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  • 1
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    Petrological nature of the stable continental crust (1966)
    Am. Geophys. Un.
    In:  Bull., Open-File Rept., The Earth beneath the Continents: A Volume in Honor of Merle A. Tuve, Leiden, Am. Geophys. Un., vol. 10, no. 87-17, pp. 611-, (ISBN 0080419208)
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    Publication Date: 1966
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    BIBLIOGRAPHY SEISMOLOGY
  • 2
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    Water and its influence on the lithosphere-asthenosphere boundary (2010)
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2010-09-25
    Description: The Earth has distinctive convective behaviour, described by the plate tectonics model, in which lateral motion of the oceanic lithosphere of basaltic crust and peridotitic uppermost mantle is decoupled from the underlying mechanically weaker upper mantle (asthenosphere). The reason for differentiation at the lithosphere-asthenosphere boundary is currently being debated with relevant observations from geophysics (including seismology) and geochemistry (including experimental petrology). Water is thought to have an important effect on mantle rheology, either by weakening the crystal structure of olivine and pyroxenes by dilute solid solution, or by causing low-temperature partial melting. Here we present a novel experimental approach to clarify the role of water in the uppermost mantle at pressures up to 6 GPa, equivalent to a depth of 190 km. We found that for lherzolite in which a water-rich vapour is present, the temperature at which a silicate melt first appears (the vapour-saturated solidus) increases from a minimum of 970 degrees C at 1.5 GPa to 1,350 degrees C at 6 GPa. We have measured the water content in lherzolite to be approximately 180 parts per million, retained in nominally anhydrous minerals at 2.5 and 4 GPa at temperatures above and below the vapour-saturated solidus. The hydrous mineral pargasite is the main water-storage site in the uppermost mantle, and the instability of pargasite at pressures greater than 3 GPa (equivalent to more than about 90 km depth) causes a sharp drop in both the water-storage capacity and the solidus temperature of fertile upper-mantle lherzolite. The presence of interstitial melt in mantle with more than 180 parts per million of water at pressures greater than 3 GPa alters mantle rheology and defines the lithosphere-asthenosphere boundary. Modern asthenospheric mantle acting as the source for mid-oceanic ridge basalts has a water content of 50-200 parts per million (refs 3-5). We show that this matches the water content of residual nominally anhydrous minerals after incipient melting of lherzolite at the vapour-saturated solidus at high pressure.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Green, David H -- Hibberson, William O -- Kovacs, Istvan -- Rosenthal, Anja -- England -- Nature. 2010 Sep 23;467(7314):448-51. doi: 10.1038/nature09369.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Earth Sciences and Centre for Ore Deposit Studies, University of Tasmania, Hobart 7001, Tasmania, Australia. David.H.Green@utas.edu.au〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20865000" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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    PAPER CURRENT
  • 3
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    A photosynthetic alveolate closely related to apicomplexan parasites (2008)
    Nature Publishing Group (NPG)
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    Publication Date: 2008-02-22
    Description: Many parasitic Apicomplexa, such as Plasmodium falciparum, contain an unpigmented chloroplast remnant termed the apicoplast, which is a target for malaria treatment. However, no close relative of apicomplexans with a functional photosynthetic plastid has yet been described. Here we describe a newly cultured organism that has ultrastructural features typical for alveolates, is phylogenetically related to apicomplexans, and contains a photosynthetic plastid. The plastid is surrounded by four membranes, is pigmented by chlorophyll a, and uses the codon UGA to encode tryptophan in the psbA gene. This genetic feature has been found only in coccidian apicoplasts and various mitochondria. The UGA-Trp codon and phylogenies of plastid and nuclear ribosomal RNA genes indicate that the organism is the closest known photosynthetic relative to apicomplexan parasites and that its plastid shares an origin with the apicoplasts. The discovery of this organism provides a powerful model with which to study the evolution of parasitism in Apicomplexa.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Moore, Robert B -- Obornik, Miroslav -- Janouskovec, Jan -- Chrudimsky, Tomas -- Vancova, Marie -- Green, David H -- Wright, Simon W -- Davies, Noel W -- Bolch, Christopher J S -- Heimann, Kirsten -- Slapeta, Jan -- Hoegh-Guldberg, Ove -- Logsdon, John M -- Carter, Dee A -- England -- Nature. 2008 Feb 21;451(7181):959-63. doi: 10.1038/nature06635.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Molecular and Microbial Biosciences, University of Sydney, Darlington, New South Wales 2006, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18288187" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Nucleus/genetics ; Chlorophyll/metabolism ; Codon/genetics ; Eukaryotic Cells/*classification/cytology/*metabolism/ultrastructure ; Parasites/*classification/*cytology/genetics/ultrastructure ; *Photosynthesis ; *Phylogeny ; Plasmodium falciparum/classification ; Plastids/genetics/*metabolism ; RNA, Ribosomal/genetics
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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    PAPER CURRENT
  • 4
    Electronic Resource
    Electronic Resource
    Age Determinations of Rocks in the Lizard (Cornwall) Area (1961)
    [s.l.] : Nature Publishing Group
    Nature 192 (1961), S. 1175-1176 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Potassium-argon measurements have now been made on five hornblendes collected from the Kennack Gneiss (96392), the regionally metamorphosed Landewednack Hornblende Schist (96389, 96396) and the dynamothermal aureole of the peridotite (96394, 96395). The argon measurements were made by the method of ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/1921175a0
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  • 5
    Electronic Resource
    Electronic Resource
    Preliminary Age-Determinations in the Lizard Area (1961)
    [s.l.] : Nature Publishing Group
    Nature 191 (1961), S. 159-160 
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    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Four muscovite samples from the Old Lizard Head series and two samples of biotite from the Kennack gneiss have been measured, using the total volume technique. Determinations of potassium oxide were made using a flame photometer. Results are shown in Table 1. Overall errors are estimated at ...
