ABSTRACTS AND DISCUSSIONS OF PAPERS 391 



of the Pacific Coast," at the University of California, August 5 ; but it 

 was soon found that absent and tardy members on the list to read papers 

 would disorganize the program. The program, however, was followed as 

 closely as circumstances would permit. As carried out, the papers were 

 presented as follows: 



TITLES AND ABSTRACTS OF PAPERS PRESENTED AND DISCUSSIONS THEREON 



EPIGENE PROFILES OF THE DESERT 

 BY ANDREW C. LAWSON 



(Abstract) 



This paper was a discussion of the development of the characteristic profiles 

 of the relief of arid regions, with particular reference to the penultimate and 

 ultimate stages of the processes involved. 



Read in full from manuscript. 



Discussion 



Mr. R. S. HoLWAY : Is there a limit on the Pan- Fan stage, and can it be 

 readily perceived? 



Professor Lawson replied : The limit is reached only occasionally. A change 

 of climate usually interrupts the Pan-Fan stage and a degradational cycle 

 ensues. 



Prof. Bailey Willis : Instances in China and Patagonia show that the Pan- 

 Fan stage is rarely reached. Wind erosion is a vital and important agent. 

 Many agencies that cause modifications have not been indicated in the ideal 

 Pan-Fan. 



Professor Lawson replied that the Great Basin furnished the ideal region 

 to illustrate instances cited, and that he was inclined to limit his paper to a 

 consideration of Great Basin features. 



BAJADAS OF THE SAXTA CATALINA MOUNTAINS, ARIZONA 

 BY C. F. TOLMAN, JR. 



(Abst7-act) 

 A description of the composition, structure, and origin of these desert slopes. 



Presented in full extemporaneously. 



Discussion 



Mr. Sidney Paige discussed the use of the term "bajada." 



Professor Tolman replied: Bajada, coalescing fan.s that connect the moun- 

 tain with the holson. 



Prof. A. C. liAWsoN oxjtrossed the feoling that the term is superficial and 

 does not refer to other dimonsions of space. 



Professor Tolman replied that bajada should be applied only to the surface 

 feature. 



