摘要:

ABSTRACTA description of planning, organisation and field procedure of a test profile of 150 km length is given. This profile was laid out as an experiment for a detailed investigation of the velocity–depth–structure of the earth's crust in a selected area. The line was to be shot as a wide angle profile with a common reflection po

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01739.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYThis report gives a description of Fortran II programs for filtering and spectral analysis. All programs are tested.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01767.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

ABSTRACTFrom travel time observations on a test profile ranging from o to 145 km four main events can be distinguished. They represent reflections and diving waves from various discontinuities within the earth crust. A low‐velocity zone of a few kilometres thickness begins at a depth of about 10 km, another one probably at 25 km.For the MohoričIć discontinuity (=MD)a gradient zone with a large velocity gradient instead of a first order interface is postulated in order to explain some irregularities of the travel time curve. Comparisons between theto‐time of theMDwith the statistical data from Dohr and Liebscher show an excellent correlation.ZusammenfassungAufgrund von Laufzeitbeobachtungen eines Weitwinkelprofils in der Bayrischen Molasse von o bis 145 km Länge können im wesentlichen vier verschiedene Einsätze unterschieden werden, die sich aus Reflexionen bzw. aus Tauchwellen zusammensetzen. Eine Zone geringerer Geschwindigkeit beginnt bei etwa 10 km Tiefe. eine weitere liegt wahr‐scheinlich unterhalb 25 km Tiefe. Von den Unregelmäßigkeiten der Laufzeitkurve der MohorovičIć‐Diskontinuität (=MD)wird eine Zone mit einem starken Geschwindigkeits‐gradienten anstelle einer “scharfen” Grenzfläche abgeleitet. Vergleiche zwischen derto‐Zeit derMD‐Reflexionskurve mit den statistischen Untersuchungen von Dohr und Liebscher zeigen ei

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01740.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractThe region of Graus (Central Spanish Pyrenees) has been surveyed by the conventional seismic reflection method in the years 1963–64.This region is strongly accidented and there are only a few roads of access. Thus a good grid of seismic lines could not be realised. Therefore a seismic survey with completely portable equipment was tried out. For that reason drilling was abandoned.The results seem to show that the method of the air‐shots is completely comparable with that of buried sh

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01741.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

ABSTRACTSpurious reflections showing a residual move‐out are generally present on both corrected seismic cross‐sections and common depth point composites.We propose to determine a space‐time filter satisfying the following conditions: to attenuate as much as possible reflections presenting a given move‐out, to retain intact reflections whose time gradient is zero (or has a predetermined value), to be applicable efficiently even to a small number of traces, not to amplify random noise unduly.After briefly indicating the design principle of these filters, we shall give the results of their application to the theoretical examples, in order to bring out: the influence of sampling interval and filter length (possibility of achieving efficient filtering using an apparatus with a small number of terms), the effect of filtering on dipping reflections (reduction in amplitude and distortion increasing with the time gradient), the range of reflection move‐out that can effectively be filtered with the same apparatus, the disturbing influence of random noise.RESUMEOn constate généralement, tant sur les films sismiques corrigés que sur les résultats de couverture multiple, la présence de réflexions parasites présentant une courbure résiduelle d'indicatrice.Nous nous sommes proposé de déterminer un opérateur de filtrage spatio‐temporel satisfaisant aux conditions suivantes: filtrer le plus possible les réflexions présentant une courbure donnée, conserver intégralement les réflexions dont le gradient temps est nul (ou a une valeur déterminée), pourvoir être appliqué efficacement à un petit nombre de traces, ne pas amplifier outre mesure les bruits inorganicés.Après avoir indiqué brièvement le principe du calcul de ces filtres, nous présenterons les résultats de leur application à des exemples théoriques, afin de mettre en évidence:ľ'influence du pas d'échantillonnage et de la longueur du filtre (possibilityé d'obtenir un filtrage efficace avec un opérateur comportant un petit nombre de termes),ľ'effet du filtrage sur les réflexions pentées (réduction d'amplitude et distorsion croissant avec le gradient temps),ľ'ouverture de ľ'éventail des réflexions courbes que ľ'on peut filtrer efficacement avec un même op

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01742.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

ABSTRACTThe authors propose a method of determining the sedimentary composition of the sea‐bottom by studying the variation of the frequency contents of the consecutive multiple reflections between bottom and surface of the se

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01743.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

ABSTRACTThis paper gives a report about experiments with the geomagnetic field‐balance with ribbon suspension of the FANSELAU‐type under extreme climatic conditions. These experiments were carried out by several institutions. The results show that the field balances “H” and “Z” give right records even under extreme

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01744.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

ABSTRACTAn ill‐defined seismic marker has been identified as the top of the sandstone lower Trias in the “Landes”– small area within the whole Aquitaine region for which the S. N. Repalobtained prospecting licences. Before any drilling was made, this marker was thought to belong to the early saliferous triassic series.The quantitative use of the residual gravity anomaly has made the seismic reflection interpretation easier. This interpretation was found to give excellent results along the coastline where all postulated hypothesis proved true in the bore holes of Contis and St Girons.As a first approximation, it appears that the substratum of the saliferous bed in sub‐horizontal and has a fairly steady gravity. The Jurassic and the Cretaceous, both limestones, are prevailing (0,15) in comparison with the argillaceous‐saliferous Trias and the early Tertiary which was revealed to us with accuracy through seismic surveys. The use of an approximative linear equation where the gravimetric residue is expressed as a function of the limestone thickness allows a better seismic interpretation.This makes possible a more reliable approach of the structural study of post‐triassic deposits. The same holds good for the sandstone substratum which shows on an isochronous map strains due to thickness and velocity changes in the overburden. These facts help us to get a better insight into the origin and formation of salt accumulations in this pa

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01745.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

ABSTRACTIn a previous paper by the present author a method was developed for direct interpretation of resistivity observations made with a Schlumberger electrode configuration. This method consisted of two steps. The first of these was to derive the kernel function in the integral expression for the apparent resistivity from the observed data; the second step was to derive the resistivity stratification from this kernel function.The first of these two steps depends on the electrode configuration that has been used. In the present paper the above mentioned method is modified so as to make it apply to a Wenner electrode configuration. The procedure is indicated by which the method may be adapted to any other electrode configuration in which the distances between the electrodes are finite.The second step in the interpretation, i.e. the derivation of the resistivity stratification from the kernel function, is independent of the electrode configuration used, and therefore needs no further discussion in the present context.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01746.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractThe design and construction of hydroelectric works, and more particularly of storage reservoirs and dams, in karst areas pose extremely varied and complex engineering, geological and hydrogeological problems, for the solution of which no widely applied techniques have yet been developed.In addition to conventional geological and hydrogeological methods for the study of karst phenomena, the application of more efficient methods of a primarily geophysical nature is called for. These methods, which provide the best means for solving the complex problems encountered in karst, are steadily gaining acceptance.The Miruše storage reservoir and the Grančarevo dam are the key structures in the Trebišnjica hydroelectric complex and are located in an area of typical Dinaric karst. Many of the engineering, geological and hydrogeological problems connected with their design and construction were solved with the aid of electrical geophysical prospecting methods (especially the resistivity method). The investigations provided data on the depth of karstification (the relief of the base level of karst erosion), the position of intensively karstified and tectonically broken zones, as well as on the general orientation of the process of karstification. All these data were helpful in providing a more accurate insight into the impermeability of the rocks that formed the storage reservoir (in relation to the proposed impounding level); they also enabled the consolidation structures (impervious curtains), aimed at preventing excessive losses due to seepage, to be designed more economical

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1966.tb01747.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY