ABSTRACT

The Houma embayment is a structural downwarping of the middle Miocene continental shelf which has been contemporaneously filled with a northward thickening wedge of deltaic plain sands and deep marine shales. The embayment wedge is terminated on the north by an arcuate down-to-the-coast growth fault system. To the south the wedge thins to a thickness of a few hundred feet where it is down faulted below existing well control by post embayment faulting. A series of paleostructure maps demonstrates that the basin subsided by northward rotational tilting into the boundary fault system. Hydrocarbon accumulates where regional northward dip is interrupted by local south dip, or, as in most cases where northward plunging noses are terminated on the south by faulting. It is the thesis of this paper that regional northward dip and thickening of rotational blocks into arcuate down-to-the-coast growth faults can be observed in all similar embayment type structures, of which there are many in south Louisiana. The Houma embayment is seen at relatively shallow depths and major hydrocarbon accumulations within the embayment wedge have encouraged a great amount of deep drilling. Information obtained from the deep drilling allows the structural history of the Houma embayment to be accurately reconstructed and used as a model for deep exploratory drilling in other areas.