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Storm-drain flow-routing methods based on kinematic-wave routing and storage-routing methods are compared with the MLSR (multiple-linearization storm-drain routing) method for hypothetical circular pipe problems. The MLSR method, based on a diffusion-wave routing concept, is shown to give very good results without incurring the numerical solution or damping problems of other methods.
Many of the more than 2,200 storm-water basins on Long Island, N.Y., are potential sites for infiltration of large volumes of reclaimed water (highly treated domestic and industrial sewage). By use of a finite-difference method of calculation, changes in basin storage during idealized high-intensity storms were determined for the North Massapequa basin, a typical basin on Long Island. Calculations for a 100- year storm, in which a runoff coefficient of 20 percent was used but in which infiltration rate, storm intensity, storm duration, and return period were varied, indicate that this test basin would not overflow even if the infiltration rate declined from its present 1.5 feet per hour (0.46 meter per hour) to about 0.03 ft/h (0.009 m/h). The large reserve capacity of the test basin and similar basins on Long Island demonstrates the feasibility of using storm-water basins for infiltration of a supplemental water supply (supplemental recharge). If reclaimed water were ponded to a depth of 4 ft (1.2 m) in the test basin and if water application were alternated for equal periods between the test basin and a nearby basin with similar characteristics, the volume of infiltration would be slightly more than two million gallons per day (0.09 cubic meters per second) at an infiltration rate of 1.5 ft/h (0.46 m/h). With supplemental recharge, 60 percent of available storage capacity would be used during a 10-yr storm, and 80 percent would be used during a 100-yr storm, using a runoff coefficient of 20 percent.
Obsidian hydration dating of pumice and obsidian from Newberry Crater, Oreg., shows that the postcaldera activity began about 6700 yr ago and that the latest major eruptive event occurred about 1400 yr B.P. Two of the hydration dates correlate with 14 C-dated pumice eruptions.
Contrasts of electrical properties between uranium deposits and their host rocks in South Texas are subtle. In places where deposits are small or deep, conventional geophysical well-logging techniques and hole-to-hole measurements may be the only practical method to detect changes in rock properties associated with the occurrence of uranium ore deposits. Two separate ore-producing areas in South Texas were chosen for studying borehole geophysical techniques applied to uranium-exploration problems. Extensive measurements of physical properties were made on cores and taken from holes where electrical-resistivity, induced-polarization and gamam-ray logs were run. These analyses show that: (1) induced-polarization anomalies are caused by a change in pyrite content and clay-sized material content and (2) resistivity anomalies are associated with a change in clay-sized material content and cementation. In addition to conventional borehole techniques, hole-to-hole induced-polarization and resistivity tests were made in South Texas. These measurements were made by placing a current source down one hole and a receiver cable down an adjacent hole whose separation ranged from 30 to 300 m and hole depths varied from 80 to 270 m. These tests show that hole-to-hole measurements can be used to detect changes in physical properties, associated with uranium ore, that occur between boreholes. Hole-to-hole measurements provide a link between surface measurements and well logs and can minimize the amount of drilling needed to locate an ore deposit. Accordingly, borehole geophysics will become an increasingly important evaluation tool as mineral exploration goes deeper.
Large-scale gravitational spreading and fracturing of steep-sided ridges in the mountainous area of Colorado are characterized by horizontal linear fissures, trenches, and uphill-facing scarps on tops and sides of ridges. A pronounced north-trending cleft and several minor scarps have split a ridge extending northward from Dolores Peak in the San Miguel Mountains of southwestern Colorado. This ridge is capped by granogabbro of a Tertiary laccolith that intruded the Cretaceous Mancos Shale. Numerous active landslides in shale mantle the once glaciated lower slopes. Trenches in the granogabbro probably originated after glacial ice melted, leaving steep sides of the ridge unsupported. The soft Mancos shale moved outward toward the direction of least stress, placing the overlying granogabbro under tension. A ridge that extends southwest from Bald Eagle Mountain, north of Mount Massive in central Colorado, is marked by a graben on the top and several trenches on the northwest side, parallel to the long axis of the ridge. Rock exposed in graben and trenches is the Precambrian St. Kevin Granite, which includes some schist and migmatite. Gravitational movement probably took place after steepening of the valley sides by glacial erosion and melting of the glaciers. Movement followed preexisting discontinuities in the rock. A survey course approximately 2.4 km (1.5 mi) long has been placed across .the fractured ridge. It will be monitored periodically to determine whether movement is continuing, and if so, at what rate.
