In the latter, igneous activity is related to lithosphere rifting that was perhaps aided by a mantle plume. Considering the small volumes and slow eruption rates, an origin due to the impact of a proper mantle plume is unlikely for the magmatic rocks in the Baltic Sea region and NE Poland.

D/H ratios in basalt glasses from the Salas y Gomez mantle plume interacting with the East Pacific Rise: water from old D-rich recycled crust or primordial water from the lower mantle?

Investigators suggest that volcanic chains in the middle of tectonic plates, such as the Hawaiian Islands, are caused by giant pillars of hot molten rock known as mantle plumes. These rise up from near the Earth's core, penetrating overlying material like a blowtorch.

While the core heat is mostly transported outwards by mantle plumes, the sinking of cold, subducted plate material is balanced by a pervasive warm counter flow, transporting the mantle-generated radiogenic heat.

A zone of low mantle seismic velocity that has been imaged ~150 km northeast of Bowie Seamount at a depth of ~700 km is interpreted as a mantle plume (Nataf and VanDecar 1993).

More than 4,900 feet ill elevation, its summit plateau marked by a cavernous caldera more than 3,000 feet deep, Fernandina is one of the most active volcanoes in the Galapagos, and indeed in the world--a "hot spot" fed by a deep mantle plume rising through the Earth's crust.

These lavas emerge from a mantle plume (hotspot), which may or may not be situated at a spreading center or plate boundary.

* The geochemical evidence for a mantle plume origin and the selective crustal contamination of basaltic magmas.

However, others think just the opposite is true, that Ishtar formed over an upwelling mantle plume! How can such a basic dispute -- whether the interior under a major region on Venus is rising or sinking -- be settled?