224 REPORTS ON INVESTIGATIONS AND PROJECTS. 



GEOPHYSICAL RESEARCH. 



Adams, F. D., McGill University, Montreal, Canada. Grant No. 503. Con- 

 tinuation of investigation into the -flow of rocks. (For previous reports 

 see Year Books Nos. 2-7.) $1,500 



This investigation is now nearly completed. During the past year a study 

 of the effect of deformation on the strength of compact and more or less im- 

 pure limestones was completed. Solenhofen lithographic stone and black 

 Belgian limestone ("Noir fin") were selected, and it was found that even at 

 the ordinary temperature, under differential pressure, they can be deformed 

 without loss of strength. It is evident from these and from the experiments 

 of former years that limestones of any kind, pure or impure, may in the fold- 

 ing of the earth's crust be contorted without losing strength during the 

 process. An extended series of experiments has also been carried out on 

 the deformation of granite, diabase, and essexite at temperatures ranging 

 from the ordinary temperature of the laboratory up to iooo C. The tem- 

 peratures chiefly employed, however, were 450 C. and 550 C. In these ex- 

 periments a modification of the method described was adopted with very sat- 

 isfactory results. This consists in deforming those hard Plutonic rocks in 

 the form of disks which are placed between disks of marble, the whole being 

 then inclosed in steel in the usual manner. It is found that the marble effects 

 a distribution of the pressure upon the flowing disk of granite or diabase 

 which it was impossible to secure under the older method. The rocks in 

 question, as well as the essexite, developed a very perfect Cataclastic struc- 

 ture under the movement, but remain hard and compact. A series of experi- 

 ments has been made to determine what proportion of their strength they 

 retain after deformation at the ordinary temperature and at a temperature 

 of 450 C. 



Another investigation, referred to in a former report, has also been con- 

 tinued. This deals with the pressures required to cause small holes bored 

 through columns of limestone or granite to close, the rocks being inclosed 

 in very heavy tubes of steel, so that this can not become deformed in the 

 usual manner. These are developing results of considerable interest. Two 

 preliminary papers presenting some of the results obtained have appeared 

 during the past summer and others will be published within the next few 

 months. The titles of the two papers are as follows : 



An experimental investigation into the flow of rocks. First paper. The flow of 



marble. (Amer. Jour, of Science, June 1910.) 

 An experimental investigation into the action of differential pressure on certain 



minerals and rocks, employing the process suggested by Professor Kick. 



(Jour, of Geology, Sept.-Oct., 1910.) 



