bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bedding-parallel shear zones as landslide mechanisms in horizontal sedimentary rocks
Authors: Hart Michael W. 
Published: December 2014

Abstract
The occurrence of large translational paleolandslides in horizontally bedded sediments can not be completely explained by the presence of "weak" clay rocks and oversteepened natural slopes. When the shear strength of a landslide's basal rupture surface is back-calculated, residual shear strengths are usually required for failure. This is because peak shear strengths are too high to allow failure, even assuming the most conservative estimate of ground-water levels. Data obtained during geologic mapping and downhole logging of large-diameter borings suggest that the principal factor leading to translational landsliding within horizontally bedded sediments is the presence of a pre-existing shear zone. A new term, bedding-parallel shear zone (BPS), is proposed for these features. When shearing parallel to bedding results from folding or thrust faulting, it is tectonic in origin. When similar shearing is found in horizontally bedded sediments that have not been tectonically deformed, it is often misinterpreted as conclusive evidence of landsliding. Mechanisms that produce BPS are: 1. Elastic rebound. 2. Progressive failure of overconsolidated claystone. 3. Differential consolidation. 4. Gravitational creep. It is important for engineering geologists to recognize BPS and to have an understanding of the mechanisms responsible for their formation and relationship to translational landsliding. Knowledge of where and how BPS occur allows an understanding of why landslides have occurred in the past as well as allowing prediction of where large landslides are likely to occur in the future. Their misinterpretation as landslide slip surfaces has obvious effects on the accuracy of engineering geology studies and stability analyses. For example, a stability analysis for a typical landslide yielded a factor-of-safety of 1.2. An analysis of the same slope configuration representing a condition where a BPS is present, but not the entire landslide failure surface, yielded a factor-of-safety of 1.9.
Deterministic and probabilistic approaches to geologic hazard assessment
Authors: Haneberg William C. 
Published: December 2014

Abstract
The occurrence of potentially hazardous geologic events such as landslides, rock falls, earthquakes, floods, and debris flows can be predicted using two fundamentally different approaches: deterministic and probabilistic. The most significant difference between the two approaches to geologic hazard assessment is whether a process is envisioned to be the result of an exact causal relationship or if some element of random behavior is assumed to be part of the system. Although the assumption of random behavior may seem self-defeating, it can provide a useful tool for the solution of important problems as long as the randomness can be quantified using statistical models. Each of these two methods can be approached either rationally (sing models derived from accepted physical or chemical principles) or empirically (by studying the occurrence of events without explicit regard to their driving mechanism). The complexity of the geologic process commonly dictates which approach is used for a particular problem, ranging from rational deterministic models for relatively simple systems such as small landslides to empirical probabilistic models for complicated processes such as floods and earthquakes. Examples of each type of model are discussed throughout the paper, primarily within the context of slope stability and the recurrence of extreme events such as floods.
Fissure behavior in the Chihuahuan Desert, and depth estimation using sediment strength
Authors: Landford Richard P. , Eshete Tefera 
Published: December 2014

Abstract
Earth fissures are large open cracks in sediment and are controversial factors for siting waste facilities in the United States. Fissures were cited as potential hazards at each of the last two Texas radioactive waste sites. The fissures were considered potential conduits to the surface or to underlying aquifers. This research describes the behavior of earth fissures near Fort Hancock, Texas, and presents a method for estimating fissure depth using standard soil strength measurements. Observations described in the literature indicate that fissures open suddenly and episodically, swallowing large volumes of sediment and water. The author's observe that once a fissure is flooded and eroded, the fissure may become inactive and water may episodically pond in it for several years. This study suggests that during fissure flooding and erosion, the walls of the fissure weaken and collapse, closing the fissure until the sediment dries and hardens. Results indicate that fissures are limited in depth by the strength of the materials they form in. Using data from studies by previous researchers, we calculated maximum depths ranging from 2.3 to 17 m, within the fissures. The fissures in this study were in silty sand with an estimated depth of 5 m. Resistivities above the fissures indicated wetting and drying of the sediments to a 6 to 8 m depth, slightly deeper than the theoretical crack depth. Because wetting can extend below the depth of the fissure, these results are compatible. Trenches in fissures nearby bottomed in what was believed to be the fissure base at 6 m.
Aerial-photointerpretation of landslides along the Ohio and Mississippi rivers
Authors: Su Wen-June , Stohr Christopher 
Published: December 2014

