APPENDICES A AND B 401 



drawn in the wrong place. A precisely parallel case is shown by Sinclair 

 in his contribution on the Pnereo-Torrejon stratigraphy. The division 

 between these two formations was arbitrarily placed by Gardner at a 

 certain sandstone level between the npper and lower fossiliferous beds, 

 the upper carrying the Torre j on fauna, the lower the Puerco fauna. 

 Subsequently Granger and Sinclair found the Torrejon fauna at a level 

 100 feet below Gardner's line of division. The natural conclusion was 

 that the division line had been placed at least 100 feet too high up. 



As to the alleged occurrences of Dinosaurs associated with Tertiary 

 mammals in Patagonia, this is positively asserted by Ameghino and 

 Roth, who, however, consider the beds Cretaceous, not Tertiary. Loomis, 

 who has recently collected in these formal ious, has shown iliat the 

 mammal-bearing beds occur in stream-channels and pockets in the older 

 formations, and believes that the reports of dinosaur remains in strata 

 "above" the mammal-bearing beds are due to errors in stratigraphy in 

 failure to recognize these conditions of deposition. There would indeed 

 be no a pripi'i improbability in the survival of dinosaurs in the isolated 

 continent of South America after their extinction in the northern world ; 

 but the evidence that they did so seems 'open to very serious question. 



Appendix B. Unconformity between the Laramie and the Lance 



"The asserted magnitude of the break between Laramie and Lance 

 rests not on evidence l)ut on a definition of the Laramie." This remark 

 appears to require explanation, altliougli tlie subject is outside the scope 

 of tills paper. The evidence for an "unconformity of 20,000 feet" is not, 

 as one might suppose from Knowlton's re])eated references to it, derived 

 fiom measurements of the strata removed beneath an angular uncon- 

 formity. It is based on the occurrence in the l)asal conglomerates of the 

 Lance and equivalents of pebbles derived from the older formations of 

 (presumably) the adjoining mountains. The assumption is made that 

 the Laramie, along with the rest of the underlying formations, had ex- 

 tended over the area of these mountains and was upheaved, swept away 

 by erosion, and the underlying formations cut down to the Paleozoic 

 series, from which these pebbles are derived, during the interval between 

 Laramie and Lance. But although Lee has reported evidence for such 

 an extension of the older Cretaceous beds in New Mexico, there is no 

 evidence that the Laramie had the same extension, save its definition as 

 the "latest conformable member of the Cretaceous succession." It was 

 to this circumstance that the remark had reference. It appears to me, 

 on the other hand, that whatever inferences may have been made from 



