8 GEOLOGICAL SUEVEY OF THE TEERITOEIES. 



to continue Mr. Croxton's boring, which is already 400 feet deep, to a 

 depth of 800 feet, if necessary, so as to settle a vexed question one way 

 or the other. Several thin beds, fifteen to eighteen inches thick, of coal 

 have been found in various parts of the State, and these beds have been 

 wrought with some profit. 



The results of our examinations north of the Platte were that the 

 limestones of the Upper Ooal-Measures pass from sight beneath the 

 water-level of the Missonri at De Soto, and are then succeeded by sand- 

 stones of a Cretaceous age ; that these Coal-Measure limestones occupy 

 about two-thirds of Douglas County ; that no coal-beds of workable 

 character can be found in this country at a less depth than from 800 to 

 1,000 feet beneath the water-level of the Missouri. Limestone of good 

 quality for economical purposes generally is found at Omaha, and all 

 over Sarpy County. On both sides of the Platte Eiver as high up as the 

 Elkhorn are excellent quarries of limestone. There is one ledge of lime- 

 stone on the Platte about four feet in thickness, very compact and du- 

 rable, which tally satisfied the wishes of Mr. J. L. Williams, one of the 

 commissioners for accepting the Union Pacific Railroad, and he in- 

 formed me that its discovery would settle the location of the great rail- 

 road-bridge across the Missouri. One singular geological phenomenon 

 occurs which I have not before observed in any part of the West. The 

 surface of this rock, where the superincumbent drift is removed, has 

 been planed so smoothly by glacial action that it will make most ex- 

 cellent material for caps and sills without farther working. Sometimes 

 there are deep grooves and scratchings, all of which have a direction 

 nearly northwest and southeast. This glacial action is also seen at 

 Plattsmouth, and the evidence is that if the superficial deposits were 

 stripped off, a large area of the upper surface of the limestones would 

 appear to be planed in this way. This is an exceedingly important 

 geological discovery. At various points I found potters' clay in abun- 

 dance. A factory for making potters' ware is about to be established at 

 JSTebraska City. At Plattsmouth, Rock Blaff, and ^Nebraska City there 

 is a bed of this clay about fifteen feet in thickness, of various colors, 

 mostly red, colored with the sesquioxide of iron. This clay is not only 

 most excellent for potters' use, but it is employed in Iowa as a paint, and 

 by a judicious mixture of the different colored clays any shade desira- 

 ble may be produced. This is a matter of some interest to the people. 

 Namerous beds of sand occur also, which are of much value for building- 

 purposes. 



With the sand and the yellow marl, the materials for making brick 

 are without limit in this State. 



THE SALT-BASINS OF LANCASTER COUNTY. 



I returned last evening from a tour of five days to the salt-basins in 

 Lancaster County, about fifty miles west of Nebraska City. It has 

 been determined by the State to locate the capital near these basins, 

 and therefore the examination of them and the country in the vicinity 

 became a matter of some importance. The basins and scattering springs 

 occupy a large area several miles in extent, but the main basin is located 

 near the town of Lancaster. These basins are depressions in the sur- 

 face nearly destitute of vegetation, and the white incrustations of salt 

 give the surface the appearance in the distance of a sheet of water. 

 The Great Basin, as it is called, is situated about one mile from Lancas- 

 ter, township 10, range 6, section 22, and covers an area of about four 

 hundred acres. The brine issues from a large number of places all over 



