Geology topics
Research about Texas
Source-linked reports with geographic coverage including Texas.
Quality of water from test wells in the Castolon area, Big Bend National Park, Brewster County, Texas
No abstract available.
Floods on White Rock Creek above White Rock Lake at Dallas, Texas
The White Rock Creek watershed within the city limits of Dallas , Texas, presents problems not unique in the rapid residential and industrial development encountered by many cities throughout the United States. The advantages of full development of the existing area within a city before expanding city boundaries, are related to both economics and civic pride. The expansion of city boundaries usually results in higher per capital costs for the operation of city governments. Certainly no responsible city official would oppose reasonable development of watersheds and flood plains and thus sacrifice an increase in tax revenue. Within the words "reasonable development" lies the problem faced by these officials. They are aware that the natural function of a stream channel, and its associated flood plain is to carry away excess water in time of flood. They are also aware that failure to recognize this has often led to haphazard development on flood plains with a consequent increase in flood damages. In the absence of factual data defining the risk involved in occupying flood plains, stringent corrective and preventative measures must be taken to regulate man's activities on flood plains to a point beyond normal precaution. Flood-flow characteristics in the reach of White Rock Creek that lies between the northern city boundary of Dallas and Northwest Highway (Loop 12) at the upper end of White Rock Lake, are presented in this report. Hydrologic data shown include history and magnitude of floods, flood profiles, outlines of areas inundated by three floods, and estimates of mean velocities of flow at selected points. Approximate areas inundated by floods of April 1942 and July 1962 along White Rock Creek and by the flood of October 1962 along Cottonwood Creek, Floyd Branch, and Jackson Branch, are delineated on maps. Greater floods have undoubtedly occurred in the past but no attempt is made to show their probable overflow limits because basic data on such floods could not be obtained. Depths of inundation can be estimated from the information shown. Elevations shown are in feet above mean sea level, datum of 1929. The data and computations supporting the results given herein are in the files of the Geological Survey in Austin, Texas.
Effects of drought in central and south Texas
The effects of drought upon ground-water storage and discharge, and upon streamflow, vary tremendously in the central third of Texas (the area from the Panhandle to the Gulf of Mexico). Extremes are represented by (a) the Llano Estacado, where the drought had negligible effect upon ground-water resources, which are being progressively depleted by pumping for irrigation; and (b) the Balcones fault-zone aquifer west of San Antonio, whose storage and natural discharge declined substantially during the drought, but increased even more rapidly during succeeding years of more abundant precipitation.
Ground-water geology of Edwards County, Texas
Edwards County occupies 2,075 square miles of the southern part of the Edwards Plateau in southwest Texas. In 1950 it had a population of 2,908. Its thin limestone soil supports the characteristic flora of a semiarid region. The county is underlain by nearly flat-lying beds of limestone and a few beds of shale and marl. The Glen Rose limestone of Cretaceous age, the oldest formation tapped by water wells in the county, yields small quantities of rather highly mineralized water. Springs in the Glen Rose discharge water that is generally less mineralized than that from wells. Nearly all the wells and springs tapping the Glen Rose are in the southeastern part of the county, where the Edwards and associated limestones have been removed by erosion or are very thin. The Comanche Peak, Edwards, and Georgetown limestones, collectively called the Edwards and associated limestones, underlie most of the county and form the principal aquifer. Generally, the water in the Edwards is under water-table conditions, but locally it may be artesian. The Edwards and associated limestones yield small to moderate quantities of water that is hard but otherwise of good chemical quality. The alluvium in the major stream valleys yields small to moderate quantities of hard water similar in quality to that of the Edwards and associated limestones. The main ground-water divides in the Edwards and associated limestones follow the topographic divides. Most of the ground water flows southward and either appears as springflow in the Nueces River drainage or flows underground into Kinney or Val Verde County. The remainder flows northward and ultimately appears as springflow in the South Llano River drainage. About 150,000 acre-feet of water is recharged annually to and discharged from the Edwards and associated limestones in Edwards County. Most of this water is available for additional development inasmuch as only about 900 acre-feet per year is currently being used; however, additional development of ground water will result in a reduction in streamflow.
Geologic and topographic maps of Marble Canyon-Mine Canyon area, Sierra Diablo, Culberson County, Texas
No abstract available.
Occurrence of Trichomonas gallinae in the ground dove, Columbigallina passerina (L.)
No abstract available.
Preliminary isoradioactivity map of the Tordilla Hill-Deweesville area, Karnes County, Texas
No abstract available.
Memorandum on ground-water conditions and suggestions for test drilling in the Logan Heights area, El Paso, Texas
In response to a request from the U. S. Army, Corps of Engineers, Albuquerque District, a brief investigation was made in March 1957 of the ground-water resources of the Logan Heights area, El Paso, Texas. The purpose of the investigation was to collect and evaluate pertinent available data on existing wells in the vicinity of Logan Heights and to determine the most promising locations for the installation of two wells capable of yielding a minimum of 800 gpm (gallons per minute) each. Most of the data used in the investigation have been published in Water-Supply Paper 1426 of the Geological Survey (Knowles and Kennedy, 1958) .
