30 RESOURCES OF TENNESSEE. 



course, applies to those areas where all the formations occur, 

 as they quite certainly do in southwestern Tennessee, and as 

 is indicated in the Reelfoot Lake area, by the depth of the well 

 south of Samburg. If wells should be put down on or a short 

 distance east of the bluffs of the Mississippi, there should be 

 added to this, perhaps 10 feet for the Lafayette and on an 

 average of 50 feet for the loess, making a total thickness of 

 approximately 2348 feet. One of the wells at Memphis was 

 sunk 2517 feet without reaching the old rock floor, which indi- 

 cates, as elsewhere mentioned in this paper, a thickening of the 

 Cretaceous in the middle of the Embayment. 



STRUCTURE OF THE AREA. 



As will be seen by reading the preceding article in this num- 

 ber of the Resources, the occurrence of oil or gas in any area 

 depends largely upon the structure, or the lay of the forma- 

 tions occurring beneath the surface ; and as the Reelfoot Lake 

 district is a part of the Embayment area, its structure can be 

 understood only when taken in connection with that of the 

 whole area. 



In Tennessee, the general dip of the formations described 

 above is to the west. According to the observations of Dr. 

 Glenn* this does not much exceed 20 feet to the mile. In Ken- 

 tucky, the dip swings around to the southwest, in Illinois to the 

 south, and in Missouri and Arkansas to the southeast and east. 

 It will thus be seen that the formations of the Embayment area 

 lie as a wide trough, the sides of which slope in a general way 

 toward the Mississippi, though the lowest part of the trough 

 may not be on the present line of the river ; and that the Reel- 

 foot district, situated as it is near the head of the Embayment 

 area, is in the focus of the southwest, south, and southeast dips 

 of that part of the Embayment area in Kentucky, Illinois and 

 Missouri. 



The above is the general structure in the Embayment area. 

 As to smaller structural features, it will be recalled that since 

 the early deposits of the area were formed, there have been 



*Loc. cit. 