Abstract
A landslide inventory was conducted along the Ohio and Mississippi rivers in the New Madrid Seismic Zone of southern Illinois, between the towns of Olmsted and Chester, Illinois. Aerial photography and field reconnaissance identified 221 landslides of three types: rock/debris falls, block slides, and undifferentiated rotational/translational slides. Most of the landslides are small- to medium-size, ancient rotational/translational features partially obscured by vegetation and modified by weathering. Five imagery sources were interpreted for land-slides: 1:250,000-scale side-looking airborne radar (SLAR); 1:40,000-scale, 1:20,000-scale, 1:6,000-scale, black and white aerial photography; and low altitude, oblique 35-mm color photography. Landslides were identified with three levels of confidence on the basis of distinguishing characteristics and ambiguous indicators. SLAR imagery permitted identification of a 520 hectare mega-landslide which would not have been identified on medium-scale aerial photography. The leaf-off, 35-mm color, oblique photography provided the best imagery for confident interpretation of detailed features needed for smaller landslides.
Black shales are insignificant sources of residential radon in the Kansas City area
Authors: Spencer Charles G. 
Published: December 2014

Abstract
Results of 128 radon screening tests performed by homeowners living in Jackson County, Missouri, and Johnson County, Kansas, are compared to four geologic variables. Slightly higher radon levels are associated with gray shale bedrock and loess-derived soil, but no statistically-significant relationships are found between radon screening levels and bedrock types, soil parent or soil permeability. Previous emphasis on black shales as a principal source of radon precursors in the Kansas City area is unwarranted. The single significant relationship found in this study is that homes built on slopes do possess statistically-higher radon screening levels than those built in upland areas.
Improving elastic modulus measurements for rock based on geology
Authors: Santi Paul M. , Holschen Jason E. , Stephenson Richard W. 
Published: December 2014

Abstract
Since many engineering projects in rock never mobilize strengths near the uniaxial compressive strength (UCS) of the rock, elastic modulus becomes a critical parameter to describe the rock's behavior under loading. There are a number of methods available for calculating the elastic modulus from laboratory test data, and each method gives a slightly different value. The objective of this study is to evaluate the most repeatable method for each of a number of rock types, and then to develop guidelines to aid the practitioner in selecting the best method as a function of rock behavior. UCS tests were performed on 78 samples of nine rock types, including two basalts, two granites, two limestones, a quartzite, a sandstone, and a gypsum. Elastic moduli were calculated using six different methods reported in the literature or modified for this study. The modified secant and modified secant-at-50-percent-strength moduli (modified by shifting the origin to best intercept the extension of the main straight-line portion of the stress-strain curve) were the most repeatable methods for rocks with elastic and plastic-elastic behavior. Elastic-plastic materials, which have a broad concave-downward stress-strain curve, are best evaluated using the tangent modulus on the upper of two distinct straight-line segments. For materials which show creep or extended plastic deformation with no sharp failure, the secant-at-50-percent-strength modulus and modified secant-at-50-percent-strength modulus are the most repeatable.
The significance of buried landscape in subsurface migration of dense non-aqueous phase liquids; the case of perchloroethylene in the Sussex Aquifer, New Brunswick
Authors: Broster B. E. , Pupek D. A. 
Published: December 2014

