DETAILED TEXTURE AND HEAVY MINERALOGY OF RECENT SANDS ALONG THE NORTHEASTERN TEXAS GULF COAST AND A RESULTING MODEL FOR BARRIER FORMATION

[摘要] Numerous textural and heavy mineralogical analyses have been performed on sand samples from the northeastern Texas Gulf coastal region. Analyses of local point-bar samples result in the delineation of major river and sources, with average histograms of grain-size data showing combinations of discrete modes characteristic of each river. Similar study of area coastal sands allows distinction of river, beach, and fluvial- and wave-dominated deltaic sands on the basis of texture. Kyanite/garnet/hornblend + pyroxene ratios are an excellent criterion for evaluating source contributions to the coast. Combining approximated age (radiocarbon) dates and heavy-mineral ratios results in the delineation of two distinct sand types. Spatial relationships between the two are used to develop a model for barrier formation. The model is then compared with previous models, applied to local problems of beach erosion, and discussed with regard to the ancient record.

[发布机构] Rice University