Hardeman County Research Articles

An environmental health survey of drinking water contamination by leachate from a pesticide waste dump in Hardeman County, Tennessee.

Ground water that was used as a source of potable water by residents of a small community became contaminated by leachate from a 300,000 barrel pesticide waste dump. An environmental health survey of the residents and an apparent control group was conducted to determine if any adverse health effects resulting from exposure to the toxic compounds, many of which were hepatotoxins, could be detected. The survey utilized a health questionnaire, a clinical examination, and a biochemical screening. The latter included analysis of serum for liver and kidney function parameters, determination of hepatitis A and B serology, and bile acid determinations on fasting and postprandial serum and urine specimens. Air and water from representative homes and urine from study participants were analyzed for selected organic compounds. The biochemical screening was conducted on two occasions 2 months apart. The initial hepatic profile testing revealed elevated concentrations of the serum enzymes, alkaline phosphatase and serum glutamic oxaloacetic transaminase, in residents who had used the contaminated water. During follow-up testing of these same persons 2 months later, these values were significantly reduced, as were postprandial serum concentrations of the bile acid of cholyglycine. Six individuals in the exposed group had slight hepatomegaly compared to one individual in the intermediate exposure group and none in the controls. Concentrations of carbon tetrachloride were as high as 18,700 microgram/L in the well water samples. The biochemical and clinical observations are suggestive of a transitory liver injury probably related to exposure to the contaminated drinking water.

A three‐dimensional study of seismic diffraction patterns from deep basement sources

In 1975 the Consortium for Continental Reflection Profiling (COCORP) acquired 37 km of 12‐fold common‐midpoint (CMP) stacked seismic reflection profiles in Hardeman County, Texas (Oliver et al, 1976). The entire crustal section was the object of study, so a record length of 15 sec (two‐way traveltime) was recorded. Three separate profiles were arranged in an H‐shaped pattern to provide two‐dimensional (2-D) surface coverage. In addition to numerous reflections, the seismic sections exhibit pronounced apparent diffractions. These deep diffractions are more numerous and pronounced here than on any other COCORP survey to date. In many cases diffractions on different profiles intersect at the profile junctions. If these intersecting diffractions represent the same structural feature observed along different profiles, the diffraction time‐surface provides an estimate of the location of the diffractor and an effective velocity (analogous to a stacking velocity) to the depth of the diffractor. Arrival times of these diffraction events were read, and a least‐squares technique was developed to model intersecting diffractions simultaneously and derive location and velocity assuming point or line diffractors. Nine apparent diffraction events were identified, occurring mostly in the 5–9 sec range (∼15–30 km). Point diffractor models generally give a closer fit than line models, with most of the resulting velocities between 6.0 and 7.5 km/sec. However, the introduction of a radial dimension (such as a dome instead of a point) significantly lowers these velocities without affecting the quality of fit. The locations of the point models, when projected to the surface. are distributed roughly along a northwest‐southeast trend. The trend is subparallel to the Wichita Mountains and may indicate deep intrusive and/or tectonic structures related to their evolution. These results are important evidence that strong heterogeneities on the scale of a few kilometers are present at midcrustal depths.

North-Central Texas

Total drilling in north-central Texas increased by 28.3%. The wildcat success rate increased slightly, to 23.46%. Total footage drilled increased by 22.7%. Both oil and gas production increased. Significant discoveries were made in Hardeman County.

Developments in North-Central Texas in 1979

Total drilling in north-central Texas increased 8.2% during 1979. The wildcat success rate increased slightly to 20.24%. Total footage drilled increased 12.9%. Oil production declined and gas production increased. Significant discoveries were made in Hardeman County.

Seismic imaging of deep crust

We introduce here an integral two‐dimensional (2-D) scheme for the processing of deep crustal reflection profiles. This approach, in which migration occurs before stacking, is tailored to the unique character of the data in which nonvertically propagating energy is as important as vertically propagating energy. Since reflector depths range beyond 30 km, the horizontal displacement of reflections which occurs in migration can be as large as reflector depths; under these circumstances, the common‐midpoint (CMP) stack is inadequate. In our scheme, each common‐source trace gather is transformed into a set of traces (beams) corresponding to set of different incidence angles. A correction for wavefront curvature similar to the normal moveout (NMO) correction yields traces (focused beams) which are focused at image points along the direction of arrival. While the method is equivalent to the Kirchhoff integral migration method, and therefore to any complete continuation method, it gives rise to an intermediate data set which is characterized by the direction of arrival of the upward propagating energy. By a geometrical transformation of the beams and summation, we may synthesize images composed of a specified range of Fourier spatial components. Geologic examples suggest that complex structures in the basement may be most easily characterized by their local direction of layering, a quantity we may determine by this approach. Noise‐free synthetic data examples illustrate the limits of horizontal and vertical resolving power at mid‐crustal depths for any imaging method. Velocity determination is difficult at these depths due to the small NMO and may be possible only by evaluating the effects of velocity models on the imaged data. Examples of the imaged section from the COCORP test profile in Hardeman County, Texas, show a combination of horizontally continuous reflectors and an irregular pattern of scatterers with locally horizontal layering.

