Global satellite triangulation and trilateration     

I. I. Mueller 《Journal of Geodesy》1968,42(1):53-71

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Inferred Palaeoproterozoic arc rifting along a consuming plate margin: insights from the stratigraphy,volcanology and geochemistry of the Kangerluluk sequence,southeast Greenland     

W. Mueller  J. Dostal  H. Stendal 《International Journal of Earth Sciences》2002,91(2):209-230

The 200- to 300-m-thick volcano-sedimentary sequence in the Kangerluluk Fjord, associated with penecontemporaneous and late-tectonic dykes, as well as a synvolcanic plutonic suite, represents an integral component of the Palaeoproterozoic Ketilidian Mobile Belt, south Greenland. The ca. 1808-Ma Kangerluluk supracrustal sequence contains four distinct mappable lithofacies: (a) a conglomerate-sandstone lithofacies; (b) a pyroclastic lithofacies; (c) a volcanic lithofacies; and (d) a peperite lithofacies. The volcanic lithofacies, up to 200 m thick, is characterized by shallow-water subaqueous brecciated and pillowed flows. Flows are either (a) feldspar-phyric, or (b) feldspar-pyroxene-phyric, with 0.2- to 3-cm-size plagioclase and 0.2- to 3-cm-size pyroxene that constitute between 20 and 30% (locally up to 50%) of the flows. Mafic dykes intruded wet unconsolidated pyroclastic lithofacies, resulting in the formation of peperites. Geochemically, the volcanic and pyroclastic units represent a distinct tholeiitic magmatic suite enriched in incompatible trace elements including Th, La, Yb, Zr and Nb, and exhibiting (La/Yb)_n~10. The plutonic suite and associated dykes display a calc-alkaline trend with enriched LREE and unfractionated flat HREE patterns, La_n ranging between 50 and 100, (La/Yb)_n ratios between 8 and 22, and negative Nb and Ti anomalies on the mantle-normalized, incompatible multi-element patterns. The pillowed flows lie in the continental flood basalt field on the Y-Nb-Zr discrimination diagram, and display a Nb anomaly and K₂O-enrichment that collectively suggest a crustal component and/or a subduction-modified mantle source. The geology, stratigraphy of the Kangerluluk area and geochemistry can be used to infer a change in magma genesis from arc to rift volcanism. The 1850- to 1800-Ma calc-alkaline Julianehåb batholith represents a magmatic arc that rifted during crustal extension, allowing for the ascent of mantle-derived mafic magma. The geochemistry of the mafic volcanic flows, synvolcanic dykes and pyroclastic deposits favours a crustal component in magma genesis and offers new insights into the tectonic evolution of the Ketilidian Mobile Belt.  相似文献   

On the reliability of lithospheric constraints derived from models of outer-rise flexure     

Steve Mueller  Roger J. Phillips 《Geophysical Journal International》1995,123(3):887-902

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Paleogeographic and paleotectonic response to magmatic processes: a case history from the Archean sequence in the Chibougamau area,Quebec     

Erich Dimroth  Michel Rochelau  Wulf Mueller  Paul Archer  Harold Brisson  Gabriel Fortin  Marc Jutras  Christian Lefebvre  Mathieu Piché  Pierre Pilote  Pierre Simoneau 《International Journal of Earth Sciences》1985,74(1):11-32

The Chibougamau area, Québec, is characteristic of the internal zone of the Archean Abitibi Orogenic Belt. The paleogeographic, paleotectonic and magmatic history of the Archean sequence in the Chibougamau area is subdivided into three stages.In the first stage a submarine volcanic chain formed mainly by the effusion of submarine lava flows composed of primitive, potash-poor, tholeiitic basalt. The volcanic chain gradually grew to sea level. In the second stage, volcanic islands emerged and grew. Mainly pyroclastic eruptions of strongly differentiated, calc-alkaline andesite and dacite concentrated on the volcanic islands, whereas effusion of basalt continued at first in the surrounding basin. A felsic volcaniclastic apron was deposited around the volcanic islands. In the third stage, the volcanic islands were uplifted and were eroded to the level of their subvolcanic plutons. The debris derived from this volcanic-plutonic terrain was deposited in downfaulted marine and continental basins. The contemporaneous volcanism was shoshonitic.The first paleogeographic stage is interpreted as the growth of an immature island arc. During the second stage, the island arc became mature and its crust was thickened by accretion of plutonic material. The third stage is a period of back-arc extension.

