Paleontology is the primary basis for these correlations. In general, it may be 

 said that the greater the distance between stratigraphic sections, the more dif- 

 ficult and uncertain the correlation. 



GENERAL TO DETAIL Before an attempt is made to unravel geologic 



PROCEDURE IN problems, whether they involve structure, 



CORRELATION paleontology, or stratigraphy, it is sound 



practice to outline, first, the broad aspects of 

 the problem — in other words, generalize the situation. Once a problem is 

 generalized, the details within its boundaries then can be investigated. Follow- 

 ing the detail stage, the problem should be re-generalized and re-detailed 

 periodically. Figure 23-7 serves as a basis for this procedure. Let it be assumed 

 that stratigraphic sections 1, 2, and 3 have been measured, sampled, and accur- 

 ately described lithologically and paleontologically and that the major lithic 

 units (1, 2, 3) of the sections have been defined. Correlation of the minor beds 

 within each major unit is the next step. This procedure is extremely applicable 

 also in correlating mechanical well-log profiles — the entire profile should be 

 examined before the minor peaks and valleys between major boundaries are 

 evaluated. 



Figure 23-8. Simple structure and stratigraphy. Correlation of stratigraphic units in the 

 three wells should offer no difficulty provided sufficient well samples and cores were 

 available. 



446 



