Sedimentary facies of the modern Trinity Delta

The Trinity River Delta is a recent bayhead or estuarine delta at the head of Trinity Bay. It has grown outward from the eastern edge of the Trinity alluvial valley and has isolated a small segment of Trinity Bay, forming Lake Anahuac. It differs significantly from the several major deltas which have been so thoroughly described in geologic literature in that it is small; the subaerial part occupies less than six square miles - and in that it is growing into a shallow protected bay characterized by water salinities much lower than normal marine. This chapter describes the physical setting and surface facies of the delta and adjoining bay and the three dimensional distribution of the facies within the delta.