338 TJic American Geologist. June, i90u 
is the remarkable Cabazon peak, which forms an interesting 
landmark conspicuously visible for many miles in all direc- 
tions. South-east of Cabazon is a large., flat-topped table-land. 
Mesa Prieta, upon whose sides over a thousand feet of the 
Cretaceous are visible, the whole being capped by basalt, prob- 
ably derived from the ancient Cabazon crater. Isolated buttes 
and hills to the south-east permit one to inspect the several 
members of that series to advantage. In the valley of the Rio 
Puerco farther south the whole series of Cretaceous as found 
in this area is exposed with a dip to the east and south-east. 
The sequence is as follows, beginning at the bottom: 
Feet. 
White and yellow sandstone 75 
Dark and yellow shales loo 
Fossiliferous zone with bands of sandstone and flags, 
(Gasteropod zone) 25 
Yellow shales 100 
Massive sandstone with large concretions, 
(Tres Hermanos sandstone) 75 
Shales with occasional flags (at least) 100 
Zone of concretions with sandy flags (Cephalopod zone) 25 
Shales 80 to 100 
Fossiliferous sandstone (Punta de la Mesa 
sandstone) 25 to 50 
Shales and flags (about) 100 
A series of yellow fine-grained sandstone and 
shales estimated at over 1 200 
White massive sandstone alternating with bands 
of lignite from 25 to 75 feet thick of 
which there are three prominent bands 
accompanied by remains of deciduous 
trees, the whole being over 250 
Massive white and ferrugineous sandstone with 
numerous marine fossils in its lower 
portions while at the upper part are teeth 
of sharks and other vertebrate remains. 
Entire thickness exposed perhaps 500 to 600 t 
At this point the Cretaceous is cut off by a fault which 
l)rings it into direct contact with the lower portion of the 
Tertiary sandstone exposed in the western face of the Albu- 
([uerque mesa, i. e., the extensive table-land on the west side 
of the Rio Grande valley opposite Albuquerque and topped 
bv the so-called Santa Fe m.arls. 
