Jcuic:: — Albuquerque, X. Mc.r. — Reagan. 97 
tremely broken up ; and in its canyons are to be found numerous 
springs, celebrated for their medicinal properties. Its hills 
are few ; but its hogbacks parallel ridges, weathered cones and 
castled buttes are many ; and its fault lines and escarpments 
are numerous. The valley tloors are covered with shifting 
sands, and along the lower course of the Jemez sand dunes are 
piled up by the ever blowing wind. Much of the upper coun- 
try is covered with tufa, and many of the lower mesas have 
a cap of basalt often of the "Malpais" type. The culminating 
points of the Jemez-Albuquerque region are : the crest of the 
San Dias, the monolith Mt. Cabizon on the Rio Puerco, and 
Mt. Pelado, the culminating point of the Jemez mountains 
The rivers and mountains having been discussed under ge- 
ography and physiography, they will receive no further men- 
tion here ; but the remaining physiographical features of the 
section will be treated at some length. 
Sand Dunes. — The sand dunes are in the lower Jemez val- 
ley. They are the result of the piling of the shifting sands of 
that valley by the winds ; as has been stated, this valley was a 
lake in Pleistocene times, and the shifting sands of today were 
the beach sands of that lake. As evidence that this conclusion 
is true : first, the sands are all rounded and water-worn, and 
second, in the eastern part of the lake where the clay sediment 
brought down by the streams to the west and north of the then 
lake did not extend, the sands are deepest, because here the 
chopping waters reduced the surrounding partly lithified Ter- 
tiary sandstone lake-wall to sand : besides, the drift of the 
sandy particles deposited in this lake to the northwest would 
naturally drift toward the southeastern beach. This sand, as 
we have seen, is of Post-Tertiary origin. 
Mt. Cabizon. — Mt. Cabizon is a volcanic neck of great size. 
It is situated just across the Rio Puerco from the village of 
Cabizon (La Poste). Its crest is more than thirteen acres in 
area and its hight above the plain in which it is situated ex- 
ceeds 1400 feet. It is, therefore, a land mark throughout the 
entire region to the west of the Xacimiento mountains, and 
even further east to the Rio Grande area below those moun- 
tains. Its age is Post-Cretaceous, though it probably continued 
in action till the Tertiary was far advanced. A further men- 
tion of this volcanic neck will be given later under volcanoes 
and lava flows. 
