FLUID-FLOW PROCESSES ALONG FAULT SYSTEMS: INTEGRATING FIELD CHARACTERIZATION WITH REMOTE SENSING (Invited Presentation)

Structural deformation is likely to be found on most terrestrial planetary bodies and mapping of faults/joints can be used to understand their evolution. However, documenting only faulting/joints may ignore associated/contemporaneous processes and faulting or jointing may not be expressed within spatial resolution limitations of available datasets. Therefore, utilizing associated attributes that may be expressed at greater spatial resolution than the fault plane itself may aid in identification of structural features and interpretation of faulting and structural-diagenetic processes active in an area. The Baseline Fault in southern Nevada, U.S.A., juxtaposes the Cretaceous Baseline Formation and Jurassic Aztec Sandstone. The fault damage zone is negligible (<30 cm thick), but the diagenetic alteration that resulted from fault-influenced fluid flow can be identified at a variety of scales and expressed in detectable mineralogical changes. The Baseline Fault exhibits diagenetic facies that include red/purple, yellow, and stark white coloration in the hanging wall, and dense iron oxide mineralization along the fault plane and that extends up to ~10 cm into the footwall. Diagenetic facies are fault-parallel and crosscut stratigraphic fabrics and stratigraphy-controlled diagenetic facies, and extend from the fault up to ~50 m into the hanging wall. The clay mineralogies and coloration overprinting suggests that the fault acted as a conduit for fluid flow, possibly of meteoric origin, and potentially contemporaneous with fault motion. Other examples of faults from the Western United States provide additional data to consider. The structural-diagenetic attributes then extend the identifiable attributes to within the spatial and spectral resolution limits of available datasets aiding in mapping based on remote sensing methods. These attributes can also elucidate fluid source, timing, and role in structural processes and the specific structural-diagenetic history of the area.