UOl PROCEEDINGS OF THE WASHINGTON MEETING 



.Mountain region, because, with very few exceptions, no such discussion has been 

 published by the observers who have reported the facts and theories. What the 



conclusion of the discussion will be remains to be seen, but the discussion seems to 

 me extremely desirable. In the mean time I do not desire to assert either a 

 lacustrine or a tluviatile origin for these formations. 



The four following papers were read by title: 



ON THE AGE AND DISTRIBUTION OF THE SEDIMENTARY ROCKS OF PATAGONIA 



BY J. 13. HATCHER 

 CRETACEOUS INVERTEBRATES FROM PATAGONIA COLLECTED BY J. B. HATCHER 



BY T. W. STANTON 



ENRICHMENT OF MINERAL VEINS BY LATER METALLIC SULPHIDES 



BY WALTER HARVEY WEED 



This paper is printed as pages 179 to 206 of this volume. 



VEIN FORMATION AT BOULDER HOT SPRINGS, MONTANA 

 BY WALTER HARVEY WEED 



The following paper was read by the author: 



1IERON1TE AND ITS RELATED ROCKS 

 BY A. P. COLEMAN 



The next paper was entitled : 



IGNEOUS COMPLEX OF MAGNET COVE, ARKANSAS 

 BY HENRY S. WASHINGTON 



Remarks were made by J. P. Iddings, L. V. Pirsson, W. H. Weed, and 

 the author. The paper is printed as pages 389 to 416 of this volume. 



The last paper read was the following : 



FURTHER STUDIES ON THE HISTORY OF THE CINCINNATI ANTICLINE 



BY AUG. F. FOERSTE 



In discussing the paper W. M. Davis said : 



The section given by Doctor Foerste shows that the strata of the Cincinnati arch 

 were denuded to a lowland enclosed by a monoclinal ridge of small relief before 

 the unconformable deposition of the Devonian beds. The thickness of the over- 

 lying strata is less on the monoclinal ridge than on the lowland within and with- 

 out. If, as is probable, the arch was denuded by subaerial forces, it is to be ex- 

 pected that outflowing consequent streams must have here and there cut notches 

 in the ridge; and if these notches were now open to observation, the covering 



