Crystal chemical implications on some alkali hydrated sulphates

Summary This paper deals with some unsolved crystal chemical questions concerning a group of alkali iron hydrated sulphates based on clusters of composition [Fe ₃ ³⁺ O(SO₄)₆(H₂O₃]^5– Taking the experimental chemical formulae, X-ray data and known crystal structures into account it is possible to establish the theoretical boundaries of the Na–K diadochy in metavoltine and also to define the influence of the Na–K replacement on the structure of -Maus' salt. These considerations allow us to propose more general crystal chemical formulae, both for metavoltine and -Mous' salt. Finally, the causes which affect the stability of metavoltine and and -Maus' salt are discussed.

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Kristallchemische Überlegungen zu einigen wasserführenden Alkali-Sulphaten

Zusammenfassung Diese Arbeit befaßt sich mit einigen noch ungelösten kristallchemischen Fragen einer Gruppe von wasserführenden Alkali-Eisen-Sulphaten, die auf Gruppierungen der Zusammensetzung [Fe ₃ ³⁺ O(SO₄)₆(H₂O)₃]^5– basieren. Aufgrund der experimentall ermittelten chemischen Formeln, Röntgendaten und der bekannten Kristallstrukturen ist es möglich, die theoretischen Grenzen der Na–K Diadochie in Metavoltin zu ermitteln. Außerdem gelang es, den Einfluß des Na–K Ersatzes auf die Struktur des -Maus'schen Salzes zu definieren. Diese Überlegungen führten dazu, allgemeine chemische Formeln sowohi für Metavoltin wie für -Maus'sches Salz vorzuschlagen. Schließlich werden die Faktoren diskutiert, die die Stabilität von Metavoltin sowie von und -Maus'schem Salz bestimmen.

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With 6 Figures     

Ground-Water Protection Zones

In many areas, the water demand of households, industries and farms is satisfied by ground water. Because of many human activities ground-water quality decreases, it is necessary to protect it. The quantity of pollutants entering the aquifers can be minimized by technical and legal measures. But it seems to be almost impossible to solve the problem regionally or nationwide. The delineation of protection zones around existing or planned wells is a more effective way. The intake area of wells or well fields have to be protected by legal measures against all activities which may affect ground-water quality. Regarding the migration of viruses and bacteria, it is well known that these biological pollutants have a distinct limited lifetime in aquifers, which is for West Germany estimated at 50 days. Because during this limited time they can move with the ground water, transfer diseases, and cause epidemics, certain zones around wells must be kept free from activities which may introduce bacteria into the subsurface systems. These zones are generally smaller than the catchments. For the determination of the zones, careful studies and calculations of the distance-velocity of ground water are necessary. Primary methods are the use of tracers and simple calculations. Examples are given for calculating the distance to the 50-day line, based on West German experience.     

Recent climatic change and unusual weather in the Northern Hemisphere

Occurrence frequency of unusual weather caused by anomalous synoptic patterns has its peaks in the middle latitude regions and the subtropical regions. Height anomaly patterns at the 500 mb level for the last three decades show the expansion of negative area in the northern hemisphere, resulting in increase of variability in space and time.     

Palynology of the circum-mediterranean triassic: Phytogeographical and palaeoclimatological implications

Following a tentative evaluation of palynological information from Ladinian and, more particularly, Karnian successions, there seems to be every indication that qualitative and quantitative compositional differences of palynological assemblages could well be applied in testing concepts of Triassic phytogeography and palaeoclimatology. The following implications are emphasized:

1. There is sufficient palynological evidence that the Mediterranean region includes a domain of mixed northern (Laurasian) and southern (Gondwana) types of floras.
2. The concept of an essentially arid nature of a wide equatorial climatic belt during Triassic times finds palynological support.
3. Palynological evidence does not contradict a concept of pronounced decrease in precipitation towards the western part of the Mediterranean region.
4. In Europe, occurrences of hygrophytic palynofloras and coals within an arid climatic zone can be explained by the water-supply of extensive river-systems.

     

Wegeners „Kontinentverschiebungen“ zu seiner Zeit und heute

Zusammenfassung Ausgangspunkt der Wegenerschen Theorie war der unmittelbare Eindruck von der Kongruenz der atlantischen Küsten. Das eigentliche Fundament bildeten jedoch die Argumente aus Paläontologie, Geophysik, Geologie, Paläoklimatologie und Astrogeodäsie. Wegener war nicht nur der Schöpfer, sondern auch der Propagandist seiner Theorie. Von bleibendem Wert erwiesen sich seine Forderungen: Jede Theorie der Entstehung der Ozeane und Kontinente muß von allen geowissenschaftlichen Disziplinen getragen werden und sie muß sich durch Messungen bestätigen lassen.

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The starting-point of Wegener's theory was the direct impression of the congruity of the Atlantic coastlines. The fundamental principle, however, is formed by the argumentation of paleontology, geophysics, geology, paleoclimatology and astrogeodesy. Wegener was not only the creator of his theory but he also propagated it. His demands proved to be of lasting value: every theory of the origin of oceans and continents has to be supported by all geosciences and it should be possible to be verified by physical measurements.

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Resume Le point de départ de la théorie de Wegener fut l'impression immédiate de la concordance des côtes atlantiques. Les bases véritables furent les arguments tirés de la Paléontologie, de la Géophysique, de la Géologie, de la Paléoclimatologie et de l'Astrogéodésie. Wegener fut non pas seulement le créateur de sa théorie, mais encore son propagandiste. Sa démarche reste valable d'une théorie de la genèse des continents et des océans qui soit étayée part toutes les sciences de la terre et verifée par des mesures physiques.

