Study of Active Surface Faults in Fort Bend County, Texas, USA

Due to many active surface faults, public structures in the greater Houston area have suffered damage, resulting in costly reconstruction and condemnation. Fault studies are essential to predict further damage of existing structures, determine how to mitigate potential hazards, and prevent future construction too close to faults. Detailed studies have thoroughly mapped the more than 300 active surface faults in Harris County. Many of them have been established as part of a larger, regional, down-to-the-basin fault system along southeastern Texas. Others are considered to be radial faults caused by the salt domes. Some may have recently become active due to subsidence. However, detailed study on the faults of Fort Bend County is lacking. Fort Bend County borders the southwestern edge of Harris County, and so is subject to the same regional depositional tectonics. Previous studies have indicated faults in Fort Bend County. However the causes and precise mapping is not done yet. Based on the newly acquired Light Detection And Ranging (LiDAR) digital elevation models, several lineations can be observed. One such lineation is cutting the levee of the Brazos River. Another one appears to be a fault recognized by earlier studies in Needville. The Brazos and Needville faults appear to follow the pattern of the faults in northwestern Houston. For this study LiDAR images were analyzed in ArcMap to locate scarps. Field work was carried out to confirm LiDAR results. Ground Penetrating Radar (GPR) was used to determine the structural trends and subsurface geometry of these possible faults. Comparing results of this work with the earlier work in Harris County may provide more information on faulting in Fort Bend County.