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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Journal ArticleDOI
Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites
TL;DR: In this paper, 19 samples from three Miocene to Quaternary carbonatite areas in the East African Rift were analysed for their Sr, Nd, and Pb isotopic compositions.
Journal ArticleDOI
Constructing the Early Mesozoic Gangdese Crust in Southern Tibet by Hornblende-dominated Magmatic Differentiation
Wei Xu,Di-Cheng Zhu,Di-Cheng Zhu,Qing Wang,Roberto F. Weinberg,Rui Wang,Shi Min Li,Liang-Liang Zhang,Zhidan Zhao +8 more
TL;DR: For the first time, a systematic dataset for the petrology, mineralogy, geochronology, and geochemistry of the Cuijiu Igneous Complex in the eastern Gangdese Arc of southern Tibet was presented in this article.
Book ChapterDOI
Petrogenesis of Italian Alkaline Lavas Deduced from Pb‐Sr‐Nd Isotope Relationships
Journal ArticleDOI
Chemical versus Temporal Controls on the Evolution of Tholeiitic and Calc-alkaline Magmas at Two Volcanoes in the Alaska---Aleutian Arc
Rhiannon George,Simon Turner,Chris J. Hawkesworth,Charles R. Bacon,Christopher J. Nye,Pete Stelling,Scott T. Dreher +6 more
TL;DR: In this article, the authors investigated the role of chemical and temporal controls in generating contrasting liquid lines of descent from Akutan volcano in the Aleutian arc and calc-alkaline products from Aniakchak volcano on the continental Alaskan Peninsula.
Book ChapterDOI
Geochemical and Isotopic Systematics of Eastern Sunda Arc Volcanics: Implications for Mantle Sources and Mantle Mixing Processes
R. Varne,John Foden +1 more
TL;DR: In this paper, the authors studied the geochemical properties of the eastern Sunda volcanic arc and found that the increase in K-group element contents is well correlated with increase in 87Sr/86Sr values.
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.