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Show 212 In this paper we propose to describe oply 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- third* 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 v 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 oi 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 tweuty 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 9,0W sqnare miles of Kansas, consisting of 6,000 covering the entire north west part of the State and 3,000 interspersed with the Cretaceous alon{ 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 Cop and Marsh have both, in their visits to the Cretaceous, made sow casual notices of the southern portion, without spending time i| searching for its fossils. During the summer of 1874 and 1875, we spent much time along tb line of its union with the Niobrara, and thus became acquainted wit its outlines and a few of its fossils. The line of demarkation, at m< M poiuts, is very clear and well defined. In numerous places we hat found the fossil bones of the mammalia of the Pliocene within ten ve| tical feet of the marine shells and fish of the Cretaceous; aud in slide we frequently found them intermingled. The contrast was remarkabl as hardly a single type was common to both. The material of the Pliocene deposits consists of sandstone of varioi shades of gray and brown, occasionally whitened by a small admixtaj of lime. The lower strata are usually composed of finer sand than tl upper, and much more loose aud friable in their texture. The overlyii beds are of coarser ingredients, consisting of water- worn pebbles metamorphic rocks- quartz, greenstone, granite, syenite, and sometimi fragments of fossil wood from an older formation. These portions the deposit, when crumbled and the finer parts washed away, bai much the appearance of drift, and have been mistaken for it. The sandstone is usually friable, . crumbling on exposure to tl atmosphere. When more compact, its mechanical construction is | irregular as to render it almost entirely unfit for a building matem When firmly consolidated, it forms the hill- tops of the table- like eq nences along the line of the boundary of the Plioceue and Cretaeeo formations. At Breadbowl Mound, Phillips County, it is about 400 feet aW Beer Creek, and at Sugarloaf Mound, in the western part of Rod County, it is about 300 feet above the Solomon River. Iu these hil as in many others, the upper strata belong to the Pliocene, while V |