titles of papers 225 



Session op Thursday, December 29 



The Society convened about 9.00 o'clock and took up the program of 

 papers, as follows : 



PRESENTATION OF PAPERS 

 ORE DEPOSITS OF LEAD] ILLE, COLORADO 

 BY G. F. LOUGH LI A 



GOLD-BEARING CUMMINGTONITE SCHISTS OF THE BLACK HILLS, SOUTH 



DAKOTA 



BY J. J. RUNNER 5 



Discussed by Waldemar Lindgren. 



PETROGRAPHIC NOTES ON THE FRANKLIN, NEW JERSEY, ZINC ORES 



BY W. C. BOWEN 6 



The paper was discussed by L. C. Graton, H. Ries, and others. 



PRIMARY NATIVE SILVER ORES NEAR WICKENBURG, ARIZONA, AND THEIR 

 BEARING ON THE GENESIS OF THE SILVER ORES OF COBALT, ONTARIO 



BY E. S. BASTTN 



Discussed by L. C. Graton, M. B. Baker, and A. M. Bateman. 



NEED OF EXPEDITING TOPOGRAPHIC MAPPING OF THE UNITED STATES 



BY F. W. DE WOLF 



The paper was largely discussed, and on motion of L. C. Graton a 

 resolution of appreciation was adopted. 



Session of Friday, December 30 



The following program of papers was presented at the session of Fri- 

 day, December 30 : 



PRESENTATION OF PAPERS 



HAZARDS OF THE OIL INDUSTRY 



BY RALPH ARNOLD 



Read in abstract by Waldemar Lindgren in the absence of the author. 



5 Introduced by E. S. Bastin. 

 8 Introduced by H. Ries. 



XV— Bill. Geol. Soc. Am., Vol. 3.°,, 1021 



