Speleogenesis and Delineation of Megaporosity and Karst Geohazards Through Geologic Cave Mapping and LiDAR Analyses Associated with Infrastructure in Culberson County, Texas

The Gypsum Plain region of the Delaware Basin hosts approximately 1800 km2 of the Castile Formation outcrop. A myriad of karstic developments from closed sinkholes to large multi-kilometer cave systems have been documented within the region. Karst studies on the distribution and speleogenetic evolution within Castile strata began within the last decade with ever increasing data resolution. In this study, a combination of both physical field surveys and analyses of high resolution (~30 cm accuracy) LiDAR data was used to create a theoretical model for karst development across the region. This idealized model considers speleogenetic formation type variations (hypogene and epigene), the density of karstic features based on lithology variations, and the connection between the local hydrostratigraphic setting and the regional hydrogeological framework. Field studies included physical mapping of 20 km2 of the Gypsum Plain from the Castile’s western outcrop to where it dips into the subsurface to the east. These surface surveys involved the recording of all surfically-expressed karstic phenomena and the mapping of all enterable caves so that the speleogenetic evolution could be analyzed. The way in which hypogene and epigene caves are surfically expressed across the region indicates that many of the caves have been affected by either multi-stage epigenetic development or multi-stage hypogenetic development with epigenetic overprinting. Through the use of the methods outlined above, surficial karst manifestations vary across the region, from hypogenetic exposures in the west and epigenetic phreatic / vadose exposures in the east. Additionally, supplementary LiDAR data was used to create digital elevation models (DEM) so that the effectiveness of physical field surveys versus remote sensing techniques could be determined. Previous works in the area by Stafford et al., (2008b) determined that remote sensing preserved only 36% of all karstic features found through physical field surveys. Given today’s advancements in remote sensing accuracy, this study determined that on average LiDAR analysis identifies almost seven times more karstic features than physical surveys over a given area

Evaporite karst geohazards in the Delaware Basin, Texas: review of traditional karst studies coupled with geophysical and remote sensing characterization

Evaporite karst throughout the Gypsum Plain of west Texas is complex and extensive, including manifestations ranging from intrastratal brecciation and hypogene caves to epigene features and suffosion caves. Recent advances in hydrocarbon exploration and extraction has resulted in increased infrastructure development and utilization in the area; as a result, delineation and characterization of potential karst geohazards throughout the region have become a greater concern. While traditional karst surveys are essential for delineating the subsurface extent and morphology of individual caves for speleogenetic interpretation, these methods tend to underestimate the total extent of karst development and require surficial manifestation of karst phenomena. Therefore, this study utilizes a composite suite of remote sensing and traditional field studies for improved karst delineation and detection of potential karst geohazards within gypsum karst. Color InfraRed (CIR) imagery were utilized for delineation of lineaments associated with fractures, while Normalized Density Vegetation Index (NDVI) analyses were used to delineate regions of increased moisture flux and probable zones of shallow karst development. Digital Elevation Models (DEM) constructed from high-resolution LiDAR (Light Detection and Ranging) data were used to spatially interpret sinkholes, while analyses of LiDAR intensity data were used in a novel way to categorize local variations in surface geology. Resistivity data, including both direct current (DC) and capacitively coupled (CC) resistivity analyses, were acquired and interpreted throughout the study area to delineate potential shallow karst geohazards specifically associated with roadways of geohazard concern; however, detailed knowledge of the surrounding geology and local karst development proved essential for proper interpretation of resistivity inversions. The composite suite of traditional field investigations and remotely sensed karst delineations used in this study illustrate how complex gypsum karst terrains can be characterized with greater detail through the utilization of rapidly advancing technologies, especially in arid environments with low vegetation densities

Evaporite karst geohazards in the Delaware Basin, Texas: review of traditional karst studies coupled with geophysical and remote sensing characterization

Evaporite karst throughout the Gypsum Plain of west Texas is complex and extensive, including manifestations ranging from intrastratal brecciation and hypogene caves to epigene features and suffosion caves. Recent advances in hydrocarbon exploration and extraction has resulted in increased infrastructure development and utilization in the area; as a result, delineation and characterization of potential karst geohazards throughout the region have become a greater concern. While traditional karst surveys are essential for delineating the subsurface extent and morphology of individual caves for speleogenetic interpretation, these methods tend to underestimate the total extent of karst development and require surficial manifestation of karst phenomena. Therefore, this study utilizes a composite suite of remote sensing and traditional field studies for improved karst delineation and detection of potential karst geohazards within gypsum karst. Color InfraRed (CIR) imagery were utilized for delineation of lineaments associated with fractures, while Normalized Density Vegetation Index (NDVI) analyses were used to delineate regions of increased moisture flux and probable zones of shallow karst development. Digital Elevation Models (DEM) constructed from high-resolution LiDAR (Light Detection and Ranging) data were used to spatially interpret sinkholes, while analyses of LiDAR intensity data were used in a novel way to categorize local variations in surface geology. Resistivity data, including both direct current (DC) and capacitively coupled (CC) resistivity analyses, were acquired and interpreted throughout the study area to delineate potential shallow karst geohazards specifically associated with roadways of geohazard concern; however, detailed knowledge of the surrounding geology and local karst development proved essential for proper interpretation of resistivity inversions. The composite suite of traditional field investigations and remotely sensed karst delineations used in this study illustrate how complex gypsum karst terrains can be characterized with greater detail through the utilization of rapidly advancing technologies, especially in arid environments with low vegetation densities

Unconfined hypogene evaporite karst: West Texas and southeastern New Mexico, USA

Diverse karst phenomena occur throughout the Gypsum Plain where the Castile Formation crops out over ~1800 km2 in West Texas and southeastern New Mexico. Hypergene karst is extensive and widespread, while traditional hypogene karst manifestations (both caves and intrastratal dissolution) occur in high frequency in the western outcrop region where surface denudation has been the greatest so as to induce surficial breaching. Unconfined hypogene karst occurrences have been recently identified, including two general variations: 1) artesian-like discharge features; and 2) venting structures. Artesian-like discharge features arise at surficially-breached hypogene caves and through high permeability regions on the margins of breccia pipes; these occur when aquifer pressures within the underlying Bell Canyon siliciclastics are sufficiently elevated subsequent to anomalously high precipitation events. Venting structures associated with condensation corrosion-like processes coupled with ascending moisture-rich vapor occur as fracture vents and hydration buckles; fracture vents develop along near-vertical joint sets and hydration buckles form at intermittent zones of high permeability within the core regions of breccia pipes. All venting structures form highly porous, low density, secondary sulfate mineralization at the land surface, creating local topographic highs decimeters to a meter in scale that preclude interception of meteoric waters into these unconfined hypogene karst features. The Gypsum Plain hosts complex karst phenomena that present unique engineering challenges as variable geohazard occurrences ranging from shallow, hypergene caves to deep, complex, hypogene features both formed in semi-confined and unconfined speleogenetic conditions

The Effects of Person–Organization Ethical Fit on Employee Attraction and Retention: Towards a Testable Explanatory Model

ethics, person-organization fit, attraction, retention, corporate social responsibility, corporate social performance,