Isotope geochemistry of early Kilauea magmas from the submarine Hilina bench: The nature of the Hilina mantle component

Relicts of the Early Cretaceous seamounts in the central-western Yarlung Zangbo Suture Zone, southern Tibet

“…These characteristics suggest that the Zhongba mafic rocks bear an OIB geochemical signature and these Sun and McDonough (1989). The field of the Hawaii alkaline basalts are from Clague et al, 2006;Gaffney et al, 2004;Kimura et al, 2006. magmas were derived from a deep OIB reservoir, i.e. an enriched asthenospheric mantle source.…”

Evidence for recycled plate material in Pacific upper mantle unrelated to plumes

“…These suggest that the petit-spot magmas formed by small degrees of partial melting of a fertile mantle source, leaving garnet as a residue (e.g., Kimura et al, 2006;Willbold and Stracke, 2006), rather than from a depleted mantle source such as DMM (Salters and Stracke, 2004;Workman and Hart, 2005). Combined with its EM-1 isotopic signature, the petit-spot lava reflects an enriched component in the Pacific upper mantle domain.…”

“…stage and thus are alkalic, therefore, the degree of melting of the mantle source is likely to be low (0.5-5%; e.g., Kimura et al, 2006;Willbold and Stracke, 2006), similar to petit-spot. Thus, voluminous alkalic volcanism of OIB indicates large-scale heterogeneity in the source mantle.…”

Petrogenesis of the Neoproterozoic Bikilal-Ghimbi gabbro, Western Ethiopia

“…At pressures less than 2.5 GPa, the clinopyroxene is the principal host for the REE and, therefore, can be used to calculate the melt REE composition from the clinopyroxene composition in cumulate and plutonic rocks, where the melt is not preserved (e.g., Wood and Blundy, 1997). The spidergram patterns calculated for the clinopyroxenes (from Samples TCH 23 and BG 28) are similar to those of intraplate type tholeiites, as represented by the Hawaiian Mauna Loa and Kilauea (Hilina) primitive tholeiitic to transitional basalts (Kimura et al, 2006), and clearly differ from N and E MORBs or oceanic island alkali basalts (Fig. 11a).…”

“…A primitive mantle (Sun and McDonough, 1989) normalized plot of: (a) the calculated clinopyroxene (Cpx) composition of the liquids; the results are averaged from unaltered clinopyroxene analysis from olivine gabbro (TCH 23 and BG 28), and (b) the calculated melt composition that produces the olivine gabbros (TCH 23 and BG 28). The N MORB, E MORB (Sun and McDonough, 1989), and OIT fields, including the Hilina (tholeiitic and transitional) and Moana Loa (tholeiitic) after Kimura et al (2006), are plotted for comparison.…”