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In tliis paper we propose to describe only the Tertiary and Cretaceous 

 deposits, as they are a part of the formations first described in the reports 

 of the United States Geological Survey under Dr. F. V. Hayden. It will 

 be seen by inspection of the map that they occupy the western two-thirds 

 of the State. The outlines of the formations cannot be given in detail 

 where the scale is so small. But one feature must be kept in mind. It 

 is this : The dip of the strata in all parts of the State is so slight, aver- 

 aging about five feet to the mile, that, as you travel to the northwest, 

 the more modern strata, or deposits, are always seen first on the tops of 

 the hills, and gradually descend into the lower grounds and disappear 

 under the still more recent deposits. Thus, on the border of the Plio- 

 cene Tertiary and Cretaceous there is a belt about twenty miles in com- 

 mon, where the former occupies the higher and the latter the lower por- 

 tions of the country. In this way the Tertiary covers about 9,000 

 square miles of Kansas, consisting of 6,000 covering the entire north- 

 west part of the State and 3,000 interspersed with the Cretaceous along 

 its southeastern boundary. 



II.— TERTIARY SYSTEM. 



Pliocene. 



This geological area has been but little examined, and consequently 

 our knowledge of its local features is quite limited. Professors Cope 

 and Marsh have both, in their visits to the Cretaceous, made some 

 casual notices of the southern portion, without spending time in 

 searching for its fossils. 



During the summer of 1874 and 1875, we spent much time along the 

 line of its union with the Niobrara, and thus became acquainted with 

 its outlines and a few of its fossils. The line of demarkation, at most 

 points, is very clear and well defined. In numerous places we have 

 found the fossil bones of the mammalia of the Pliocene within ten ver- 

 tical feet of the marine shells and fish of the Cretaceous; and in slides 

 we frequently, found them intermingled. The contrast was remarkable, 

 as hardly a single type was common to both. 



The material of the Pliocene deposits consists of sandstone of various 

 shades of gray and brown, occasionally whitened by a small admixture 

 of lime. The lower strata are usually composed of finer sand than the 

 upper, and much more loose and friable in their texture. The overlying 

 beds are of coarser ingredients, consisting of water-worn pebbles of 

 metamorphic rocks — quartz, greenstone, granite, syenite, and sometimes 

 fragments of fossil wood from an older formation. These portions of 

 the deposit, when crumbled and the finer parts washed away, have 

 much, the appearance of drift, and have been mistaken for it. 



The sandstone is usually friable, crumbling on exposure to the 

 atmosphere. When more compact, its mechanical construction is so 

 irregular as to render it almost entirely unfit for a building-material. 

 When firmly consolidated, it forms the hill-tops of the table-like emi- 

 nences along the line of the boundary of the Pliocene and Cretaceous 

 formations. 



At Breadbowl Mound, Phillips County, it is about 400 feet above 

 Deer Creek, and at Sugarloaf Mound, in the western part of Eocks 

 County, it is about 300 feet above the Solomon Eiver. In these hills, 

 as in many others, the upper strata belong to the Pliocene, while the 



