ERRATA 

 Fig. 3, page 31, should be inverted. 



OIL IN THE REELFOOT AREA. 



31 



several recessions of the sea from the land. 

 As above stated, one of these recessions 

 took place at the close of the Lower Cre- 

 taceous, one at the close of the Upper Cre- 

 taceous, and several during the Tertiary. 

 Between these, there were the correspond- 

 ing advances of the sea upon the land. A 

 retreat of the sea is usually taken to mean 

 an elevation of the land, forcing the shore 

 lines seaward. The other possibility is 

 that the ocean bed may subside, causing 

 the shore line to retreat, or the ocean bed 

 may rise, causing the shore line to advance. 

 Many of the geographic changes of the 

 past certainly have been due to the one 

 cause and probably some of them to the 

 other. In the case of the Embayment area, 

 the evidence is strongly in favor of at least 

 the more important of geographic changes 

 having been produced by elevations and 

 subsidences of the area itself. 



Whether the changes from sea to land 

 and back again, came from oscillations of 

 the area itself or changes in the bed of the 

 ocean is of great importance in considering 

 the possibilities of gas and oil within the 

 area. For if they were due to rising and 

 lowering of the land (both very slow pro- 

 cesses) , it must have followed, as shown by 

 the rocks of all land areas, that some parts 

 moved more than others, while the general 

 movements were in progress. If so, this 

 meant a bending of the beds making up 

 the different formations above described, 

 and this resulted in the formation of anti- 

 clines and synclines; and this in turn 

 formed reservoirs in which oil and gas 

 might collect. 



