Xlii REPORT OF THE STATE GEOLOGIST. 



On the southern portion of this seam, or that within the Colorado 

 Coal Field, there have been numerous prospecting shafts sunk, but no 

 coal of any consequence has been mined except for local consumption. 

 The various mines were described in the First Annual Report. The 

 principal ones are located north of Santa Anna, on Bull Creek, Home 

 Creek, and at and near Waldrip. 



The thickness of these two seams is about equal, each averaging about 

 thirty inches of clean coal. They are similar also in having at most 

 places a parting of clay, or " slate," of a few inches in thickness. While 

 the outcrops of the two seams are parallel to each other in a general 

 way, they vary from twenty-five to forty miles apart. 



In the northern portion the seams are separated by some twelve hun- 

 dred feet vertical thickness of limestones, clays, and shales. This thick- 

 ness, however, increases rapidly toward the south. 



As has been stated, the dip is gentle ; that of seam No. 1 will not aver- 

 age over sixty-five feet, and that of No. 7 is less than forty feet. The 

 average increase of elevation of the surface of the country toward the 

 west is only a few feet per mile (not exceeding ten), and in consequence 

 the extension of these beds can be found anywhere within eight to ten 

 miles west of their outcrops at less than six hundred feet in depth. 



The linear extent of the outcrops of these two seams is fully two 

 hundred and fifty miles. They are probably workable for at least ten 

 miles west of their line of outcrops, giving us an area of twenty-five 

 hundred square miles of coal lands. Even if only two-fifths of this 

 area prove to be fully adapted to coal mining, we have one thousand 

 square miles, each of which contains nearly three millions of tons of 

 coal. 



The roof of these coal seams is sandstone, limestone, or a hard clay 

 which makes a good roof. The mines are generally dry. 



The quality of the coal varies considerably. In some few places it 

 is high in sulphur, in others very little is found. It also varies greatly 

 in the amounts of ash and moisture contained in it, as well as in its 

 fuel constituents, but careful selection will result in a fuel that will give 

 perfectly satisfactory results. 



Of its value as a steam coal there can be no doubt, for it has been 

 fully tested for railroad and other uses, and is taken as fast as it can be 

 mined, leaving practically none to be sold for ordinary purposes. 



So far as I am informed there has been but one attempt at testing its 

 coking qualities in regular coking ovens. This was done by the man- 



