Review of the Huaytapallana project in Peru     

Adam Chrzanowski  Walter Welsch 《Tectonophysics》1986,130(1-4):23-31

In 1969, two consecutive earthquakes activated a reverse fault at an elevation of 4600 m in the Huaytapallana mountain range near Huancayo in central Peru. In 1975, a small geodetic network was established and measured across the fault covering an area of about 1.5 km². The network has been remeasured in 1976, 1977, 1978, and 1982, using standard geodetic instruments, as a joint effort by two Canadian and one German universities in cooperation with the Peruvian Institute of Geophysics. In 1978, the network was expanded to cover 6 km². High-altitude sickness, logistic problems with old vehicles, civil unrest and riots plagued the survey expeditions. The results show a cyclic rigid body motion of the southwest side versus the northeast side of the fault in a general east-west direction of about ± 3 mm/year. The direction of the motion agrees with the direction of compressive forces expected in this subduction region. The next survey campaign is planned for 1987.  相似文献   

Thallium: A potential guide to mineral deposits     

Mohammed Ikramuddin  Yemane Asmeron  Paul M. Nordstrom  Kirk P. Kinart  Walter M. Martin  Sharon J.M. Digby  Danelle D. Elder  Walter F. Nijak  Adolphus A. Afemari 《Journal of Geochemical Exploration》1983,19(1-3)

Several recent studies have suggested that rocks associated with mineral deposits of hydrothermal origin are generally enriched in Rb. TI is similar in its geochemical characteristics to Rb, but its use as a potential guide to ore deposits has not been suggested. Although TI has the same size and valency as Rb, it is concentrated more in residual melts than Rb and K because the TI-O bond is more covalent and weaker than either the Rb-O or K-O bonds.A new method which is rapid and precise has been developed by one of the authors for the determination of TI in geological materials at the ppb level. About 350 rocks from 4 mineralized areas in northeastern Washington and central Montana were analyzed for TI by this method. Most of these rocks were also analyzed for SiO₂, A1₂O₃,Fe₂O₃, MgO, CaO, Na₂O, K₂O, TiO₂, P₂O₅, MnO, Ag, As, Au, Ba, Co, Cu, F, Li, Mo, Ni, Pb, Sr, Sb, Sn, Sr, Te, U, W, and Zn. The ore deposits of the areas studied include the gold-silver deposits of the Republic district, the uranium deposit of the Midnite mine, the coppermolybdenum deposit of Mount Tolman, and the gold deposits of the North Moccasin mining district.In all the mineralized areas there is significantly more TI in hydrothermally altered rocks than in unaltered rocks. The very high abundance of TI in the altered rocks of the North Moccasin gold district, and the significant positive correlations of TI and K and TI and Rb in the mineralized rocks of the other three areas suggest that TI was concentrated in hydrothermal fluids. In altered rocks the average K/Rb and K/TI ratios are lower, and the Rb/Sr and TI/Sr ratios are higher.Often the abundance of TI and the K/TI and TI/Sr ratios are more useful in delineating mineralized areas than the abundance of Rb and the K/Rb and Rb/Sr ratios. The ternary relationships between TI and several other elements, especially Rb, K, Ba, and Sr, show mineralized rocks to fall near the TI apices or near the TI-Rb or TI-K boundaries.  相似文献   

Chesapeake Bay nutrient and plankton dynamics: III. The annual cycle of dissolved silicon     

Christopher F. D&#x;Elia  David M. Nelson  Walter R. Boynton 《Geochimica et cosmochimica acta》1983,47(11):1945-1955

