138 Scientific Intelligence. 



N. S. Shaler presented three papers, of which the following 

 abstracts give the substance. 



1. JVbtes on the Pleistocene dislocations of the Atlantic Coast of 

 the United States. 



The dislocations of the Cretaceous, Tertiary and Pleistocene 

 strata of northeastern Massachusetts described by the writer in the 

 Seventh Annual Report of the director of the U. S. Geol. Survey, 

 p. 297, et seq., and in the Bulletin of the Geol. Soc. of Am., vol. 

 i, p. 443 et seq., appear to be a part of a mountain-building pro- 

 cess which, in relatively recent times since the beginning of the 

 Pleistocene, has affected the Atlantic coast from North Carolina 

 to Massachusetts Bay. South of New York the type of the dis- 

 locations have the fault type, north and east of the Hudson they 

 take on the character of foldings. These movements, though 

 extensive and intense in southern New England, appear to have 

 satisfied the stresses which caused them, for since the development 

 of the topography of the district, so far as it was formed on these 

 dislocated rocks, no considerable movements have taken place. 



The foldings of the rocks in the Cretaceous, Tertiary and 

 Pleistocene strata of Martha's Vineyard and neighboring districts, 

 seem to have been due to the formation of a broad, I'ather com- 

 pressed synclinal in the crystalline rocks upon which they rest; 

 in this respect resembling the down-fold which encloses the Rich- 

 mond, Va., coal field. 



The disturbed strata of the New England shore district are 

 now at about the level in which they were formed. There 

 thus appears to have been no considerable permanent change of 

 level of this part of the continent due to their orogenic action. 

 (Author's abstract.) 



2. Relation of Mountains and Continents. 



Modern investigations show that mountains do not develop on 

 the deep sea floors in the manner in which they are formed on 

 the continental folds. This shows that there is some causal rela- 

 tion between these two types of relief. 



An inquiry into the sub-aerial reliefs of the great coasts shows 

 that they are in the main, made up of the broad pedestals which 

 have been formed in the districts where mountain building has 

 occurred. The mass of these pedestals, or regional uplifts is 

 generally very great. They indicate the movement of inner 

 earth matter toward the seats of dislocation : a large part of the 

 material going to form the uplifted section of the earth's crust 

 on either side of the mountain-built area. A part of this pedestal 

 is in many cases formed of debris worn from the central axes. 



Deep-sea soundings show that there are folds of the crust 

 formed in the thalassal areas. Although the number and precise 

 shape of these folds is unknown, it seems not improbable that 

 they are the original type of surface deformations. When one 

 of these ridges attained a supra-marine level, local erosion, with 



