Surface & subsurface geologic mapping, south louisiana project period: 12/15/2025 - 12/14/2026 project 1: purpose ? Project 1 is set to produce two surface geology maps at 1:24,000 scale along the…

The U.S. Geological Survey awarded Louisiana State University a cooperative agreement of $397,861 on December 15, 2025, under the National Cooperative Geologic Mapping Program (CFDA 15.810), StateMap component, for surface and subsurface geologic mapping in South Louisiana.

Project 1 delivers two full-color annotated surface geology maps at 1:24,000 scale covering the Robert, Louisiana and Martinville, Louisiana quadrangles along the northern boundary of the Pontchartrain Structural Basin. The maps depict Pliocene, Pleistocene, and Holocene sedimentary deposits disrupted by the Tepetate-Baton Rouge fault system. Map unit distributions will be interpreted from LiDAR imagery, reconnaissance sampling, and field observations, verified through microscopic examination and X-ray diffraction analysis of subsurface samples processed to separate clay, silt, and sand components. Lithostratigraphic section logs from stream and quarry exposures will support unit correlations. Deliverables include maps with standard marginalia, unit descriptions, correlation diagrams, and accompanying technical reports documenting field and laboratory activities and geologic interpretations.

Project 2 advances Louisiana's 3-D subsurface geologic model covering the area bounded by the Atchafalaya Basin to the east, the Sabine River to the west, the 31° latitude to the north, and the modern Gulf of Mexico shoreline to the south. Existing geophysical wireline logs within the study area will be scanned and digitized for incorporation into subsurface modeling software.

Work is performed in Louisiana. The period of performance runs from December 15, 2025 through December 14, 2026.

Surface & subsurface geologic mapping, south louisiana project period: 12/15/2025 - 12/14/2026 project 1: purpose ? Project 1 is set to produce two surface geology maps at 1:24,000 scale along the northern boundary of the pontchartrain structural basin within the coastal region of southeast louisiana, encompassing pliocene, pleistocene, and holocene sedimentary fluvial and coastal margin deposits disrupted by segments of the west-east striking tepetate-baton rouge system of high angle normal faults. Activities ? Map unit distributions will be interpreted from lidar elevation imagery and reconnaissance sampling and field observations. Interpretations will be verified and unit lithologies determined from microscopic examination and XRD analysis of subsurface samples mechanically processed to separate clay VS. Silt and sand components. Map unit correlations will be supported by lithostratigraphic section logs from stream and quarry exposures. Professional graphic software is used to construct final maps with unit descriptions and correlation diagrams. Deliverables & outcomes ? Two full color and annotated surface geology maps with standard marginalia of geographic information, map unit descriptions, and correlation diagrams: robert, LA, 1:24,000 quadrangle, martinville, LA, 1:24,000 quadrangle. Maps will be accompanied by technical reports describing field and laboratory activities, observations produced, and resultant geologic interpretations and conclusions. Project 2: purpose ? Project 2 continues LGS? Effort to build a 3-d subsurface geologic model of the state of louisiana, with the immediate goal of a subsurface model of the area bound (roughly) by the atchafalaya basin to the east, the sabine river to the west, the 31O latitude to the north, and the modern gulf of mexico shoreline to the south. Activities ? Existing geophysical wireline logs within the study area will be scanned and digitized for incorporation into subsurface modeling software, such as petrel. Information collected from well logs, such as borehole trajectories and locations, down-hole temperatures, and stratigraphic markers, and from older subsurface correlation models and surface geologic maps will be synthesized in subsurface modeling software (petrel) to build a 3-d subsurface model. Deliverables and outcomes ? The study is expected to produce the following items for the ncgmp gems level 3 digital database: north-south and west-east bearing digital cross-sections, subsurface structural maps of lithostratigraphic units, and isopach maps for individual units. Beneficiaries ? This information will represent a significant upgrade of subsurface information for exploration and harvesting of natural resources such as hydrocarbons, ores, and geothermal energy, for natural resource management agencies such as the louisiana department of natural resources, for carbon sequestration and other waste disposal ventures, and for state and federal legislators and regulators tasked with formulating conservation and use policies. Project 3 purpose ? This project is the first in a long range plan to convert previously published geologic maps of louisiana into the ngmdb gems level 3 database. The two maps selected for this pilot project are the deridder and lake charles 1:100K scale geologic maps funded by USGS over 20 years ago. Activities ? LGS cartographer and GIS specialist will perform conversions by transferring relevant data from digital and lithograph map files into the gems-3 online database. Deliverables and outcomes ? Gems level 3 database entries for two 1:100,000 scale geologic maps: deridder, LA and lake charles, LA. Beneficiaries ? Beneficiaries will be all interested parties and programs that access gems geologic map data.