104 The American Geologist. August, 1904. 
The above records are sufficient to show that Socorro is in 
a belt of crustal disturbances which, while they are not violent 
enough to render the region in any sense unsafe, yet they may 
be pronounced enough to be worth careful study and should 
be accuratelv measured by instruments prepared for that pur- 
pose. With the present improvements made in the seismo- 
graphs in the basement of the School of Mines we shall be in 
better shape to record such earth tremors should they con- 
tinue. There seems to be no record of any damage to public 
or private property, however, although the recent shocks have 
been so pronounced that people are awakened from sound 
slumber Avhen they occur. 
All these jars are of short duration, come at irregular in- 
tervals, and the more violent appear to be followed by a num- 
ber of minor tremors Avhich are more or less distinct. The 
turbidity of the waters in Socorro springs in 1869 and the 
number of fault planes found on Socorro mountain go far to 
substantiate the hypothesis that these earthquakes are due to 
local displacements in Socorro mountain and its outliers. One 
such fault is visible close to the Magdalena railroad track as 
it bends around the mountain at the arroyo crossing a few 
miles from Socorro. These slippings are presumably going 
on slowly with now and then a sudden displacement strongly 
marked which results in these local earthquakes. It is quite 
likely that the region is slowly uplifting which assists in pre- 
serving the rugged topography of the mountain which is so 
characteristic. That such elevation is assuredly taking place 
in the southwest portion of Colorado among the San Juan 
mountains has already been shown by the geologists of the 
United States Geological Survey who have studied the dis- 
trict. 
