8 
MESOZOIC FORMATIONS. 
the Jurassic, its softer lower beds having been cut out by the passage of 
the Gallinas Creek. This stream cuts through the hog-back, escaping from 
the valley of No. 2, and returns to it again, after j)ursuing a short course 
between No. 1 and the gypsum. Southward five miles, the Triassic beds 
with the sandstone cap have been lifted to a greater elevation, of at least 
1,000 feet above the level of the Gallinas. This has naturally been accom¬ 
panied with a greater lateral extension. The foreground consists of its red 
bed and intercalated sandstones, which extend to the valley of the Gallinas; 
the Jurassic beds being undiscoverable on its flanks, and even Cretaceous No. 
1 is lost for a short distance. This projection, or angle, is opposite to an 
isolated mass of this formation, which, in the absence of another name, I 
called Red Peak. The area of the Trias is concentric with its base; the 
boundary retiring eastward on the south side. Here the Jurassic beds 
re-appear, the gypsum standing vertical, and forming a line of narrow, 
steep hills; the lower beds are not visible, but form the bottom of a valley 
which separates the Jurassic hills from the inountain. The relation of the 
two formations is here clearly seen. The elevation of the Red Peak and 
adjacent mountain-axis has fractured the Triassic beds, so that the upper' 
sandstone, which is horizontal on their summits, also lies at a steep angle 
(45°) on their southwestern flanks. An interesting example of curved 
strike is here exhibited.' The tilted sandstone at the left strikes northwest 
and southeast; the same ledge in the middle foreground, north and south. 
These beds lie immediately on the blood-red Triassic marls, as in the 
mountains and elsewhere. 
Two miles south, the Jurassic and Cretaceous No. 1 beds disappear 
through the erosion of a drainage-valley; but, south of the latter, the Juras¬ 
sic rises steeply, with a dip northwest 25°, to an elevation of 700 feet above 
the valley. The upper surface is composed exclusively of the gypsum, and 
the eastern is precipitous, exhibiting the usual three strata of white, yellow, 
and red in descending order. But below these appear the deep-red marls 
of the Trias, which occupy the valley separating the Jurassic hill from the 
Trias mountain, and form a body of Triassic bad-lands. The surface of this 
tract is eroded into canons, ravines, and arroyos, with irregular masses of a 
deep-red color between them. Perhaj)S three-quarters of a mile separate 
