GEOLOGIC RECONNAISSANCE IN BAJA CALIFORNIA 735 
The yellow beds outcrop for many miles along the Arroyo San 
Raimondi (or San Miguel), 30 miles northwest of La Purisima, 
from a point a half-mile above Rancho las Tules to its mouth, 
with relations shown in Figure 16. Pale-yellow, loamy sands or 
soft sandstone prevail, and at several points, notably at Rancho 
San Antonio and near the outcrop of the Monetrey beds 6 miles 
southwest of Caije (a very small settlement 35 miles northwest of 
La Purisima), a basal limestone member is exposed filled with 
Fic. 13.—San Ignacio, Baja California, from thesouth. MHighsierra in distance; 
later Miocene capped by basalt in middle distance. 
Fic. r4.—Upper Miocene strata capped by basalt at San Ignacio, Baja California 
fossils (not determined). Agglomerate and sheets of lava occur 
in the lower part of the formation in this valley, as shown in 
Figure 16. 
In the valleys of the Arroyo Juanico and the Arroyo Mesquital, 
20 to 25 miles west of La Purisima, the yellow beds are exposed in 
slopes and cliffs of considerable extent, overlain in part by lava and 
to the east by gravell beds at the base of the mesa sandstone. 
The principal material is soft, yellowish sandstone, in part contain- 
ing some clay. The top beds have been eroded and the base is 
