Detailed facies analysis of the Brazos wave-dominated delta, Freeport, Texas
Hamilton, Michael Darren
Anderson, John B.
Master of Arts
In order to better define the facies architecture and controlling processes of a wave-dominated delta, a detailed sedimentary and geomorphologic study was undertaken on the New Brazos River delta. The study indicates a much more complex facies architecture than previously postulated and expands the facies model for wave-dominated deltas. The New Brazos delta is primarily composed of fine-grained sediments. Prodelta clay composes more than half of the sediment volume in the delta. Sands are isolated to the bar and nearshore environments. The facies architecture is distinct from adjacent interfluvial zones and not representative of the strandplain model for wave-dominated deltas. The unique facies architecture is a function of the primary depositional process for the delta--floods. In early 1992, statewide flooding facilitated a major constructional phase of the delta. Significant quantities of fine-grained sediments were deposited in the prodelta. One year after the onset of flooding, a bar emerged offshore of the river mouth, and enabled progradation of the delta.