Abstract
At Sussex, New Brunswick, dissolved perchloroethylene (PCE) as high as 28.0 mu g/liter, was detected within the upper aquifer and in concentrations to 1.6 mu g/liter within the lower aquifer that serves as the main source of municipal water supply. Predominantly formed as an esker ridge, the lower aquifer consists of well-sorted, glaciofluvial/ice-contact, sand and gravel layers mostly confined by underlying till and/or bedrock and an overlying unit of laminated silt-clay glaciolacustrine sediments (middle aquitard). The middle aquitard is in turn overlain by an upper aquifer of variable thickness, extending from a depth of about 18 m to near surface, consisting of coarsening-upward sand and gravel, with occasional lenses of clay, silt and diamicton. A dispersal plume was identified by contouring PCE concentrations from 72 samples from the upper aquifer; PCE was not detected in 16 surface soil samples. The highest concentrations imply that the PCE originated from a surface spill near the urban business center and that subsurface migration was influenced significantly by a buried relict river channel cut into the middle aquitard. Scouring along the channel bottom cut through the middle aquitard and intersected the esker ridge of the underlying water supply aquifer, forming windows through the aquitard. Contamination of the lower aquifer has likely originated from the PCE being drawn through these windows during pumping of a water-supply well that is now out of service. Results indicate that withdrawal rates and placement of original municipal water wells, as well as the stratigraphy, conductivity and topography of subsurface units are controlling factors in Dense Non-Aqueous Phase Liquid migration at this site.
Long-term water quality trends at a sealed, partially flooded underground mine
Authors: Stoertz Mary W. , Hughes Michael L. , Wanner Nathaniel S. , Farley Mitchell E. 
Published: December 2014

Abstract
An abandoned underground coal mine complex in southeastern Ohio was hydraulically sealed in 1980 by a 300-m long subsurface clay dike and mine-entry seals near the down-dip coal outcrop. Clay plugs also were emplaced in separate entries at a higher elevation than the dike. The intent was to flood the mine to decrease acid mine drainage. A few months after construction, an entry-seal clay plug blew out at an elevation corresponding to 85-90 percent inundation, and drains in natural materials supporting the dike began flowing, indicating leakage through or around the dike. Given these early setbacks, the objective of this study was to assess the sealing project after 20 years. Seasonally, inundation can reach 85-90 percent, but high water levels are transient because of leakage. Nevertheless, mine water chemistry indicates partial suppression of pyrite oxidation. Since sealing, mine water pH increased from 2.7 to 5.3, conductivity decreased from 2700 to 600 mu S/cm, and DO is <2 percent saturation. In a stream receiving the mine drainage, acidity and metals concentrations are highest at low flow due to release of stored mine water, but acid and metal loadings are lowest at those times. The improvement in water quality due to sealing is distinguished from annual variance or natural attenuation by using a nearby unsealed mine as a control. Factoring out pre-sealing differences between the two mines, decreases in acidity loading due to sealing are significant, and the sealing project has been beneficial.
The influence of subsidence attributable to coal mining on the environment, development and restoration; some examples from Western Europe and South Africa
Authors: Bell F. G. , Genske D. D. 
Published: December 2014

Abstract
Coal mining has been practised in some parts of the world, notably western Europe, for centuries and this type of mining has evolved over time as mines became deeper and larger. Today coal is worked primarily by room-and-pillar, and by longwall methods. One of the consequences of mining is subsidence, and it is associated with past and present mine workings. Indeed, old abandoned coal mines worked by the room-and-pillar method, which occur at shallow depth, often present a potential hazard as pillars collapse or voids migrate to the surface. Frequently, the situation is compounded by the fact that such workings are unrecorded. Subsidence prediction in such cases is impossible. In longwall mining, the total extraction of panels takes place, the working face being supported, while support is removed from behind the working face allowing the roof to collapse. Subsidence consequent on longwall mining can be regarded as more or less contemporaneous with mining and is normally predictable. This means that it is possible to develop an area after subsidence due to longwall mining has occurred or to incorporate features into the design of buildings and structures that will accommodate ground movements generated by subsidence. The nature of subsidence can be affected by discontinuities in the surface strata or the presence of superficial deposits. Of course, subsidence can adversely affect existing buildings and structures which do not incorporate special design features. In severe cases of subsidence damage, buildings may have to be demolished. Important buildings may be restored. Another problem associated with subsidence is flooding due to notable lowering of the ground surface. Examples of such problems and solutions are highlighted by the examples given.
Debris-flow generation from recently burned watersheds
Authors: Cannon Susan H. 
Published: December 2014

