Figure 18 - uploaded by Kenneth S. Johnson
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Map showing zones of salt dissolution in the lower and upper San Andres Formation in the Palo Duro and Dalhart Basins (Presley, 1981a), and in the equivalent Blaine Formation and associated strata in the Anadarko Basin (Jordan and Vosburg, 1963; Johnson, 1976). Salt beds of the San Andres Formation in the Palo Duro Basin are dissolved where they approach the eastern outcrops (A-A', Fig. 19), and where they go over the Amarillo Uplift to the north (B-B', Fig. 20). The "East Palo Duro Basin area" is shown in Figure 21.
Source publication
The Permian Blaine Formation outcrops of western Oklahoma are a series of gypsum, dolomite, and shale units that can be correlated directly into the San Andres Formation in the Palo Duro Basin of north-central Texas. This was first established during extensive studies in the subsurface of the Palo Duro Basin, and the current paper affirms this corr...
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Red Bluff Dam and Reservoir, located on the Pecos River between Loving and Reeves Counties in west Texas, has been losing water since impoundment began in early 1937—mainly due to seepage through evaporite-karst features beneath the dam. Water flows through collapse structures and brecciated-karst zones in the Permian-age Rustler Formation, which i...
Citations
... Total thickness of the Blaine Formation in outcrops is about 60 m in southwest Oklahoma and about 30 m in northwest Oklahoma. Nomenclature for the individual gypsum and dolomite beds of the Blaine differs in southwest and northwest Oklahoma, because they were originally thought to be two different formations: it was not until the early 1920s that it was realized that they were outcrops of the same formation on the north and south flanks of the then-newly recognized Anadarko Basin, but the dual nomenclature for beds in the Blaine Formation was retained (summarized in Johnson, 2021b). All gypsum beds in the upper part of the Van Vacter Member of southwest Oklahoma grade laterally into shales in the subsurface of the Anadarko Basin, and these shales comprise the lower part of the Dog Creek Shale on the north flank of the basin. ...
Two notable sinkholes have formed in the past 63 years as a result of gypsum karst in the Permian Blaine Formation of western Oklahoma. The Delhi Sinkhole, located in Beckham County, southwest Oklahoma, formed in 2011: it was originally 12 m wide and 12 m deep, and eventually reached a diameter of 18 m. The Watonga Sinkhole, located in Blaine County, northwest Oklahoma, formed in 1957: it reached a diameter of 14 m and a depth of 5.2 m. Both sinkholes formed in open fields where about 15 to 30 m of Quaternary terrace deposits and dune sands overly the gypsum beds. The Blaine Formation consists of multiple gypsum beds, about 3 to 6 m thick, interbedded with shale beds, 1 to 10 m thick, and thin dolomites. Total thickness of the formation is about 60 m in the southwest part of the State, and about 30 m in the northwest.
... Natural dissolution of salts in the San Andres Formation is widespread in the Texas Panhandle ( Figures 6A, 10, 11), and has been going on since at least Miocene-Pliocene times (Gustavson, 1986). The Bureau of Economic Geology, at The University of Texas at Austin, has conducted extensive studies of salt deposits and salt karst in the Texas Panhandle: pertinent references and a brief summary of these studies are given by Johnson (2021a). Presley (1981) in the Palo Duro Basin, and by Jordan and Vosburg (1963) and Johnson (1976) in the Dalhart and Anadarko Basins. ...
... Anadarko Basin Salt Dissolution. Examples of natural dissolution of Permian salts in the Anadarko Basin of Oklahoma are given by Ward (1961) and Johnson (1976Johnson ( , 2003aJohnson ( , 2017Johnson ( , 2021a (Figures 6A, 12). Salts in the Blaine Formation and associated strata (the Beckham evaporites) are up to 250 m thick along the axis of the Anadarko Basin in eastern Beckham County, and they tend to be dissolved on the flanks of the basin where they rise to depths of less than 150 to 300 m ( Figure 12). ...
... Outcropping strata in this part of the Anadarko Basin normally dip at angles of less than one degree (less than 10 m/km) toward the axis of the basin, but dissolution of these salts has resulted in a number of collapse structures at the land surface. Where salt has been dissolved (primarily the Yelton salt), overlying strata have subsided, settled, or collapsed into underground water-filled cavities, producing outcrops of collapse blocks that dip erratically at angles of 5 to 30°, as well as breccia pipes in which blocks of Cretaceous limestone and sandstone have been dropped some 50 m, or more, and are juxtaposed against various Permian formations (Suneson, 2012;Johnson, , 2017Johnson, , 2021a. ...
