben along the Main Border Fault the analysed samples show microstructural characteristics related to repeated tectonic and hydrothermal activities. The integration of microstructural observations of the cataclastic fault gouge with the FT data identifies the existence of repeated tectonic-related fluid flow events characterised by different thermal conditions. The older took place during the Variscan and/or Mesozoic time at temperatures lower than 280°C, whereas the younger was probably contemporary with the Cenozoic rifting of the Upper Rhine Graben at temperatures not higher than 150°C.