Case histories and geological applications

Introduction This chapter describes selected modern applications of magnetotelluric surveys. The examples included illustrate many of the analysis and modeling methods described in Chapters 2–8, as well as the geological information that can be derived from magnetotelluric studies. The exemplars are divided into crustal studies, lithospheric mantle investigations, resource exploration applications and marine surveys. There are many excellent descriptions of magnetotellurics in the published literature, and those described in this chapter represent just a sample of the information that is available. Magnetotelluric studies of continental crust This section examines the application of magnetotellurics to define structures and processes in the continental crust. The examples presented are all large-scale projects, involving multiple university and government groups, and, in two of the examples, multiple phases of data acquisition. The studies demonstrate the importance of very careful dimensionality analysis in crustal studies, application of multidimensional modeling and the incorporation of anisotropic conductors. They also demonstrate the interpretation of electrical resistivity in terms of geology.