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Geology topics

K.S. Johnson

Publications and source records attributed to K.S. Johnson.

9 recordsLinked to original sources
USGS2007

Identification, prediction, and mitigation of sinkhole hazards in evaporite karst areas

Sinkholes usually have a higher probability of occurrence and a greater genetic diversity in evaporite terrains than in carbonate karst areas. This is because evaporites have a higher solubility and, commonly, a lower mechanical strength. Subsidence damage resulting from evaporite dissolution generates substantial losses throughout the world, but the causes are only well understood in a few areas. To deal with these hazards, a phased approach is needed for sinkhole identification, investigation, prediction, and mitigation. Identification techniques include field surveys and geomorphological mapping combined with accounts from local people and historical sources. Detailed sinkhole maps can be constructed from sequential historical maps, recent topographical maps, and digital elevation models (DEMs) complemented with building-damage surveying, remote sensing, and high-resolution geodetic surveys. On a more detailed level, information from exposed paleosubsidence features (paleokarst), speleological explorations, geophysical investigations, trenching, dating techniques, and boreholes may help in investigating dissolution and subsidence features. Information on the hydrogeological pathways including caves, springs, and swallow holes are particularly important especially when corroborated by tracer tests. These diverse data sources make a valuable database-the karst inventory. From this dataset, sinkhole susceptibility zonations (relative probability) may be produced based on the spatial distribution of the features and good knowledge of the local geology. Sinkhole distribution can be investigated by spatial distribution analysis techniques including studies of preferential elongation, alignment, and nearest neighbor analysis. More objective susceptibility models may be obtained by analyzing the statistical relationships between the known sinkholes and the conditioning factors. Chronological information on sinkhole formation is required to estimate the probability of occurrence of sinkholes (number of sinkholes/km2 year). Such spatial and temporal predictions, frequently derived from limited records and based on the assumption that past sinkhole activity may be extrapolated to the future, are non-corroborated hypotheses. Validation methods allow us to assess the predictive capability of the susceptibility maps and to transform them into probability maps. Avoiding the most hazardous areas by preventive planning is the safest strategy for development in sinkhole-prone areas. Corrective measures could be applied to reduce the dissolution activity and subsidence processes. A more practical solution for safe development is to reduce the vulnerability of the structures by using subsidence-proof designs. ?? 2007 Springer-Verlag.

Conference Paper↗
USGS2007

Gypsum-karst problems in constructing dams in the USA

Gypsum is a highly soluble rock and is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are also present in limestones and dolomites. Gypsum karst is widespread in the USA and has caused problems at several sites where dams were built, or where dam construction was considered. Gypsum karst is present (at least locally) in most areas where gypsum crops out, or is less than 30-60 m below the land surface. These karst features can compromise on the ability of a dam to hold water in a reservoir, and can even cause collapse of a dam. Gypsum karst in the abutments or foundation of a dam can allow water to pass through, around, or under a dam, and solution channels can enlarge quickly, once water starts flowing through such a karst system. The common procedure for controlling gypsum karst beneath the dam is a deep cut-off trench, backfilled with impermeable material, or a close-spaced grout curtain that hopefully will fill all cavities. In Oklahoma, the proposed Upper Mangum Dam was abandoned before construction, because of extensive gypsum karst in the abutments and impoundment area. Catastrophic failure of the Quail Creek Dike in southwest Utah in 1989 was due to flow of water through an undetected karstified gypsum unit beneath the earth-fill embankment. The dike was rebuilt, at a cost of US $12 million, with construction of a cut-off trench 600 m long and 25 m deep. Other dams in the USA with severe gypsum-karst leakage problems in recent years are Horsetooth and Carter Lake Dams, in Colorado, and Anchor Dam, in Wyoming. ?? 2007 Springer-Verlag.