Memorandum on the water-supply wells at Biggs Air Force Base, El Paso, Texas
During March and April 1957, a brief investigation was made at the request of the U. S. Army, Corps of Engineers, Albuquerque District, to determine the cause for the decline in the performances of the wells used at Biggs Air Force Base, El Paso, Texas. The investigation included a general survey or the existing wells, pumping schedules, and records of pumpage and water levels. Appreciation is expressed for the cooperation of personnel or the Corps of Engineers, particularly to H. B. Norain and H. Wortman. In addition, the Layne-Texas Co., the C. L. North Co., and Mr. C. F. Gill of the El Paso Public Service Board were helpful in supplying data not available in the files of Biggs Air Force Base. A considerable amount of data used in this report are published in Water-Supply Paper 1426 of the Geological Survey.
Conodonts from the Chappel limestone of Texas
The Chappel limestone of Early Mississippian (late Kinderhook and probably partly early Osage) age crops out in the Llano region of Texas where it is as much as 45 feet thick. It contains three conodont faunal zones which, from youngest to oldest, are herein designated: (1) the Bactrognathus communis zone of probable early Osage age; (2) the Gnathodus punctatus zone of late Kinderhook (Chouteau) age—this zone ranges throughout the greater thickness of the Chappel; and (3) the Siphonodella cooperi zone, also of late Kinderhook (Chouteau) age. This zonation is based on an examination of the disjunct conodonts in more than 150 collections, as well as on a study of the frequency distribution of species in 68 collections. These 68 collections contain 22,946 identifiable specimens, some representing reworked material derived from Ordovician, Devonian, and lower-most Mississippian sources. Four generic names, Dollymae , Branmehla , Hindeodina , and Pandorinellina , are new; the last named replaces Pandorina Stauffer, 1940, which is preoccupied. A new classification of disjunct conodonts is presented. This classification, utilitarian rather than biologic, is based on the fact that each individual conodont was built up by the accretion of lamellae about the apex of the pulp cavity. This cavity is used as the point of reference for all other parts of the conodont structure. Separation of the lamellae from one another, along one or more growth axes and in one or more directions, resulted in the development of fanglike structures without dentides (Distacodontidae); fanglike structures with denticles (Belodontidae); denticulated blades and bars (Coleodontidae, Prioniodinidae, and Prioniodontidae); platelike structures with platforms (Polygnathidae); and platelike structures with greatly expanded pulp cavities (Idiognathodontidae).
Geology and quicksilver deposits of the Terlingua district, Texas
The Terlingua quicksilver district, which has produced more than 150,000 flasks of quicksilver, is in the southern part of the Big Bend region of southwestern Texas. It is a narrow, eastwest area about 20 miles long and lies mainly in southwestern Brewster County. The district is connected by graded road with the nearest railroad, 84 miles north of its center. Quicksilver minerals were first discovered in the district in the latter part of the 19th century, but there was no substantial production until 1900. Although there are about 20 mines and many prospects, more than 90 percent of the quicksilver came from the Chisos-Rainbow, Mariposa, and Study Butte mines. The most productive years were during World War I; since 1946 the district has been idle. Future production depends upon the discovery of new ore bodies-which will be costly-and the working of deposits now considered of too low grade to be profitable.
Geology of part of the Horseshoe atoll in Scurry and Kent Counties, Texas
The subsurface Horseshoe atoll is an arcuate accumulation of fossiliferous limestone 70 to 90 miles across in the northern part of the Midland basin, in western Texas. The stratigraphy, the lithologic character of the rocks, and the petroleum reservoirs of the southeastern part of the atoll in Scurry County and parts of adjacent counties are described herein. Rocks of Strawn, Canyon, and Cisco ages, belonging to the Pennsylvanian system, and rocks of Wolfcamp age, belonging to the Permian system, form the Horseshoe atoll. Reworking of these rocks at several times during the growth of the atoll has resulted in the formation of large amounts of limestone breccia, in the mixing of the fusulinid faunas used to date the rocks, and in the complex age relations between rocks in different parts of the atoll. Thin beds of shale within this limestone mass are the only lithologic units that can be correlated for any appreciable distance in the atoll, but studies of micrologs from wells penetrating the atoll have revealed many zones of low porosity that can be correlated with reasonable certainty over much of the area described in this report. The atoll rests on a platform of bedded limestone and shale, which has been designated as equivalent in age to the Bend and Strawn groups of the Pennsylvanian system. It is covered mainly by shale, which has been designated as equivalent in age to the Wolfcamp series of the Permian system and is partly equivalent in age to the youngest rocks within the atoll. Reworking of the rocks, the complex distribution of rocks of different ages, the presence of thin beds of shale, and the stratification of porosity in the atoll suggest that this structure has many of the characteristics of a reef. Its growth in the Midland basin was apparently cyclic and may have been related to changes of sea level during the Late Pennsylvanian and early Permian periods. Oil is contained in porous zones within the atoll, mainly in reservoirs in hills along the crest of the structure where the overlying shale formed an impervious cap, but some is found in the lower part of the limestone mass where the reasons for the oil traps are not as apparent. The source of the oil was probably the shale of Wolfcamp age that surrounds the atoll.