368 B. BROWN CRETACEOUS-EOCENE CORRELATION IN NEW MEXICO 



From Kneehills to the end of the formation there is no marked litho- 

 logic change. The beds are chiefly shaly clays, alternating with in- 

 durated sands and pronounced dark carbonaceous layers. There are 

 many lignite seams of good quality, several of which are mined at Drum- 

 heller, near the mouth of Michichi Creek and at the mouth of the Rose- 

 bud. One large seam, which apparently continues over a large area, is 

 prominent below the mouth of the Eosebud on the left bank. One mile 

 below the mouth of the Eosebud it has been burned, and the clays above 

 and below to a depth of 50 feet indurated sufficiently to resist erosion, so 

 that brilliant vermilion cliffs stand out in front of the somber back- 

 ground. Four miles below the mouth of the Eosebud this seam measures 

 over 6 feet in thickness where it is approximately 100 feet above the 

 Pierre. 



Edmonton-Pierre Contact 



Twelve miles below the Eosebud a small stream — Willow or Saule 

 Creek — joins the Eed Deer from the east. Many fine sections, showing 

 the contact of the Edmonton and Pierre, appear near the junction of 

 these two streams. 



The first unmistakable marine beds containing fragments of Ammo- 

 nites sp., Scaplites sp. were observed 1 mile above the mouth of Willow 

 Creek. The clay-shales of these beds are thin, finely laminated layers 

 from one-half inch to 3 inches thick, int^r stratified with seams of ocher. 

 and vary from buff to a deep coffee color, the colors alternating with one 

 another. Above the shales and conformably overlying them in all ob- 

 served points of contact are 50 feet of light, almost white, sandy clays, 

 sometimes cross-bedded and interstratified with layers of dark carbona- 

 ceous clays. Selinite crj^stals occur all through these strata. The over- 

 lying sandy clays mark the transition from purely marine to brackish- 

 water beds. In them frequently occur beds of oysters ajid considerable 

 wood. At the mouth of Willow Creek, in the bluffs back of the home of 

 Mr. J. H. Caldwell and 50 feet above the coffee-colored shales, I collected 

 the following shells: Ostrea snbtrigonalis E and S., Osirea glabra M. and 

 IT. ? Doctor Stanton comments on this lot: "These two species are found 

 in both Judith Eiver and Lance formations." Xear by in the same hori- 

 zon were the remains of a Trionichid turtle. 



The Edmonton formation differs greatly in lithologic character from 

 the Fox Hills, which occupies the same relative position in the United 

 States where it is a sandstone formation, hut T believe it to have been, 

 in part at least, synchronous with the Fox Hills. Tt may possibly be 

 correlatpd with the Laramie, according to its original definition. 



