Caracterización morfotectónica de Galicia, España

Résumé

The morphotectonic analysis of Galicia permits to present a territorial regionalization scheme with the most active units. For the elaboration of this material were used different geologic, geophysical and geomorphological methods and on the base of the methodology of Rantsman (1979) are distinguished three fundamental categories of the regionalization: 1- Territorial Units (megablock, macroblock, mesoblock, block, microblock and nanoblock); 2- Morpholineaments (of second, third, fourth and fifth range); 3- Morphotectonic knots (from order two until order six). The Iberian megablock (microplate) has nine macroblocks, being Galicia one of them. The Northwest macroblock (Galicia, identified as VIII) is in its continental part in direct interaction with two large adjacent macroblocks (of approximately rectangular shape, VII: Arqueado and IX: Septentrional) through two morpholineaments of 2nd order (A7: Santa Tecla and A8: Ponferrada). The intersection of these elements determine a 2nd order (N9: Nogueira de Ramuín). Under the A7 is determined another knot, but of 3st order (N11: Triacastela-Santalla), in the vecinity of Sarria-Becerreá, where is detected a significant seismic activity. There are also 39 morpholineaments of order three (2), order four (11) and five (26). This net to the scale that is presented (1:250,000) configures 23 knots (order:cuantity= 2o:1, 3o:2, 4o:7, 5o:6, 6o:7). According to the arrangement and the characteristics of the delimited blocks is considered that the influence of the pressure of the Mid Atlantic Center is very important in Galicia and prevails on the compression derived from the interaction between the African and Euro-Asian plates.