104 K. ORTON (iKOLoaiCAJ. STKU(.'TITRE OF lOLA GAS I'IKLT) 



sisting largely of shale, as the name would lead us to expect, thin 

 courses of limestone and considerable bodies of sandstone also occur 

 in it. Some of the sandstones rise in important and valuable outcrops ; 

 but other beds begin and end in the shale series, and for our knowledge 

 of them we are indebted wholl}'' to the driller. They are capricious 

 and unstable to a high degree. 



Other divisions. — Above the Cherokee shales come several well marked 

 and easily identified divisions known in Kansas geology as the " Oswego 

 and the Pawnee limestones," about 100 feet in combined thickness, the 

 " Pleasanton shales," about 250 feet thick and carrying in certain locali- 

 ties valuable beds of coal, the " Erie limestone and shale," the " Thayer 

 shale," and the " Tola limestone," together aggregating several hundred 

 feet of strata. 



The divisions here named comprise all the strata traversed in the 

 wells of the lola gas field. 



lola gas rock. — The gas rock already described is one of the unstal>le, 

 lenticular sandstones of the Cherokee shale, and lies near the bottom of 

 this division. Its upper surface is above 75 feet above the Mississippian 

 limestone. 



All these strata are described by Haworth as dipping to the west at 

 an average rate of 17 feet to the mile. 



The surface of this portion of the state also slopes to the west, but not 

 as rapidly as the strata descend. The surface slope to the westward is 

 given by Haworth as about 10 feet to the mile. These facts are indicated 

 in the accompanying diagram (plate 11). The elevation of Tola is 956 

 feet above tide; of Taharpe, 5 miles to the eastward, 1,045 feet, and of 

 Moran, 12 miles east of Tola, 1,098 (see Gannett's Gazetteer of Kansas). 

 This gives an average descent from Moran to Tola of nearl}' 12 feet to the 

 mile. Other elevations used in this paper were obtained from the ane- 

 roid and can not vary far from the true figures. 



fold arch at Edwards well. — At the Edwards well, two miles ])e3'ond 

 Laharpe, the lola gas rock has completely disappeared as a-sandstone, 

 l)ut the driller continued his work until he reached the Mississippian 

 limestone, or the " flint," as it is commonly called. This was reached 

 at 1,061 feet, or very nearly at tide level. The same stratum was also 

 struck in one of the wells at Laharpe, but here at a depth of 982 feet, or 

 63 feet above tide, showing a rise to the westioard of 31 feet to the mile in 

 place of the normal descent in that direction of 17 feet to the mile. 



A low arch, which may, perhaps, with greater propriety be styled a 

 terrace, thus comes into view. So far as present knowledge goes, the 

 arch begins at the location of the Edwards well, in which, as will be re- 

 membered, the surface of the Mississippian limestone lies 3,t tide level, 



