NO. 5 PRE-DEVONIAN PALEOZOIC FORMATIONS 269 



the Lower Cambrian quartzites are thrust over onto the upper Mons, 

 and the Sarbach and Devonian of the Fossil Mountain section are cut 

 out by the fault which extends north-northwest to Baker Creek Can- 

 yon and south-southeast down Johnston Creek to Bow Valley. These 

 two canyons mark the dividing line between the massive-bedded 

 Middle Cambrian limestones of Castle Mountain and the Ordovician 

 Sarbach and Ozarkian Mons limestones of the southwesterly ridges 

 of the Sawback Range massif. The relations of the Castle Mountain 

 strata to those of the Sawback Range are well shown at the Johnston 

 Creek-Wild Flower Canyon Pass. At this point the Lower Cambrian 

 quartzite beneath the Middle Cambrian limestones forms the floor 

 of the pass and extends a short distance down Wild Flower Canyon. 

 It is thrust on to cherty and siliceous layers of limestone such as 

 occur in the Sarbach formation of Ranger Brook Canyon and Bonnet 

 Peak sections. The strata are somewhat broken and displaced, but the 

 strike and dip are essentially the same above and below the quartzite. 

 The dip of the Mons limestones is about 45° to the southwest for 2 

 miles (3.2 km.) or more along Wild Flower Canyon, while the Cam- 

 brian limestones dip at about 30°. At the pass between the Ozarkispira 

 zone of the upper Mons and the magnesian limestone next to the fault 

 and beneath, the Cambrian there are 200 feet (61 m.) of thin are- 

 naceous limestones and shales with annelid trails and borings that 

 correspond to similar shallow water deposits above the Mons limestone 

 and shale in the Ranger Canyon and Douglas Canyon sections, where 

 they are referred to the Sarbach. 



A diagrammatic section across the strike of the strata on the John- 

 ston Creek Pass is illustrated by text figure 25. 



CANADIAN 

 Sarbach Formation 



On the Johnston-Wild Flower Canyon Divide, the 

 Lower Cambrian Fort Monntain quartzite of Castle 

 Mountairr is thrust over the cherty and siliceous 

 annelid limestones of the Sarbach formation. Ad- 

 joining the line of the fault (Johnston) the layers of 

 limestones are more or less crushed, crumpled, and 

 broken, but 50 feet (15.2 m.) from the outcrop of 

 quartzite, the northeast dip of 35° to 45° prevails 

 and is maintained down through the Sarbach to the 

 gray Mons limestones beneath. The middle and 

 upper portions of the Sarbach as seen on Fossil Moun- 

 tain 7.5 miles (12. 1 km.) to the northwest are here cut 

 out by the Johnston fault, or are absent as in the 

 Bonnet Peak section 4 miles (6.4 km.) to the north- 



