FUNDAMENTAL PROBLEMS OF GEOLOGY 269 



ample. As the known fundamental agencies, such as the loss or the 

 redistribution of heat, work constantly rather than periodically, it 

 is inferred that the stresses arising from them are sustained by the 

 strength of the body of the earth until they have accumulated to an 

 intensity sufficient to compel yielding and consequent deformation. 

 The magnitude of the deformations being measurably determinable 

 from geological data, the problem is to determine what states of the 

 interior matter are required to accumulate such stresses, and how 

 large portions of the mass, in these requisite states, must have been 

 involved to meet the requirements of the case. The preliminary 

 tests seem to indicate that at least a large portion of the whole globe 

 must have been involved, and that the effective resistance of this 

 must have been of a high order. These results tally well thus far 

 with those derived from studies on the rigidity of the earth on inde- 

 pendent lines. Professor Hoskins's other engagements have not 

 permitted him to seriously attack the more difficult phases of this 

 promising line of inquiry. 



The logical connection between atmospheric studies and the fore- 

 going problems may not be evident, but it is quite real. My own 

 special interest in them sprang from climatic problems which led 

 back through the history of the atmosphere to primitive states and 

 fundamental conditions. A special study of a gypsum deposit of 

 Iowa, conducted in part under my supervision, by a fellow of the 

 university, Mr. F. A. Wilder, seemed to the suggestive mind of Dr. 

 Stieglitz to afford a means of testing the atmospheric conditions 

 relative to the critical element, carbon dioxide, at the time of the 

 precipitation of the gypsum, which Dr. Wilder interprets as Per- 

 mian. At my request, Dr. Stieglitz has undertaken the investiga- 

 tion. It is not yet complete, but its nature may be indicated. The 

 significant feature of the gypsum deposit is its remarkable freedom 

 from calcium carbonate. Since in the evaporation of sea water of 

 the present content of salts and under the present conditions calcium 

 carbonate is precipitated before calcium sulphate (gypsum), and 

 since with a constant supply of fresh sea water calcium carbonate 

 would be precipitated continuously with the gypsum, various hy- 

 potheses were suggested to account for the obvious removal of the 

 calcium carbonate from the brine during its evaporation without its 

 being deposited before or with the gypsum of these beds. 



The present investigation is intended to apply the laws of equi- 

 librium in salt solutions to this problem. The solubility of calcium 

 carbonate at a given temperature is primarily a function of the 



