87 
By Pror. Grorcr D. LouperBack 
University of California. 
It is with considerable satisfaction that I reeall the enjoyable and 
stimulating visit to San Diego last August, which included the very 
successful meetings of the Scientific Societies, the charming Exposition, 
the Scripps Institution at La Jolla, and the U. S. S. Albatross—two 
agencies of scientifie research, and. finally, sight-seeing trips through 
city and county. Among the varied activities of that time, I look back 
with particular satisfaction on the ‘ 
a pleasant and exhilarating outing with most congenial companions and 
‘eross-country’’ exeursion, both as 
a most instructive display of the general geographical and geological 
conditions of southernmost California. 
The use of automobiles for transportation naturally broke the party 
into small groups, and the group of which T was a member encountered 
a series of minor mishaps and failures of cooperation on the part of the 
automobile-controlling elements of the local fauna. The chief resulting 
disadvantage was our separation from companionship and opportunities 
for discussion with the larger membership of the party. On the other 
hand, the smaller group was a very congenial one, and the delay made 
it possible for most of us to take a very profitable unscheduled side trip 
across the Mexican border near Campo. 
For the amount of time involved, the route of the excursion was 
excellently chosen to present a general view of the major geological 
features of the extreme Southwest. The main structural features of the 
region show an approximately north-south elongation or trend, and the 
trip was essentially a transverse section of these features from coast 
to desert, showing their suecession and spacial relations to the best ad- 
vantage. 
General Features.—In a general way the region traversed may be 
divided into three parts: the coastal, the mountain, and the desert belts, 
and these are separated by two border or transition zones. In many 
ways these three belts show contrasted conditions and geological ac- 
tivities. But a more general and fundamental view will unite the three 
into a greater diastrophie provinee. Their histories, although different 
in detail or in character, have been closely bound together. Their chief 
periods of disturbance, or quiet, their relative clevations and lines of 
separation have been primarily determined by a closely related group 
of movements that have also determined the formal relation of ocean 
to continent in that region and given rise to the group of structures 
that, extending hundreds of miles to the south, express themselves in 