Uranium deposits in the San Rafael Swell are related to sedimentary depositional environments in the Upper Triassic Chinle Formation. The sedimentary textures resulting from depositional processes operating in low-energy environments appear to have influenced uranium mineralization. The Ohinle consists of three fining-upward, fluvial-lacustrine sequences. Uranium minerals are concentrated in the lower part of the lowest sequence in areas where sediments of low-energy environments are complexly interbedded with sediments of other environments. Areas favorable for uranium exploration exist in the subsurface to the north, west, and south of the Chinle outcrop in the Swell. This determination is based on the spatial distribution of depositional environments and the pattern of Chinle deposition through time.
Ostracodes are abundant and diverse in Pliocene and lower Pleistocene deposits of Virginia and North Carolina. Many readily identified species are short ranging or have well-defined beginning and (or) end points to their stratigraphic range. These microscopic crustaceans, therefore, are very useful in zonation and correlation in the region. In this paper, 54 particularly useful species are illustrated, and their ranges are indicated graphically. The range zones, concurrent range zones, and local range zones of these forms allow the recognition of the chronozones of previously proposed ostracode assemblage zones in Virginia and North Carolina as well as in other regions.
A new method for measuring the solubility of simple salts in water at elevated temperatures involves heating assemblages of salt crystals plus solution vapor at a constant rate in a platinum-lined bomb. The dissolution of the last salt crystal is evidenced by a distinct discontinuity in the pressure-temperature curve. Studies of the solubilities of NaCl and of KC1 in water yielded equations expressing the solubility as functions of temperature, t in °C, at the vapor pressure of the solutions as follows: weight percent NaCl=26.218+0.0072 t +0.000106 t 2 ±0.05 weight percent NaCl weight percent KCl=27.839+0.0794 t +0.000027 t 2 ±0.10 weight percent KCl The NaCl and KC1 data were measured over the temperature range 148° to 425°C and 148° to 371°C, respectively. However, the equation for NaCl appears to be valid over the range 0° to 800°C, and the KC1 equation appears valid over the range 100° to 450°C.
Epithermal neutron-activation analyses results of the 8 new USGS standard rocks are compared with results by spectrographic, X-ray fluorimetric, atomic absorption, radiochemical neutron-activation, instrumental neutron-activation (thermal neutrons), isotope-dilution mass spectrometric, spectrofluorimetric, radioisotopic dilution and delayed-neutron techniques for 22 elements. Results indicate the technique to be useful and dependable especially for Ni, Se, Rb, Sr, Mo, Ba, Tm, Ta, Th and U.
The advanced spaceborne thermal emission and reflection (ASTER) radiometer was designed to record reflected energy in nine channels with 15 or 30 m resolution, including stereoscopic images, and emitted energy in five channels with 90 m resolution from the NASA Earth Observing System AMI platform. A simulated ASTER data set was produced for the Iron Hill, Colorado, study area by resampling calibrated, registered airborne visible/infrared imaging spectrometer (AVIRIS) data, and thermal infrared multispectral scanner (TIMS) data to the appropriate spatial and spectral parameters. A digital elevation model was obtained to simulate ASTER-derived topographic data. The main lithologic units in the area are granitic rocks and felsite into which a carbonatite stock and associated alkalic igneous rocks were intruded; these rocks are locally covered by Jurassic sandstone, Tertiary rhyolitic tuff, and colluvial deposits. Several methods were evaluated for mapping the main lithologic units, including the unsupervised classification and spectral curve-matching techniques. In the five thermalinfrared (TIR) channels, comparison of the results of linear spectral unmixing and unsupervised classification with published geologic maps showed that the main lithologic units were mapped, but large areas with moderate to dense tree cover were not mapped in the TIR data. Compared to TIMS data, simulated ASTER data permitted slightly less discrimination in the mafic alkalic rock series, and carbonatite was not mapped in the TIMS nor in the simulated ASTER TIR data. In the nine visible and near-infrared channels, unsupervised classification did not yield useful results, but both the spectral linear unmixing and the matched filter techniques produced useful results, including mapping calcitic and dolomitic carbonatite exposures, travertine in hot spring deposits, kaolinite in argillized sandstone and tuff, and muscovite in sericitized granite and felsite, as well as commonly occurring illite/muscovite. However, the distinction made in AVIRIS data between calcite and dolomite was not consistently feasible in the simulated ASTER data. Comparison of the lithologie information produced by spectral analysis of the simulated ASTER data to a photogeologic interpretation of a simulated ASTER color image illustrates the high potential of spectral analysis of ASTER data to geologic interpretation.
