About This Item
Share This Item
The Palo Duro basin, part of the broad northern shelf of the Midland basin during the Late Permian, accumulated cyclic, regressive, carbonate-anhydrite-halite sequences. Detailed interpretation of more than 2,000 m (6,500 ft) of halite core from 9 wells drilled by the United States Department of Energy in the northern Palo Duro basin permitted recognition of textures formed during halite deposition.
Textures formed on the bottom of a halite-saturated water body include color banding due to variation in composition and amount of impurities in halite beds, and vertically elongated anhedral halite mosaic, formed due to competition for space on the pool floor. Abundant fluid inclusions trapped along halite growth faces reflect rapid precipitation of halite in shallow water. Darker halite with sparse inclusions may have formed less rapidly in slightly deeper water.
Anhydrite partings, truncating the bottom-deposited fabrics, represent
influx of marine-derived brine concentrated during transport across the broad, shallow shelf. The brine corroded existing halite and deposited gypsum before evaporation increased salinity and reinitiated halite deposition.
Halite precipitation ceased when brine supply decreased and the flat became emergent. Mudstone was transported onto the flat by wind and sheetwash. Exposure of the halite to meteoric water during this phase caused development of halite karst and destruction of other fabrics by recrystallization.
End_of_Article - Last_Page 488------------