GRENVILLE-HASTINGS UNCONFORMITY 539 



Lawson, A. P. Coleman, H. M. Ami, and C. E. Van Hise. This address 

 was published as pages 1-28 of this volume. 



The following papers were then read by title : 



RED SANDSTOys FORMATION OF SOUTHEASTERN MINNESOTA 



BY C. W. HALL 



GEOLOGICAL HISTORY OF THE REDSTONE QUARTZITE 

 BY Frederick; w. sardeson 



Published as pages 221-242 of this volume. 



PALEOZOIC AND ME80Z0IC OF CENTRAL WYOMING 

 BY N. H. DARTON' 



Published as pages 403-474 of this volume. 



SOME FEATURES OF THE GEOLOGY OF ARIZONA AND WESTERN NEW MEXICO 

 ALONG THE SANTA FE RAILROAD 



BY N. H. DARTON 



After this the Society listened to the reading of a paper on 



GRENVILLE -HASTINGS UNCONFORMITY 

 BY WILLET G. MILLER AND CYRIL W. KNIGHT 



[Abstract] 



The crystalline limestone and associated pre-Cambrian sedimentary rocks of 

 southeastern Ontario and the adjacent parts of the province of Quebec, to 

 which Logan and his colleagues long ago gave the names of Grenville and 

 Hastings series, have never been satisfactorily classified as regards their age. 

 Recent worli by the present writers has shown that much at least of what has 

 been called the Hastings series, consisting of limestones, conglomerates, and 

 other fragmental rocks, is much younger than, and forms a well defined uncon- 

 formable series with, the typical crystalline limestones and associated frag- 

 mental rocks of what has been called the Grenville series proper. The view 

 that the Grenville and Hastings constitute one series, the former being a more 

 highly altered phase of the latter, is no longer tenable. 



The writers find the Keewatin series of the Lake Superior region represented 

 in southeastern Ontario by ancient rocks of like character. The Grenville 

 limestones have been deposited on the surface of the Keewatin. The writers 

 class the Grenville limestone as regards age with the Keewatin iron formation 

 of lake Superior, which it has not been found possible in that region to sepa- 

 rate from the greenstones. The pre-Cambrian conglomerate and associated 

 sedimentary rocks overlying, uncomformably, the Grenville limestone are 

 classed as Huronian. The conglomerate contains not only ordinary fragments 

 of the Grenville limestone, but "eozoou"-like boulders as well, thus showing that 

 the limestone is much older than the conglomerate. Moreover, the "pebbles of 



