ABSTRACTS AND DISCUSSIONS OF PAPERS 85 



Edwards of the Gulf. An adjacent bed of hematite contained some fossil 

 leaves. These I have submitted to Doctor Berry and Doctor Knowlton, who 

 tell me that while they are not critical, yet they tend to substantiate the evi- 

 dence of the corals. 



A few miles farther south and higher in the stratigraphic series, as worked 

 out by purely structural methods, I found the lower portion of a Venaricardia 

 alticosta index for the Chickasawan and Claibornian of the Gulf. 



The Cretaceous and Eocene strata in which these fossils were found have 

 been folded to high angles — as much as 90° in places — and peneplained. The 

 evidence of this peneplanation is decisive. It is shown by the even heights 

 and flat crests of the mountains, the discordant relation existing between the 

 drainage and the structure, which shows superimposition, and by the presence 

 of deep residual soils. 



On this peneplain was laid down the "later limestones." From fossils col- 

 lected in Porto Rico by Doctor Berkey and studied by Miss O'Connell, we know 

 these to be of Oligocene age. 



Thus in Porto Rico we have positive proof that the Eocene is separated 

 from the Oligocene by a period of time during which there was uplift and 

 intense folding, followed by long erosion. This is entirely a new fact to 

 science and throws light on the small thickness and extent of the Oligocene, 

 both in the eastern United States and Porto Rico. It follows that the Oligo- 

 cene present is probably very late Oligocene. 



Doctor Reeds replied that as the collection was very large nothing definite 

 could be said at present regarding the age of the beds. 



CRETACEOUS OF ALBERTA, CANADA 

 BY JOSEPH H. SINCLAIR 1 



(Abstract) 



Recent explorations by the author in the foothills of southern Alberta, 

 Canada, have resulted in the identification of a very complete Benton fauna 

 and accurate measurements of 4,500 feet of Cretaceous sediments. 



The application of the Missouri River succession of Cretaceous rocks to the 

 foothill district is questioned in several horizons, and Stebinger is borne out 

 in his prophecy that the Clagett does not exist there as a lithologic unit. 



The presence of the Bearpaw is also uncertain, although it may exist as a 

 thin, brackish-water formation containing coal seams. 



The adoption of the name "Dakota" for a thick formation lying between the 

 Kootanie and the Benton is questioned on the ground that a not sufficiently 

 great variation exists between the few specimens found in it by Cairnes and 

 the flora of the Kootanie formation. 



While the adoption of the section of the Missouri by Dawson may appear 

 correct farther east in the Great Plains, it appears that continental conditions 

 have pinched out certain marine phases of the eastern section, in the foothills 

 of Alberta. The unsatisfactory line of demarcation between the Cretaceous 

 and the Tertiary is also shown. Certainly no lithologic break is seen and the 



1 Introduced by Charles P. Berkey and A. W. Grabau. 