Controls on mudstone deposition at high latitudes are poorly known relative to low latitudes. In recent sediments deposited in these environments, ice significantly influences sediment transport and primary productivity. The products of ice transport are relatively well known in glacimarine settings, but are less well known from below melting sea ice. This latter setting is significant as today it is associated with high primary organic productivity. The aim of this study is to assess how sea ice might have controlled lithofacies variability and organic-matter distribution and preservation in an ancient marine, siliciclastic mudstone-dominated succession deposited at high latitudes. Combined sedimentary logging, optical and electron optical (back-scatte red electron imagery), geochemical, and isotopic methods were used to determine sample variability in forty-five samples collected from the Lower Cretaceous succession in the Mikkelsen Bay State #1 borehole (North Slope, Alaska). The succession overall fines upward and contains muddy sandstones and sand- and silt-bearing, clay-rich mudstones towards its base in contrast to clay-rich and clay-dominated mudstones towards its top. Some of the mudstone units exhibit thin (< 5 mm), relic-beds that fine upward weakly. In some units small (0.5 mm), bed-parallel silt-filled microburrows disrupt depositional laminae whereas in others pervasive burrowing completely obliterates original depositional textures. Many of the units are pelleted. These mudstones are unusual in that they contain minor but very striking outsize grains, composed of subrounded to rounded sand and granule-size material. In addition, they are good petroleum source rocks, with between 2.8 and 5.9 wt % total organic carbon, of predominantly Type II kerogen. The organic matter has an isotopic signature ranging from -25.4??? ??13C to -28.1??? ??13C. Thin tuffs (< 20 mm) and carbonate-cemented units are also present. Given the absence of significant polar ice in the Early Cretaceous the outsized grains are interpreted to have been deposited from a combination of melting, dirty anchor, and fast ice. The mud fraction, which forms the bulk of the sediment, is interpreted to have been deposited from melting, sediment-laden frazil ice, and fast ice. After deposition sediments were partially reworked by bottom currents generated by brine rejection during sea ice formation. Sympagic organisms, grazing on algae and bacteria both within and below the ice, pelleted the sediment. Bioturbation, which varies through the succession, indicates that sedimentation probably occurred beneath a predominantly oxic or dysoxic water column. In this setting productivity was fueled by nutrients released from melting sea ice in the marginal ice zone. The good petroleum source potential of these mudstones is attributed to high organic productivity coupled to episodic and rapid sedimentation rather than existence of bottom-water anoxia linked to upwelling. Because sea-ice rafting was probably the dominant sediment transport mechanism it is not appropriate to use sequence stratigraphic methodology to predict lithofacies variability in this environment. Copyright ?? 2005, SEPM (Society for Sedimentary Geology).
Introduction Water-quality activities and water-level measurements conducted by the U.S. Geological Survey (USGS) Idaho National Laboratory (INL) Project Office coincide with the USGS mission of evaluating the quantity and quality of the Nation’s water resources. The activities are conducted in cooperation with the U.S. Department of Energy’s (DOE) Idaho Operations Office. Results of water-quality and hydraulic head research efforts are presented in various USGS and scientific journal publications (refer to Fisher, 2022). These data are stored internally in the Aquarius Time Series and Aquarius Samples databases and are publicly accessible through National Water Quality Monitoring Council (2025) and U.S. Geological Survey (2025). Data collected from our studies are used by researchers, Federal and State agencies, water management and regulatory organizations, as well as the public. This quality assurance plan (QAP) describes the methods and processes for field methods, data collection, data management, data auditing, and equipment management for both the water-quality and water-level programs at the USGS INL Project Office (hereto referred to as INL Project Office). A comprehensive quality assurance (QA) plan ensures that the processes defined in this document will guide the program staff to collect and publish reliable, useful, and defensible data products for stakeholders. This QAP supersedes previous versions of this document and is intended to complement the Quality Assurance and Data Management (QADM) Plan for the Idaho Water Science Center (IDWSC; Christopher Mebane and Lauren Zinsser, written commun., 2024).
