Models of the formation of these focus on the D-double-prime layer, which may be made of suducted lithosphere.
Alternate ideas that explain the major observation that these entities were hypothesized to explain include the theory of delamination, while evidence that argues for them includes helium abundance ratios in MORB's. The Luther-Whitehead model of these predicts abrupt widening near their tops, which may explain the Siberian Traps and resulting flood basalts. Models of the formation of these focus on the D-double-prime layer, which may be made of suducted lithosphere. The Hawaii'an-Emperor chain was used as evidence to support the theory behind these objects, which was stated by Morgan and Wilson. For ten points, identify these geological objects and which are pockets of abnormally hot rock under the crust and which were hypothesized to explain hot spots.
Alternate ideas that explain the major observation that these entities were hypothesized to explain include the theory of delamination, while evidence that argues for them includes helium abundance ratios in MORB's.
{mantle plume}s (prompt on {plume}s; do not accept or prompt on “hot spots”)  (EDITOR’S NOTE: hot spots are observable crustal phenomena, whereas mantle plumes are largely theoretical features posited to explain some hot spots, a fact to which the question alludes; the two are thus distinct)