CUBIC SPLINE APPROXIMATION OF INACCURATE RMS‐VELOCITY DATA*

AbstractThe reliable determination of the root‐mean‐square seismic velocity from multiple coverage seismic reflection data requires coherent horizontal reflections equally spaced in time. Observational error in the rms‐velocity data produces significantly greater error in the instantaneous or interval velocity.A cubic spline approximation technique developed by Powell (1967) is designed to minimize the rapid velocity variation due to observational error and retain the significant variation in the rms‐velocity data. The approximation algorithm requires the difference between the observed and approximated rms‐velocity to be statistically random, and seeks to follow the “real” trends in the rms‐velocity measurements and reject observational error. Provided the trends of the rms‐velocity are reproduced, the instantaneous velocity derived from the spline approximation to rms‐velocity data with significant scatter is more reliable than the interval velocity determined from the inaccurate rms‐velocity values using the Dix (1955) approximation. This interval velocity is also a more reliable indicator of variations of lithology.The utility of the spline approximation of rms‐velocity is illustrated for a special common depth point (CDP) expanding reflection spread test recorded in Hardeman County, Texas by the Consortium for Continental Reflection Profiling (COCORP). In this wave test reflections are observed from several CDPs which are closely spaced. It is desired to combine the inaccurate observations from a collection of nearby CDPs. The approximation algorithm for the rms‐velocity determination is applied to both the rms‐velocity data for the individual CDPs and the collection of rms‐velocity data for eight nearby CDPs.

Developments in North-Central Texas in 1978

Total drilling in north-central Texas increased 11.7%. The wildcat success rate dropped slightly to 17.3%. Total footage drilled increased 16%. Oil production declined 5.8% and gas production increased 3.8%. Significant discoveries were made in Hardeman County.

Continuous seismic reflection profiling of the deep basement, Hardeman county, Texas : Oliver, J; Dobrin, M; Kaufman, S Geol Soc Am Bull, V87, N11, Nov 1976, P1537–1546

Continuous seismic reflection profiling of the deep basement, Hardeman county, Texas : Oliver, J; Dobrin, M; Kaufman, S Geol Soc Am Bull, V87, N11, Nov 1976, P1537–1546

Continuous seismic reflection profiling of the deep basement, Hardeman County, Texas

Our understanding of the crust and upper mantle would be enhanced if geophysical studies of the deep basement rocks provided information of resolution and character more nearly like that of geological observations of basement rocks at and near the surface. A test of the continuous seismic reflection profiling technique, the geophysical method with by far the highest resolution and the best potential in this regard, at a site in the midcontinent provided abundant information on intrabasement diffractors and reflectors to depths as great as about 45 km. Conventional equipment and techniques, including nonexplosive vibratory sources, were used with minor modification. In the upper part of the section below the sediments, there are reflectors continuous over the entire length of a profile that give evidence for warping, faulting, unconformities, and other structural features. An age of 1,265 ± 40 m.y. for a sample from a nearby hole indicates that these are Precambrian rocks and not part of the Cambrian basement rocks of the Wichita Province. Detailed correlation with the Precambrian section is inhibited by scarcity of geological information. In the lower part of the section, reflections are not, in general, continuous over more than a few kilometres, but zones and discontinuities within the basement may be distinguished on the basis of spatial density, length, and dip of reflectors. Zones of low reflector density may be plutons; curvature of reflections may indicate deep folded structures. The scale of such features is a few kilometres, and it contrasts with the markedly larger scale of the smallest features of the deep basement that can be resolved by other methods. The method appears to have outstanding potential.

COCORP REPORT

The first of a planned series of tests to be conducted by the Consortium for Continental Profiling (COCORP) was accomplished during March 1975 in Hardeman County, Tex., near the town of Quanah. The purpose of the tests is to demonstrate the feasibility of applying continuous seismic reflection techniques to the solution of geologic problems in the deep crust and, possibly, the upper mantle of the earth. The work is funded by the National Science Foundation and is part of the U.S. Program for the International Geodynamics Project. The Consortium consists of representatives from Cornell University, the University of Houston, Princeton University, and the University of Wisconsin. Cornell University has the operational responsibility.