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Zusammenfassung Das Gebiet von Chibougamau, Québec, ist characteristisch für die interne Zone des Archaischen Abitibi Orogens. Man kann seine paleogeographische, paleotectonische und magmatische Geschichte in drei Phasen gliedern.Eine submarine Vulkankette formte sich in der ersten Phase, hauptsächlich durch Effusion von submarinen Lavaergüssen aus primitivem, kaliarmen, tholeiitischem Basalt. Die Vulkankette wuchs langsam bis zum Meeresspiegel. Vulkanische Inseln bildeten sich und wuchsen während der zweiten paleogeographischen Phase. Vorwiegend pyroklastische Eruptionen von stark differenzierten, kalk-alkalischem Andesit und Dazit konzentrierten sich mehr und mehr auf den Inselvulkanen, während die Effusion von Basalt zunächst in den Becken noch stattfand. Ein Mantel aus felsitischen vulkanoklastischen Gesteinen wurde um die Inselvulkane abgelagert. Die dritte Phase begann mit einer Hebung der Inselvulkane und mit ihrer Erosion bis zum Niveau ihrer subvulkanischen Plutone. Der Detritus dieses vulkanisch-plutonischen Geländes wurde in marinen und kontinentalen Verwerfungsbecken abgelagert. Der gleichalte Vulkanismus ist shoshonitisch.Wir deuten die erste paleogeographische Phase als Wachstumsphase eines primitven Inselbogens. Während der zweiten Phase reifte der Inselbogen und seine Kruste verdickte sich durch Akkretion plutonischen Materials. Die dritte Phase ist eine Periode der Dehnung im Hinterland eines Inselbogens.

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Résumé La région de Chibougamau, Québec, est caractéristique de la zone interne de la ceinture orogénique archéenne de l'Abitibi. Son évolution paléogéographique, paléotectonique et magmatique se subdivise en trois phases.Lors de la première phase paléogéographique, une chaîne sous-marine de volcans se formait, essentiellement par l'émission de coulées de lave composée de basalte primitif, hypopotassique, tholéiitique. Graduellement cette chaîne volcanique s'élevait jusqu'au niveau de la mer. A la phase suivante, des îles volcaniques émergeaient et croissaient. Des éruptions essentiellement pyroclastiques d'andésites et de dacites calco-alcalines et fortement différenciées se concentraient sur les îles tandis que l'effusion de laves basaltiques continuaient dans le bassin. Un manteau de roches volcaniclastiques felsiques se déposait autour des îles volcaniques. Lors de la troisième phase, les îles volcaniques furent soulevées et furent érodées jusqu'au niveau des masses plutoniques sub-volcaniques. Le débris de ce terrain volcano-plutonique fut déposé dans des bassins de faille marins et continentaux. Des shoshonites dominaient le volcanisme contemporain.Nous interprétons la première phase paléogéographique comme une phase de croissance d'un arc insulaire immature. Lors de la deuxième phase, 1'arc insulaire devenait mature et sa croûte s'epaissît par accrétion de matériel plutoni-que. Enfin, la troisième phase est une période d'extension en arrière d'un arc insulaire.

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Further considerations on combining earth rotation observations from different space geodetic systems     

Brent A. Archinal  Ivan I. Mueller 《Journal of Geodesy》1989,63(1):35-49

Additional results are presented concerning a study that consider improvements over present Earth Rotation Parameter (ERP) determination methods by directly combining observations from various space geodetic systems in one adjustment. Earlier results are extended, showing that in addition to slight improvements in accuracy substantial (a factor of three or more) improvements in precision and significant reductions in correlations between various parameters can be obtained (by combining Lunar Laser Ranging (LLR), Satellite Laser Ranging (SLR) to Lageos, and Very Long Baseline Interferometry (VLBI) data in one adjustment) as compared to results from individual systems. Smaller improvements are also seen over the weighted means of the individual system results. Although data transmission would not be significantly reduced, negligible additional computer time would be required if (standardized) normal equations were available from individual solutions. Suggestions for future work and implications for the new International Earth Rotation Service (IERS) are also presented.  相似文献   

Effects of adopting new precession,nutation and equinox corrections on the terrestrial reference frame     

