220 The American Geolof/itit. October, 1897 
possibly later than the Pliocene, it is found to be overlaid by 
horizontal or nearly horizontal .strata containing Elephas 
bones with evidences of a huid period between. Since these 
beds were laid down, therefore, there has been a movement 
which has tilted them at an angle of 5-40 degrees followed by 
their being exposed to subaerial erosion, and later by being 
submerged and covered by deposits at one place over 200 feet 
thick, and then the whole subjected to a more or less general 
elevation to its present level. On page 352 of the same paper 
Mr. Ashle}^ gives additional prof>f of the above statement. 
Demakkation between the Pliocene and Pleistocene. 
General Discussion. The Pliocene has been considered to 
have been closed in eastern North America b}^ a marked ele- 
vation preceding glaciation. Lawson has already been quot- 
ed as to the condition of the California coast at this time. He 
has maintained that the coast was sinking through the Plio- 
cene until 800-1500 feet below the present level. When this 
point had been reached a reversal took place, being preceded 
by local disturbances, gradually uplifting (epeirogenic move- 
ment) the coast to its present level. He considers the divid- 
ing line between the Pliocene and Pleistocene the point of 
greatest depression. Although I would explain differently 
the movements at the close of the Pliocene, considering them 
epeirogenic as well as orogenie, I think we must agree with 
professor Lawson that the point of change or disturbance 
forms a natural division between the two periods. This point 
is not an arbitrary one, not merely the reversal of an epeiro- 
genic movement, as Lawson has said, but is marked b}" an im- 
portant non-conformity. His statements have led Lindgren in- 
to a misconception of the actual condition of affairs in the 
Coast Ranges. Lindgren* says in a recent article: "It seems 
thatin the maps of the valley border of the Sierra Nevada, the 
arbitrary line between the Neocene and the Pleistocene has 
been drawn considerably lower than the similar arbitraiy line 
established by professor Lawson at the top of the Merced se- 
ries. In other w^ords the Pleistocene as defined in the gQld 
belt maps occupies a considerably longer time than the Pleis- 
tocene on the coast as defined by professor Lawson. The Mer- 
*Journal of Geology, Vol. IV, p. 905. 
