GEOLOGICAL SURVEY OF THE TERRITORIES. 529 



tion, but that the two shade into each other through perhaps several 

 hundred feet of non-fossiliferous sandstones and shales, and without 

 fossils it is not possible to decide the question. In the other beds only 

 a few oyster-shells were obtained, but fossil leaves were abundant in 

 some, and in No. 17 we obtained some huge reptilian bones. The 

 remaining portions of the skeleton were exhumed by Professor Cope 

 a little after our visit, and found to belong to a large Dinosaurian, 

 for which he has proposed the name Agathaumns sylvestris, and which 

 he considers as aftbrding conclusive proof of the Cretaceous age of these 

 strata. 



The thin sandstones and clays, No, 27, forming the lowest member of 

 the section last given, appear at the base of the bluffs on the northern 

 edge of the bottom-lands of Bitter Creek for a distance of two or three 

 miles northwest of Black Buttes Station, where there appears below 

 them, and apparently dipping unconformably beneath them, a massive, 

 bluish-white soft sandstone, with some intercalated clays and harder 

 laminae of grayish sandstone. This apparent unconformability is best 

 noticed by viewing it from a little distance to the westward, but is suf- 

 ficiently prominent at the point where the two beds appear nearest to- 

 gether, only a little valley intervening. At this point the dip of the 

 underlying beds is nearly southeast about 18°, while that of the over- 

 lying rocks is only from 5° to 7°, and nearly due east. This unconfor- 

 mability also makes the thickness of these lowest beds of the Black 

 Buttes section less at this point than elsewhere; here it appears not 

 over 130 feet, while a range of bluffs stretching away to the southward, 

 and to all appearance capped with the heavy sandstone which is seen 

 at the station, show a long slope of not less than two or three hundred 

 feet of these beds. 



The following section was taken by Mr. Meek and myself in a wind- 

 ing walk over the hills from a point some six miles northwest of the 

 station, to the place where the two apparently unconformable series 

 come together, already mentioned as some two or three miles from the 

 station at Black Buttes. It was made by walking across the dip, esti- 

 mating or measuring the thickness of each bed. In this manner the 

 lowest beds were first met with, but for the sake of uniformity with the 

 other local sections given in this report, and for convenience of refer- 

 ence, I number the different strata in the descending order, commen- 

 cing with the uppermost member already described as underlying No. 

 27 of the previous section : 



Sectian taJcen beUceen Black Buttes and a point six miles east of Point of 



Rocks. 



Feet. 



1. Soft bluish- white sandstone, with intercalated clays "J 



and harder grayish laminae 90 



2. Whitish clays and shales with some laminated sand- 



stone 48 



3. Coarse grayish and buff sandstone 6 



4. Whitish sandy clays and dark carbonaceous shale ^ H. 



with thin seam of coal 20 



5. Massive light gray and whitish sandstone 33 



6. Whitish sandy clays with some carbonaceous shale ; 



traces of coal 23 



7. Grayish butt' sandstone, mostly heavy bedded 37 



8. Grayish and dark carbonacous shales with appear- 



ance of coal ; fused and burnt red in parts 20 



9. Soft grayish sandstone with Ostrea 5 



34 G s 



