A note on the effect of the ground on the convective temperature field in the atmospheric surface layer

Summary The paper presents the solution of the equation of heat conduction with density of heat sources given generally. For two special cases the computed central temperature excesses of model[5] are compared with the results of some authors[1, 6] who deal with convection in the surface layer.     

Lunar deflections of the vertical and their elementary interpretation

Summary The selenopotential was determined at the Apollo 12 landing site (A12) using the selenocentric constant, Stokes' constants of the Moon up to n=13, the angular velocity of rotation of the Moon and the value of gravity directly observed at A12. Using and the constants mentioned above, the radius-vector of the equiselenopotential surface passing through A12 was derived. The fundamental selenocentric parameters, based on this surface, were computed, as well as the deflections of the vertical especially in some strongly anomalous regions of the Moon. For some mascons an elementary interpretation has been carried out.Dedicated to Academician Alois Zátopek on His 65th BirthdayPresented at the XVth Plenary Meeting of COSPAR, Madrid, May 10–24, 1972, under the title:Selenocentric Reference Parameters and Deflections of the Vertical Related to the Equipotential Surface Passing through the Apollo 12 Landing Site.     

Cs137 gamma-ray absorption in eclogites

Summary The coefficient of the gamma-ray absorption _Cs ¹³⁷ investigated in eclogites of the Bohemian Massif varies with fresh samples from0.2477 cm ^–1 to 0.2804 cm ^–1 . Symplectite is the main factor decreasing the value of down to0.242 cm ^–1 . On the contrary, the coefficient increases with the increasing content of clinopyroxene and especially of garnet. The linear dependence of the coefficient on the density may be expressed by the equation =0.0682+0.028.     

Classification of landslides and other mass movements

Summary This paper presents a new universal classification of slope movements, destined for the purpose of engineering geological mapping. This classification was compiled after critical evaluation of the classifications used by now, on the basis of the experience gained by systematic study of slope movements in Czechoslovakia.The following 4 types of slope processes are recognized regarding to the geomechanical character and velocity of the movement: creep, sliding, flow and fall. Creep is a geologically long-term movement of non-increasing velocity without well-defined sliding surfaces. Sliding is a slope movement of coherent masses along one or more well-defined shear surfaces. Flow represents slope movements in rocks and soils, analogous to the movements in liquids. Fall is a sudden slope movement; the moving mass loses its coherence and, for a short time, also its contact with the underlying rock.The pictures show the elementary types of movements that are obvious in the European climatic conditions. Graphical representation of dimensions and velocity of the phenomena is included.

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Zusammenfassung Die vorgeschlagene Klassifikation geht zurück auf systematische Untersuchungen an Rutschgebieten in der SSR. Sie lehnt sich an die besten gebräuchlichen Klassifikationen an, wobei letztere einer kritischen Beurteilung unterzogen werden. Ziel des neuen Vorschlages ist die Erarbeitung von Kriterien für die ingenieurgeologische Kartierung.Auf Grund des geomechanischen Charakters der Bodenbewegungen werden folgende vier Vorgänge unterschieden: Kriechen — geologisch langandauernde, nicht beschleunigte Bewegungen ohne ausgeprägte Gleitflächen; Gleiten — Hangbewegungen zusammenhängender Massen längs einer oder mehrerer Gleitflächen; Fließen — Hangbewegungen von flüssigkeitsähnlichem Charakter; Fallen — plötzliche Hangbewegungen, wobei die bewegte Masse den inneren Zusammenhang und kurzfristig auch den Kontakt mit dem Liegenden verliert.Die Grundtypen werden an Hand europäischer Beispiele graphisch dargestellt und durch Angaben über Größenordnung der Massen und deren durchschnittliche Geschwindigkeit ergänzt.

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Résumé D'après les expériences acquises pendant les études de glissements en Tchécoslovaquie et d'après l'examen critique des classifications employées jusqu'ici, on a recommendé la classification suivante, destinée avant tout au levé de géologie de l'ingénieur.En relation avec le caractère géomécanique des mouvements de pente et de leur vitesse, quatre processus sont distingués: fluage, glissement, écoulement, écroulement. Le fluage — mouvements géologiquement de longue durée, sans accélération et sans surfaces de glissement exprimées. Le glissement — mouvements de pente de masses cohérentes, le long d'une ou de plusieurs surfaces de glissement. L'écoulement — mouvements de pente dans les roches et les sols, analogues aux mouvements dans les liquides. L'écroulement — mouvements de pente soudains, au cours desquelles les masses en mouvement perdent entièrement leur connexion intérieure et, pour un temps aussi, le contact avec le sous-sol.Les exemples sur les figures représentent les types principaux des mouvements courants dans les conditions climatiques de l'Europe. On indique aussi les dimensions et la vitesse moyenne des types individuels.

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With 4 Figures     

Geomagnetic field intensity during the Plio-Pleistocene derived from the thermo-remanence of porcellanites and palaeo-slags (Czechoslovakia)

Summary The present paper deals with the derivation of the intensity of the geomagnetic field in the Plio-Pleistocene, Central Europe. The intensity was derived from the thermo-remanence of porcellanites and palaeo-slags. These rocks represent a common product of intense thermal alteration of loams due to spontaneous combustion of coal seams. Porcellanites and palaeo-slags show outstanding palaeomagnetic properties, their remanent magnetization is of thermo-remanent origin and they were mineralogically stabilized under natural conditions in the geological past, during the coal combustion. It was found, that the intensity of the geomagnetic field during the Plio-Pleistocene oscillated about the value of the present-day intensity.     

Sur le magmatisme et les minéralisations hydrothermales du Massif de Bohême

Résumé Après un bref aperçu sur les types intrusifs de roches plutoniques, sont décrits les divers types d'associations min7'erales isogénétiques d'origine hydrothermale du Massif de bohême, sur le territoire de la Tchécoslovaquie. L'étude de la répartition spatiale de certaines associations minérales conduit à la différenciation de 2 zones et de 7 sous-provinces, dans la province du Massif de Bohême. Du point de vue chronologique, trois époques de minéralisation sont distinguées: antéhercynienne, hercynienne et posthercynienne, qui comportent plusieurs sous-époques distinctes de minéralisation. En conclusion, une distinction est faite entre: 1°) des associations hydrothermales montrant des relations chronologiques et spatiales nettes avec des granitoïdes voisins; 2°) des associations ne montrant que des relations spatiales; 3°) des associations, les plus nombreuses, qui sont sans aucun rapport évident avec les massifs connus de granitoïdes.

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After a brief survey of intrusive types of plutonic rocks, the present paper contains a review of isogenetic mineral associations of hydrothermal origin occurring in the Bohemian Massif in the territory of Czechoslovakia; further, the distribution of some mineral associations is discussed; the result is the differentiation of 2 zones and 7 subprovinces of the province of the Bohemian Massif. From the chronological point of view three epochs can be distinguished: pre-Variscan, Variscan and post-Variscan which include marked mineralisation subepochs. In conclusion the authors discern: 1°) hydrothermal associations showing spatial and chronological relations to the surrounding granitoids; 2°) associations displaying spatial relations only; 3°) those — the most numerous — which do not show any distinct relations to the known massifs of granitoids.