TITLES AND ABSTRACTS OF PAPERS 133 



thermal stage. There has been only slight migration and secondary transfer 

 of the ore minerals subsequent to the magmatic stage. 

 The paper emphasizes the role of mineralizers in magmatic differentiation. 



Presented by title in the absence of the author. 



LOCAL GLACIATION IN THE CAT8KILL MOUNTAINS 

 BY JOHN L. RICH 



(Abstract) 



This paper presents certain results of a study of the glacial geology of the 

 Catskill Mountains made during the past summer for the New York State Geo- 

 logical Survey. 



Evidence is presented M^hich indicates that in the closing stages of the Glacial 

 period independent local glaciers, some of them several miles Ipng, occupied 

 many of the higher mountain valleys. Certain features suggest the possibility 

 that instead of being entirely lingering remnants of a waning ice-sheet, the 

 local glaciers may have been in part developed independently during an ad- 

 vance of the continental glacier which failed to override more than the north- 

 ern and eastern borders of the mountains. 



Presented in abstract extemporaneously. 



Discussion 



Dr. Frank B. Taylor: I visited the Fly Brook locality in 1908 and found 

 the moraines beautifully formed, and evidently formed by an ice-tongue com- 

 ing from the mountain range to the south or southwest. It seemed to me, 

 however, that the ice-tongue came from a gap or col in the range rather than 

 from the higher part of the range. The so-called "pedestals" which Mr. Rich 

 describes as occurring in small side ravines seem to me to correspond to cer- 

 tain forms of lateral moraines which are common in the Ta conic Range in 

 Massachusetts and southern Vermont. In a number of cases I found eskers 

 and border drainage associated with them in such a way as convinced me that 

 they are lateral forms of the main valley tongue rather than terminal moraines 

 formed by tongues descending the side ravines. 



Author's reply to Doctor Taylor: Tlie pedestal moraines do not appear to be 

 lateral moraines. They commonly bulge outward into the trunk valleys and 

 are, in some places, almost fan-shaped, being highest in the center. The theory 

 that they may be lateral was considered in the field and rejected for most, but 

 not all, pedestals. 



Prof. J. W. GoLDTHWAiT : Mr. Rich's interesting observations in the Catskills 

 appear to conflict in two respects with those made by me in the White Moun- 

 tains of New Hampshire. (1) In the White Mountains cirque sculpture seems 

 to be confined to the sides of summits that approach or exceed 5,000 feet alti- 

 tude, and even then to appear only where there was opportunity for the catch- 

 ment of exceptionally large amounts of drifting snow. The Catskills have an 

 altitude of only about 3,000 feet and lie farther south than the White Moun- 

 tains. (2) The local glaciation in the White Mountains appears to have been 