Sheng-Yuan Zhu  Ivan I. Mueller 《Journal of Geodesy》1983,57(1-4):29-42

First, the paper is devoted to the effects of adopting new definitive precession and equinox corrections on the terrestrial reference frame: The effect on polar motion is a diurnal periodic term with an amplitude increasing linearly in time; on UT1 it is a linear term. Second, general principles are given the use of which can determine the effects of small rotations (such as precession, nutation or equinox corrections) of the frame of a Conventional Inertial Reference System (CIS) on the frame of the Conventional Terrestrial Reference System (CTS). Next, seven CTS options are presented, one of which is necessary to accommodate such rotations (corrections). The last of these options requiring no changes in the origin of terrestrial longitudes and in UT1 is advocated; this option would be maintained by eventually referencing the Greenwich Mean Sidereal Time to a fixed point on the equator, instead of to the mean equinox of date, the current practice. Accommodating possible future changes in the astronomical nutation is discussed in the last section. The Appendix deals with the effects of differences which may exist between the various CTS's and CIS's (inherent in the various observational techniques) on earth rotation parameters (ERP) and how these differences can be determined. It is shown that the CTS differences can be determined from observations made at the same site, while the CIS differences by comparing the ERP's determined by the different techniques during the same time period. Presented at XVIII General Assembly of the International Astronomical Union Patras, Greece, August 17–26, 1982.  相似文献   

Pyrite-induced hydroxyl radical formation and its effect on nucleic acids   总被引：1，自引：0，他引：1  

Corey A Cohn  Steffen Mueller  Eckard Wimmer  Nicole Leifer  Steven Greenbaum  Daniel R Strongin  Martin AA Schoonen 《Geochemical transactions》2006,7(1):3-11

Background  

Pyrite, the most abundant metal sulphide on Earth, is known to spontaneously form hydrogen peroxide when exposed to water. In this study the hypothesis that pyrite-induced hydrogen peroxide is transformed to hydroxyl radicals is tested.  相似文献   

Stochastic Modelling of Mineral Exploration Targets     

Talebi  Hassan  Mueller  Ute  Peeters  Luk J. M.  Otto  Alex  de Caritat  Patrice  Tolosana-Delgado  Raimon  van den Boogaart  K. Gerald 《Mathematical Geosciences》2022,54(3):593-621

Mathematical Geosciences - Mineral deposits are metal enrichment anomalies, occurring as local manifestations of the interplay between various geological processes that operate at a wide range of...  相似文献   

Impact of Air Pollution on Genetic Material of Shallot (Allium cepa L. var. ascalonicum) Exposed at Differently Polluted Sites in Slovenia     

Erika Glasenčnik  Cvetka Ribarič-Lasnik  Karin Savinek  Meta Zaluberšek  Maria Mueller  Franc Batič 《Journal of Atmospheric Chemistry》2004,49(1-3):363-376

Test shallot plants Allium cepa L. var. ascalonicum were exposed to field conditions at six research plots in the most polluted areas in Slovenia in the vegetation seasons in 1999 and 2000. The intention of this research was to evaluate the influence of air pollution on mitotic activity and frequency of chromosomal aberrations in meristematic tissues of root tips of bioindication plants. Significant differences in the mitotic index and in frequency of chromosomal aberrations at different sampling plots in pot experiments were found and the correlation between the ozone concentration and the mitotic index was determined. The results showed the presence of cytotoxic substances at chosen sampling sites, which caused the decrease of mitotic cell division and the presence of genotoxic substances, which resulted in the increase of frequency of chromosomal aberrations.  相似文献   

Geochemical and tectonic implications of igneous rocks from ODP leg 114, sub-antarctic South Atlantic     

Paul A. Mueller  Michael R. Perfit  Ann L. Heatherington  Paul D. Kirk  Eva Schandl 《Geo-Marine Letters》1992,12(4):214-222

Igneous rocks recovered from three major tectonic features of the sub-antarctic South Atlantic Ocean during ODP Leg 114 have a range of compositions: Northeast Georgia Rise, basalt to andesite; Meteor Rise, basalt to trachyte; spreading center in the West South Atlantic Basin, MORB-like basalt. Major and trace element as well as Sr and Nd isotopic data clearly indicate that all rocks share the enriched elemental and isotopic signatures typical of both hotspot and mid-ocean ridge volcanism in the southern ocean basins. Data for the Northeast Georgia and Meteor Rises also suggest the influence of older, continental lithosphere.  相似文献