Conference Paper↗
USGS2002

In situ osmotic analyzer for the year-long continuous determination of Fe in hydrothermal systems

A submersible osmotically pumped analyzer (Fe-OsmoAnalyzer) has been adapted for the long-term continuous high resolution monitoring of iron(II) and (III) in deep-sea hydrothermal vents. Ferrozine is used as the colorimetric reagent. The detection limit for our analyzer is 0.1??M for a 0.7cm pathlength with a linear response up to 50??M. The Fe-OsmoAnalyzer uses periodic injections of standards and blanks to self calibrate and can operate unattended for over a year collecting data every 15min. The Fe-OsmoAnalyzer was field tested during a 6 week test deployment at 900m in Monterey Bay and a year-long deployment at 1100m off the coast of Hawaii. A second year-long deployment in a low temperature hydrothermal vent on the Juan de Fuca Ridge provided high resolution continuous monitoring of Fe and was able to distinguish tidally influenced fluctuations in Fe concentrations. ?? 2002 Elsevier Science B.V. All rights reserved.

Analytica Chimica Acta↗
USGS1997

Geologic and hydraulic characteristics of selected shaly geologic units in Oklahoma

Information was collected on the geologic and hydraulic characteristics of three shale-dominated units in Oklahoma-the Dog Creek Shale and Chickasha Formation in Canadian County, Hennessey Group in Oklahoma County, and the Boggy Formation in Pittsburg County. The purpose of this project was to gain insight into the characteristics controlling fluid flow in shaly units that could be targeted for confinement of hazardous waste in the State and to evaluate methods of measuring hydraulic characteristics of shales. Permeameter results may not indicate in-place small-scale hydraulic characteristics, due to pretest disturbance and deterioration of core samples. The Dog Creek Shale and Chickasha Formation hydraulic conductivities measured by permeameter methods ranged from 2.8 times 10 to the negative 11 to 3.0 times 10 to the negative 7 meter per second in nine samples and specific storage from 3.3 times 10 to the negative 4 to 1.6 times 10 to the negative 3 per meter in four samples. Hennessey Group hydraulic conductivities ranged from 4.0 times 10 to the negative 12 to 4.0 times 10 to the negative 10 meter per second in eight samples. Hydraulic conductivity in the Boggy Formation ranged from 1.7 times 10 to the negative 12 to 1.0 times 10 to the negative 8 meter per second in 17 samples. The hydraulic properties of isolated borehole intervals of average length of 4.5 meters in the Hennessey Group and the Boggy Formation were evaluated by a pressurized slug-test method. Hydraulic conductivities obtained with this method tend to be low because intervals with features that transmitted large volumes of water were not tested. Hennessey Group hydraulic conductivities measured by this method ranged from 3.0 times 10 to the negative 13 to 1.1 times 10 to the negative 9 meter per second; the specific storage values are small and may be unreliable. Boggy Formation hydraulic conductivities ranged from 2.0 times 10 to the negative 13 to 2.7 times 10 to the negative 10 meter per second and specific storage values in these tests also are small and may be unreliable. A substantially higher hydraulic conductivity of 3.0 times 10 to the negative 8 meter per second was measured in one borehole 30 meters deep in the Boggy Formation using an open hole slug-test method.

Water-Resources Investigations Report↗
USGS1997

Evaporite karst in the United States

Evaporites, including gypsum (or anhydrite) and salt, are the most soluble of common rocks; they are dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are found in limestones and dolomites. The four basic requirements for evaporite karst to develop are: (1) a deposit of gypsum or salt; (2) water, unsaturated with CaSO4 or NaCl; (3) an outlet for escape of dissolving water; and (4) energy to cause water to flow through the system. Evaporites are present in 32 of the 48 contiguous states, and they underlie about 35-40% of the land area; they are reported in rocks of every geologic system from the Precambrian through the Quaternary. Evaporite karst is known at least locally (and sometimes quite extensively) in almost all areas underlain by evaporites. The most widespread and pronounced examples of both gypsum and salt karst are in the Permian basin of the southwestern United States, but many other areas are also significant. Human activities have caused some evaporite-karst development, primarily in salt deposits. Boreholes may enable (either intentionally or inadvertently) unsaturated water to flow through or against salt deposits, thus allowing development of small to large dissolution cavities. If the dissolution cavity is large enough and shallow enough, successive roof failures above the cavity can cause land subsidence or catastrophic collapse.

