1XX REPORT OF THE STATE GEOLOGIST. 



DOUBLE MOUNTAIN" BEDS. 



The shoaling of the water continued until the time of the Double 

 Mountain Beds was ushered in. These show a series of land-locked 

 shallow seas, which were subject to periodical overflows from the wider 

 ocean, and in which were deposited the beds of gypsum and rock salt, 

 the sands and clays, the sandstones and shales that go to form the rocks 

 of this division. 



The rocks stretch with very gentle dip towards the northwest until 

 they are hidden under the Plains deposits. The greatest element of 

 wealth within the region covered by this system is its grand soil. The 

 Abilene Wichita country, as it is called, which was in former times sup- 

 posed to be so far within the arid region as to be practically worthless, 

 has proved on actual trial to have sufficient rainfall to mature the finest 

 crops under intelligent farming. From the very origin of the soils and 

 the constituents they receive from the underlying rocks, great fertility 

 is assured, and since the rain has proved sufficient it would seem impos- 

 sible to predict too bright a future for its agriculture. It seems destined 

 to be the great wheat and small grain region of the State, although other 

 crops also do well. The other principal materials of economic value 

 consist of excellent building stones, which are found in the beds of 

 limestone and sandstones, some of the latter being of a most beautiful 

 light red color, fully equal to any that is brought to the State for trim- 

 mings or fronts for buildings ; the great beds of salt, some of which, like 

 that at Colorado, are 100 feet thick ; the deposits of gypsum — embracing 

 all known varieties and of all states of purity, from a gypsiferous clay 

 to alabaster and selenite — which exist in really inexhaustible quantities, 

 and will be used for fertilizing or the manufacture of plaster of paris, 

 and for many ornamental purposes; and the copper deposits, which will 

 sooner or later become of some value. 



With these Permian Beds the great group of deposits classed as 

 Paleozoic ended. The fauna which characterizes the Permian shows 

 clearly, by the intermingling of the older and newer forms of life which 

 are there found = together, that it was a transition formation, and it is 

 probable that at the close of this era this entire area was elevated into 

 dry land and remained such during the early part of the Mesozoic era, 

 for so far we find little evidence of the existence of the lower systems 

 of that group. 



