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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Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California?
TL;DR: In this paper, chemical and isotopic data demonstrate that Pliocene volcanic rocks in the Kings and San Joaquin volcanic fields in the central Sierra Nevada, California, are more potassic, trend toward more mafic compositions, and have distinctly lower e N d values than Miocene volcanic materials found in the southern half of the mountain range.
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Magma sources of the Cape Verdes archipelago: Isotopic and trace element constraints
TL;DR: In this article, the isotopic and trace element characteristics of a component predominant in northern Cape Verdes magma sources with relatively radiogenic Pb and Nd (HIMU) suggest an origin for this component as ancient recycled oceanic crust.
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Sr, Nd, Pb and Hf isotopic compositions of late Cenozoic alkali basalts in South Korea: Evidence for mixing between the two dominant asthenospheric mantle domains beneath East Asia
TL;DR: In this article, the authors determined the Sr, Nd, Pb and Hf isotopic compositions of 13 samples from six late Cenozoic centers of basaltic volcanism in South Korea, including Baengnyeong Island, Jogokni, Ganseong, Jeju Island, Ulleung Island and Dok Island, to understand the nature of the mantle source and melt-generating processes.
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Sr, Nd, and Pb isotope geochemistry of Tertiary and Quaternary alkaline volcanics from West Germany
Gerhard Wörner,Gerhard Wörner,Alan Zindler,Hubert Staudigel,Hubert Staudigel,Hans-Ulrich Schmincke +5 more
TL;DR: In this article, the isotopic variations of Eifel mafic magmas from the Quaternary East and West Eifels volcanic fields (West Germany) and a range of basalts from various Tertiary Provinces in West Germany were analyzed.
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Speculations on the Archean mantle: Missing link between komatiite and depleted garnet peridotite
TL;DR: In this paper, a model for mid-oceanic ridge in the Archean (AMOR) is constructed using high-pressure melting experiment data on a mantle peridotite and some key observations on Archean rocks (DGPs and PKs).
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.