766 



SCIENCE 



[N. S. Vol. XXV. No. 646 



Relations between Climate and Bi/ver De- 

 posits: Joseph Bakeell. 

 The nature of subaerial river deposits is 

 controlled by the geographic and climatic 

 conditions of origin. The importance of 

 the climatic factor is appreciated by con- 

 trasting the nature of deposits accumula- 

 ting under similar geographic but dissim- 

 ilar climatic conditions. As a result, where 

 an ancient sedimentary deposit can be 

 shown to be of subaerial origin, if the geo- 

 graphic conditions existing at the time can 

 be allowed for, the climatic conditions of 

 origin may be determinable. To that end, 

 the geographic and climatic influences upon 

 river sediments are examined under three 

 headings: (1) relation of sediments to re- 

 gions of erosion, (2) effects of transporta- 

 tion, (3) relation of sediments to regions 

 of deposition. Under the latter heading 

 the character of the surface of deposition 

 is considered, and finally the relations of 

 the deposits to four kinds of climates, 

 namely, constantly rainy, intermittently 

 rainy, subarid and arid. The effects of 

 climatic changes upon sedimentation are 

 also considered, and it is concluded that 

 climatic as well as tectonic hypotheses must 

 be considered in interpreting the cause of 

 sedimentary variations. 



Continental Origin of the Mauch Chunk 



Shale: Joseph Baerell. 



The discussion of the previous paper 

 allows the presentation of the facts and 

 conclusions of the present one. The Mauch 

 Chunk Shale and the Pocono Sandstone 

 represent the Mississippian, or sub-Carbon- 

 iferous, in Pennsylvania. The former, 

 consisting of red shales and sandstones, is 

 considered in detail. After a statement of 

 the relations to the underlying and over- 

 lying formations the lithologie and struc- 

 tural characters and the nature of the life 

 record are stated. The problem of origin 

 is then discussed, and it is concluded that 



within the limits of the anthracite coal 

 fields the entire formation originated as 

 flood-plain deposits on the subaerial surface 

 of a large delta. The climate under which 

 the formation accumulated is next consid- 

 ered, and it is inferred that it was of a sub- 

 arid character. The long continuance of 

 similar conditions through the Upper De- 

 vonian is then indicated, and emphasized 

 by contrast with the opposite character of 

 the coal measures. In this connection, the 

 possible importance of subarid climates 

 upon the evolution of amphibians is sug- 



Professor Barrell's two papers were dis- 

 cussed by Professors David White, Willis, 

 Huntington, Grabau and Davis. 



Origin of Ocean Basins in the Light of the 

 New Seismology: William Hekbert 



HOBBS. 



A review of the arguments upon which 

 the permanence of the ocean basins has 

 been assumed, with the modifications in 

 them which time has wrought ; particularly, 

 however, as a consequence of zoo-geo- 

 graphic, comparative geologic and struc- 

 tural studies. The 'distant' study of 

 earthquakes has shown that they are fif- 

 teen to twenty-fold as numerous as formerly 

 supposed, and that over ninety per cent, 

 occur upon the floor of the seas, and appear 

 to proceed from the scarps bordering the 

 great ocean deeps. The data for elevation 

 or depression available within the coral 

 seas have been assembled, and differential 

 vertical movement is thus shown to have 

 been recently the greatest within the zones 

 of earthquakes, as mapped by de Mon- 

 tessus. 



Hypothesis of Continental Structure: 

 Bailey Willis. No abstract received. 

 Mr. Willis's paper was discussed by 



Professors Heilprin, Schuchert, Emerson 



and F. E. Wright. 



