Main morphotectonic characteristics of Asturias, Spain

Asturias is part of one of the four morphotectonic mesoblocks that make up the Northern macroblock (Number 9) of the Iberian plate. The framework of territorial regionalization was developed on the basis of the methodology of Rantsman (1979) using different geologic-geophysical and geomorphological methods. The territorial units (1 mountain mesoblock, 8 blocks, 208 microblocks and 668 nanoblocks), morphoalignments (quantity/order: 1/2, 1/3, 10/4, 35/5 and 77/6) and morphotectonic knots (quantity/order: 2/3, 11/4, 31/5 and 86/6) can be distinguished in the cartography of Asturias. The number of well defined morphostructures increases, significantly, from west to east. At the block level, a very well defined transverse differentiation of the territorial units and morphoalignments is noticeable. This differentiation is interpreted as an expression of the region’s lithospheric heterogeneity. There is a clear relationship between morphostructures and seismicity, especially with respect to the higher activity found in the blocks adjacent to Oviedo and the northern and eastern regions. The oceanic sector is decidedly seismically active.