Abstract
The Burton Flats, a 259-km² gypsum-dominated outcrop of the Permian Rustler Formation 26 km northeast of Carlsbad, New Mexico, contains more than 3,500 documented karst features — an anomalously high density relative to surrounding areas of equivalent lithology. The proposed explanation is a two-step brine-enhanced dissolution mechanism driven by the spatial intersection of three factors: the eastward-dipping Rustler Formation outcrop, the underlying Capitan Aquifer, and the intervening Permian Salado Formation. Fresh Capitan water dissolves Salado halite, generating an NaCl-enriched brine up to three times more aggressive toward gypsum dissolution than fresh water; this brine ascends into the Rustler Formation along the Capitan flowpath, driving hypogenic cave and karst development at anomalously high rates. As surface denudation progressively exposes the Rustler Formation eastward, the karst hazard zone is expanding into previously unrecognized areas with significant implications for infrastructure planning in the northern Delaware Basin. Geophysical characterization methods are addressed in a companion paper.
Rights Information
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DOI
https://doi.org/10.5038/9781967518012.1033
Figure 1 regional overview
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Figure 2 geologic overview
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Figure 3 process graphic
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Figure 4 hypogene cave
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Authors Response to Reviewer
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Authors Response to Reviewer 2
Brine-Enhanced Hypogenic Speleogenesis and Concentrated Karst Development in the Burton Flats, Eddy County, New Mexico
The Burton Flats, a 259-km² gypsum-dominated outcrop of the Permian Rustler Formation 26 km northeast of Carlsbad, New Mexico, contains more than 3,500 documented karst features — an anomalously high density relative to surrounding areas of equivalent lithology. The proposed explanation is a two-step brine-enhanced dissolution mechanism driven by the spatial intersection of three factors: the eastward-dipping Rustler Formation outcrop, the underlying Capitan Aquifer, and the intervening Permian Salado Formation. Fresh Capitan water dissolves Salado halite, generating an NaCl-enriched brine up to three times more aggressive toward gypsum dissolution than fresh water; this brine ascends into the Rustler Formation along the Capitan flowpath, driving hypogenic cave and karst development at anomalously high rates. As surface denudation progressively exposes the Rustler Formation eastward, the karst hazard zone is expanding into previously unrecognized areas with significant implications for infrastructure planning in the northern Delaware Basin. Geophysical characterization methods are addressed in a companion paper.