Plan-view and subsurface architectural study of ancient fluvial deposits and modern coast

This study explored the potential of using different remote sensing tools to study poorly-exposed sedimentary deposits. In the first two chapters, two ancient fluvial deposits in the Cretaceous Ferron Sandstone, were studied which are extensively exposed in plan-view near Hanksville, Utah. In the last chapter, the effect of severe-storm events on modern coastal settings were studied in parts of Galveston Island and Follets Island, Texas.

In the second chapter, closely-spaced paleocurrent and grain-size data from an outcrop of point bar assemblages were combined with Airborne Light Detection and Ranging (LiDAR) in the delta plain deposits. Four meander loops with scroll bars were identified on hillshade images. The loops show a combination of growth by lateral expansion and downstream translation. Paleocurrent directions closely follow the shape of individual scroll bars. Comparison with larger sand bodies in underlying valley systems suggests that the studied channels represent the upper delta plain distributary channels and indicate an overall backstep with respect to channels in the immediately underlying incised valley.

In the third chapter, we integrated LiDAR, and Ground Penetrating Radar (GPR) to investigate the three-dimensional architecture of plan-view outcrops of an ancient fluvial channel-belt. The belt was built by migration and amalgamation of smaller unit bars. GPR data shows that the mid-channel bars were formed by downstream accretion and had a vertical aggradation component as well. However, the side channel bars were exclusively developed by lateral accretion toward the outer bank. In between the mid-channel bars and sidebars, small channel-fill deposits were found filled up by vertical aggradation.

In the fourth chapter, we studied the effect of Hurricane Ike on the selected areas of Galveston Island and Follets Island by combining time-series of Airborne LiDAR and GPR. The results shows that Hurricane Ike caused massive erosion in both islands that was followed by shoreline accretion during the storm recovery phase. The shoreline in Follets Island had recovered but not in Galveston Island. In 2012, the dune system was still recovering in both islands. The subsurface data shows that although the whole island was covered with flood water during Ike, storm surges only eroded the frontal dunes.

In the fourth chapter, we studied the effect of Hurricane Ike on the selected areas of Galveston Island and Follets Island by combining time-series of Airborne LiDAR and GPR. The results show that Hurricane Ike caused massive erosion in both islands that was followed by shoreline accretion during the storm recovery phase. The shoreline in Follets Island had recovered but not in Galveston Island. In 2012, the dune system was still recovering in both islands. The subsurface data shows that although the whole island was covered with flood water during Ike, storm surges only eroded the frontal dunes.