Journal ArticleDOI
A large-scale isotope anomaly in the Southern Hemisphere mantle
Reads0
Chats0
TLDR
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
Citations
More filters
Journal ArticleDOI
Sabzevar Ophiolite, NE Iran: Progress from embryonic oceanic lithosphere into magmatic arc constrained by new isotopic and geochemical data
TL;DR: The Sabzevar ophiolite belt (STOB) as mentioned in this paper is a large region in NE Iran, over 400 km E-W and almost 200 km N-S, which includes harzburgite, lherzolite, dunite and chromitite.
Journal ArticleDOI
The Dodecanese Province, SE Aegean: A model for tectonic control on potassic magmatism
U. Robert,John Foden,R. Varne +2 more
TL;DR: In the south-eastern Aegean several composite Upper Miocene volcanoes have erupted a variety of extrusive and intrusive rocks of mainly intermediate composition with potassic affinities.
Journal ArticleDOI
Growth of subcontinental lithosphere: evidence from repeated dike injections in the Balmuccia lherzolite massif, Italian Alps
TL;DR: In this paper, the authors show that the upper mantle acquires its heterogeneous isotopic character through several different processes, including in situ radiogenic growth, addition of asthenospheric melts, dike-wall rock ionic exchange, redistribution of the lithospheric dike and vein materials by melting, and in the late stages of emplacement, assimilation of crustal materials.
Journal ArticleDOI
Geological and Geochemical Evolution of the Quaternary Süphan Stratovolcano, Eastern Anatolia, Turkey: Evidence for the Lithosphere–Asthenosphere Interaction in Post-Collisional Volcanism
Journal ArticleDOI
The Cameroon Line: Analysis of an intraplate magmatic province transecting both oceanic and continental lithospheres: Constraints, controversies and models
TL;DR: The near 1700 km long Cameroon Line (CL) is an African intraplate ‘fan-shaped’ alkaline volcano-plutonic rift zone of variable width ( as mentioned in this paper ).
References
More filters
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.