Magnetotelluric Investigation of Geoelectrical Dimensionality and Study of the Central Betic Crustal Structure, A
[eng] The magnetotelluric (MT) method is a geophysical method that allows characterizing the electric properties of the Earth materials. Within the frame of this method, this thesis is divided in two parts. The first part presents a series of methodological contributions to the dimensionality analys...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/34908 |
| Acceso en línea: | https://hdl.handle.net/2445/34908 http://www.tdx.cat/TDX-0115107-115853 http://hdl.handle.net/10803/1920 |
| Access Level: | acceso abierto |
| Palabra clave: | Prospecció magnetotel·lúrica Prospecció geofísica Geomagnetisme Serralades Bètiques Magnetotelluric prospecting Geophysical exploration Geomagnetism Benéticos Range (Spain) |
| Sumario: | [eng] The magnetotelluric (MT) method is a geophysical method that allows characterizing the electric properties of the Earth materials. Within the frame of this method, this thesis is divided in two parts. The first part presents a series of methodological contributions to the dimensionality analysis of the MT data, emphasizing on the effects produced by errors. Thus, the WAL and the Bahr dimensionality methods, both based on the use of rotational invariants, have been studied. In the first, the method has been extended in order to consider data errors and the fact that geological structures can not always be approached to the ideal cases. In this sense, a program, WALDIM, has been created, which allows performing the dimensionality analysis in real data. With reference to the Bahr method, its limitations and inconsistencies have been analysed, and have been solved through the redefinition of the threshold limits of the invariants, and the use of an additional parameter, Q, also used by the WAL method. In the second part, the magnetotelluric study of the geoelectric structures of the Central Betics crust is presented. The data show a complex dimensionality, for which these have been modelled using a 3D model at crustal level. The model shows a good correlation between the resistivity structures and the surface geology, as well as the continuation of them at lower depths. Below the Internal Zone, at upper crustal level, the model shows a conductive body between the Nevado-Filabride complex and the Betics detachment level. This conductor is interpreted as a differentiated lithologic unit, formed by basic or low crustal rocks, containing a conducting mineral phase, such as graphite or pyrite. |
|---|