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of a gravelly constitution. They are fissured in comparatively large masses, 

 which assume a rounded form as they are worn away, so that a ledge of 

 sandstone projecting from the declivity of a butte will appear like a row of 

 cotton bales. As they disintegrate less rapidly than the contiguous clays, 

 musses are often observed resting upon cones and columns of the latter, con- 

 tributing greatly to the picturesque and sometimes fantastic appearance of 

 the buttes. 



Many of the table-lands and lesser buttes in the vicinity of the Uintah 

 Mountains arc thickly covered with drift from the latter, consisting of gravel 

 and bowlders of red and gray compact sandstones or quartzites. The drift 

 material is usually firmly imbedded in -the surface of the plains so as to 

 appear like a pavement. The bowlders are generally small, but assume larger 

 proportions approaching the Uintahs. In many cases the drift completely 

 covers the terraces or buttes, descending upon the declivities so as entirely to 

 conceal their structure. Usually, however, it accumulates in the ravines of 

 the declivities, leaving bare the intervening ridges of light-colored clays and 

 sandstones. Many of "the buttes are nearly or quite free of drift material. 

 Some, again, are strewn with fragments of rock, consisting of the harder materials 

 from the terraces themselves, and these likewise occur mingled with the 

 drift-pebbles and bowlders from the mountain-heights. 



The stone-fragments from the buttes consist of harder siliceous and cal- 

 careous clays, impure limestones, jaspers, and less frequently agate and chalce- 

 dony. In some instances they consist of singularly black incrustcd and 

 rounded saudstones, somewhat of the character of septaria. Specimens ot 

 these occasionally bear a resemblance to fossil turtles, and when found with 

 the harder crust broken they look like turtle-shells filled with a sandstone 

 matrix. 



In the buttes in the vicinity of Carter Station, on the Union Pacific Rail- 

 road, I observed many large nodular and cylindroid masses of agate. These 

 have a concentric arrangement of layers resembling that of fossil wood, for 

 which they are taken. Many of the masses contain a nucleus of amber- 

 colored crystals of calcite. 



Nodules of chalcedony with dendritic markings occur in some of the 

 buttes. These, together with the condition of many of the fossils of the 

 buttes, indicate the presence of a considerable proportion of soluble silica in 



