Adakites (Kay 1978; Defant and Drummond 1990; Defant and Kepezhinskas 2001; Grove et al.
Adakites have recently been recognized in many other localities in the modern and ancient record.
Adakites, however, which do show significant HREE depletion, may well be representative of slab melts, but they are rare, and their formation requires anomalous local supplies of heat within the subduction regime.
adakites, shoshonites, and boninites) are reviewed and the paper concludes with a brief overview of arc rocks in ancient settings.
Shoshonites, boninites and adakites are volumetrically small, but are nonetheless petrologically significant igneous rocks that form in specialized arc environments.
Role of subducted slab, mantle wedge and continental crust in the generation of adakites from the Andean Austral Volcanic Zone.
Variable enrichment of Ba relative to Rb and Th of the type displayed by the Ross Island Formation andesite samples is also observed in adakites from the Austral Volcanic Zone of the Andes (Stern and Kilian 1996; Wilson 1989).
Furthermore, the relationship between MgO and incompatible element abundances among the Ross Island Formation andesite samples is opposite to that postulated for adakite genesis.