Sondages sismiques continus en Mediterranée occidentale. Enregistrement, analyse, interprétation
Leenhardt, O. (1970). Sondages sismiques continus en Mediterranée occidentale. Enregistrement, analyse, interprétation. Mémoires de l'Institut océanographique, Monaco, 1. Musée Océanographique: Monaco. 120 pp.
Part of: Mémoires de l'Institut océanographique, Monaco. Musée Océanographique: Monaco. ISSN 0304-5714, more
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| Abstract |
Continuous seismic profiling is defined and its evolution is traced back. Then it is shown how the signal is transformed, from emission to recording time. Special attention is paid to the resolution penetration antithesis and the importance of carefully controlled operations at sea. The different stages of record analysis are precisely detailed: reflection of character analysis and other chart drafting are both work for the geophysicist; tectonic study and interpretation require geodynamics. Geological interpretation needs a good knowledge of seismic velocities. The author develops the difunconsolidated sediments and also mentions new methods for determining velocity functions in deeper formations. Many geological problems to be solved need appropriate means in the use of the material. Various kinds of interpretation could be given to these questions, using geological data. When pinger probing, cores are both easy to obtain and to interpret. On the continental shelf, cores can only be taken on the rare outcrops, but the necessary continuity for the geological formation leads to a better definition of the structural units that have been defined by continuous seismic profiles. The example of the Planier area illustrates this point. In abyssal plains the only mean that can be used is the geophysical method. As deep coring is not yet utilizable, the author uses morphological data, seismic refraction and magnetic results, combined with detailed seismic profiles to show that the abyssal hills of the Ligurian plain are most certainly salt domes. Continuous seismic profiling is an essentially marine technique, begun in the 1950's, highly flexible and allowing precise analysis. It has proved rich results, and now, ten years later, its use in oceanography has become generalized. |
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