DIASTROPHISM AND THE FORMATIVE PROCESSES 415 
geologic ages. If the lunar craters are volcanic, as we assume, 
the evidence against a molten moon becomes still more imperative, 
for even in its cold, mature state the moon cannot hold free volcanic 
gases. All such gases should have escaped while the moon was 
still hot and boiling, and it should later have cooled to a smooth, 
gasless globe, singularly unfitted for the explosive action which its 
surface implies.* 
CLUES FROM SURFICIAL DIASTROPHISM 
77. The diastrophism of a solid earth should have been a unit, 
in all its great essentials. The deformations of the shell should 
have been intimately related to the diastrophism within the shell, 
if indeed not largely dependent on it. The mode of junction of the 
under surface of the shell with the upper surface of the interior 
mass should be especially instructive. One of the newer methods 
of study has disclosed the important fact that very notable down- 
ward protrusions are developed. ‘These are defined by plunging 
zones of accommodation that are at least suggestive. The intima- 
tions of these are herewith added as Part II, since these seem to 
belong with this résumé of ground work for megadiastrophic study. 
Other studies in the zone of observation offer clues of great value; 
indeed, no line of inquiry lacks them. Two of these are very 
specially related to the study of inner diastrophism: the experi- 
ments of Adams? that point toward a higher degree of rigidity than 
was accepted previously, and the contributions of Van Hise? and 
Leith? to the methods of metamorphism, especially the selective 
and rejective phases of anamorphic action, which point toward 
methods of reorganization very like the more radical selective 
and rejective metamorphism assigned to the deep interior of the 
earth. 
t Article XIII, Jour. Geol., Vol. XXVIII (1920), pp. 694-95. 
2 Frank D. Adams, ‘‘An Experimental Contribution to the Depth of the Zone 
of Flow in the Earth’s Crust,’’ Jour. Geol., Vol. XX (1912), pp. 97-118; F. D. Adams 
and J. A. Bancroft, ‘‘On the Amount of Internal Friction Developed in Rocks during 
Deformation, and on the Relative Plasticity of Different Types of Rocks,” Jour. Geol., 
Vol. XXV (1917), pp. 597-637. 
3C. R. Van Hise, “‘A Treatise on Metamorphism,” Monogr. 47, U.S. Geol. Survey 
(1904). 
4 Leith and Mead, Metamorphic Geology (1915). 
