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
2016.81.10Mantle Sulfides and their Role in Re–Os and Pb Isotope Geochronology
TL;DR: In this article, a review of the role of base metal sulfides (BMS) in the distribution of Re, Os, and Pb isotope systematics of the mantle is presented.
Journal ArticleDOI
Helium isotopic textures in Earth's upper mantle
TL;DR: In this article, the authors report 3He/4He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian Ridge (SEIR).
Journal ArticleDOI
An isotopic and geochronological investigation of the younger igneous rocks of the Seychelles microcontinent
TL;DR: Rb/Sr and K/Ar dating of younger igneous rocks of the Seychelles Islands reveals a peak of magmatic activity at 63 Ma as mentioned in this paper, which corresponds very well with the timing of continental rifting between the SEYchelles microcontinent and the Indian plate deduced from ocean floor magnetic anomaly patterns.
Journal ArticleDOI
On the orgin of the Italian potassic magmas
TL;DR: The role of a subduction zone in the genesis of these potassic magmas is re-assessed in this article, where results of a previously published new metasomatic model are discussed that can reconcile apparently conflicting evidence for subduction Zone or rift environment for these alkaline magmas.
Journal ArticleDOI
Tracing the origin of subduction components beneath the South East rift in the Manus Basin, Papua New Guinea
TL;DR: In this paper, the authors compared the geochemical data of SER lava to published data from New Britain Arc (NBA) and Tabar-Lihir-Tanga-Feni (TLTF) island chain.
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.