Graphic Correlation Analysis of Upper Tertiary Rocks in the Gulf of Suez and Nile Delta, Egypt, and the Adana Basin, Southern Turkey: Advantages and Improvements in Stratigraphic Resolution for Exploration and Production

By

William N. Krebs¹

(1) Energy and Geoscience Institute, Houston, TX

 Graphic correlation illustrates the relationship of rock sections to geologic time. A line of correlation (LOC) drawn through paleontological datums that have been calibrated to geologic time depicts this relationship. The LOC consists of oblique line segments separated by horizontal lines or “terraces.” If not fault related, these terraces represent hiatuses produced by erosion (unconformities) or transgression (condensed intervals). The oblique segments are rock sections with continuous deposition, or “chronostratigraphic sequences.” Sedimentation rates and missing geologic time are estimated from the LOC’s, and their integration with seismic and geologic data on the workstation enhances stratigraphic interpretations in exploration and production.

Graphic correlation of Upper Tertiary rocks in two tectonic and one deltaic basin in the eastern Mediterranean region indicates that they consist of several chronostratigraphic sequences. The Upper Tertiary section of the Gulf of Suez is divided into nine widespread sequences that reflect basin evolution through rift initiation, climax, and post-rift phases. Play types are related to rift phase: half-graben fills during rift initiation, turbidites and fans at climax, and deltas and evaporites in the post-rift phase. Hiatal events within the syn-rift section reflect major tectonic events. Correlative rocks in the Adana Basin of southern Turkey consist of four chronostratigraphic sequences whose hiatal boundaries are also related to tectonism. The Messinian-Quaternary section of the Nile Delta, however, contains six widespread hiatuses produced by eustatic fluctuations. Those formed by regional flooding are effective gas seals in the Nile Delta.