The Jurassic Cotton Valley Group in Mississippi is considered generally to be one formation, roughly equivalent to the Schuler Formation of Louisiana. Gross changes in lithology and electric log characteristics are observed across the state of Mississippi. These lateral variations are best discussed in terms of the depositional systems operant during Cotton Valley sedimentation. Through use of sand percentage and sand isolith maps, various depositional systems can be discerned.

Two delta systems existed in Mississippi: a constructive delta in the west-central part of the state, and a destructive delta in the east-central part. An interdeltaic system in central Mississippi, between the two delta systems, was bounded possibly on the south by a barrier-bar system. Elevation above wave base, caused by positive influence of the Wiggins arch and Hancock County high, resulted in development of a strand-plain system in southeast Mississippi. Lack of well control precludes a definitive statement about depositional environment in the southwest part of the state. By geographic relationship to the other depositional systems, a shelf system is inferred.

Recognition of the Cotton Valley depositional systems in Mississippi aids in identifying potentially productive trends which have yet to be adequately explored.

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