These summaries of data on metallic and selected nonmetallic mineral occurrences and lists of selected references to .them in Geological Survey, U.S. Bureau of Mines, and State of Alaska Division of Geological and Geophysical Surveys (and predecessor State and Territorial agencies) reports and maps and a very.few journal articles are designed to aid in library research on the mineral resources of the McCarthy quadrangle, Alaska. The references listed are selected in the sense that mainly statistical reports such as the annual Minerals Yearbook of the U.S. Bureau of Mines and many annual and biennial reports of the Alaska Division of Geological and Geophysical Surveys and its predecessor agencies are not included. Also not included are data on claims about which little more than their locations is known (for example, localities 126- 130 in MacKevett and Holloway, 1977 (OF 77-169A). These omissions should not be interpreted as a judgement that the claims are not on valid mineral occurrences, but only chat there are insufficient data to describe any mineral deposits that might be present. Geochemical anomalies determined by analyses of rock and stream-sediment samples in which no metallic mineral was indentified are also omitted.
The morphometric characteristics of the axial regions of oceanic spreading centers are determined by (1) the type of volcanic flows, (2) the relation between primary volcanic relief (on a scale of a few meters to tens of meters) and degree of sediment cover, and (3) the extent of surficial expression and timing of tectonic disruption of the young oceanic crust. Even within a single, continuous, linear spreading-ridge segment with relatively uniform axial valley dimensions over a distance of 50 or more kilometers, such as along the southern Juan de Fuca Ridge, the changes in morphometric characteristics along axis within the youngest crust indicate distinct variation in tectonic and volcanic activity over short distances within short time periods. An integrated analysis of Sea MARC I, Sea MARC II, and photographic data for the southernmost continuous segment of the Juan de Fuca Ridge shows that generalizations about tectonic and volcanic processes at spreading ridges must consider both the temporal scale of processes as well as the physical scales of observations if predictive models are to be successful. Comparison of the morphometric expression within the major hydrothermal vent area and the rest of the southernmost ridge segment suggests that the mapped distribution of hydrothermal vents may reflect the extent of survey effort rather than uniqueness of geologic setting.
Centimeter-scale measurements on several Powder River floodplains provide insights into the nature of overbank depositional processes that created the floodplains; during a 20-year period after a major flood in 1978. Rising stages initially entered across a sill at the downriver end of the floodplains. Later, as stages continued to rise, water entered the floodplains through distinct low saddles along natural levees. The annual maximum depth of water over the levee crest averaged 0.19 in from 1983 through 1996, and the estimated flow velocities were approximately 0.15 m s-1. Water ponded in the floodplain trough, a topographic low between the natural levee and the pre-flood riverbank, and mud settled as thin layers of nearly constant thickness. Mud layers alternated with sand layers, which were relatively thick near the channel. Together, these beds created a distinctive natural levee. In some locations, individual flood deposits began as a thin mud layer that gradually coarsened upwards to medium-grained sand. Coarsening-upwards sequences form initially as mud because only the uppermost layers of water in the channel supply the first overbank flows, which are rich in mud but starved of sand. At successively higher stages, fine sands and then medium sands increase in concentration in the floodwater and are deposited as fine- and medium-sand layers overlying the initial mud layer. Theoretical predictions from mathematical models of sediment transport by advection and diffusion indicate that these processes acting alone are unlikely to create the observed sand layers of nearly uniform thickness that extend across much of the floodplain. We infer that other transport processes, notably bedload transport, must be important along Powder River. Even with the centimeter-scale measurements of floodplain deposits, daily hydraulic data, and precise annual surface topographic surveys, we were unable to determine any clear correspondence between the gauged flow record of overbank floods and the depositional layers mapped in the floodplain. These results provide a detailed example of floodplain deposits and depositional processes that should prove useful for interpreting natural levee deposits in a variety of geologic settings. Copyright ?? 2008, SEPM (Society for Sedimentary Geology).
