Abstract: "The Precambrian rocks of Colorado consist of a metaphoric complex more than 1,700 million years in age, three groups of igneous rocks about 1,700, 1,400, and 1,000 million years in age, here designated informal age groups, and two areally restricted units of sedimentary rocks, one between 1,400 and 1,700 million years in age and one between 950 and 1,400 million years. A systematic nomenclature for many of the rocks does not exist, but the present state of knowledge will permit establishment of a comprehensive nomenclature. Numerous formal names that have been applied to elements of the Precambrian assemblage are appraised and classified in a table, and eight names are abandoned."

A report that provides details about fire assaying techniques to separate and concentrate the noble metals from many varieties of samples.

A report about mapping in the northern and central parts of the Piceance Creek basin of northwestern Colorado where several relatively thin dominantly marlstone units tongue northward into the Eocene Uinta Formation.

From introduction: The purpose of this report is to evaluate and describe relationships between the volcanic activity on Mount Baker and the possible impacts on Baker Lake water.

Abstract: The Oquirrh Group of Pennsylvanian and Permian age in the southern East Tintic Mountains, Utah, is more than 15,000 feet (4,572 m) thick and consists of an incomplete section of the West Canyon Limestone (Morrowan) 960 feet (293 m) thick, a nearly complete section of the Butterfield Peaks Formation (Atokan(?) and Des Moinesian) about 5,800 feet (1,768 m) thick, a complete section of the Bingham Mine Formation (Missourian) 3,200-3,400 feet thick (975-1,036 m), and a complete section of the newly named Furner Valley Limestone (Missourian to Wolfcampian) 5,000-6,000 feet (1,524-1,829 m) thick. The formations below the Furner Valley Limestone are generally similar to their counterparts in their type areas in the central and southern Oquirrh Mountains but are somewhat thinner and less arenaceous. The Furner Valley Limestone, more than 90 percent carbonate, is apparently unique. Strata of the same age in the Wasatch, Stansbury, Cedar, Hogup, and Promontory Mountains in Utah are all considerably arenaceous; in the southern Oquirrh Mountains in the upper plate of the Midas thrust fault they have been largely removed by erosion. The Oquirrh Group in the East Tintic Mountains is overlain by the Diamond Creek Sandstone; the latter, in turn, is overlain by the …

Abstract: Structural and petrologic studies in the Berry Creek quadrangle at the north end of the western metamorphic belt of the Sierra Nevada have yielded new information that helps in distinguishing between the chemically similar Paleozoic and Mesozoic rocks. The distinguishing features are structural and textural and result from different degrees of deformation. Most Paleozoic rocks are strongly deformed and thoroughly recrystallized. Phenocrysts in metavolcanic rocks are granulated and drawn out into lenses that have sutured outlines. In contrast, the phenocrysts in the Mesozoic metavolcanic rocks show well-preserved straight crystal faces, are only slightly or not at all granulated, and contain fewer mineral inclusions than do those in the Paleozoic rocks. The groundmass in the Paleozoic rocks is recrystallized to a fairly coarse grained albite-epidote-amphibole-chlorite rock, whereas in the Mesozoic rocks the groundmass is a very fine grained feltlike mesh with only spotty occurrence of well-recrystallized finegrained albite-epidote-chlorite-actinolite rock. Primary minerals, such as augite, are locally preserved in the Mesozoic rocks but are altered to a mixture of amphibole, chlorite, and epidote in the Paleozoic rocks. In the contact aureoles of the plutons, and within the Big Bend fault zone, which crosses the area parallel to the structural trends, all …

Abstract: Examination of previously described and some undescribed leaves of Ulmus and Zelkova from the later Oligocene, Miocene, and Pliocene of western North America indicates that at least eight species of Ulmus and two species of Zelkova are represented. Three new species are described: Ulmus chaneyi, U. knowltoni, and Zelkova browni.

From abstract: The seismic history of the southeastern United States is dominated by the 1886 earthquake near Charleston, S.C. An understanding of the specific source and the uniqueness of the neotectonic setting of this large earthquake is essential in order to properly assess seismic hazards in the southeastern United States. Such knowledge will also contribute to the fundamental understanding of intraplate earthquakes and will aid indirectly in deciphering the evolution of Atlantic-type continental margins. The 15 chapters in this volume report on the first stage of an ongoing multidisciplinary study of the Charleston earthquake of 1886.

