STRATIGRAPHICAL GEOLOGY 
147 
STRATIGRAPHICAL GEOLOGY 
Permian Rocks of Grand Canyon. Three-quarters of a cen¬ 
tury ago, when Jules Marcou, geological attache of the Thirty- 
fifth Parallel route of the Pacific Railroad Surveys, reached the 
Rio Colorado Chiquito, near the Grand Canyon, he pronounced 
the surface rocks of the region, now called the Aubreyan or 
Kaibab limestones, Permian in age. Like his identification of the 
European Jurassic sections farther eastward in New Mexico at 
that early date, the Permian suggestion met with sweeping denial 
from the Government experts. And for two generations the lat¬ 
ter continue the same stand. 
A new generation, a third generation, now enters the field, and 
unacquainted with the controversies of the long ago, again pro¬ 
claim a Permian age for these very same formations. However, 
the Permian sections which it knows are not the original Permian 
successions of Russia. They are only the home terranes, the so- 
called Permian beds of eastern Kansas; which is a very different 
thing. 
Of those who so strenuously urge a Permian age for the eastern 
Kansas formations no one has indicated that he ever saw the 
typical Permian rocks, ever collected fossils from the Uralian 
region, or ever had Russian fossils for comparison. Neither has 
he ever defined the typical Permian faunas so that others may 
know what is really meant. On this very point Prof. Charles 
Schuchert recently observed: “That the Kaibab limestone is of 
early Permian age is now admitted by most American strati- 
graphers. This view, however, has been attained rather from its 
field relations than through a study of its marine fossils, for these 
in several forms are very like those of the Pennsylvanian.” 
If ever there wei^ antipodal rock sequence, and representative 
faunas from the antipodes, the eastern Kansas rocks certainly 
