116 PROCEEDINGS OF THE BOSTON MEETING 



of the changes brought about in railroads and bridges at the time of earth- 

 quakes, I showed that in the cases of all known earthquakes from which data 

 were available the normal faulting which accompanied the quakes corre- 

 sponded to a reduction of area of the surface affected. 



. Prof. W. M. Davis suggested that the contrast between folding and faulting 

 described by Professor Woodworth might possibly be two phases of one phe- 

 nomenon, the folding being deep seated and the faulting being superficial. 

 The areas described as folded had been greatly denuded, so that their deep- 

 seated structure was revealed, although their original surface structure was 

 lost. The faulted areas had been less eroded; their surface structure is still 

 visible, while their deep-seated structure is buried. This suggestion was based 

 on one of Gilbert's statements regarding the contrast between the folded 

 Appalachians and the faulted Basin ranges, the former being regarded as of 

 deep-seated origin, revealed by great erosion, while the latter are of superficial 

 origin, not yet much eroded. 



Prof. J. B. Woodworth replied, that if normal faulting is the surface ex- 

 pression of deeper-seated folding, the phenomena ought to be found as extem- 

 poraneous structures in the same region and not in the sequence set forth 

 in the scheme presented in this paper. 



STRUCTURE OF SOME MOUNTAINS IN NEW MEXICO 

 BY NELSON H. BARTON 



i Abstract) 



» 



In determining tHe stratigraphy of the red beds in New Mexico and obtain- 

 ing data for a geological map of the State, the author has determined the 

 structure of the various mountain ranges. Numerous types are represented, 

 comprising tilted mesa blocks, anticlinal uplifts in some cases faulted, volcanic 

 piles and cones, early paleozoic ridges, and laccoliths. Physiographic features 

 are in part dependent on structure and in part independent of it, excepting 

 so far as to determine the altitude and distribution of hard and soft rocks. 



Presented by title in the absence of the author. 



NATURE OF PALEOZOIC CRUST AL INSTABILITY IN EASTERN NORTH AMERICA 



BY CHARLES SCHUCHERT 



Eead from manuscript. 



STRATIGRAPHY AND DIASTR0PHI8M OF WESTERN NEWFOUNDLAND 

 BY CHARLES SCHUCHERT AND CARL O. DUNBAR 



Presented by title by request of the authors. 



