DISCUSSION OF ANTICLINE IN CHAGRIN SHALES 773 



probably occur at points where the sulfides were more concentrated by concre- 

 tionary action. 



Discussion 



Prof. H. L. Fairchild: The photographs shown by Professor Van Horn of 

 folding in the shales at Cleveland might be taken as illustrations of similar 

 crushing in the Rochester shales in the Rochester district. The superficial 

 Rochester shales are frequently crumpled, with some compression faulting. 

 The suggestion of expansion due to hydration of sulfides does not apply here, 

 as the shales do not contain any perceptible amount of unoxidized minerals. 



Mr. J. L. Rich : In the Cretaceous shales of southwestern Wyoming a small 

 anticline similar to that just described was observed. The shales underneath 

 were entirely undisturbed. The anticline was sharp in the lower part, and 

 gradually merged above into undisturbed shale. It was observed in a small 

 stream gorge in the middle of a wide valley, a mile or more from any high 

 land and in a region entirely unglaciated. No marked signs of the decay of 

 pyrite or similar minerals was noted. 



EXPERIMENTAL INVESTIGATION INTO THE FLOW OF DIABASE 

 BY FBANK D. ADAMS 



(Abstract) 



The author mentioned that the results of an investigation into the flow of 

 marble had been presented to the Society at the Montreal meeting, and that 

 since that time the investigation into the flow of rocks had been continued 

 under a grant from the Carnegie Institution of Washington, the work having 

 been extended to a study of impure limestones, dolomites, and various silicate 

 rocks. He then gave the results of an experimental study of the deformation 

 of a typical diabase. This deformation had been carried out at various pres- 

 sures and at temperatures ranging as high as 1,000 degrees Centigrade. It was 

 shown by means of lantern slides that the diabase at temperatures of about 

 450 degrees Centigrade was deformed with the development of the typical 

 cataclastic structure, the structure exactly resembling that of certain varieties 

 of flaser gabbro. The rock, furthermore, was not crushed to a powder during 

 the process, but remained throughout solid and compact, and was found after 

 deformation to have a crushing strength approximately one-half as great as 

 that of the original diabase. It was shown that the structure of the deformed 

 rock was identical with that seen not only in flaser gabbro, as above men- 

 tioned, but in many other foliated rocks whose structure had been impressed 

 on them by movements in the earth's crust. 



COON BUTTE AND METEORITIC FALLS OF THE DESERT^ 

 BY CHARLES R. KEYES 



(Abstract) 



Coon Butte is regarded as only one of the many manifestations of the ex- 

 plosive type of vulcanism so prevalent in eastern Arizona. The apparently 



Read by title, In the absence of the author. 