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Expanding a network of public facilities with some fixed supply points

Conclusions In general terms, this paper has demonstrated how the expansion of public facilities can be phased and implemented within the framework of certain policy objectives. Given an existing network of hospitals, for instance, it is possible to plan and implement the provision of additional facilities in a manner that enhances the spatial efficiency of the expanded network. The expansion can be executed in such a way that with the addition of each new facility, not only is aggregate travel minimized, but also a specified proportion of the population can be brought within easy reach of hospital services. This method is a particularly useful one because in planning the location of facilities, authorities hardly ever start off with a clean slate. Usually some facilities of the same kind might already be occupying some locations which may or may not be optimal. But whether or not the already existing network is optimal, the overall efficiency of the expanded network can be enhanced by proceeding in the manner outlined above.This method can be applied to a wide range of public facilities, like schools for instance. But its application depends, among other things, on the clear definition of locational and policy objectives. Different objectives could produce different locational patterns. Even variations in the measures of distance used can produce different locational patterns.     

Fibroferrite: A mineral with a {Fe(OH) (H2O)2SO4} spiral chain and its relationship to Fe(OH)SO4, butlerite and parabutlerite

Summary The mineral fibroferrite has the chemical formula Fe(OH)SO₄·xH₂O; the value forx has not been definitely settled, but as a rule it is found to be near five. Several symmetries are given in the literature.A sample from Saint Felix de Paillères, France, proved to be rhombohedral with space group R3; lattice constants for the hexagonal cell area=24.176,c=7.656 Å. As calculated from the experimental density (=1.95 g·cm^–3)Z=18 for this cell. Intensities were collected on an automated X-ray diffractometer from a thin fiber extended along [00.1]. The structure was determined by Patterson and Fourier methods. Least squares refinement with 818 observed reflections resulted inR=0.076.The structure contains hydroxo-bridged {Fe(OH)(H₂O)₂SO₄} spiral chains built of [Fe(OH)₂(H₂O)₂O₂] octahedra and SO₄ tetrahedra. Hydrogen bonds provide connections between these chains. The spiral chains are a stereoisomer variant of the hydroxo-bridged linear chains of Fe(OH)SO₄, butlerite and parabutlerite. A comparison of these compounds is givenm to understand the relationship between the structure and their water content.

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Fibroferrit: Ein Mineral mit einer {Fe(OH)(H₂O)₂SO₄} Spiralkette und seine Beziehung zu Fe(OH)SO₄, Butlerit und Parabutlerit

Zusammenfassung Das Mineral Fibroferrit hat die chemische Formel Fe(OH)SO₄·xH₂O; der Wert furx scheint nicht endgültig geklärt zu sein, liegt aber meist nahe 5. Verschiedene Symmetrien werden in der Literatur angegeben.Eine Probe von Saint Felix de Paillères, Frankreich, erwies sich als rhomboedrisch mit der Raumgruppe R3; die Gitterkonstanten der hexagonalen Zelle sinda=24,176,c=7,656 Å. Die experimentelle Bestimmung der Dichte (=1,95 g·cm^–3) führt für diese Zelle zuZ=18. Von einer nach [00.1] gestreckten dünnen Faser wurden die Intensitäten auf einem automatischen Röntgendiffraktometer gesammelt. Die Struktur wurde mit Patterson-und Fouriersynthesen gelöst. Eine Verfeinerung nach der Methode der kleinsten Quadrate führte für 818 beobachtete Reflexe aufR=0,076.Die Struktur enthält durch Hydroxil-Gruppen verknüpfte {Fe(OH)(H₂O)₂SO₄}-Spiralketten, die aus [Fe(OH)₂(H₂O)₂O₂]-Oktaedern und SO₄-Tetraedern aufgebaut sind. Die Spiralketten von Fibroferrit sind eine stereoisomere Variante der annähernd linearen Fe–O–S-Ketten von Fe(OH)SO₄, Butlerit und Parabutlerit. Diese Verbindungen werden mit Fibroferrit verglichen, um Beziehungen zwischen Struktur und Wassergehalt zu verstehen.

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Paper presented at the Fifth European Crystallography Meeting, Copenhagen, Denmark 1979.     

Paläozoische und frühmesozoische Orogenesen am pazifischen Rand Gondwanas

Zusammenfassung In Südamerika, in der Antarktis und in Australien läßt sich gleichermaßen vom Kambrium bis in die Trias ein pazifikwärtiges Wandern der orogenen Aktivität beobachten. Aus der relativen Lage dieser Orogene ergibt sich, daß vor dem Jura die Antarktische Halbinsel westlich der Südspitze von Südamerika gelegen hat.

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In South America, Antarctica and Australia, from the Cambrian to the Triassic Pacificward shifting of the orogenic activity is observed. From the relative position of these orogenes is deduced that before the Jurassic the Antarctic Peninsula was situated west of the southern tip of South America.

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Resumen Tanto en Sudamérica como en la Antártida y en Australia desde el Cámbrico hasta el Triásico se observa una transposición continua de la actividad orogénica hacia el Pacífico. De la posición relativa de estos orógenos se concluye que antes del Jurásico la Península Antártica fue situada al Oeste de la punta Sur de Sudamérica.

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