Abstract
Evaluation of the erosional response of 95 recently burned drainage basins in Colorado, New Mexico and southern California to storm rainfall provides information on the conditions that result in fire-related debris flows. Debris flows were produced from only 37 of 95 ( approximately 40 percent) basins examined; the remaining basins produced either sediment-laden streamflow or no discernable response. Debris flows were thus not the prevalent response of the burned basins. The debris flows that did occur were most frequently the initial response to significant rainfall events. Although some hillslopes continued to erode and supply material to channels in response to subsequent rainfall events, debris flows were produced from only one burned basin following the initial erosive event. Within individual basin, debris flows initiated through both runoff and infiltration-triggered processes. The fact that not all burned basins produced debris flows suggests that specific geologic and geomorphic conditions may control the generation of fire-related debris flows. The factors that best distinguish between debris-flow producing drainages and those that produced sediment-laden streamflow are drainage-basin morphology and lithology, and the presence or absence of water-repellent soils. Basins underlain by sedimentary rocks were most likely to produce debris flows that contain large material, and sand- and gravel-dominated flows were generated primarily from terrain underlain by decomposed granite. Basin-area and relief thresholds define the morphologic conditions under which both types of debris flows occur. Debris flows containing large material are more likely to be produced from basins without water-repellent soils than from basins with water repellency. The occurrence of sand-and gravel-dominated debris flows depends on the presence of water-repellent soils.
L'unite du Koudiat Mesbah; flysch allochtone d'age senono-nummulitique des versants meridionaux du Chenoua et du cap Tenes
Authors: Lepvrier Claude 
Published: December 2014

Abstract
Cretaceous-lower Tertiary stratigraphy, structural analyses, relationship to Albian-Aptian and Tithonian-Neocomian flysch units, Tipasa-Tenes region, Algeria
Le volcanisme dinantien dans la partie orientale du bassin de Chateaulin; region de Saint-Martin-des-Pres, Allineuc (Cotes-du-Nord)
Authors: Sagon Jean Paul 
Published: December 2014

Abstract
Lower Carboniferous basaltic and rhyolitic rocks, petrography, genesis, relation to Hercynian orogeny, Breton phase, tabulated chemical and modal analytical data, Brittany, France
Les gres rouges au sommet du Paleozoique du massif du Sultan Dag et les niveaux ferrallitiques de la couverture mesozoique (Nord-Est du Taurus occidental, Turquie); analyses chimiques et mineralogiques, Signification paleogeographique
Authors: Desprairies Alain , Gutnic Marcel 
Published: December 2014

Abstract
Continental detrital facies, lateritic paleosols, mineral composition, chemical composition, paleogeographic interpretation
Structures majeures et correlations stratigraphiques dans les Taurides occidentales
Authors: Brunn Jan H. , Graciansky Pierre-Charles de , Gutnic Marcel , Juteau Thierry , Lefevre Roger , Marcoux Jean , Monod Olivier , Poisson Andre 
Published: December 2014

Abstract
Tectonics, sedimentary rocks, metamorphism, nappes, biostratigraphy, Turkey
Les quartzites Botella et leur faune trilobitique; le probleme de la limite Llandeilien-Caradocien en Sierra Morena
Authors: Carre Daniel , Henry Jean-Louis , Poupon Ginette , Tamain Guy 
Published: December 2014

Abstract
Similarities to Ordovician trilobite associations from May Sandstone, Normandy, France, lithofacies, Spain
Le metamorphisme de contact de la bauxite de Bedarieux et quelques aspects generaux du metamorphisme des bauxites
Authors: Bardossy Gyoergy , Mesko Laszlo , Panto Gyoergy , Sajgo Csanad 
Published: December 2014

