38 PROCEEDINGS OP THE WASHINGTON MEETING 



The late Mr. Willmott was a most genial and lovable man, who made 

 friends among all classes, and his premature death has been a sorrow to 

 his many friends, as well as a serious loss to science. He leaves a widow 

 and a son and daughter. 



BIBLIOGRAPHY 



Michipicoten Mining Division. Bureau of Mines, Ontario, volume 7. 1S97, 



pages 184-206. 

 Michipicoten iron range. A. P. Coleman and A. B. Willmott. Bureau of Mines, 



Ontario, volume 8, part 2, 1899. 

 Mineral industries of Sault Ste. Marie. Bureau of Mines, Ontario, volume 11, 



pages 91-100. 

 The Michipicoten iron region. (A. P. C. and A. B. W.) Bureau of Mines, 



Ontario, volume 11, 1901, pages 152-185. 

 The nomenclature of the Lake Superior formations. Journal of Geology, 



volume X, No. 1, 1902. 

 The contact of the Archean and post-Archean in the region of the Great Lakes. 



Journal of Geology, volume XII, No. 1, 1904. 

 The exploration of the Ontario iron ranges. Journal of the Canadian Mining 



Institute, volume VII, 1904. 

 The iron "ores of Ontario. Journal of the Canadian Mining Institute, volume 



XI, 1908. 



The Societ}' then proceeded to the consideration of scientific papers. 



TITLES AND ABSTRACTS OF PAPERS PRESENTED BEFORE THE MORNING ■ 

 SESSION AND DISCUSSIONS THEREON 



GEOGRAPHIC HISTORY OF THE SAN JUAN MOUNTAINS SINGE THE CLOSE OF 



THE MESOZOIC ERA* 



BY WALLACE W. ATWOOD AND KIRTLEY F. MATHER 



{Abstract) 



This paper gave a preliminary summary of physiographic studies which have 

 been in progress during the last six field seasons. 



At the close of the Mesozoic era and the opening of the Cenozoic era there 

 were mountain-making movements which affected the entire Rocky Mountain 

 province of North America, and the great dome which was then formed in the 

 San Juan area was at once subjected to vigorous erosion. As the mountain 

 mass rose erosion began, and as the great dome was more and more deeply 

 dissected a mountain topography must have been produced, and those moun- 

 tains may be thought of as the first generation of the San Juan Range. Cer- 

 tain deposits of Eocene till in this region indicate that during the dissection 

 of these early San Juan Mountains ice formed in the range and descended to 

 the bordering lowlands. 



1 Presented with permission of the Director of the U. S. Geological Survey. 



