ABSTRACT

The West White Lake field, located in White Lake in southwest Vermilion Parish, Louisiana, is a faulted, northwest-southeast elongated, ridge-like anticline. The elongation is normal to the regional strike of the beds and is attributed to anticlinal buckling operating parallel to the strike. The structure is cut by both down-to-the-basin and up-to-the-basin faults. The down-to-the-basin faults are generally regional in nature while the up-to-the-basin faults are mostly smaller compensating faults confined to the West White Lake field.

The West White Lake structure originated with anticlinal folding and faulting on the continental slope during Abbeville and Planulina time. Fault movement and anticlinal buckling were contemporaneous with sedimentation, acted more or less continuously from Abbeville to Pliocene time, and were greatest when the structure was located on the outer continental shelf. Structural activity steadily decreased as the hinge line with its unstable environment migrated seaward and the structure became positioned progressively closer to the shoreline.

A multitude of down-to-the-basin faults are present parallel to the regional arcuate strike of the beds in South Louisiana. Where anticlinal folds, which occur at frequent intervals normal to the strike, are cut by such faults, a producing structure such as West White Lake may result. Other structures, including salt domes, may occur at the points of weakness created by the intersection of down-to-the-basin faulting with the anticlinal folds. Producing structures are therefore aligned at right angles, as well as parallel to, the regional bed strike. The result of this orderly structural arrangement is a grid or "checkered" pattern of the producing structures in South Louisiana.