s g 
390 General Notes. o [Apa 
Durness limestone can be detected. The crystallization increases, 
however, so much that it becomes impossible to determine the 
original character of the rock by examination in the field. From 
the remarkably constant relation between the dip of the Silurian 
strata and the inclination of their reversed faults, Professor 
Geikie concludes that these dislocations took place before the 
strata had been seriously disturbed. 
THE THEATER OF THE EARTHQUAKES IN SpAIn—M. Hébert 
recently presented to the French Academy of Sciences a commu- 
nication upon the earthquakes in the south of Spain—cataclysms 
more violent than any which have visited Spain in historic times. 
If the details furnished by the papers are examined, it will be 
* evident that the localities recently disturbed by earthquakes are 
almost all situated on two zones, the one to the south of the 
Jurassic and Cretaceous mass which bounds the provinces of 
Malaga and Granada, the other to the north of it. In the south- 
ern zone the most severely visited localities were Antequera, 
alaga, Velez, Torros, Alhama, Granada, etc.; while the north- 
ern zone comprehends Cadiz, Xerez, Seville, Cordova, Linares, 
etc., and Valencia, all towns where shocks have been felt. The 
rest of the peninsula does not seem to have suffered much from 
this instability of the Mediterranean regions, except Albuquerque 
in the parallel of Lisbon, destroyed Dec. 26th and 27th, and 
some slight shocks in Galicia. M. Hébert called attention to the 
Balearic isles, which are situated between the two zones, are ele- 
vated eighty meters or more above the sea-level, and are com- 
posed at the: surface of horizontal beds of Quaternary age. These 
islands have therefore been raised more than a hundred meters 
since the Quaternary epoch, and this elevation has been limited 
northward and southward by fractures in the line of prolonga- 
tion of the defined zones of dislocation above. Thus it is clear 
_ that the cause of dislocations in these regions is always present 
and always active. 
GroLocicaL Notes.—General—A letter from Capt. C. E. Dut- 
ton upon the basalt fields of New Mexico, has been contributed 
to Nature. The center of activity is Mount Taylor, otherwise 
the San Mateo mountains, a volcanic pile 11,380 feet high, carve 
into numerous spurs by magnificent gorges. It was originally 
built by outbreaks both from its flanks and summit. From this 
ft 
