NIO, S. D., and C. S. YANG, International Geoservices, Leiderdorp, Netherlands; N. TEWFIK and M. DARWISH, Earth Resources Exploration, Cairo, Egypt; and H. JONKMAN, International Geoservices, Leiderdorp, Netherlands
ABSTRACT:
Sequence
Stratigraphy and High-Frequency Cycles: New Aspects for a Quantitative Evaluation of the Gulf of Suez Basin, Egypt
A new development in the application of
sequence
stratigraphic concepts in marine as
well
as continental basins is the recognition of high-frequency cyclic patterns in rock successions in the subsurface. Studies of six wells from the northern, central, and southern parts of the Gulf of Suez show the presence of
well
-preserved, high-frequency cycles with periodicities similar to the orbitally forced Milankovitch parameters. Subsurface rock successions, third-order sequences, and high-frequency cycles were compared with outcrops. After establishing the biostratigraphic framework for the above-mentioned wells, a
sequence
analysis
was performed.
Sequence
boundaries and maximum flooding positions in each
well
were calibrated with the occurrences and evaluation of the high-frequency cycles.
It became obvious that there is an intimate relationship between these high-frequency Milankovitch cycles and
sequence
organization. In addition, a close relationship can be observed in the subsurface as
well
as in outcrops between high-frequency climatic changes (connected to the Milankovitch cycles) and (litho)facies variability. Quantitative evaluations of each
sequence
and/or systems tract can be computed with the International Geoservices' cyclicity
analysis
tool (MILABAR). The results are summarized in a
well
composite chart, which includes interval time estimates (ITE), net accumulation rates (NAR), and ratio of preserved time. In correlations between the wells, an accuracy of 500-100 Ka can be obtained. The quantitative evaluation of the
sequence
and high-frequency cycle
analysis
gave some new aspects concerning the (litho)facies and geodynamic development during the pre- as
well
as the synrift stages of the Gulf of Suez Basin.
AAPG Search and
Discovery Article #90990©1993 AAPG International Conference and Exhibition, The
Hague, Netherlands, October 17-20, 1993.