298 University of California Publications in Geology [Vol. 8 



CONCLUSIONS AS TO STRATIGRAPHIC SEQUENCE IN THE 

 ROCK CREEK AREA 



1. The Martinez Group is associated with four other terranes in 

 the Rock Creek Quadrangle, the Basement Complex, a Miocene (?) 

 formation, an andesite of post-Miocene ( 1) and pre-Pleistocene age, and 

 a Pleistocene (? ) formation. 



2. The Martinez rests unconformably upon the Basement Complex, 

 and is unconformably mantled by both the Miocene (?) and the 

 Pleistocene ( ?) formations. 



3. The sediments composing much of the Martinez indicate that 

 deposition here was chiefly within the littoral zone. 



4. The Martinez sea probably did not extend much farther east 

 than the present site of Rock Creek Quadrangle during early Eocene 

 time. 



5. No evidence of marine Tejon was found in the area studied, and 

 it appears probable that the Tejon sea did not extend as far east as 

 the Mohave Desert. 



Transmitted September 17, 1914. 