Fairmont State University (FSU) and the West Virginia Geological and Economic Survey (WVGES) provided a small pilot group of West Virginia science teachers with a professional development session designed to mimic experiences obtained by geology majors during a typical summer field camp. Called GEOTECH, the program served as a research capstone event complimenting the participants' multi-year association with the RockCamp professional development program. GEOTECH was funded through a Improving Teacher Quality Grant administered by West Virginia Higher Education Policy Commission. Over the course of three weeks, eight GEOTEACH participants learned field measurement and field data collection techniques which they then applied to the construction of a surficial geologic map. The program exposed participants to authentic scientific processes by emphasizing the authentic scientific application of content knowledge. As a secondary product, it also enhanced their appreciation of the true nature of science in general and geology particular. After the session, a new appreciation of the effort involved in making a geologic map emerged as tacit knowledge ready to be transferred to their students. The program was assessed using pre/post instruments, cup interviews, journals, artifacts (including geologic maps, field books, and described sections), performance assessments, and constructed response items. Evaluation of the accumulated data revealed an increase in participants demonstrated use of science content knowledge, an enhanced awareness and understanding of the processes and nature of geologic mapping, positive dispositions toward geologic research and a high satisfaction rating for the program. These findings support the efficacy of the experience and document future programmatic enhancements.
The differences of radar data from more familiar photographic images, coupled with the unique geologic characteristics of Venus's surface, can make interpretation of the standard Magellan data products difficult for both planetary scientists and nonspecialists. We describe a set of digital processing techniques for transforming individual remote‐sensing datasets in order to make the information they contain more apparent, and for combining multiple datasets of diverse resolution and information content into synthetic images that allow the viewer to explore correlations among the data. The creation of derived data products by techniques like those we describe is becoming increasingly widespread and important, both for scientific research and for use in educational and media presentations. We apply our processing techniques to Magellan synthetic aperture radar images, altimetry, and microwave emissivity measurements of four areas that exemplify some of the most important styles of geologic activity on Venus.
Paleogeographic, isopach, and deltaic lithofacies mapping of thirteen depositional sequences establish a 35 myr high resolution (> 1 Myr) record of Late Cretaceous wave- and tide-influenced deltaic sedimentation. We integrate sequences defined on the basis of lithologic, biostratigraphic, and Sr-isotope stratigraphy from cores with geophysical log data from 28 wells to further develop and extend methods and calibrations of well-log recognition of sequences and facies variations. This study reveals the northeastward migration of depocenters from the Cenomanian (ca. 98 Ma) through the earliest Danian (ca. 64 Ma) and documents five primary phases of paleodeltaic evolution in response to long-term eustatic changes, variations in sediment supply, the location of two long-lived fluvial axes, and thermoflexural basement subsidence: (1) Cenomanian-early Turonian deltaic facies exhibit marine and nonmarine facies and are concentrated in the central coastal plain; (2) high sediment rates, low sea level, and high accommodation rates in the northern coastal plain resulted in thick, marginal to nonmarine mixed-influenced deltaic facies during the Turonign-Coniacian; (3) comparatively low sediment rates and high long-term sea level in the Santonian resulted in a sediment-starved margin with low deltaic influence; (4) well-developed Campanian deltaic sequences expand to the north and exhibit wave reworking and longshore transport of sands, and (5) low sedimentation rates and high long-term sea level during the Maastrichtian resulted in the deposition of a sediment-starved glauconitic shelf. Our study illustrates the widely known variability of mixed-influence deltaic systems, but also documents the relative stability of deltaic facies systems on the 106-107 yr scale, with long periods of cyclically repeating systems tracts controlled by eustasy. Results from the Late Cretaceous further show that although eustasy provides the template for sequences globally, regional tectonics (rates of subsidence and accommodation), changes in sediment supply, proximity to sediment input, and flexural subsidence from depocenter loading determines the regional to local preservation and facies expression of sequences. Copyright ?? 2008, SEPM (Society for Sedimentary Geology).