36 RESOURCES OF TENNESSEE. 



Lower and Upper Cretaceous times, and equally probable that 

 it was the last to be vacated. Granting that these conditions 

 were true, it was the area of longest deposition, and conse- 

 quently the thickest deposits should be expected there. 



6. As above stated, any well started should be sunk to the old 

 hard rocks upon which the Cretaceous beds rest, unless com- 

 mercial amounts of oil or gas should be struck before that depth 

 is reached. To the present, no prospective gas or oil well has 

 reached these old rocks, but their top is probably not very far 

 below the point reached in the deepest drill hole at Memphis 

 arid in the one at Reelfoot Lake. 



7. It must be understood that no assurance can be given of a 

 successful well in an undeveloped area, but if prospecting 

 should be continued in the Reelfoot district, the low flat anti- 

 cline described by Mr. Fuller* as the Tiptonville dome should 

 be the guide to it. The wells should be sunk near a straight 

 line beginning some 4 miles south of Tiptonville and running 

 just east of that place, toward New Madrid. The northern 

 limit of the area is about half way between the State line and 

 New Madrid, in the loop of the river. 



8. The Caddo oil field of northwestern Louisiana is located on 

 a structural dome, and the oil comes from the Upper Creta- 

 ceousf the deposits which are similar in character to those 

 of Tennessee. This lends encouragement to the formation 

 being oil bearing in Tennessee, provided the necessary struc- 

 tural conditions occur. 



9. The formations considered in this paper are those of Cre- 

 taceous and Tertiary age. As far as our knowledge of them 

 goes, it is not impossible for the old rocks that form the floor 

 of the Embayment, in places to contain oil and gas; but the 

 difficulty in locating wells in them is even greater than in the 

 younger rocks above. 



*Loc. cit. 



fHarris, G. D., U. S. Geol. Surv., Bull. 429, pp. 127-8. 



