FAUNAL RELATIONSHIPS OF THE MEGANOS GROUP 145 
localities. ‘The sandstones below the contact, due to the uncon- 
formity, thicken and thin very noticeably along the strike. Also, 
at a number of localities the lower sandstones show a dip and 
strike appreciably different from those of the Tejon beds above. 
While these differences amount at the most to only a few degrees, 
it is sufficient to cause the lower sandstone layers to be cut off 
obliquely, and on the cliff sections they are seen to abut against 
the basal beds of the Tejon (Figs. 3 and 4). Other evidence of 
this unconformity is the fact that numerous bowlders of sandstone, 
derived from the Meganos beds below, are found in the conglom- 
erate at or near the base of the Tejon (Figs. 4 and 5). 
Fauna.—An invertebrate fauna, listed by Dickerson, was — 
obtained from the beds above the unconformity just noted. It 
is, apparently, of typical Tejon age, containing a considerable 
number of highly ornamental molluscan species which have not 
been found in the Meganos. 
The fauna obtained from the beds below the unconformity, the 
“Turritella andersoni beds,” is essentially the same as that of 
the Meganos in the region of Mount Diablo, the ends in both 
places containing a fairly large number of highly ornamented 
species in common. The recognizable described species, which 
have been obtained from this portion of the section, are indicated 
in the list on page ooo. 
Correlation.—Dickerson correlated the Turritella andersoni beds, 
just mentioned—the Martinez ( ?) as mapped by Anderson and Pack 
of the United States Geological Survey—with the lowest Eocene 
southeast of Mount Diablo (see p. ooo), the horizon of his Turbi- 
nolia zone. He believed that the beds of this horizon were older 
than the lowest beds in the type section of the Tejon. The writer 
agrees with both of these conclusions. 
MEGANOS AT THE SOUTH END OF THE SAN JOAQUIN VALLEY 
General statement—An important problem which presented 
itself in connection with the differentiation of the Meganos from 
the Tejon, was whether any portion of the type section of the 
t See list given under University of California locality 672. R. E. Dickerson, 
“Stratigraphy and Fauna of the Tejon Eocene of California,” Univ. Cal. Pub. Bull. 
Dept. Geol., Vol. IX (1916), No. 17, p. 430. 
