La « Mission d'Andalousie », expédition géologique de l'Académie des sciences de Paris à la suite du grand séisme de 1884

Abstract

A major earthquake affected the Betic Cordilleras between Granada and Malaga on Christmas 1884. At once the French Academy of Sciences sent a mission of senior scientists to survey the physical effects of the earthquake and decipher its geological background. The isoseist map constructed by the ‘Mission d'Andalousie’ shows an elliptic maximum intensity zone the great axis of which is remarkably parallel to the EW-trending boundary between the Outer (Sub-Betic) and Inner Betic Zones. The geologists of the Mission finally favoured the hypothesis of a causal link between mountain belt fracturing and seismicity. They performed a remarkable mineralogical study of the metamorphic rocks, unravelling the occurrence of glaucophanites and eclogites. The stratigraphic description of the Triassic to Miocene sedimentary levels by the Mission resulted in the definition of the Sub-Betic Zone. However, the scientific interpretations were hampered both by the lack of technical means (seismographs), and by that of some basic geological concepts (thrust nappes, syntectonic metamorphism). To cite this article: J. Bonnin et al., C. R. Geoscience 334 (2002) 795–808.