DIASTROPHISM AND THE FORMATIVE PROCESSES 6097 
of its collective nucleus, a solid body, built of heterogeneous plane- 
tesimal matter at the start, that it was subjected to a slowly growing 
gravitative pressure whose total accession was spread over a 
period of the order of two or three billion years, and that there 
were large allowances of time for metamorphism and for the 
adjustment of the strain arising from each increment of pressure. 
On these assumptions the chief partitions and paths of the com- 
pressional energy, seem logically to have been as follows: 
The first step was the partition of the initial increment of 
energy by the passage of a part of the stress into strain, while 
another part took the thermal form. So long as the strain lasted, 
its energy was stored or latent. A varying but large measure 
of energy seems thus to have been stored all through the geologic 
ages. It appears from stratigraphic evidence that the strain- 
limit in the sub-surficial material has been high enough at several 
periods to permit the accumulation of stored energy sufficient to 
- actuate declared deformative ‘‘revolutions”’ in spite of such partial 
easement as may have taken place, during the stages of accumula- 
tion, from the milder forms of idiomolecular action about to be 
described. 
The second step in the compressive process was the co-operative 
action of the stored energy of strain and the agitative thermal 
energy. The latter aided change by loosening the fixed elastico- 
rigid attachments of the molecules, the essential properties that 
gave rigid symmetry to the crystals and solidity to the amorphous 
fragments. The hold of crystals and of clastic fragments upon 
their constituent molecules was unequal because some of them lay 
at the angles, or on the edges, or on sharp curves of the little 
masses, where fewer other molecules supported them. So also 
the strains arising from pressure upon the interlocking crystals or 
fragments was greatest on these outlying molecules. The particular 
molecules thus least securely held and those most severely strained, 
yielded first. This eased the strain on these particular points and 
threw the stress on new molecules; from this, new action of like 
order arose and the process was essentially repeated.* 
tIn many cases, especially near the surface, solution and chemical reaction 
greatly aided molecular transfer and crystalline reorganization, but these are ac- 
cessory agencies rather than factors of the compressional process, as such. 
