FURTHER DATA ON THE STRATIGRAPHIC POSITION 

 OF THE LANCE FORMATION ("CERATOPS BEDS") 1 



F. H. KNOWLTON 



In June, 1909, I published a paper entitled: "The Stratigraphic 

 Relations and Paleontology of the 'Hell Creek Beds,' 'Ceratops 

 Beds,' and Equivalents, and Their Reference to the Fort Union 

 Formation." 2 In that paper, as suggested by the title, the con- 

 clusion was reached that the beds considered — namely, the "Hell 

 Creek beds," "Ceratops beds," "somber beds," and "Laramie" 

 of many writers — are " stratigraphically, structurally, and paleon- 

 tologically inseparable from the Fort Union, and are Eocene in 

 age." 



It was expected that this somewhat radical innovation would 

 be received with a storm of protest, especially by the vertebrate 

 paleontologists, but so far as known to the author only three 

 papers have since appeared which deal specifically with the posi- 

 tion of the "Ceratops beds." These comprise two papers by 

 Dr. T. W. Stanton and one by Dr. O. P. Hay. 



As two field seasons have intervened since the publication of 

 my paper, during which important data were secured confirming 

 the position there assigned the Lance formation, 3 it seems oppor- 

 tune to present the case as it now stands. The areas in which 

 these observations were made are in the main in Eastern Wyoming 

 and Eastern Montana and adjacent portions of North and South 

 Dakota. 



1 Published with the permission of the Director of the U.S. Geological Survey. 



2 Proc. Wash. Acad. Sci., XI (1909), 179-238. 



3 The name Lance formation has been formally adopted by the U.S. Geological 

 Survey in place of the term "Lance Creek beds" or "Ceratops beds." Wherever 

 Lance formation is employed in the following paper it is to be understood as including 

 "Lance Creek beds," "Ceratops beds," "Hell Creek beds," "somber beds," "Lower 

 Fort Union," and beds identified as "Laramie" by many writers. 



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