Silicic acid (H₄SiO₄) flux from the sediment, H₄SiO₄ concentration and river flow were used to obtain an annual dissolved silicon budget for Chesapeake Bay. H₄SiO₄ concentrations vary seasonally in the estuary: for a 12-year period, mean H₄SiO₄ concentrations in the mesohaline region were high both in spring and in late summer to early fall, and were low in late spring—occasionally approaching levels potentially limiting to diatom growth. Most of the annual allochthonous H₄SiO₄ supply to the estuary derives from the three major rivers, but regenerative H₄SiO₄ flux from the sediment to the water column exceeds the total riverine input by a factor of at least five. Sediment H₄SiO₄ efflux exhibits seasonality and averages approximately 2–3 mol Si m^?2 yr^?1. The high rates of sediment dissolution and efflux appear to maintain high levels of H₄SiO₄ in the mesohaline region, and Si-limitation of diatom growth there seems unlikely. The relative rates of biogenic silica formation and dissolution do not vary synchronously: seasonal variations in diatom productivity, sedimentary release of H₄SiO₄ and river flow all contribute to the observed late winter and late summer seasonal maxima and late spring minimum in water column H₄SiO₄ concentrations. If the only source of Si to support sedimentary H₄SiO₄ efflux is biogenic particulate silica recently deposited from the water column and this silica in turn was produced by diatoms in a ratio of 8C:1 Si, the minimum annual primary production by diatoms is at least 260 g C m^?2, approximately half of annual total plankton primary production. This estimate would be revised upwards according to the amount of particulate biogenic silica dissolving in the water column. Burial of biogenic silica amounts to from 2 to 84% of the sediment efflux of H₄SiO₄, depending on location in the bay. On an annual basis, burial represents from 60 to 100% of fluvial H₄SiO₄-Si inputs.  相似文献   

Subsurface Venting of Vapors Emanating from Hydrocarbon Product on Ground Water   总被引：6，自引：0，他引：6  

Walter L. Crow  Eric P Anderson  Edward M. Minugh 《Ground Water Monitoring & Remediation》1987,7(1):51-57

The results of an API-sponsored pilot-scale subsurface venting system study are presented. The purpose of this study was to evaluate the effectiveness of forced venting techniques in controlling and removing hydrocarbon vapors from a subsurface formation. Both qualitative and quantitative sampling and analytical procedures were developed to measure hydrocarbon vapors extracted from the soil. Vapor recovery and equivalent liquid product recovery rates were measured at each test cell evacuation rate.
Two identical test cells were installed. Each cell contained 16 vapor monitoring probes spaced at distances from 4 to 44 feet from a vapor extraction (vacuum) well. Each cell was also configured with two air inlet wells to allow atmospheric air to enter the subsurface formation. The vapor monitoring probes were installed at three discrete elevations above the capillary zone. In situ vapor samples were obtained periodically from these probes to measure changes in vapor concentration and composition while extracting vapors from the vacuum well at three different flow rates (18.5 scfm, 22.5 scfm and 39.8 scfm). In situ vapor samples were analyzed using a portable gas chromatograph to quantify and speciate the vapors. Vacuum levels were also measured at each vapor sampling probe and at the vacuum well.
The soil venting techniques evaluated during this study offer an alternative approach for controlling and eliminating spilled or leaked hydrocarbons from sand or gravel formations of high porosity and moderate permeability. These techniques may also be used to augment conventional liquid recovery methods. The data collected during this study will be useful in optimizing subsurface venting systems for removing and controlling hydrocarbon vapors in soil. Study results indicate pulsed venting techniques may offer a cost-effective means of controlling or eliminating hydrocarbon vapors in soil.  相似文献   

Dynamics of the down-going lithosphere     

Jack Oliver  Bryan Isacks  Muawia Barazangi  Walter Mitronovas 《Tectonophysics》1973,19(2):133-147

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Sedimentologische Untersuchungen im Golf von Manfredonia (Südadria)     

Hansjörg Oeltzschner  Walter Sigl 《International Journal of Earth Sciences》1970,60(1):131-144

Zusammenfassung Der Golf von Manfredonia spielt als Mündungsgebiet der Flüsse Ofanto, Carapelle und Cervaro im meeresgeologischen Geschehen der Südadria eine wichtige Rolle. Die charakteristische, durch den vulkanischen Komplex des Monte Vulture geprägte Mineralgesellschaft der Ofanto-Sedimente läßt sich über den Golf hinaus in der gesamten Südadria nachweisen.Zwischen 1966 und 1969 wurden im Golf und in seinem Küstenbereich 305 Proben genommen, 540 km Echographprofile gefahren, an 80 Tagen Strömungsmessungen durchgeführt und ausgedehnte Tauchbeobachtungen gemacht.In der sog. Scogliera, einer Untiefe im Südteil des Golfes, unterscheidet sich der Meeresboden durch seine Morphologie und Lithofazies deutlich von dem des übrigen Golfes.Anhand von Schwermineral-Untersuchungen wurde festgestellt, daß sich innerhalb des Golfes zwei Schwermineral-Gesellschaften unterschiedlicher Herkunft und Paragenese miteinander vermischen.Durch Strömungsmessungen ließen sich innerhalb des Golfes Strömungen in vorwiegend nordwestlicher bis nordöstlicher Richtung nachweisen.

