650 
GEOLOGY: W. M. DAVIS 
coasts are embayed in spite of recent emergence, and cannot serve as 
witnesses to a recent rise of ocean level. 
Furthermore, the supposition that coastal embayments result from a 
rise of the ocean around still-standing continental borders carries with 
it the implication that the coastal valleys, now submerged and embayed, 
were everywhere eroded during the same period of previous emergence, 
and hence that they should all be eroded to the same depth, and that 
their width should be proportionate to the weakness of the rocks in 
which they were carved during the emergence period. But as a matter 
of fact, the coastal embayments of the continents occupy valleys of 
depths and widths so various that they cannot be accounted for by these 
simple conditions : the diversity of the embayments demands many local 
and diverse movements of continental borders, even though a universal 
rise of ocean level has recently taken place, such as that which the final 
climatic changes at the close of the Glacial period should produce. The 
chief effect of such a rise of ocean level would only be to bring about a 
slight preponderance of embayed coasts along continental borders which 
had suffered local uplifts and depressions in about equal proportions. 
Diverse movements of continental borders are demanded not only by 
the diversity of their embayments, but also by the not rare occurrence 
of emerged coastal plains of marine sediments. Thus the western side 
of the Adriatic is bordered by an emerged and more or less dissected 
coastal plain, while the eastern side is bordered by a partly submerged 
and elaborately embayed mountain border. Greece and the Bosphorus 
bear marks of recent submergence, but the coast of Palestine appears to 
bear marks of recent emergence. The small embayments of the Texas 
coastal plain cannot be explained as resulting from the same amount of 
submergence which produced the deep rias in the montainous coast of 
northwestern Spain; nor can the unlike valleys of those two coasts have 
been eroded during the same antecedent period of emergence. The 
elevated shore lines of the California coast have no equivalent on the 
volcanic islands of the Pacific. The recent submergence of the north- 
eastern coast of New Caledonia following a long-enduring emergence, 
as indicated by the deep embayments of its strongly clift shores, de- 
mands a different succession of changes of level from those recorded on 
the coast of Peru or of Virginia. 
The postulate that the embayed coasts of the world demand a uni- 
versal rise of the ocean for their explanation is largely based upon the 
indoor study of coastal charts, and not upon the field study of the coasts 
themselves; and inasmuch as most of the coastal charts of the world 
have been made by hydrographers, who concerned themselves little 
