SOMETHING ABOUT OIL. 293 



which accumulates (2) in the fissured shaly limestones of 

 the Hamilton group, and thus supplies (C) the Ontario oil 

 region, locally divided into (a) the Bothwell district, (b) 

 the Oil-Sj^rings district, and (c) the Petrolea district. 



The Marcellus shale affords also a large portion of the 

 oil which accumulates (3) in the drift gravel of the Onta- 

 rio region. 



III. The Genesee shale, with perhaps some contributions 

 from the Marcellus shale, affords oil which accumulates (4) 

 in cavities and fissures within itself in (D) some of the Glas- 

 gow region of Southern Kentucky. 



It affords also the oil which accumulates in (5) the sand- 

 stones of the Portage and Chemung groups in (E) North- 

 western Pennsylvania and contiguous parts of Ohio. 



It affords also the oil which accumulates in (6) the sand- 

 stones of the Waverly (Marshall) group, in (F) Central Ohio. 



It affords also that which accumulates in (7) the moun- 

 tain limestone of the Glasgow region of Kentucky and con- 

 tiguous parts of Tennessee, as also some of that which is 

 found in the drift gravel of the Ontario region. 



IV. The shaly coals of the false Coal-measures, aided, 

 perhaps, by the Genesee and Marcellus shales, seem to af- 

 ford the oil which assembles in (8) the coal conglomerate 

 as worked in (G) Southwestern Pennsylvania, (H) West 

 Virginia, (I) Southern Ohio, and the contiguous but com- 

 paratively barren region of Paint Creek, in Kentucky. 



V. The Coal-measures may perhaps be regarded as af- 

 fording a questionable amount of oil, which may have been 

 found within the limits of (9) the Coal-measures in the West 

 Virginia and neighboring regions. 



From this exhibit it appears that the principal supplies 

 of petroleum east of the Rocky Mountains have been gen- 

 erated in four different formations, accumulated in nine dif- 

 ferent formations, and worked in nine different districts. 