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    URL: http://dx.doi.org/10.1038/191159a0
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  • 6
    Electronic Resource
    Electronic Resource
    Experimental Investigations Bearing on the Nature of the Mohorovičić Discontinuity (1964)
    [s.l.] : Nature Publishing Group
    Nature 201 (1964), S. 566-567 
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    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] THE hypothesis that the Mohorovi?i? Discontinuity (Moho) might be caused by a phase change from basalt to eclogite has been widely discussed during recent years1?3. Evaluation of this hypothesis has been impeded by the paucity of experimental data on the nature of the transition. We have recently ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/201566a0
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  • 7
    Electronic Resource
    Electronic Resource
    Highly Undersaturated Rocks in Upper Mantle Conditions (1970)
    [s.l.] : Nature Publishing Group
    Nature 226 (1970), S. 748-749 
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    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Table 1. COMPOSITION OF THE SYNTHETIC OLIVINE NEPHELINITE GLASS USED IN THE EXPERIMENTAL WORK Si02 44-3 CIPW norm Ti02 1-5 Or 6-1 A1203 14-2 Ab 2-0 FeaOa 0-5 Ne 15-3 FeO 9-7 An 19-4 MnO 0-2 Bi 26-4 MgO 13-3 01 25-9 CaO 11-2 Ap 1-3 Na2O K20 3-6 1-0 11 Mt ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/226748a0
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  • 8
    Electronic Resource
    Electronic Resource
    Critical mechanical behavior in the fluid/solid transition of suspensions (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 67 (1995), S. 3087-3089 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Velocity and attenuation measurements of compressional waves at 3 and 5 MHz, as a function of solid volume concentration, are reported for different suspensions. The suspensions were made of 1 μm size particles of kaolinite or glass beads in water or light oil. At a volume concentration of 40%, a sharp peak in attenuation accompanied by a change in velocity is observed. The volume concentration at which this peak occurs is independent of frequency and particle geometry. The observed critical change in attenuation around 40% is consistent with an excess attenuation induced by the fluid-shearing processes between neighboring particles, and corresponds to the jamming point concentration predicted by particle packing simulations. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.114873
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  • 9
    Electronic Resource
    Electronic Resource
    The effect of bulk rock composition on the stability of amphibole in the upper mantle: Implications for solidus positions and mantle metasomatism (1991)
    Springer
    Mineralogy and petrology 44 (1991), S. 1-19 
    Details
    ISSN: 1438-1168
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Description / Table of Contents: Zusammenfassung Die Stabilität pargasitischer Amphibole im oberen Mantel ist eine Funktion von Wassergehalt und Gesamtgesteins-Zusammensetzung. Unter wasser-untersättigten Bedingungen, kontrolliert die Stabilität von Amphibol die Solidus-Position. Experimente in dem System “Tinaquillo Peridotit +0,2% H2O”, einem refraktären Peridotit unter wasser-untersättigten Bedingungen, zeigen daß Amphibol bis 1030°C und 26 Kb stabil ist. Im Gegensatz dazu ist pargasitische Hornblende in einem Hawaii-Pyrolit, von mehr fertiler Peridotit-Zuammensetzung, bis 1150°C und 30 Kb stabil. Das zeigt, daß bei wasser-untersättigten Bedingungen der am meisten produktive Teil eines kristallisierenden Mantel-Diapirs mit inhomogener Zusammensetzung sich zuerst verfestigen wird, während eine mehr refraktäre Komponente eine alkali-reiche Schmelze enthalten wird, die wiederum die Fähigkeit hat, umliegende Bereiche metasomatisch zu beeinflussen. Die relativen Stabilitäten von Amphibol in refraktären und fertilen Gesamtzusammensetzungen können dazu führen, daß die chemischen Gegensätze in Hochtemperaturlherzoliten eher zunehmen als abnehmen, d. h. ein Prozeß metamorpher Differentiation. Ti, Fe, Al und Na Metasomatose können deshalb als ein verbreiteter Vorgang, der mit der Aufwärtsbewegung und Verfestigung eines H2O-führenden Mantel-Diapirs assoziiert ist, betrachtet werden.
