"CERATOPS beds" OF WYOMING AND_MONTANA 267 



tain light-colored sandstone strata in the upi:)er part of the lower 

 member thin out and disappear southward along the strike. Some 

 brownish and yellow sandy strata that lie still higher, near the top 

 of the same member on Tongue River, seem to thin out toward the 

 south and give place to dull-colored shale or sandy strata on Goose 

 and Beaver creeks in T. 55 N., R. 85 W. These conditions seem to 

 indicate that the parting between the two members rises in the rock 

 section toward the south. 



The upper member also changes in character southward along the 

 strike of the rocks. From the central part of the field southward the 

 differentiation between the sandstone and the shale strata becomes less 

 distinct. The sandstone on the whole is duller in color, and near the 

 southern boundary of the mapped area the sandstone beds contain 

 pebbles of limestone, quartz, and chert. In the southeastern part of 

 T. 54 N., R. 83 W., and in T. 54 N., R. 84 W., many hundred feet of 

 strata in the central part of the upper member merge into conglomer- 

 ate. The constituent parts of the conglomerate become coarser rather 

 abruptly on the approach to the Paleozoic rocks of the Bighorn 

 Mountains, upon which the conglomerates overlap unconformably. 

 The exposed section of conglomerate strata is more than 1000 feet thick 

 between Little Goose and Sandy Creek valleys, at the base of the Big- 

 horn Mountains, on the southern border of the Sheridan field. The 

 gradation from the conglomerate into the sandy and shaly strata 

 takes place toward the east and north, and involves almost the whole 

 section of this member from the Tongue River coal group upward 

 nearly to the top of the rock section. The economic bearing of the 

 conglomerate is a negative one, for the coal beds thin out and disappear 

 near its outer fringe. 



The Kingsbury conglomerate has a maximum thickness of at least 

 2500 feet west and southwest of Buffalo, Wyoming, where the basal 

 beds and all the underlying formations are sharply upturned. Some of 

 the beds are very coarse and the boulders and pebbles include granite 

 and all of the harder Paleozoic rocks of the Bighorn Mountains. Fossil 

 plants and invertebrates were collected here by Mr. T. E.Williard in 1907 

 and additional collections, including a mammal jaw found by Mr. Gale, 

 were obtained by Messrs. H. S. Gale, C. A. Fisher, and myself in 

 1908. Mr. Gale made a plane table map (unpublished) and structure 

 section of several land sections in the southwest part of T. 50 N., 

 R. 82 W., and in the northwest corner of T. 49 N., R. 82 W., which 

 enabled him to determine accurately the stratigraphic positions of 

 the various collections and to demonstrate that there was a large 



