2IO KNOWLTON 



Kingsbury conglomerate has been given. It occupies a narrow band 

 only 6 or 8 miles in width and 25 to 30 miles in length, adjacent to 

 the mountains, and strikes approximately north and south. Its 

 north and south extent coincides very nearly with faults which, accord- 

 ing to Darton, attended an uplift of some 9000 feet of this portion 

 of the Bighorn Mountains. This uplift, which involved also the 

 Piney formation, resulted in a sharp fold, or in some cases probably 

 a break, of the underlying beds resting against the granite mass, 

 while the increased elevation of the mountain mass accelerated ero- 

 sion and precipitated the debris which forms this conglomerate, 

 embracing as it does rocks of all ages from the granites to and includ- 

 eng the Piney. That the unconformity at the base of the Kings- 

 bury is not of wide significance is shown by the fact that it was not 

 detected in a section made at Parkman, only about 25 miles north 

 of the northernmost extension of the Kingsbury, nor has it been found 

 a few miles to the southward of the southern limits of the formation. 

 Along the eastern margin of the Kingsbury it may be observed finger- 

 ing into the soft shales and sandstones of the De Smet formation, 

 the name given by Darton to the 5000 feet or more of beds overlying 

 the Piney, and with which sedimentation was apparently continuous; 

 in fact the Kingsbury was regarded by Mr. J. A. Tail, who surveyed 

 this area for coal in 1907, as merely the near-shore phase of the upper 

 member of the Fort Union. At a number of horizons in the Kings- 

 bury Fort Union plants have been collected, and at a point about 650 

 feet above its base Mr. H. S. Gale obtained a mammal jaw which 

 Air. Gidlcy identifies as identical with a Fort Union species found 

 at Fish Creek, Montana. 



The first two of the following lists of plants are from the Kings- 

 bury conglomerate, and are given to show how similar is the flora 

 of the upper and lower members of the Fort Union; the others are 

 from the lower member: 



Sequoia sp. ? 

 Cyperarites sp. 

 Populus sp. ? 

 Platanus haydenii Newb. 

 Ficus plani ostata? Lesq. 

 Cinnavwmum a (fine Les(|. 

 Sapindiis grandifolioliis Ward. 

 Diospyros ficoidea Lesq. 



