FACTORS CONTROLLING 



CORRELATION 



INVESTIGATIONS 



Some of the more critical factors controlling 

 the solution of correlation problems are the 

 following : 



Lateral Continuity of Deposits 



The more uniform the lithology and paleontology of a stratigraphic se- 

 quence, the less difficult the correlation of surface and subsurface units (fig. 

 23-8). 



Structural Complexity of Section 



In areas where the section is highly folded and faulted, and unconform- 

 ities are present, correlations are frequently complicated — at least, until a 

 normal stratal sequence has been established (fig. 23-9 . 



Availability of Basic Data 



In some areas stratigraphic data are extremely meager or absent. In such 

 cases the geologist is greatly handicapped and must bide his time until data 

 become available. 



Figure 23-9. Complex structure and stratigraphy. Correlations of stratigraphic units above 

 and below the unconformity would be difficult and would require considerable sub- 

 surface control. The pre-unconformity section in Well 1 would be practically impossible 

 to correlate with its equivalent section in Well 3 without intervening facies control. 

 The same would apply in the post-unconformity sections of Wells 1 and 3. 



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