1 7 8 



mata and certain Arthropoda are abundantly represented 

 [10]. 



Eldon Formation. — This formation has a thickness 

 of 2,728 feet (831 m.) where it was measured in Castle 

 mountain. It consists essentially of massive-bedded, 

 arenaceous limestones, which form steep castellated crags 

 on the erosion surface, thus making the formation readily 

 recognizable wherever exposed. It is this formation 

 which forms the steep escarpment about the upper part 

 of Castle mountain. 



The Mitre and Death Trap (pass) to the right. The cliffs on the right are of Middle 



Cambrian limestone in Mt. Lefroy. A typical bergschrund is shown around 



this portion of the Lefroy glacier. 



UPPER CAMBRIAN. 



Bosworth Formation. — This formation is exposed in 

 the mountain of the same name on the Continental 

 Divide. It consists largely of thin-bedded limestone 

 with a few more thick-bedded layers, interbedded with 

 siliceous and arenaceous shale. One band of shale makes 

 a good horizon-marker because it weathers greenish, 

 yellowish, deep red, and purplish. 



Paget Formation. — A band of grayish oolitic lime- 

 stone, typically exposed in Paget peak, on the west slope 

 of Mt. Bosworth, has been placed in this formation. 

 These beds can not be readily distinguished from the 

 underlying limestone. 



