368 F. H. OLIPHANT 



portion of the production however, comes from the Catskill 

 division, upper Devonian, which o^roup is petroleum bearing 

 from northern Pennsylvania, near the northern portion of 

 Venango comity, southwest to the Little Kanawha river in 

 West Virginia. In Warren, McKean, and Elk counties Pa., 

 productive sands are found below this group and are largely 

 productive. They extend into south central New York and 

 belong to the middle Devonian formation. The overMng 

 Berea and the Pocono or Big Injun and lower carboniferous 

 sands are above the Catskill group m the geological scale, and 

 are largely productive in West Virginia, southeastern Ohio, 

 and to some extent in eastern Kentucky. The highest series 

 of productive strata in the region east of the ^lississippi river 

 are composed of the sands of the upper and lower coal series, 

 which are productive m southwestern Pennsylvania, West 

 Virghiia and southeastern Ohio. The sandstone series of the 

 Appalachian division produce 36 per cent of the total produc- 

 tion. 



Over 85 per cent of the petroleum produced in the United 

 States from the begummg of production up to the present 

 time also comes from the sandstone strata of the Appalachian 

 field. Here there are 40 distmct horizons m 3,300 feet of 

 measures, and the individual beds of sandstone var\' from 2 to 

 120 feet m thickness and differ in texture from an open light 

 colored sand \\'ith layers of pebbles, which is very prolific, 

 to sand of a close and hard texture, which it is necessar}' to 

 torpedo in order to secure production. The highest produc- 

 tive sand of an}' practical value in the geological scale is the 

 ^lahonmg, or Dmikard sand of Pemisylvania or the first Cow 

 Rmi sand of Ohio; the lowest is the Kane sand in Elk and 

 McKean coimties, Pa., and the sands of western Xew York. 



The source of the petroleum in the Lima, Indiana field 

 is the Trenton limestone, which has produced verj^ largely 

 since first discovered in this field in 1S85. From its first dis- 

 covery this formation has produced 9 per cent of the total 

 output of the United States. It is productive only in the 

 region which embraces northeastern Ohio and central Indiana, 

 kno\Mi as the Lima, Indiana field. 



The horizon in which petroleum is found in Kansas and 



