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GEOLOGY. — Structure of the Vicksburg-Jackson area, Mississippi. 

 Oltver B. Hopkins. U. S. Geological Survey Bulletin 641-D. 

 Pp. 93-120, with 1 plate. 1916. * 



The object of this report is to show which of the areas in west- 

 central Mississippi that were examined by the Survey are considered 

 favorable and which unfavorable for the occurrence of oil, to discourage 

 drilling in the unfavorable localities, and thus to aid those interested 

 in making conclusive tests to determine the presence or absence of oil 

 and gas. 



All the rocks of the area are sedimentary in origin and are relatively 

 young, the exposed rocks ranging in age from Claiborne (Eocene) to 

 Recent. Of these formations the loess and the Jackson underlie by 

 far the greater part of the area, and the Vicksburg and Catahoula 

 formations and the terrace sand and gravel underlie smaller areas. 



The genera] structure of the Gulf coastal plain is simple. A series 

 of beds slopes gently southward and passes successively deeper and 

 deeper beneath more recent deposits toward the coast. This general 

 dip toward the coast is interrupted by local steepening or flattening 

 and in a few places by a reversal in direction. These irregularities of 

 dip, which are of greatest significance in the accumulation of oil and 

 gas in valuable pools, are well illustrated in the Vicksburg-Jackson 

 area. The geologic structure is represented on a map by contours on 

 the Vicksburg limestone. The possibilities of oil and gas occurring in 

 the area are dicussed and the most promising areas for prospecting 

 are pointed out. R- W. S. 



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