THE HORIZON OF THE MARINE JURASSIC OF UTAH 



C. L. DAKE 



Missouri School of Mines 



Some time ago the writer, during the course of a reconnaissance 

 in southern Utah, made a small collection of fossils from marine 

 beds near the base of what is quite probably the McElmo formation. 

 These were collected about a half-mile southwest of Teasdale 

 (Teardale on the Fish Lake reconnaissance topographic sheet of 

 the United States Geological Survey), probably in section 20, 



Fig. I . — Contact of thin-bedded marine Jurassic limestone on white cross-bedded 

 sandstone of La Plata group. One-half mile southwest of Teasdale, Utah. (Contact 

 at black line.) 



T. 29 S., R. 4 E. At the point where the fossils were collected the 

 exposures consisted of about 100 feet of white massive cross- 

 bedded sandstone, taken to be the top of the La Plata, above which 

 were a few feet of thin-bedded shaly limestones, constituting the 

 fossil-bearing horizon (Fig. i). On account of the inaccessibility 

 of the slopes and the very limited time available, no detailed section 

 was measured at this point. 



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