The following report is an evaluation of the mineral potential of the Laramie Peak area, Wyoming.

From purpose and scope: The purposes of this investigation are (1) to define the ground-water system in the Arikaree Formation, (2) to determine the hydrologic cause-and-effect relationships resulting from the current ground-water development, and (3) to provide a means of indicating the hydrologic effect of future ground-water development.

Purpose and scope: The major purpose of this study is to evaluate the ground-water resources in the Pineland Sands area and their potential for development. The study focuses mainly on the surficial aquifer, the single most readily available source of ground water. Primary objectives of the study are (1) map the areal extent and thickness of the surficial aquifer, (2) determine its ability to transmit water to wells and define the availability of the water, (3) describe the chemical quality of the water, and (4) model the aquifer and simulate probable effects of future development. By evaluating the adequacy of the surficial aquifer, this study should aid in the proper development and management of water resources in the Pineland Sands area.

From introduction: The purpose of this report is to provide sufficient geologic and hydrologic data to aid in the future development of ground- and surface-water supplies. The objectives were to determine the availability, quantity, and quality of ground- and surface-water supplies with reference to problems of development, and to determine the limitations of the water resources.

Purposes of study and report: This report presents the results of a continuing study conducted by the U.S. Geological Survey in cooperation with the Denver Board of Water Commissioners. Purposes of the study are: (l) To define the amounts of net evaporation losses from the Denver storage reservoirs; and (2) to conduct experiments for improving methods for measuring evaporation, particularly at reservoirs at high elevations.

From introduction: The purpose of the low-flow characteristics are in some instances affected by the period of record. These characteristics can vary as much as +/- 30 percent at some gaging stations depending on whether or not the severe drought of the 1930's was included in the analysis.

From purpose and scope: The purpose of the investigation was to make a preliminary evaluation of the effects of the Faka Union Canal system on water levels in the Fakahatchee Strand. The evaluation includes more of a data collected specifically for the report as well as other data.

From purpose and scope: This report provides basic information on the ground-water resources of Chester County, Pennsylvania, which is an area of about 760 square miles (1970 meters) in southeastern Pennsylvania. It discusses the availability and quality of the water in the water-bearing units in the county and the relation of the ground water to surface water.

Report and geographical survey. This report examines the distribution of nitrates in the Redland area's ground water and concludes that this distribution depends primarily upon depth below the water table and areal location. Includes several maps and figures.

Abstract: Dissolved-solids concentrations and loads can be estimated from streamflow records using a regression model derived from chemical analyses of monthly samples. The model takes seasonal effects into account by the inclusion of simple-harmonic time functions. Monthly mean dissolved-solids loads simulated for a 6-year period at U.S. Geological Survey water-quality stations in the Green River Basin of Wyoming agree closely with corresponding loads estimated from daily specific-conductance records. In a demonstration of uses of the model, an average gain of 114,000 tons of dissolved solids per year was estimated for 6-year period in a 70-mile reach of the Green River from Fontemelle Reservoir to the town of Green River, including the lower 30-mile reach of the Big Sandy River.

From introduction: The purpose of the study was to describe the differences between ponds that developed within and abandoned mine site and in control ponds not affected by mining.

From purpose and scope: The purpose of this report is to describe the development and calibration of a regional digital model of the Floridian aquifer in the Tampa Bay area. This model can be used to provide regional analyses of the effects of present and proposed pumping from the Floridian aquifer.

Report and geological survey. This report is on the effects of the domestic secondary-treated effluent used for irrigation of pastures near Lakeland, Florida. Includes a number of maps, tables, and other figures.

From introduction: Ground water is a source of municipal, domestic, stock, and irrigation water supply for most of northeastern Larimer County, Colorado. This report presents the results of a study made to determine the quantity, availability, and quality of the ground water. This information should be useful particularly for land-use planning and the utilization and protection of the ground-water resources.

Abstract: The basic field data for time-of-travel measurements on six streams in Ohio are presented. In general, additional data on stream cross sections, tributary inflows, and chemical analyses for mainstream and tributary flows are given.

From introduction: For the purpose of this evaluation, which is qualitative, and which is based on an arbitrary numerical ranking of the thickness and hydraulic conductivity of the different materials involved, the intent was to include only the relatively pure sand beds, which would most readily store and transmit appreciable quantities of water and the clay beds, which would most effectively retard the downward movement of water to the Floridian aquifer.