176 J'. W. Stanton — Fox Hills Sandstone. 



In this section the sandstone forms relatively a small part of 

 the Fox Hills and the absence of a prominent lower bed makes 

 the base of the formation uncertain. The fossils from the 

 underlying shale so far as it is exposed belong to the Fox Hills 

 fauna. The oyster bed in the upj^er member of the section at 

 one point is a conspicuous indurated very fossiliferous bed 

 fully hf teen feet thick, but it thins abruptly within a few yards 

 to two feet or less, the variation being due to the irregularity 

 of its base. In other exposures less than j;^ mile distant its 

 position is only marked by scattering brackish-water shells. 

 The Lance formation is seen in neighboring higher exposures. 



The exposures a few miles farther south in T. 14 N., R. 

 19 E., on the south side of Moreau Hiver show a section 

 similar to that last described, but they give a better contact 

 with the overlying Lance formation. 



Section on south side of Moreau River. 



Feet 



1. Soft sandstone, sandy shale, and carbonaceous shale in 



alternating beds a few feet thick, forming the base of 

 the Lance formation. Fossil plants at the top and 

 associated with Unio in the lower 4 feet (Lot 5423. See 

 list below), - .- 40 



2. Soft friable cross-bedded gray sandstone irregularly strati- 



fied with bands of dai'ker sandy shale. Large concre- 

 tions or indurated masses near the base contain Fox 

 Hills species of Scaphites associated with Corbicula 

 (No. 5969. See list on p. 180). The Corbicula occurs 

 in abundance to the top of the bed 30 to 40 



3. Banded shale with a few marine Fox Hills fossils _ 60 



4. Dark, somewhat sandy, sliale referred to the Pierre but 



containing a Fox Hills fauna. Exposed 50 



The fossil plants collected in the lower 4 feet of the Lance 

 formation at this place have been examined by Dr. F. H. 

 Knowlton, who refers them to the Fort Union and identifies 

 the following species : 



5423. Thuya interrupta Newb. 



Sequoia N ordenskioldi Heer 

 Populus cuneata Newb. 



Viburnum marginatum Lesq. 



Sequoia acuminata ff Lesq. 

 Legumlnosites? n. sp. 



Cyperacites sp. 

 Monocotyledon — new 



This list is given for the purpose of showing that the Fort 

 Union flora ranges to the base of the Lance formation. All 

 the other plant collections from this formation were likewise 

 referred to the Fort Union. 



