3-D Facies Architecture, Grain Size Variability and Paleohydrology Study of Point Bar Deposits by Integrating Field Data With Airborne LiDAR and GPR in Ferron Sandstone, Hanksville, Utah

Abstract

The geometry of amalgamated channel belt and associated bar deposits and the nature of interconnectivity has significance in characterization as an analog for fluvial hydrocarbon reservoirs. Plan-view outcrops of ancient point bars in the Cretaceous Ferron Sandstone near Hanksville, Utah permit study the 3D geometry of fluvial deposits and allow paleohydraulic reconstruction of the ancient river. Five hundred paleocurrent and eleven hundred grain size data are integrated with a 16 km2 airborne Light Detection And Ranging (LiDAR) and Color Infrared (CIR) aerial photographs. There is a general downstream decrease in grain size from south to north. Paleocurrent analysis shows that in a east to west traverse, the dominant flow direction gradually changes from north-west to south-east. However, the flow direction progressively shifts from south-east to north-west along a north-south traverse. We hypothesize that these changes in flow direction indicate different channel-belt deposits. The dimension and distribution of point bars were determined with the airborne LiDAR data. LiDAR intensity data and CIR images are used to discriminate grain size of sediements as coarse grains are more reflective than finer ones. The grain size variability map shows the bar migration style. However, the absence of cliff exposures in this region makes it challenging to assess the complete internal geometry. The 3D architecture of this deposit will be reconstructed by integrating the field data with Ground Penetrating Radar (GPR).

AAPG Datapages/Search and Discovery Article #90189 © 2014 AAPG Annual Convention and Exhibition, Houston, Texas, USA, April 6–9, 2014