510 RALPH ARNOLD 
SUMMARY AND CONCLUSIONS 
Summary 
Cycles of diastrophism 
Periods of maximum elevation and subsidence 
Changes in climate 
Diastrophic provinces 
INTRODUCTION 
This paper was presented as part of the symposium on “ Correla- 
tion” arranged by Mr. Bailey Willis as the principal subject for 
discussion in Section E of the American Association for the Advance- 
ment of Science, and later continued as the main feature of a special 
section of the Geological Society of America, at Baltimore during 
Convocation Week, 1908. ‘The paper treats in a general way of the 
character and distribution of the sediments laid down, and the faunas 
and the conditions prevailing during the Tertiary period on the 
Pacific Coast of North America, more especially that portion lying 
between Puget Sound on the north and the Gulf of California on the 
south. The discussion is also restricted almost exclusively to the 
territory directly affected by the sea, as a detailed consideration of the 
conditions and faunas prevailing inland belongs more properly 
within the province of the paleobotanist and vertebrate paleontologist. 
Special attention is called at several places throughout the discussion 
to the extraordinary localization of many of the earth-movements 
affecting the region under discussion and the writer wishes to advance 
this localization of phenomena as an argument against the too free 
use of diastrophism, unsupported by paleontologic evidence, as a 
basis of correlation. 
The preparation of the paper has necessitated the correlation of 
the various Tertiary formations of the Pacific Coast—in fact the paper 
is obviously based on these correlations—and for that reason a general 
table of correlation is here included for reference. Lack of space 
prevents a discussion of the reasons for many of these correlations. 
Some of them differ from those previously published by the writer," 
but for the most part they are those usually accepted by West Ameri- 
can geologists and paleontologists. 
1 Jour. Geol., Vol. X, 1902, p. 137; Mem. Cal. Acad. Sci., Vol. III, 1903, p. 13; 
U.S. Geological Survey Prof. Paper 47, 1906, p. 10; U. S. Geol. Survey Bull. 309, 1907, 
p- 143; ztbid., 321, 1907, p. 21; ibid., 322, 1908, p. 27. 
