Journal ArticleDOI
A large-scale isotope anomaly in the Southern Hemisphere mantle
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The authors showed that the isotopic mantle anomaly is globe-encircling in extent, centred on latitude 30° S. They also showed that this mantle anomaly has been in existence for billions of years and placed severe constraints on mantle convection models.Abstract:
Basalts from many Southern Hemisphere regions have anomalous Sr and Pb isotopic characteristics. This article shows that the isotopic mantle anomaly is globe-encircling in extent, centred on latitude 30° S. Arguments suggesting that this mantle anomaly has been in existence for billions of years place severe constraints on mantle convection models.read more
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Lithospheric Mantle Evolution beneath the Eifel (Germany): Constraints from Sr–Nd–Pb Isotopes and Trace Element Abundances in Spinel Peridotite and Pyroxenite Xenoliths
TL;DR: The Pb isotope compositions of amphiboles and clinopyroxenes in spinel peridotite and pyroxenite mantle xenoliths from the intra-plate Quaternary volcanic fields of the Eifel province(Germany) are strongly correlated with their Sr-Nd isotopeand trace element compositions as discussed by the authors.
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Petrogenesis of High-K Arc Magmas: Evidence from Egmont Volcano, North Island, New Zealand
TL;DR: Egmont Volcano (Mt Taranaki) is located 140 km west of the Taupo Volcanic Zone (TVZ), the principal locus of volcanic activity.
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Subduction-modified pelagic sediments as the enriched component in back-arc basalts from the Japan Sea: Ocean Drilling Program Sites 797 and 794
TL;DR: In this paper, the combined isotope and trace element systematics support a model of mixing between depleted, MORB-like mantle and Pacific pelagic sediments, and a best estimate of the composition of the sedimentary component has been determined by analyzing samples of differing lithology from DSDP Sites 579 and 581 in the western Pacific, east of the Japan arc.
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The mapping of geochemical provinces in China based on Pb isotopes
TL;DR: Based on a three dimensional topological diagram of Pb isotopes, six geochemical provinces can be recognized in China, namely southern China, Yangtze, northern China, northern Xinjiang, Jiamusi and Tibet.
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The Boron Systematics of Intraplate Lavas: Implications for Crust and Mantle Evolution
TL;DR: In this paper, B is depleted in OIBs relative to either mid-ocean ridge basalts (MORBs) or arc lavas, and OIB samples representing EM and HIMU isotopic reservoirs, often ascribed to the effects of ancient subducted materials, cannot be distinguished from other ocean island basalts in terms of B abundances or B ratios.
References
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Journal ArticleDOI
Mantle plumes from ancient oceanic crust
TL;DR: In this article, the authors propose a model for the origin of hot-spot volcanism, where oceanic crust is returned to the mantle during subduction and sinks into the deeper mantle and accumulates at some level of density compensation, possibly the core-mantle boundary.
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Lead isotopic study of young volcanic rocks from mid-ocean ridges, ocean islands and island arcs
TL;DR: Lead isotopic compositions of young volcanic rocks from different tectonic environments have distinctive characteristics their differences are evaluated within the framework of global tectonics and mantle differentiation Ocean island leads are in general more radiogenic than mid-ocean ridge basalt (morb) leads as discussed by the authors.
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Ore lead isotope ratios in a continuously changing earth
G.L. Cumming,J.R. Richards +1 more
TL;DR: In this paper, a critical re-assessment of the construction of simple ore lead isotopic development curves is followed by three fresh approximations, all designed to involve the minimum possible number of assumptions.
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Sr and Nd isotope geochemistry of oceanic basalts and mantle evolution
TL;DR: Sr and Nd isotope ratios for 17 mid-ocean ridge basalts and for 11 oceanic islands and island groups are reported in this article, and the results are not explained by binary mixing of depleted and undepleted mantle reservoirs or variable magmatic depletion of a planetary reservoir, but support mantle evolution models involving re-injection of crust material into the mantle.
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Pb–Sr isotope variation in Indian Ocean basalts and mixing phenomena
Bernard Dupré,Claude J. Allègre +1 more
TL;DR: Pb and Sr isotopic compositions from the Indian Ocean (active ridges, old ocean floor and aseismic ridge samples) confirm the characteristic nature of the mantle record in this region as mentioned in this paper.