In addition to the faulting and intense folding in the direction of their strikes, these rocks are also intersected by three nearly parallel transverse faults of post-Triassic age, which, aided by subsequent denudation, have cut up the whole range into a number of distinct sierras. They are represented by the broken lines in Fig. 24.
Fig. 24.—Structure of meizoseismal area of Andalusian earthquake. (Fouqué, etc.)[ToList]
One of these faults, that which passes near Motril, traverses the meizoseismal area, whose boundary, as laid down by the French Commission, is indicated by the dotted line on the sketch-map.[37] In the neighbourhood of Zafarraya, the fault intersects the broken anticlinal fold of the Sierra Tejeda, and the epicentre is thus situated in one of the most disturbed tracts of the whole region. The evidence, both seismic and geological, is insufficient to support any precise view as to the origin of the earthquake, but there can be little doubt that it was closely connected with movements along one or more of the system of faults that intersect not far from Zafarraya.
REFERENCES.
1. Agamennone, G.—"Alcune considerazioni sui different metodi fino ad oggi adoperati nel calcolare la velocità di propagazione del terremoto andaluso del 25 dicembre 1884." Roma, R. Accad. Lincei, Rend., vol. iii., 1894, pp. 303-310.
2. —— "Velocità superficiale di propagazione delle onde sismiche in occasione della grande scossa di terremoto dell' Andalusia del 25 dicembre 1884." Ibid., vol. iii., 1894, pp. 317-325.
3. Castro, M.F. de.—Terremotos de Andalucía: Informe de la comision nombrada para su estudio dando cuenta del estado de los trabajos en 7 de marzo de 1885. (Madrid, 1885; 107 pp.)
4. Fouqué, F., etc.—"Mission d'Andalousie: Études relatives au tremblement de terre du 25 décembre 1884, et à la constitution géologique du sol ébranlé par les secousses." Paris, Acad. Sci. Mém., vol. xxx., pp. 1-772.