Search

Using mantle plumes to reconstruct past plate motion is complicated, because plumes may not be fixed. Here, the authors demonstrate using ⁴⁰Ar/³⁹Ar ages that the Rurutu plume is relatively stable compared to the rapidly moving Hawaiian plume, yet it has a similar deep mantle origin.

The Hawaiian-Emperor Chain has a 60° bend that has been interpreted as the result of Pacific plate motion at 47 Ma or drift of the Hawaiian hotspot. Here, the authors show that hotspot drift cannot be the dominant mechanism for bend formation, but involves a change in the direction of Pacific plate motion at ∼47 Ma.

Volcanism across the North Atlantic region 62 million years ago is consistent with an Iceland plume source, despite the absence of a classic hotspot track, suggest tomographic images and geodynamic models.

Global-scale mantle flow patterns can be deduced from the net behaviour (convergence and divergence) of surface plate motions; persistent quadrupole divergence in central Africa and the central Pacific suggest sustained stationary upwelling beneath these locations in the mantle.

Ridges of thick, raised crust on the Indian Ocean floor were thought to be mostly volcanic seamounts formed above the Réunion mantle plume. Dating of zircon minerals in Mauritian lavas, however, indicates that fragments of an ancient microcontinent may be preserved beneath the seamounts, contributing to the thickened crust.

The observed motion of continents relative to the Earth's spin axis may be due either to rotation of the entire Earth relative to its spin axis ('true polar wander'), or to the motion of individual tectonic plates. To distinguish between these processes, the global average of continental motion and rotation in a palaeomagnetic reference frame over the past 320 Myr was computed and two components were identified: a steady northward motion and, during certain time intervals, clockwise and counterclockwise rotations, which they interpret as true polar wander.

A mantle plume induced plate rotation that initiated subduction and rifting along a >12,000 km plate boundary about 105 Myr ago, according to an analysis of geological data and numerical simulations.

Closure of the Tethys Seaway marked the last connection between the Atlantic and Indo-Pacific oceans. This Review explores how mantle convection and associated volcanic activity caused Tethys Seaway closure and discusses the implications for ocean circulation, faunal diversification and climate.

Diamonds are formed under high pressure more than 150 kilometres deep in the Earth's mantle, and are brought to the surface mainly by volcanic rocks called kimberlites. Here, plate reconstructions and tomographic images have been used to show that the edges of the largest heterogeneities in the deepest mantle, stable for at least 200 million years and possibly for 540 million years, seem to have controlled the eruption of most Phanerozoic kimberlites. This has implications for future exploration for kimberlites.

Basal melting is widespread in the north-central Greenland ice sheet. Geophysical data and numerical modelling suggest a geothermal anomaly in this region resulting from the earlier passage of Greenland over the Iceland mantle plume.

Repeated amalgamation and dispersal of continents over Earth history is known as the supercontinent cycle; however, the geodynamic processes driving this cyclicity remain debated. This Review synthesizes observations, plate reconstructions and geodynamic models of supercontinent, and older Archaean supercraton, cycles.

Mantle plumes are an integral aspect of Earth’s convection system, yet, difficulty in imaging mantle upwellings led to controversies surrounding their origin, dynamics and composition. This Review synthesizes geophysical, geodynamic and geochemical constraints on mantle plumes and their importance in the Earth system.