WIND-GRAVED MESAS 



2 35 



region of continual high wind and constant sand-storm. Nowhere else 

 in the arid region of the southwest is wind-scour in active operation so 

 advantageously viewed. Nowhere else in this country are deflative 

 effects and desert-leveling so well displayed. Nowhere else in all the 

 world is general lowering of an elevated country by the winds so strik- 

 ingly presented. Few places there are on this continent where stream- 

 action as a general erosional power is so manifestly utterly impotent. 



That this high, dry, almost waterless waste on the continental divide 

 should owe its landscape features chiefly to the incessant blowing away 

 of the dry pulverulent soils seems to need little argument in this place. 

 In the case of a desert district where the rocks alternate in hard and soft 

 strata a mesa capped by a more indurated layer might not always offer 

 conclusive evidence in support of this contention. Against the mesas 

 surfaced by lava-sheets of diverse ages such objections can not be raised. 



The existence of desert mesas whose surfaces stand at many differ- 

 ent levels throughout the broad belts of the less resistant rocks appears 

 to furnish one of the strongest proofs of the eolic character of the 

 regional erosional activities; since in situations of this kind not only 

 are rainfall and water-action very deficient and wholly inadequate to 

 produce the relief effects presented without the time-element be vastly 

 and unreasonably prolonged, but conditions are such in many cases as 

 absolutely to preclude the intervention of stream-work. 



Fig. 7. Face of the High Acoma Mesa. The Acoma Pueblo is shown on the 



summit. 



