IOWA ACADEMY OP SCIENCES. 103 



One part contains very little lime and the other nearly all 

 of it. Rock formed from the first mentioned might be a 

 granite, while from the second would come perhaps a 

 gabbro. 



EVIDENCES OF RECENT UPRISINGS OF THE SHORES 

 OF THE BLACK SEA. 



BY CHARLES R. KEYES. 



(Abstract.) 



The photographs which I have to show you are to illus- 

 trate some remarkably clear examples of very recent 

 changes in elevation of the earth's crust. Most of the 

 pictures were taken in the neighborhood of Sudak, in the 

 Crimea. The southern coast of this peninsula is very 

 rugged. It rises abruptly out of the water to a height of 

 3,000 to 5,000 feet. The waves are constantly eating back 

 so that in many places the coast land is almost a sheer 

 precipice hundreds of feet high. 



But the point to which attention is pavticularly called 

 is the sharply cut benches and narrow beaches which occur 

 at various levels, from fifty to four hundred feet and more 

 above the present sea-level. These show, in an excep- 

 tionally fine manner, the action of the waves when the 

 land stood at a much lower level than now. 



Farther to the westward near Cape Violence, not far 

 from Sebastopol, the country is less rugged than at Sudak; 

 and often broad plains are found stretching down to the 

 sea-level. These plains gradually rise to the eastward and 

 where cut by the waves display sections that show a num- 

 ber of unconformities between the various terranes. Some 

 of these unconformity-planes appear to extend inland and 

 to become continuous with well-marked peneplains now 

 being rapidly dissected. 



