MAJOR EARTH FEATURES 
181 
that it is no longer the former but the latter which are the chief 
object of discussion. It is interesting to note that Charles Dar¬ 
win ^ already in his time laid the main emphasis on the establish¬ 
ment of a permanence of the ocean basins. The present oceans, 
he thought, were neither in the Paleozoic nor in the Mesozoic 
era replaced by land masses or by very wide-spread island groups. 
The same point of view appears to-day urged by the leading 
paleogeographers of North America, Willis,'* and, in somewhat 
lesser degree, Schuchert.® The strongest adherents of the per¬ 
manence of ocean basins at present are Willis [and Chamberlin]. 
He calls ® the ocean basins, even such abyssal regions as the Gulf 
of Mexico or the Caribbean sea, permanent features in the re¬ 
lief of the earth's surface," which at least since pre-Cambrian 
times have lain in the same places as to-day, with only slight 
changes in their coast regions. In contrast to him, Edward Suess 
ascribes very different ages to the various oceans. While he 
recognizes the great antiquity of the Pacific Ocean, he holds the 
Atlantic and Indian Oceans to be considerably younger. “We 
must,” he thinks ^ “not only admit the loss of a great Paleozoic, 
Mesozoic, and Tertiary ocean in southwestern Eurasia, but also 
great subsequentf changes in the middle and southern Atlantic. 
Geologic facts do not establish the permanence of the great deeps, 
at least in oceans of the Atlantic type, indeed do not even make 
itj probable.” The profound influence of the teaching of Suess 
upon the development of Geology resulted in almost all European 
geologists and geographers becoming opponents of the theory 
of the permanence of continents and ocean basins. 
The admissibility of the conception of a complete interchange 
of sea-basins and continents in the sense of Lyell, has met with 
strong opposition in the last decade, due to geophysical research. 
The maintenance of an equilibrium, an isostasy, between the 
continental masses and the oceanic basins leads to the recognition 
of the fact that the former are composed of rocks of less density 
3 Origin of Species, German trans,, p. 458, 1872. 
4 Science, N. S., Vol. XXXI, No. 790 , 1910. 
5 Bull. Geol. Soc. America, Yol. XX, 1910. 
6 Journal of Geology, Vol. XVII, p. 203, 1909; also W. D. Matthew, Climate and 
Evolution, Ann. New York Acad. Sti., Vol. XXIV, pp. 174, 179, 305, 308, 1915. 
7 Are Great Ocean Depths Permanent? Natural Science, Vol. II, No. 13, p. 186, 
1893. The incorrectness of the comparison of Tethys with the modern oceans has been 
pointed out by Penck (1. c., p. 184). 
