A multi‐station magnetotelluric study in southern Scotland — II. Monte‐Carlo inversion of the data and its geophysical and tectonic implications

A Monte‐Carlo inversion procedure is developed and applied to magnetotelluric data from six locations, two of which are in the Midland Valley of Scotland, three in the Southern Uplands, and one in northern England. The method is described in full in respect of one of the six locations to illustrate both the importance of satisfying the phase as well as the amplitude data and the effect of model acceptance level. The electrical resistivity profiles resulting from application of the method indicate that; (a) there is a conducting zone under the Midland Valley at a depth no greater than 12 km, (b) the crust under the Southerri Uplands is mainly resistive, (c) there is a conductor at a depth greater than 24 km in this region, and (d) under northern England there is probably a very highly conducting region very close to the surface. A brief discussion of the possible geophysical and tectonic significance of these models follows.