Carbonates and Evaporites↗
USGS1997

Permian evaporites in the Permian basin of southwestern United States

During Permian time, a broad and shallow inland sea covered much of southwestern United States, extending northward from west Texas into northwestern Kansas. Slow but continual subsidence beneath all parts of this vast Permian basin caused deposition of a thick sequence of Permian red beds and evaporites, including dolomite, gypsum/anhydrite, salt, and potash. Evaporite units are notably thick and laterally persistent throughout the Permian basin. The entire Permian System ranges up to 2,000 m thick in various parts of the basin, and individual formations, consisting mostly of gypsum/anhydrite and salt, commonly are 60-500 m thick. Evaporite deposits are oldest in the northern part of the Permian basin, and they generally are progressively younger toward the south. The site of principal salt deposition during early Leonardian time (Wellington evaporites) was in Kansas and northwestern Oklahoma; it then shifted southward into western Oklahoma and the Texas Panhandle during late Leonardian and early Guadalupian time (Lower Clear Fork/Lower Cimarron evaporites, Upper Clear Fork/Upper Cimarron evaporites, and San Andres/Blaine evaporites); and finally into west Texas and southeastern New Mexico during late Guadalupian and Ochoan time (Artesia, Castile, Salado, and Rustler evaporites). These evaporites comprise a significant resource for the region: rock salt is produced from dry mines, brine fields, and solar-salt operations at 18 locations; gypsum is mined at 13 sites; potash is produced from 5 underground mines in the world-famous Carlsbad potash district; and sulfur is produced by the Frasch process at one site.

Prace - Panstwowego Instytutu Geologicznego↗
USGS1995

Regional mapping of karst terrains in order to avoid potential environmental problems

The oklahoma Geological Survey will prepare a map of the State at a scale of 1:500,000 to show karst terrains and associated environmental problems in Oklahoma. Surface and near-surface carbonates (limestone and dolomite) comprise about 6% of the surface area of the State, whereas sulphates (gypsum and anhydrite) comprise about 4% of the State. Areas of carbonates and sulphates will be differentiated and mapped separately as two zones: in zone 1 they are 0-6 m deep, and in zone 2 they are 6-30 m deep. Areas underlain by bedded salt (halite) within 300 m of the surface comprise 14.6% of the State, and they will be mapped as zone 3.

Cave and Karst Science - Transactions British Cave↗
USGS1981

Dissolution of salt on the east flank of the Permian Basin in the southwestern U.S.A.

Hydrogeologic studies prove that natural dissolution of bedded salt occurs at shallow depths in many parts of the Permian Basin of the southwestern U.S.A. This is especially well-documented on the east side of the basin in study areas on the Cimarron River and Elm Fork in western Oklahoma, and on the Red River in the southeastern part of the Texas Panhandle. Four requirements for salt dissolution are: (1) a deposit of salt; (2) a supply of water unsaturated with respect to NaCl; (3) an outlet for removal of brine; and (4) energy to cause water to flow through the system. The supply of fresh groundwater in the region is recharged through permeable rocks, alluvium, terrace deposits, karstic features and fractures. Groundwater dissolves salt at depths of 10–250 m, and the resulting brine moves laterally and upward under hydrostatic pressure through caverns, fractures in disrupted rock, and clastic or carbonate aquifers until it reaches the land surface, where it forms salt plains and salt springs. In many areas, salt dissolution produces a self-perpetuating cycle: dissolution causes cavern development, followed by collapse and subsidence of overlying rock; then the resulting disrupted rock has a greater vertical permeability that allows increased water percolation and additional salt dissolution.

Colorado, Kansas, New Mexico, Oklahoma, Texas↗