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305 sediment samples were taken from the Gulf of Manfredonia during the years 1966–1969. About 540 km echo-sounding profiles were run in the gulf. More than 20 km² of the seafloor were examined byScuba-divers. For 80 days bottom currents were measured by self-recording current meters.The Gulf of Manfredonia is supplied with sediments by the Apennine rivers Cervaro, Carapelle, and mainly by the river Ofanto, transporting clastic material from the volcanic complex of the Mount Vulture into the gulf.These sediments have a characteristical heavy mineral association (augitbasaltic hornblende - melanit), called the Ofanto-heavy mineral association. They are mainly redistributed to the North and Northwest by a clockwise (anticyclonic) eddy from the mouth of the river Ofanto.The Ofanto-heavy mineral association prevails in the sediments of the Southern Adriatic. Yet in the northern part of the gulf, the sediments with this mineral association are mixed with other sediments which are transported along the Italian coast of the Adriatic to the South-East by the SE flowing gradient current (Zore-Armanda, 1964). The provenance of these northerly sediments is assumed to be from the Apennine and the Po-River (padanic-apenninic heavy mineral association: garnet-epidote-hornblende-glaukophane).In the southern parts of the gulf a shoal, called scogliera, was observed. The scogliera morphologically and litologically is very different from the surrounding muds and silty muds; it probably represents a paleo-coastline from a time of lowered sea-level.

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Riassunto Sono riportati i primi risultati delle ricerche sedimentologiche e mineralogiche sopra i sedimenti recenti del Golfo di Manfredonia. I indagini sono stati eseguiti durante i anni 1966–1969.Sulla base dell' esame delle caratteristiche di questi sedimenti e di uno sguardo d'insieme sulla costituzione litologica della regione del golfo vengono prospettate le probabili origini e la distribuzione di detti sedimenti. Col aiuto dieRichardson-correntometri e stata provata l'influenza delle certe correnti marine nel golfo alla distribuzione delle sedimenti portati al golfo dai fiumi Ofanto, Carapelle, e Cervaro.

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Manfredonia, Ofanto, Carapella Cervaro, 1966–1969 305 . , , . 540 , , 80 . , , - -.

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Die Untersuchungen wurden mit Unterstützung der Deutschen Forschungsgemeinschaft (Schwerpunktprogramm Sedimentforschung Fa 46/7-10) durchgeführt. Wir danken dem Leiter des Forschungsvorhabens, Herrn Dr. F.Fabricius, für Anregung und Kritik. Herrn Dr. U.von Rad sind wir für seinen wissenschaftlichen Beistand und seine unermüdliche Hilfsbereitschaft sowohl im Gelände als auch bei der Auswertung der Ergebnisse besonders verpflichtet. Außerdem danken wir Herrn Dipl.-Geol. K.Braune für seine Hilfe.  相似文献   

Agrarmeteorologische Untersuchungen des Wärme- und Wasserhaushaltes im Bereichlandwirtschaftlicher Kulturen     

Dr. Walter Müller 《Theoretical and Applied Climatology》1971,19(2):199-224

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Experimentelle Untersuchungen über die Erzeugung von Salzteilchen aus den Meeren     

Walter Rau 《Pure and Applied Geophysics》1956,33(1):114-120

Zusammenfassung Die für die Erzeugung von Salzteilchen aus dem Meer wesentlichen Vorg?nge werden untersucht, wobei die Teilchen nachVittori nachgewiesen und vermessen werden. Es zeigt sich, dass Zerplatzen von aufsteigenden Luftblasen allein wenig wirksam ist. Dagegen nimmt die erzeugte Teilchenzahl mit wachsender Zersprühgeschwindigkeit rasch zu. Dichten von 10⁶ pro cm³ durchgeblasener Luft sind leicht realisierbar. Die Ergebnisse werden im Hinblick auf die für und wider dieK?hler’sche Hypothese vorgebrachten Argumente und auf die tats?chlichen Chloridgehalte der Atmosph?re diskutiert.

