GEOLOGICAL PAPERS. 85 



OIL INVESTIGATIONS IN ILLINOIS. 



By Raymond S. Blatchley, 

 Geologist in charge of oil studies, State Gelogical Survey. 



IXTRODUCTIOX. 



In the short time available, it is possible to outline only very 

 briefly the investigations by the State Geological Survey, cover- 

 ing the present immense oil fields and other prospective oil areas. 

 I will give first, a brief histcr>- of operations in Illinois, then a 

 short statistical statement, an accoimt of the origin and accimiu- 

 lation of oil. and linally an outline of the investigations. 



HISTORICAL STATEMENT. 



The first oil excitement spread over the eastern United States 

 in the early part of the "sixties' and extended westward to Illi- 

 nois. In 1865 the first "wild-catting" took place in Clark Count}-, 

 about eight miles north of Casey. Here several wells were 

 drilled in attempts to locate oil and gas but the work was aban- 

 doned. A ver>- small amount of oil was found, which, perhaps, 

 would have been greater had proper casing been used. Water 

 drowned out the oil and prevented an earlier discovery of the 

 present extensive field. Oil was foimd about this time in a simip 

 in a mine near Litchfield, Montgomery' County, but its exploita- 

 tion was delayed until 1SS2. A small field of 30 wells, that pro- 

 duced several himdred barrels annually, was outlined between 

 1SS2 and 1SS9. Production is wholly abandoned at the present 

 time. The oil came apparently from the Pottsville sands. 



A gas field was discovered along an anticline in the Niagara 

 limestone near Pittsfield, Pike Count}-, during 1SS6. About 30 

 wells have been drilled and 2i found to be productive in an area 

 covering 4 by 10 miles. Similar prospecting took place near 

 Sparta, Randolph Count}-, in 1888. Several good gas wells were 

 found in the Chester formations of the Mississippian series of 

 rocks. The field was further extended in 1906 and 1908 to the 

 north of Sparta where about 6 wells produced small amounts of 

 oil. Production is all but abandoned now. 



Further "wild-catting"' took place in Crawford Count}- between 

 1900 and 1904, but this field was not opened until 1906. The 

 Casey region was re-drilled in 1904-1905 and oil was found in 

 commercial quantities. The field spread rapidly and gradually 

 merged into the deeper and deeper pools of Crawford and Law- 



