IOWA ACADEMY OF SCIENCES. 
227 
CUESTA TOPOGRAPHY OF THE CRIMEAN PENIN- 
SULA. 
BY CHARLES R KEYES. 
(Abstract.) 
At the last meeting of the Academy I discussed briefly some 
aspects of the geographic development of the Crimea and the 
northern borders of the Black sea. Since that time certain of 
the photographs obtained by those who took part in the geo- 
logical excursions following the International Congress of 
Geologists, have been received. It is to one of these especially 
that I now wish to direct your attention. It shows very clearly 
certain phases of the surface relief of which mention was made 
last year, and in a way that is rarely ever exhibited to such a 
great advantage or to such an extent. The photograph is one 
taken by Mr. R. T. Mallet of London, who was a member of 
the party. It is through his kindness I am now able to pre- 
sent it to you. 
The photograph (plate vii) is, I think, the best one ever 
secured showing what modern geographers term Cuesta relief. 
The word cuesta is a recent American acquisition from the 
Spanish. It is a common word, used in southwestern United 
States and Mexico to express the same idea that we do by step- 
and-platform topography. The short, simple and expressive 
word has been seized with avidity and has been used widely in 
place of the longer phrase. 
The development of the Cuesta type of surface relief is, 
briefly, this: A region of slightly tilled strata composed of 
alternating hard and soft beds is planed off or worn down to a 
peneplain, or a base-level plain. This grade-plain is one of 
faint relief, lying slightly above sea level. When such a 
region again suffers differential uplifting, the agencies of ero- 
sion actively begin to work anew Long lateral valleys are 
soon opened out in the soft strata along the strike of the rocks 
or at right angles to the direction of greatest dips. These 
