734 N. H. DARTON 
by Jater Cretaceous rocks such as those reported to appear in the 
southern portion of the Santa Clara Mountains. 
Local features.—About 150 feet of the yellow beds are exposed 
under the lava cap at Cerro Angel, 17 miles west of San Ignacio 
(see sec. 10, Fig. 2). The principal material is gray to pale greenish- 
yellow sandstone with beds of volcanic ash. ‘There are extensive 
exposures about San Ignacio where the strata are capped by basalt, 
as shown in Figures 13 and 14. 
Fic. 11.—Upturned “yellow beds” overlain unconformably by Mesa sandstone, 
six miles west of La Purisima, Baja California. 
Fic. 12.—“Yellow beds” overlain unconformably by Mesa sandstone on Arroyo 
de la Purisima, five miles below La Purisima, Baja California. 
The yellow beds in the exposures extending from the Arroyo 
Valle to beyond Rancho Quarente, about 40 miles south of San 
Ignacio, present a uniform succession, about 500 feet thick, of soft, 
yellowish sandstone and loam. The base is not exposed and the 
top is eroded. Some beds contain considerable clay, and others 
are nearly pure sand. ‘The principal color is a pale greenish-yellow. 
A few thin layers of hard sandstone and conglomerate are included. 
A hard fossiliferous layer occurs in places in the middle of the beds 
exposed. 
ee 
