i;Ei'()Rr ox iii'.i.i) WORK IN (•.\:()]j)r,\. 103 



of Erie, is the lead and zinc bearing rock at the prospect borings 

 north of town, and has been provisionally named the Erie limestone. 



First above the Erie limestone, at a vertical elevation of nearly a 

 hundred feet, is the lola limestone, numbered 4 in Mr. Kirk's section. 

 This is the heavy beds exposed south of lola for miles, and in which 

 the lola (juarries are located. It extends westward to Benedict, and 

 down the Verdigris river some distance, according to Mr. Piatt. It 

 crosses the stream and extends an unknown distance to the southwest. 

 To the northeast it covers a large area, and reaches to Lane and 

 Fontana, in Kansas, from whence it crosses over into Missouri, con- 

 stituting one of the best defined and most persistent limestone systems 

 in the eastern part of the state. 



It will thus be seen that not only an occasional limestone system is 

 persistent, but that a majority of them are so, the three just mentioned 

 being the first three, save one, above the lead and zinc bearing 

 Mississippian formations in the extreme southeastern part of the state. 

 It was decided early in our work that it was of first importance to get 

 these great limestone systems located and accurately mapped, after 

 which the more varying sandstones and shales can be studied to any 

 degree of detail desired for each particular locality. Therefore the 

 drawings of the sections accompanying these papers represent the 

 limestone only. They represent accurately the location of the south- 

 eastern outcropping of each system, and the place where each passes 

 beneath the surface, but being drawn to so small a scale there is 

 necessarily some inaccuracy in the representation of the thickness 

 and vertical distance between two neighboring systems. This error, 

 however, is not great. The greatest error in the drawings is in the 

 angle of dip, which in no case was measured accurately, either in the 

 field or in making the drawings. The dip is so small that nothing 

 less precise than actual leveling by means of the engineer's transit 

 can be of value. This has thus far been impractical, very satisfacto- 

 ry results, however, have been obtained by observing where the two 

 limits of exposure are located, and determining from maps the distance 

 and variation of surface levels, frcjm which the number of feet dip 

 per mile is readily calculated. In this way it is found that the 

 general average of dip where studied is approximately nine feet to the 

 northwest. Local variations sometimes seem to contradict this, so 

 that the statement must be made in a general way. 



The sandstone formations have no such continuity. Formed along 

 coast lines and near the shores of the ancient seas they necessarily 

 will be much more limited in transverse directions, and longitudinally 

 will also be confined more or less to the neighborhood of streams 

 which brought the sand from dry land. Many instances are known 