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Summary The processes essential for the production of salt-particles from the sea are investigated, the particles being identified and measured according toVittori. Bursting air bubbles are shown to be mostly ineffective. The number of produced particles increases rapidly with accelerating velocity of spraying. Populations of 10⁶ per cm³ of air blown through the water are possible. The results are discussed with regard to the arguments stated pro and contra the hypothesis ofK?hler and to the chlorid contents of the atmosphere.

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Résumé Les facteurs essentiels pour la production de particules de chlorure de sodium hors de la mer sont examinés en indiquant et mesurant les particules selon la méthode deVittori. L’éclatement des bulles d’air ascendant dans l’eau est démontré être peu efficace. Le nombre de particules produits s’augmente très vite, si la vélocité de jaillissement s’accro?t. On peut aisément réaliser des densités de 10⁶ par cm³ d’air soufflé. Les résultats sont discutés en vue des arguments constatés pro et contre l’hypothèse deK?hler et de la quantité de chlorure, contenue effectivement dans l’atmosphère.

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Dr.W. Rau, Max-Planck-Institut für Physik der Stratosph?re,Weissenau (Würtibg.).  相似文献   

Ein einfaches Modell der Zirkulation im Meere     

Walter Hansen 《Ocean Dynamics》1956,9(2):102-106

Zusammenfassung In einem geschichteten Meer einfacher Form werden aus den vorgegebenen Randbedingungen und Randwerten, unter denen die Dichte an der Meeresoberfläche die Hauptrolle spielt, die Bewegungsvorgänge und die Massenverteilung im Innern des Meeres ermittelt. Es existiert eine Tiefe, in der die Horizontalkomponente der Geschwindigkeit Null ist. Diese Tiefe hängt in dem einfachen Modell außer von dem Verhältnis Gesamttiefe durch Länge von dem Verhältnis des horizontalen zu dem vertikalen Austausch ab. Je größer der erste ist, desto näher rückt die Tiefe mit verschwindender Horizontalkomponente der Strömung an die Oberfläche.

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A simple model of oceanic circulation

Summary The processes of motion and mass distribution in the depths of the ocean are derived from given boundary conditions (Randbedingungen) and bonudary values (Randwerte) in a stratified ocean of simple form, and especially from the density at the sea surface of such ocean. In pursuance of these assumptions one arrives at a level at which the horizontal component of velocity equals zero. In the simple model this level depends upon the ratio of the total depth to the length as well as upon the ratio of the horizontal to the vertical eddy viscosity. With intensifying eddy viscosity the zero level approaches the sea surface.

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Un modèle simple de la circulation océanique

Résumé Les processus de mouvement et de distribution de masses dans les profondeurs de l'océan sont dérivés des grandeurs supposées desRandbedingungen (conditions au-contour) et desRandwerte (valeurs au contour) dans un océan stratifié de forme simple et, surtout, de la densité superficielle d'un tel océan. Ces suppositions conduisent à un niveau où la composante horizontale de la vitesse devient égale à zéro. Dans le modèle simple, ce niveau de zéro dépend de la proportion entre la profondeur totale et la longueur d'une part et entre la viscosité virtuelle horizontale et la viscosité virtuelle verticale d'autre part. Avec l'intensification de la viscosité virtuelle le niveau de zéro s'approche de la surface de la mer.

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Herrn Professor Dr. Gerhard Schott zum 90. Geburtstag gewidmet.  相似文献   

Relieffolgende Ablagerungen Vulkanischer Lockermassen     

Walter J. Schmidt 《International Journal of Earth Sciences》1956,45(2):314-318

Zusammenfassung Als Beispiel primär in nicht horizontaler Stellung abgelagerter Schichten wird die Tuffeindeckung eines Gebirgsreliefs in Columbien beschrieben.  相似文献