    Notes: Summary The stability of pargasitic amphibole in the upper mantle is a function of water content and bulk rock composition, and under water-undersaturated conditions, the stability of amphibole controls the solidus position. Experiments in the system ‘Tinaquillo peridotite +0.2% H2O’, a refractory peridotite under water-undersaturated conditions, show that amphibole is stable to 1030°C and 26 kb. In contrast, pargasitic amphibole is stable to 1150°C and 30 kb in Hawaiian pyrolite, a more fertile peridotite composition. This indicates that under water-undersaturated conditions, the most fertile part of a crystallizing mantle diapir with an inhomogeneous composition will solidify first while a more refractory component will contain an alkali-rich melt which will have the ability to metasomatize adjacent regions. The relative stabilities of amphibole in refractory and fertile bulk compositions may result in increasing rather than diminishing chemical contrasts in high temperature lherzolite, i.e. a process of metamorphic differentiation. Ti, Fe, Al and Na metasomatism can therefore be considered a normal occurrence associated with the upward migration and solidification of an H2O-bearing mantle diapir.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01167097
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  • 10
    Electronic Resource
    Electronic Resource
    The liquidus surface of the system forsterite - kalsilite - quartz at 28 kb under dry conditions, in presence of H2O, and of CO2 (1988)
    Springer
    Mineralogy and petrology 39 (1988), S. 163-174 
    Details
    ISSN: 1438-1168
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Description / Table of Contents: Zusammenfassung Das System Forsterit-Kalsilit-Quarz (Fo-Ks-Qz) wurde bei 28 kbar und variablen Temperaturen in Anwesenheit von CO2 and H2O sowie bei Abwesenheit von Volatilen untersucht, um die Rolle des Kaliums in den Phasengleichgewichten des Erdmantels aufzuklären. Unter trockenen Bedingungen liegt das Forsterit-Enstatit(En)-Sani din(San)-Peritektikum (En + liquid -〉 Fo + San) bei 1460±:E 20°C undFo 5Ks 62Qz 33 und das Fo-San-Ks Eutektikum bei 1440± 10 °C und Fo6Ks 69Qz 25. Trockenes Schmelzen von Forsterit-Enstatit-Sanidin erzeugt Schmelzen bei 1460°C, die deutlich auf der Ks-Seite der Linie Fo-San liegen. Unter wassergesättigten Bedingungen besteht ein großer Liquidus für Phlogopit (Ph). Die Extrapolation der Fo-Ph-Linie bis zum Schnitt mit der Grenze der Fo-Ph-Reaktion definiert eine thermische Scheidelinie für Schmelzen, gegen die Eutektika von Ks-San-Ph oderQz-San-Ph zu tendieren. Unter CO2-Sättigung verschiebt sich das Olivin-Enstatit-Kotektikum zu viel niedrigeren SiO2-Gehalten, so daß das Fo-En--San-Eutektikum bei 1260°C und Zusammensetzungen klar innerhalb des Fo-San-Ks-Feldes auftritt. Das experimentelle Studium des Systems setzt die Mechanismen durch Variation von CO2-H2O (C-H-O) fest, durch welche ein vereinfachter Phlogopit-führender Harzburgit kalibetonte Schmelzen liefern kann, die von Hypersthen-normativ (und auf einem Fraktionierungsweg zu SiO2-Übersättigung führend) bis zu stark Leuzit-(oder Kalsilit-)normativ variieren. Die Fraktionierung von wäßrigen SiO2-untersättigten Schmelzen kann je nach der Rolle des Phlogopits entweder gegen ein SiO2-übersättigtes Minimum oder gegen ein SiO2-untersättigtes Minimum tendieren.
    Notes: Summary The system forsterite-kalsilite-quartz (Fo-Ks-Qz) has been studied at 28 kb and variable temperatures in the presence of CO2 or H2O and in the absence of volatiles to clarify the role of potassium in mantle phase equilibria. Under dry conditions, the forsterite--enstatite (En)-sanidine (San) peritectic (En + liquid → Fo + San) occurs at 1460°C ± 20 °C at Fo5Ks62Qz33 and the Fo-San-Ks eutectic at 1440 ± 10 °C at (Fo 6Ks 69Qz 25). Dry melting of forsterite-enstatite-sanidine produces liquids at 1460°C which lie well to the Ks side of the Fo-San join. Under water-saturated-conditions, there is a large liquidus of phlogopite (Ph). The extrapolation of the Fo Ph join to intersect the Fo-Ph reaction boundary defines a thermal divide for liquids trending either towards the Ks-San-Ph or Qz-San-Ph eutectics. Under CO2-saturated conditions, the olivine-enstatite cotectic moves to much lower SiO2 compositions, such that the Fo-En-San eutectic occurs 〈 1260 ± 20 °C at compositions well within Fo--San-Ks field. The experimental study of the system establishes mechanisms through variation of CO2 H2O (C-H-0) by which a simplified phlogopite-bearing harzburgite may yield potassic liquids ranging from hypersthenenormative (and fractionating on a path to SiO2 oversaturation) to strongly leucite (or kalsilite)-normative. The fractionation of hydrous silica-undersaturated liquids may trend either towards SO2-oversaturated minimum or towards SiO2-undersaturated minimum depending upon the role of phlogopite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01163032
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