A sedimentolgic description of a microtidal, flood-tidal delta, San Luis Pass Texas.
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Date
1987
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Abstract
San Luis pass is a microtidal inlet located at the southwest end of Galveston Island, Texas. Continuous cores taken with a portable vibracoring rig, and surface grab samples provided data for construction vertical sequences and three-dimensional sedimentologic descriptions of the flood-tidal delta complex. These descriptions are based on the type of vertical and lateral distribution of lithofacies, sedimentary structures, textures and trace fossils. A vertical sequence through the flood-tidal-delta complex consists, from base to top, of highly bioturbated bay muds and associated oyster reefs; highlty bioturbated clayey sand/sandy clay of the tidal delta margins; burrowed sand and shelly sand of the tidal delta; and rooted or burrowed mud of the marsh or mud flat. Washover shell hash deposits may occur at random intervals throughout this sequence. A vertical sequence in the vicinity of San Luis Pass consists of a basal tidal inlet deposit of graded layers of sand and shell overlain by burrowed to shelly sand of the barrier spit. This description of a microtidal, flood-tidal delta differs significantly from descriptions presented for meso-tidal, flood-tidal delta systems in the 1) general lack of large-scale, high-angle sedimentary structures; 2) presence of intense bioturbation; 3) presence of washover deposits, and 4) general coarsening-upward nature of the vertical sequence.; $
Description
p. 288-300.
Keywords
deltas, geology, sedimentation, shoaling, flooding, port installations, sediment distribution