The floodplains of many East Texas rivers contain anomalous sand mounds averaging about one meter in height and from 30 ft (10 m) in diameter to almost 20 acres (8 ha). The Brazos County reach of the Navasota River contains several of these mounds. There is very little literature addressing floodplain sand mounds and none which expresses a geomorphic explanation.
Continuous core data have revealed that the mounds are closely related to the evolution of the Navasota River. Scanning Electron Microscopy (SEM) analysis of quartz sand grains, pedologic studies, fluvial geomorphic reconstructions, and sedimentary structure investigations leads to speculation that the mounds are remnants of linguloid bars formed in Late Pleistocene (Deweyville?). These remnant bars have been topographically enhanced by vegetative trapping of aeolian sands derived from the floodplain.