MAEVISE.] 



GEOLOGY EAST OF FRONT RANGE CRETACEOUS. 



103' 



sistent as No. 1, yet, -svlien it does appear above more recent accumula- 

 tions, tbe fact that it is of a decidedly calcareous character and that it 

 usually contains numerous fossils renders it easily recognized. A com- 

 plete section of No. 3 was not obtained at any point, tbough the lower 

 beds were observed at a few places. 



Section of tlie loicer heels at Cretaceous No. 3, at Bear Canon. 



No. 



Nature of strata. 



Thickneaa 

 in feet. 



River terrace ; horizontal ; recent. 



Dip 25° east. 



Limestone, thin shaly, argillaceous, slate-color weathering white-gray ; 

 near hase beds are 2 to 5 inches thick ; argillaceous and arenaceous 

 above, growing more calcareous below ; seams of gypsum, odor of 

 petroleum, some fossils 



Covered 



Like 3, but more calcareous ; near top some beds of massive compact 

 limestonCj 3 feet thick, light-gray ; fossils quite numerous, Inocera- 

 mus 



45 

 40 



20 



Section of tlie loicer heels of Cretaceous No. 3, at Little Thompson CreeTc. 



No. 



Nature of strata. 



Thickness 

 in feet. 



4 

 3 



Terrace of very coarse gravel and. bowlders ; horizontal ; recent. 



Dy) 50° east. 

 Yellow shaly limestone, impure, weathering white or light-gray 



20 

 100 



2 



Dark-Tay shaly and thin-bedded limestone . . . . • .- - 



10 



1 



Light-gray compact limestone, beds one to 2 feet thick, some shaly; 



20 









A rude kiln had been erected on the lower bed here for burning lime, 

 making, as I was told, a good quality though not very white. The thin- 

 bedded, impure, calcareous, and fossiliferous character seems generally 

 to characterize the beds. The odor of petroleum is also often quite 

 marked, but not so much so as west of the mountains. At Bear Creek, 

 No. 3 was about 90 feet thick, but no section was made. 



CRETACEOUS NO. 4 AND NO. 5. 



Unfortunately opportunity did not offer to study in detail the dark 

 shales of No. 4, and rusty yellow and gray arenaceous rocks of No. 5. 

 The former were observed to be about 300 feet thick near Bear Creek, 

 but no detail-section was made. At several points characteristic fossils 

 were obtained from the beds, which are quite well exposed and fossil- 

 iferous near Ralston Greek j but, as before remarked, the softer charac- 



