REGION NORTH OF GALLATIN RIVER, 

 Comparison of sections of Quadrant formation. 



41 



"Pocket." 



Feet. "Amphitheater." 



Feet. 



"Quadrant," southeast 

 corner. 



Feet. 



r, q. Saudstone 



15 Sandstone with in- 





r. 



Limestone 



10 



p. Limestone 



6 terbedded lime- 

 5 stone 



265 



P,'[- 



0. 



Sandstones . > 

 Limestones . S 



15 



n. Limestone 



15 







n. 



Limestone 



12 



m. Sandstone 



18 







fc-m. 



Quartzite 



71 



1. Limestone 



2 







./• 



Limestone 



10 



k. Sandstone, etc . 



148 



/. Limestone 



4 



i. 

 h. 



Limestone 



Limestone 



30 

 5 



209 









3 



e,f,g. 



Quartzite 



130 



272 



283 







d. Limestone 



2 



d. 



Limestone 



2 







c. Sandstone 



6 



c. 



Sandstone 



6 







b. Limestone 



10 



b. 



Limestone 



10 







a. Sandstone 



36 



a. 



Talus 



100 





326 



401 



Madison limestones 1 



>eneath above series. 











On the summit of the ridge west of Fawn Creek amphitheater, the 

 Teton limestone is well exposed, the dip being 15° and the direction 

 N. 26° W. These beds are undoubtedly tilted by their proximity to the 

 Gray Peak bysmalith mass, although the tilting is not uniform, as the red 

 sandstones forming the hill farther north have a dip of but 10° in the 

 direction N. 15° W. 



REGION NORTH OF GALLATIN RIYER. 



As already pointed out, the escarpment wall on the north side of 

 Gallatin River consists of massive Madison limestones topped by the white 

 sandstone or quartzite of the Quadrant formation. These beds dip at an 

 angle of about 10° NE. throughout the greater part of the distance, having 

 a more northerly dip in the vicinity of Bannock Peak, and at the western end 

 of their exposure curving over from a northeasterly to a northwesterly dip 

 of 5° to 10°, bending down toward the profound fault plane that bounds 

 them on the west and brings them against subaerial breccias of andesite. 

 Within the limits of this low anticlinal arch the sandstone is in places 

 broken and polished with slickensides accompanying slight displacement 



