GEOPHYSICS LETTERS

Ghalib M. et. al. 59sediments deposited in shelf environment tend to generate parallel togently divergent reflection configurations having a widespread sheet orwedge-shaped external form (Sangree and Widmier, 1979).Depositional environment of Nullipore rock:On the available interpreted seismic grid, the reflection patterns, ofHammam Faraun seismic sequence (Nullipore rock), are of greatcontinuity and high amplitude in the main parts of the sequence. Bycompare the external form of the Hammam Faraun seismic sequence onthe dip lines: Line-I, Line-2, Line-3, Line-4, Line-5 and Line-6, asshown on the shoot points and well location map, Fig. (3), with theexternal form to it on the strike lines: Line-9, Line-IO and Line-I I, we, can conclude that, the external form of the Hammam Faraun sequence issheet- like to wedge-shape. These two parameters of high continuity andhigh amplitude of reflection patterns, and the sheet-like external formreflect that, the Hammam Faraun Member is deposited in shelfenvironment (shallow marine environment), which is suitable tocarbonate build-ups.On little parts of the Hammam Faraun sequence, the reflectionpatterns change from high continuity and high amplitude parallelpatterns to chaotic and reflection free to amplitude anomaly patterns.These patterns (chaotic and reflection free to amplitude anomaly) revealthat, the energy is high in these parts of the sequence than the main parts(which represent parallel patterns with high continuity and highamplitude). These conditions are suitable to reefs growth. The seismicfacies units on the sequence of Hammam Faraun, which representchaotic and reflection free to amplitude anomaly reveal the presence ofreefs in these parts of the sequence.Interpretation of reflection configuration:Seismic reflection termination and configurations are interpreted asstratification patterns and are used for the recognition and correlation ofdepositional sequences, interpretation of depositional environment, andestimation of litho-facies (Mitchum et ai, 1977- part 6). Seismic faciesunits are mappable, three dimensional seismic units are composed of agroup of seismic reflections, whose parameters (configuration,amplitude, continuity, frequency, and interval velocity) differ from the