Hotspot—migrating ridge interaction in the South Atlantic

Abstract Mantle plume fixity has long been a cornerstone assumption to reconstruct past tectonic plate motions. However, precise geochronological and paleomagnetic data along Pacific continuous hotspot tracks have revealed substantial drift of the Hawaiian plume. The question remains for evidence of drift for other mantle plumes. Here, we use plume-derived basalts from the Mid-Atlantic ridge to confirm that the upper-mantle thermal anomaly associated with the Azores plume is asymmetric, spreading over ~2,000 km southwards and ~600 km northwards. Using for the first time a 3D-spherical mantle convection where plumes, ridges and plates interact in a fully dynamic way, we suggest that the extent, shape and asymmetry of this anomaly is a consequence of the Azores plume moving northwards by 1–2 cm/yr during the past 85 Ma, independently from other Atlantic plumes. Our findings suggest redefining the Azores hotspot track and open the way for identifying how plumes drift within the mantle.

Hotspot (geology)

Mantle plume

10.1038/s41467-019-11127-7

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Citations (25)

Introduction

Cambridge University Press eBooks (2001)

A mantle plume is generally considered to be a blob of relatively hot, low-density mantle that rises because of its buoyancy. The existence of mantle plumes in the Earth was first suggested by J. Tuzo Wilson (1963) as an explanation of oceanic island chains, such as the Hawaiian–Emperor chain, that change progressively in age along the chain. Wilson proposed that as a lithospheric plate moves across a fixed hotspot (the mantle plume), volcanism is recorded as a linear array of volcanic seamounts and islands parallel to the direction in which the plate is moving. Morgan (1971) championed the idea of mantle plumes, suggesting that flood basalts formed by melting of plume heads, whereas hotspot volcanic chains were derived from partial melting of plume tails. He also showed that closely spaced hotspots on the same plate had not moved significantly relative to each other and suggested this was evidence that the plumes had come from the core–mantle boundary (Morgan 1972). Morgan noted that some hotspot tracks, like the Mascarene–Chagos–Laccadive track in the Indian Ocean, are traceable to flood basalts and can be used to reconstruct paths of opening ocean basins. Richards, Duncan, and Courtillot (1989) recognized at least 10 flood basalt–hotspot track pairs that formed from mantle plumes in the last 250 Myr.

Hotspot (geology)

Mantle plume

Flood basalt

Seamount

10.1017/cbo9780511810589.002

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Citations (1)

Geochemistry of mid ocean ridge basalts (MORB) from the northern Central Indian Ridge between 7°46 and 13°20 S: Implication of mantle heterogeneity influenced by Reunion hotspot plume?

AGU Fall Meeting Abstracts (2010)

J. Lee I. Lee S. Lee J. Kim

Hotspot (geology)

Mantle plume

Source

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On the origin of the Canary Islands: Insights from mantle convection modelling

Earth and Planetary Science Letters (2022)

Ana M. Negredo Jeroen van Hunen J. Rodríguez-González Javier Fullea

The Canary Islands hotspot consists of seven volcanic islands, mainly of Neogene age, rooted on oceanic Jurassic lithosphere. Its complex structure and geodynamic setting have led to different hypotheses about its origin and evolution, which is still a matter of a vivid debate. In addition to the classic mantle plume hypothesis, a mechanism of small-scale mantle convection at the edge of cratons (Edge Driven Convection, EDC) has been proposed due to the close proximity of the archipelago to the NW edge of the NW African Craton. A combination of mantle plume upwelling and EDC has also been hypothesized. In this study we evaluate these hypotheses quantitatively by means of numerical two-dimensional thermo-mechanical models. We find that models assuming only EDC require sharp edges of the craton and predict too narrow areas of partial melting. Models where the ascent of an upper-mantle plume is forced result in an asymmetric mantle flow pattern due to the interplay between the plume and the strongly heterogeneous lithosphere. The resulting thermal anomaly in the asthenosphere migrates laterally, in agreement with the overall westward decrease of the age of the islands. We suggest that laterally moving plumes related to strong lithospheric heterogeneities could explain the observed discrepancies between geochronologically estimated hotspot rates and plate velocities for many hotspots.

Hotspot (geology)

Mantle plume

Asthenosphere

geodynamics

10.1016/j.epsl.2022.117506

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Citations (20)

Recycled gabbro signature in hotspot magmas unveiled by plume–ridge interactions

Nature Geoscience (2011)

Nicole A. Stroncik Colin W. Devey

Hotspot (geology)

Mantle plume

Seamount

Isotopic signature

Mid-Atlantic Ridge

Asthenosphere

10.1038/ngeo1121

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Citations (23)

Interaction of a mantle plume and a segmented mid-ocean ridge: Results from numerical modeling

Earth and Planetary Science Letters (2014)

J. E. Georgen

Hotspot (geology)

Mantle plume

Transform fault

Seafloor Spreading

Asthenosphere

10.1016/j.epsl.2014.01.035

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Citations (9)

MANTLE PLUME(HOTSPOT)-RIDGE INTERACTION

Marine Geology & Quaternary Geology (2006)

Quanshu Yan Shi Xuefa

Hotspot is a window to understand mantle plume hypothesis and dynamics of mantle plume,and the area where ridge interactions with hotspot is the best place to directly find out relationship between plate tectonics and mantle plume.Based on affirming mantle plume hypothesis,the authors introduce several 2D or 3D simulation experiments about ridge-plume(hotspot) interaction and some examples of hotspot-ridge interactions existing in the three oceans.It is further pointed out that simulation experiments combined with geology,petrology,geochemistry and geophysics(especially for high resolution seismic technique) in studying mantle(hotspot)-ridge interaction will play an important role in such reseaches as plume-ridge interactions.

Hotspot (geology)

Mantle plume

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Co-location of eruption sites of the Siberian Traps and North Atlantic Igneous Province: Implications for the nature of hotspots and mantle plumes

Earth and Planetary Science Letters (2010)

A. V. Smirnov J. A. Tarduno

Hotspot (geology)

Mantle plume

Large igneous province

10.1016/j.epsl.2010.07.023

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Citations (28)

How plume‐ridge interaction shapes the crustal thickness pattern of the Réunion hotspot track

Geochemistry Geophysics Geosystems (2017)

Eva Bredow Bernhard Steinberger René Gassmöller Juliane Dannberg

Abstract The Réunion mantle plume has shaped a large area of the Earth's surface over the past 65 million years: from the Deccan Traps in India along the hotspot track comprising the island chains of the Laccadives, Maldives, and Chagos Bank on the Indian plate and the Mascarene Plateau on the African plate up to the currently active volcanism at La Réunion Island. This study addresses the question how the Réunion plume, especially in interaction with the Central Indian Ridge, created the complex crustal thickness pattern of the hotspot track. For this purpose, the mantle convection code ASPECT was used to design three‐dimensional numerical models, which consider the specific location of the plume underneath moving plates and surrounded by large‐scale mantle flow. The results show the crustal thickness pattern produced by the plume, which altogether agrees well with topographic maps. Especially two features are consistently reproduced by the models: the distinctive gap in the hotspot track between the Maldives and Chagos is created by the combination of the ridge geometry and plume‐ridge interaction; and the Rodrigues Ridge, a narrow crustal structure which connects the hotspot track and the Central Indian Ridge, appears as the surface expression of a long‐distance sublithospheric flow channel. This study therefore provides further insight how small‐scale surface features are generated by the complex interplay between mantle and lithospheric processes.

Hotspot (geology)

Mantle plume

Triple junction

10.1002/2017gc006875

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Citations (38)