O'Reilly — The Earthquakes in New Zealand and Andalucia. 457 



which occurred in the early morning of December 22nd, and 

 which was confined to the western portion of the country, its effects 

 being felt only in Gralicia and Portugal ; another, of the highest 

 importance, which occurred three days later, namely, at 9 p.m. on 

 the 25th ; while the third phase included the oscillations having 

 taken place during a certain period subsequently in the districts 

 most severely affected by the earthquake of the 25th. The earth- 

 quake extended over a very considerable surface, the district 

 affected to an appreciable degree, including approximately, it 

 would seem, the whole country lying between Cadiz and Cabo 

 de Gata, and between Malaga and the Gruadarrama range. 



The shock was quite perceptible in Madrid, the direction of 

 oscillation having been from north to south. The movement 

 gained in intensity as it proceeded southwards, more especially 

 after leaving the southern border of the central table-land, limited 

 by the fault of the valley of the Guadalquiver. He called atten- 

 tion to the relation of the phenomena with the geological structure 

 of the peninsula, and to the broad zone of great masses of granite, 

 porphyry, diabase, and other kinds of rocks which cross the pen- 

 insula from Gralicia to the valley of the Gruadalquiver, and which, 

 geologically speaking, divides the peninsula into two distinct parts. 



" This huge belt (he says), which may be regarded as one of 

 the most striking features of the peninsula of our day, cuts and 

 divides the archaic formations, interrupting them in the Ghiadar- 

 rama central chain between the Sierra de Grata and the Estrella 

 range in Portugal." This zone he considers as corresponding to a 

 great line of fracture which crosses the peninsula from north-west 

 to south-east, in the prolongation of which lies the region of earth- 

 quake shocks described by him. He concludes : — 



" The two principal coincidences observable between the phe- 

 nomena of the earthquake and the geological structure of the 

 peninsula are — 



" (1) That the disturbance of December 22nd was confined to 

 the regions lying to the west of the zone described ; and 



" (2) That the most violent shocks of December 25th were ex- 

 perienced in the region intervening between the Sierra Nevada 

 and the Sierra de Honda, and precisely on the very belt which 

 ■encloses the archaio mountain mass of the Sierras Tejea and 