Abstract
Samples from contact with basaltic dike, comparison of metamorphic bauxite of Antrim, northern Ireland and Remeti, Romania, geochemical study, France
Sur un profil des Dinarides, de l'Adriatique (Split-Omis, Dalmatie) au Bassin pannonique, (Banja Luka-Doboj, Bosnie)
Authors: Blanchet Rene 
Published: December 2014

Abstract
Dalmatian Zone, Upper Karst Zone, Prekarstic Subzone, Bosniac Zone, Serbian Zone, tectonics, stratigraphy, paleogeography, Yugoslavia
Variations lithologiques et correlations stratigraphiques dans le Lias moyen et superieur de Barles et du Plateau de Chine (Alpes de Haute-Provence)
Authors: Coadou Alain , Beaudoin Bernard , Mouterde Rene 
Published: December 2014

Abstract
Lateral evolution, lesser thickness and fewer facies, chronostratigraphy, ammonites, France
Mise en evidence d'une instabilite orogenique au Namurien inferieur entre les vallees du Guir et de la Zousfana (Bassin de Bechar, Sahara nord-occidental)
Authors: Pareyn Claude , Conrad Georges , Conrad Jacqueline , Lemosquet Yves 
Published: December 2014

Abstract
Homoceras Zone, lower Tagnana Formation, sandstone, marine sedimentation (goniatites and foraminifera), limestone, paleokarst, channels, conglomerate, pteridophytes, faults
Les olistostromes d'age miocene inferieur lies aux flyschs allochtones kabyles de l'orogene alpin d'Algerie
Authors: Bouillin Jean-Pierre , Durand-Delga Michel , Gelard Jean-Pierre , Leikine Michel , Raoult Jean-Francois , Raymond Daniel , Tefiani Mohammed , Vila Jean-Marie 
Published: December 2014

Abstract
Detrital sediments, foraminifera
Etude geochimique des elements en traces dans les series de roches volcaniques du rift d'Asal; identification et analyse des processus d'accretion
Authors: Joron J. L. , Treuil M. , Jaffrezic H. , Villemant B. 
Published: December 2014

Abstract
Study of samples of the main volcanic units of the Afar rift, from margins to late axial series, have yielded the following conclusions: 1) the magmatic liquids are strongly differentiated by a fractional crystallization process in shallow chambers, the evolution of which is limited by injection of new primary liquids as shown in the latest axial series; 2) primary liquids are generated by melting of a homogeneous mantle source, a process whereby successive partial melting in a closed system is stopped by percolation of the generated liquid. The degrees of partial melting are closely related to spreading rates; 3) the magmatic processes involve a discontinuous dynamic evolution of spreading displayed by a pulsatory magmato-tectonic activity which is controlled by the speed of decompression of mantle material.
Particularites chimiques et mineralogiques de la serie meta-evaporitique du gisement de pyrite de Niccioleta, Toscane, Italie
Authors: Dechomets Roland 
Published: December 2014

Abstract
The chemical composition of the meta-evaporitic series of Niccioleta is similar (evaporitic rocks excepted) to that of the common mica schist series. However, the sheet silicates have recorded the evaporitic nature of the sedimentation. Only the schist layers in the anhydrite rocks have relatively high Mg and B contents. Electron microprobe analysis proved that muscovites are more phengitic and more magnesian in the evaporitic rocks than in the schists. Small amounts of Mg-bearing chlorites and phlogopites are associated with the phengites (which contain micro-inclusions of tourmaline, rich in dravite). The sedimentary origin of the magnesian character is discussed, the magnesian aggradations of illites are the main factor; typical minerals of evaporite-bearing sediments, like smectites and corrensites do not appear in large quantities. The P-T conditions of regional metamorphism are postulated as 2-3 kbar and 400-450 degrees C.