One of the major evaporite regions in the world is herein named the Greater Permian Evaporite Basin (GPEB). This evaporite region extends far beyond the traditional Permian Basin of west Texas and southeast New Mexico, and embraces about 650,000 km 2 in parts of Texas, New Mexico, Oklahoma, Kan-sas, and Colorado. The eight main Permian evaporite sequences, each containing salt (halite) and gypsum and/or anhydrite, have a combined thickness generally ranging from 500 to 1500 m in various parts of the GPEB, and the evaporites extend from west Texas to northern Kansas and northeast Colorado. The GPEB embraces several structural and/or sedimentary basins, including the Delaware, Midland, Palo Duro, Hardeman-Hollis, Dalhart, Anadarko, Denver (south), Hugo-ton, and Salina Basins, each of which contains one or more thick sequences of Permian evaporites. Gypsum and/or anhydrite deposits are more widespread than salt deposits in the GPEB: anhydrite is the common form of calcium sulfate at depths below about 15 to 30 m, whereas gypsum is almost always the calcium sulfate at shallower depths and in outcrops. Evaporites are the most soluble of the common rocks. Salt (halite, NaCl) and gypsum (CaSO 4 •2H 2 O) can be dissolved naturally, or by human activities, to form the same kinds of karst features present in limestone and dolomite, such as caves, sinkholes, breccia pipes, disappearing streams, springs, and even catastrophic collapses (sinks or sinkholes). Anhydrite (CaSO 4), in contact with water, transforms to gypsum and then is susceptible to dissolution. Water in contact with salt or gypsum will dissolve some of the rock, if the water is unsaturated with respect to NaCl or CaSO 4 , respectively, and will continue to dissolve the rock if it is contacted by unsaturated water. Evaporite karst is present in most parts of the GPEB. Salt sequences underlie about 380,000 km 2 of the GPEB, and salt karst occurs naturally where the deep-seated salt beds rise to shallow depths of about 150 to 300 m. Each of the eight evaporite sequences in the GPEB has areas where natural salt dissolution occurs at least somewhere in the region. Two major examples of natural salt karst are (1) large subsidence troughs in the Delaware Basin that are now filled with Cenozoic sediments and (2) extensive dissolution of San Andres and Flowerpot/Blaine/Yelton salts in the Texas Panhandle, western Oklahoma and Kansas, and southeast Colorado. Salt karst can also occur when human activity, such as solution mining or some petroleum-related activities, enables unsaturated water to intentionally, or accidentally, dissolve the salt and create a water-filled cavity large enough to allow failure of its roof, and eventual collapse that can reach the land surface as a huge sinkhole. Examples of human-induced salt karst because solution mining are the Cargill, Denver
Evaporite rocks, mainly gypsum (or anhydrite) and salt (halite), are the most soluble of common rocks. Their dissolution produces caves, sinkholes, disappearing streams, collapse structures, breccia pipes, and other karst features that are also commonly associated with carbonate rocks (limestones and dolomites). Evaporites underlie a vast region of southwestern United States that is herein named the Greater Permian Evaporite Basin (GPEB), and both natural and human-induced evaporite karst (EK) features are present in much of the region. This evaporite basin extends far beyond the traditional Permian Basin of west Texas and southeast New Mexico, and embraces about 650,000 km2 in parts of Texas, New Mexico, Oklahoma, Kansas, and Colorado. Eight major evaporite sequences are present in Permian rocks in the GPEB, including: 1) Wellington/Hutchinson, 2) Lower Cimarron/Lower Clear Fork, 3) Upper Cimarron/Upper Clear Fork, 4) San Andres/Flowerpot/Blaine/Yelton, 5) Artesia, 6) Castile, 7) Salado, and 8) Rustler Formations or Groups.
EK results from both natural processes and human activities. Natural EK occurs when precipitation or ground water circulates through, and dissolves, part or all of an evaporite deposit. Human activities that can produce EK include: 1) construction upon, or directing water into or above, outcropping or shallow evaporites; and 2) drilling boreholes, opening mines, or other excavations into subsurface evaporites, mainly salt deposits, followed by unsaturated water coming in contact with, and dissolving, the evaporite. The principal difference between karst in evaporite rocks and in carbonates is that EK features can form rapidly, in a matter of days, weeks, or years, whereas carbonate-karst features typically take years, decades, or centuries to form. Rapid development of EK can lead to engineering or environmental problems, including damage to, and/or collapse of, homes, buildings, civil projects (such as dams, bridges, and highways), and farmlands; and it can also result in injury or loss of life.
