USING INDUSTRY SEISMIC DATA TO MAP THE DISTRIBUTION OF DEEP-SEATED FAULTS AND EVALUATE WHETHER THEY AFFECT HOLOCENE STRATA OF THE LAKE PONTCHARTRAIN BASIN, LOUISIANA

Coastal land loss stemming from relative sea level rise (RSLR) is the most significant environmental topic currently faced by southern Louisiana, and understanding the mechanisms driving RSLR is fundamental to adapting effective, land loss mitigation efforts. For this reason, an array of investigations into the processes responsible for coastal land loss and RSLR have been conducted, yielding two distinct views. One position asserts that Holocene sediment compaction is the primary process driving land-surface subsidence, whereas another position contends that fault motion along deep-seated faults is a primary driving force. This study focuses on whether deep-seated Cenozoic faults extend up section to faults that are known to offset Pleistocene and Holocene strata within the Lake Pontchartrain Basin. Recently donated industry 2-D seismic data within Lake Pontchartrain provides an unique opportunity to map the distribution of deep-seated faults and determine if they are linked to well-known near surface faults that have been mapped previously with shallow, high-resolution seismic data. Work by Roth (1999), identified five, typically down-to-the-south Pleistocene faults within Lake Pontchartrain and provides a baseline of near surface fault distribution. To date this project has identified 20 faults at depths of several thousand meters and several of these deep-seated faults project upward to areas where Roth (1999) identified Pleistocene and Holocene fault offset. The significance of this project is the opportunity to use industry seismic data and evaluate the role of long-term geologic processes, such as faulting, in modern-day land loss of southern Louisiana.