Algal-Bearing Carbonate Reservoirs of Pennsylvanian Age, West Texas and New Mexico: ABSTRACT

Leafy, platy, or phylloidal algae have been observed in many well cores from hydrocarbon reservoirs at various localities in the Permian basin of west Texas and southeastern New Mexico. These algae have a significant bearing on the quality, and in some cases the existence, of the reservoir. Three examples have been chosen to illustrate these relations. Nena Lucia field, Nolan County, Texas, produces from massive limestone of Desmoinesian (Strawn) age on the east side of the Midland basin. Inferences of eolian depositional environment published previously are not supported, for the dominant reservoir lithofacies is algal calcareous wackestone. Saunders field, Lea County, New Mexico, produces from both massive and well-bedded limestone of Permo-Pennsylvanian age on a well-defined structure just north of the Delaware basin. Although diverse elements contribute to the different porous zones, platy or phylloidal algae are a dominant factor in some of the zones. Conley field, Hardeman County, Texas, produces from three separate formations, including a limestone reservoir in the early Missourian (Canyon) Palo Pinto Formation. This unit is articularly noteworthy for the profusion of algae and the nearly complete dependence of reservoir development on the organisms. Though much smaller in volume, this reservoir is petrologically very similar to that described from the Aneth field complex of the Paradox basin. Phylloid algal reservoirs commonly are surrounded by nonporous mudstone and wackestone and thus fall in the class of reservoirs wherein sediment genesis is an important factor in pore origin. An initial pore network End_Page 726------------------------------ controlled by plate morphology helps localize later diagenetic events, which ultimately produce a well-connected, predominantly large-pore network. This provides for large initial production rates and relatively high recovery factors, which are very desirable reservoir attributes from an economic standpoint. End_of_Article - Last_Page 727------------

Mammals of North-Central Texas

North-central Texas includes five counties along the central part of the northern border of Texas. Of the 66 kinds of mammals recorded, 59 are native species and more than a third of these find their eastern or western limits of range in the area. Eastern woodland forms occupy the eastern part of the area, and Great Plains kinds the western. The Red River permits migration of both eastern and western species. Some westward immigration of eastern mammals has occurred in recent years. North-central Texas, as here defined, includes five counties that extend eastward from the eastern base of the Texas Panhandle along the Red River and make up approximately the central third of the northern border of the state. The counties, from west to east, are: Hardeman, Wilbarger, Wichita, Clay, and Montague. The area is 150 miles from west to east and averages about 30 miles from north to south. Elements of two distinct mammalian faunas meet in north-central Texas. The land west of Hardeman County is semiarid grassland and brushland and possesses a mammalian fauna typical of the Great Plains. From Montague County eastward the land is wooded and the mammals there are more typical of the woodlands of southeastern United States. From Hardeman County to Montague County the en- vironment is transitional and there is also a transition from a fauna typical of the Great Plains to a fauna of the southeastern woodlands. Many species of mammals range completely across north-central Texas. However, more than one third of the 59 full species of native mammals here listed find their eastern or western limit of range in the five-county area here considered. The woodland vole, for example, ex- tends no farther west than Montague County, and the northern grass- hopper mouse ranges no farther east than Wichita County. Neither of these species seems to have an ecological counterpart in the opposite fauna. The eastern woodrat and the southern plains woodrat meet in Clay and Montague counties. The ranges of these two species may overlap slightly but the animals are otherwise allopatric, and doubt- less they are ecological competitors.

Critical Evaluation of Hardeman Basin and Its Environs: ABSTRACT

Geologically the Hardeman basin is the easternmost extension of the elongate, east-west-trending geologic province known as the Palo Duro basin. Although the Hardeman basin apparently has not been subjected to the same violent structural unrest as other parts of North Texas (therefore, almost no structure is related to faulting), it is an area of prolific oil fields having traps of a peculiar type. Except for Conley, the largest Hardeman County oil field, oil traps here have almost no primary porosity. They seem to be either erosion remnants or small biohermal reefs with 100-200 ft of relief which have been vigorously and effectively leached by dolomitizing waters, leaving the limestone with secondary porosity values ranging from pin-point vugular to cavernous. Since the 1959 discovery of Conley, it and 14 smaller fields have produced almost 10 million bbl of oil. This added to the 20 million bbl of oil produced from the Fargo and Odell fields of northwest Wilbarger County, raise the total for the Hardeman basin to 30 million bbl. Seismic methods still provide the most reliable evidence of structure in the Hardeman basin, though increased drilling continually adds to the possibility of subsurface geological leads. As more fields are discovered, and more is understood of their structural form, there seems an increased demand for greater seismic accuracy which, because of the stratigraphic nature of the upper beds in the basin, is beyond the capacity of seismic tools. Most fields in the basin before discovery appeared on seismic maps as small low-relief closures or noses on positive structural trends. Many more such features are known, and must be explored. Economically the Hardeman basin offers the highest return on investment of any area in North Texas. Because individual wells from various fields yield engineering reserve estimates as great as 1 million bbl of recoverable oil, a return as great as 30:1 is a reality. Such high returns normally are found, or anticipated, only in Gulf Coast exploration. Though exploration costs are high in order to test the commonly cavernous Lower Mississippian lime at 8,500 ft (this is the prolific oil producer of Hardeman County), the Hardeman basin has a multiple-pay stratigraphic section to that depth, as shown by the presence of producing reservoirs in the Cisco-Canyon section (beginning at 3,900 ft), the Canyon limestone (normally Palo Pinto) below 5,000 ft, the Des Moines (Strawn) section of sandstone and conglomerate (from 6,000-7,300 ft), the Mississippian conglomerate (Holmes Sand) at 7,700 ft, the Mississippian limestone (Chappel and Osage) from 8,000 to 8,500 ft, and the Ellenberger dolomite below 8,500 ft (now producing only at Conley). Exploration in the past has been aided by acreage and dry-hole support from major companies which control large blocks of leases. It is hoped this support will continue, but even without it exploration will continue in the Hardeman basin and westward into the Palo Duro basin, because positive exploration results in the Hardeman basin are already too great, and the promise for future successful exploration too strong, to discourage those men of vision who search for new oil. End_of_Article - Last_Page 196------------

