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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Metastable superplumes and mantle compressibility
Eh Tan,Michael Gurnis +1 more
TL;DR: In this paper, the authors used a compressible thermo-chemical convection model in which each material has a distinct equation of state, and found an expanded regime of metastable superplumes.
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Geochemistry of Cretaceous mafic rocks from the Lower Yangtze region, eastern China: Characteristics and evolution of the lithospheric mantle
TL;DR: In this paper, the authors propose that an isotopically enriched, subduction-modified lithospheric mantle was replaced by or transformed into an isotope depleted seafloor mantle.
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Rapid helium isotopic variability in Mauna Kea shield lavas from the Hawaiian Scientific Drilling Project
TL;DR: A suite of lavas from phase II of the Hawaiian Scientific Drilling Project (HSDP2) core, which sampled Mauna Kea volcano to a maximum depth of 3098 m below sea level, was used in this article.
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Geochemistry of the ~ 430-Ma Jingbulake mafic-ultramafic intrusion in Western Xinjiang, NW China: Implications for subduction related magmatism in the South Tianshan orogenic belt
Sheng-Hong Yang,Mei-Fu Zhou +1 more
TL;DR: The South Tianshan orogenic belt is marked by a Proterozoic metamorphic complex, ophiolites, granitoids, mafic intrusions and younger high-pressure and low-temperature metamorphics.
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Influence of the Sierra Leone mantle plume on the equatorial Mid-Atlantic Ridge : a Nd-Sr-Pb isotopic study
TL;DR: In this article, a Pb-Nd-Sr isotope and rare earth study of mid-Atlantic Ridge basalt glasses collected across the equatorial fracture zones from 7°S to 5°N (65 stations) is reported.
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.