248 Geological remarks. " book n. 
northern branch of the Canadian river, are found ejected 
masses of half-fused sandstone, just similar to those above- 
mentioned. In other places, on the contrary, the harder 
layers that cover the sandstone and conglomerate appeared 
to be merely sandy and ferruginous incrustations of lime- 
stone, with a cellular appearance. On the Pawnee Fork 
a dense limestone has provided, and probably still provides, 
the materials for such incrustations by solution and filtra- 
tion. Upon the surface of contact are found brown sandy 
stalactites and sandy limestone crystals, similar to the 
so-called crystallized sandstone of Fontainebleau. 
A rough, sandy, dolomitic limestone, which overlies the 
softer sandstone and conglomerate on the Cimarron, sepa- 
rates these layers of the new red sandstone formation from 
the upper and more recent masses of sandstone, which at 
first appear in piled-up blocks. Their substance is remark- 
able for the quantity of quartz and mica it includes ; for 
the occasional entire absence of any perceptible cement ; 
for the complete amalgamation of its grains of quartz into 
a solid quartz rock ; for its great hardness and bright 
colours of all shades, from the purest white to a brilliant 
brick or brown red, or from light yellow to brown. Nume- 
rous knots of brown ironstone, partially detached by the 
wearing effects of the weather, stand out on the surface in 
concentric films, and form one of the characteristic features 
of the formation. The stratification of this higher and 
more recent sandstone is distinctly visible on the so-called 
Upper Springs, upon the south side of the Cimarron, and 
on the Cold Spring and Cedar Spring. Undermost are 
seen the layers of conglomerate and sandstone which form 
the quicksands of the Arkansas and the Cimarron ; over 
them the rough limestone, as a roof, and above this the 
more recent and hard sandstone which I have just described. 