SOUTHWESTERN OKLAHOMA—A GEOPHYSICAL CASE HISTORY OF A BASIN

The Eastern Palo Duro Basin, also known as the Hollis, Harmon, or Hardeman Basin, covers approximately 100 townships in southwestern Oklahoma. Approximately 18 million barrels of oil have been produced from the Altus and West Frederick trends in Jackson and Tillman Counties. The basin’s structure has been influenced by three orogenic movements: the Acadian, Wichita, and Arbuckle. Dips associated with the main Wichita structures show displacements up to 2,500 ft. Seismograph surveys have played a major part in the development of the basin. The main problems encountered are related to the surface and near‐surface material of the Quaternary deposits and the Permian Blaine Formation. The unconsolidated sands and gravels of the Quaternary deposits are particularly troublesome along the main branches of the Red River. Generally, record quality can be improved with two‐ and three‐hole patterns. The Blaine gypsum and Dog Creek shale, considered as a single unit, outcrop in the western half of the basin. Difficult drilling problems require two or three combination air‐water drills for efficient field operations. Correction problems are compounded by variations in the weathering velocity from 2,000 ft/sec to 3,850 ft/sec and in the near‐surface velocity from 8,000 ft/sec to 12,500 ft/sec. Record quality can be improved in the western area by using multiple geophone coverage, by placing the charge entirely within a shale zone, by using patterns, and by careful selection of the surface traverse to avoid gypsum outcrops. The “VIBROSEIS” system produces better data than the conventional method. Other advantages of the “VIBROSEIS” system are easier permitting and a great reduction of explosives and shothole drilling. While it is unlikely that major producing trends comparable to Altus and West Frederick remain to be found, it is concluded that adequate reservoirs are present and that there is ample room for structures comparable to Conley field in adjacent Hardeman County, Texas. By careful application of suitable seismic field techniques such structures can be reliably mapped.

Developments in North Texas in 1962

A summary of activity in this area reflects a minor increase in the number of completions as well as total production. The total production is approximately 7½% of the total for the state of Texas. The shallower depths required to reach the majority of prospective producing formations make it especially attractive to independent operators as well as major companies. Subsurface geology is the primary tool used in this area although an increase in seismic activity is noted with emphasis in Grayson County on the east and Hardeman County on the northwest end of the district.

Developments in North and West-Central Texas, 1939

Approximately 90 per cent of the production of north and west-central Texas has come from the major positive structural elements: the Bend, Electra and Muenster arches. Increased attention is now being given the bordering basins, especially the north end of the Fort Worth syncline, in which five new fields were found during 1939. In north Texas shallow reservoirs of Cisco age have contributed by far the greater part of the total production and proved reserves, but shallow production is now declining while deep production, especially from the Strawn, is of ever-increasing importance. Three 1939 discoveries in Archer, Clay, and Montague counties are producing from limestones of Bend age; previously no Bend production had been found north of Young County. The reflection seismograph has had conspicuous success in the deeper parts of the east half of the north Texas district, but west of the Bend arch it has not yet demonstrated its application except in the discovery of two reef-like masses of Canyon limestone, one of which produces oil in the Seymour field, Baylor County. Surface mapping is no longer an important exploratory tool, but systematic subsurface work is of increasing importance. Simpson sediments were encountered above the Ellenburger limestone near the axis of the Fort Worth syncline, and increased thickness of post-Ellenburger Ordovician may be looked for farther south in the deeper parts of the syncline. The top of the Ellenburger was reached in Hardeman County at the greatest depth found to date west of the Muenster arch. The name Hardeman syncline is proposed for the large syncline lying between the Electra arch and the Wichita Mountains.