PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



issued iMf^rvi^.sjIMH h '^* 



SMITHSONIAN INSTITUTION 



U. S. NATIONAL MUSEUM 



Vol.91 W«il,ington:I94l No. 3121 



THE MAMMALIAN FAUNAS OF THE PALEOCENE OF 

 CENTRAL UTAH, WITH NOTES ON THE GEOLOGY 



By C. Lewis Gazin 



Further investigation of the Paleocene deposits of central Utah by 

 the 1939 and 1940 Smithsonian Institution expeditions has added 

 considerably to the collections representative of the upper portion of 

 the North Horn deposits and has resulted in the discovery of a second 

 and distinct horizon for mammals within the Paleocene series. The 

 investigations of these years have led also to a better understanding 

 of the geologic relations pertaining to the fossil-bearing deposits in 

 and about Dragon Canyon and North Horn Mountain. 



The area investigated lies within the region of the Manti National 

 Forest and along the eastern part of the Wasatch Plateau. Physio- 

 graphically, it belongs to the High Plateaus of Utah section of the 

 Colorado Plateaus province, as defined by Fenneman and Johnson. 



North Horn Mountain (T. 18 S., R. 6 E.), due west of the towns of 

 Orangeville and Castledale, is an outlying remnant of the plateau to 

 the west, being separated from it by the troughlike depression known 

 as North or Upper Dragon. Dragon Canyon, or the Lower Dragon, 

 lies principally in the western half of T. 19 S., R. 6 E., and together 

 with North Dragon is primarily the result of a complex graben struc- 

 ture extending for a considerable distance both north and south. 



The writer wishes to acknowledge the courtesy extended by Dr. 

 Walter Granger and Dr. G. G. Simpson in permitting him to make 

 further comparisons with Paleocene materials in the American Mu- 

 seum of Natural History. The drawings illustrating the specimens 

 were made by Sydney Prentice. 



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