262 ANNALS NEW YORK ACADEMY OF SCIENCES 



Summary of Paper 



Professor Johnson, after presenting, with tlie aid of blackboard maps 

 and sketches, the criteria for distinguishing between real and apparent 

 oscillations of shorelines, further illustrated the discussion with lantern 

 views of actual conditions, explained where necessary by means of dia- 

 grams thrown on the screen. He showed how such events as the slump- 

 ing of soft formations near the shoreline or the widening of inlets so as 

 to increase the tidal flow into a lagoon, thus allowing a local rise of the 

 high-tide level or the ingress of salt-water by sheer wave-cutting into 

 fresh wat^r swamps might be misinterpreted to mean subsidence of the 

 land area involved. He showed that stability is indicated by evidences of 

 growth in place of long-life vegetation at the present high-tide level and 

 by the building of a series of beaches on a level with those now in process 

 of formation. The speaker concluded that the area under discussion is 

 probably the best example of features normally produced by subsidence 

 of a maturely dissected plain to be found on our Atlantic seaboard. He 

 finds no evidence, however, that indicates subsidence in geologically 

 recent times ; that is, within the last 2,000 years. 



The paper was followed by an interesting questionnaire, during which 

 Professor Johnson presented still other evidences bearing out his conclu- 

 sions as to the duration of stable conditions and made brief applications 

 to other localities along the Atlantic coastline of North America. 



The programme was concluded by notices of important papers given 

 at the New Haven meeting of the Geological Society of America, De- 

 cember 28-31, 1912. Ten minutes were devoted to each of the groups — 

 paleontology, economic geolog}^ and petrology. Professor A. W. Grabau 

 paid extensive attention to the proposed revision of nomenclature of the 

 Paleozoic. Professor James F. Kemp called particular attention to the 

 marvelous petroleum wells of northeastern Mexico, to the confirmation 

 by Dr. A. L. Day of aqueous volcanic emanations and to the researches 

 of Professor Jeffrey by means of his unique thin sections into the origin 

 of coal. Mr. Charles T. Kirk reviewed Dr. Fenner's determinations of 

 the thermometric values of the forms of silica, Professor Lane's observa- 

 tions on granite, etc., in the metamorphic cycle and the excellent ad- 

 vances made by Dr. F. E. Wright and Professor Charles P. Berkey in 

 methods of teaching petrography, especially to beginners. 



The meeting, though technical, was characterized by a good attend- 

 ance, about 45 persons being present. 



The Section then adjourned. Charles T. Kirk, 



Secretdry. 



