Erratum to K. Hoernle, F. Hauff, P. van den Bogaard, R. Werner, N. Mortimer, J. Geldmacher, D. Garbe-Schönberg, B. Davy (2010) “Age and geochemistry of volcanic rocks from the Hikurangi and Manihiki oceanic Plateaus”, Geochimica et Cosmochimica Acta 74, 7196–7219

Abstract

Here we present the first radiometric age data and a comprehensive geochemical data set (including major and trace element and Sr-Nd-Pb-Hf isotope ratios) for samples from the Hikurangi Plateau basement and seamounts on and adjacent to the plateau obtained during the R/V Sonne 168 cruise, in addition to age and geochemical data from DSDP Site 317 on the Manihiki Plateau. The 40 Ar/ 39 Ar age and geochemical data show that the Hikurangi basement lavas (118-96 Ma) have surprisingly similar major and trace element and isotopic characteristics to the Ontong Java Plateau lavas (ca. 120 and 90 Ma), primarily the Kwaimbaita-type composition, whereas the Manihiki DSDP Site 317 lavas (117 Ma) have similar compositions to the Singgalo lavas on the Ontong Java Plateau. Alkalic, incompatible-element-enriched seamount lavas (99-87 Ma and 67 Ma) on the Hikurangi Plateau and adjacent to it (Kiore Seamount), however, were derived from a distinct high time-integrated U/Pb (HIMU)-type mantle source. The seamount lavas are similar in composition to similar-aged alkalic volcanism on New Zealand, indicating a second wide-spread event from a distinct source beginning ca. 20 Ma after the plateau-forming event. Tholeiitic lavas from two Osbourn seamounts on the abyssal plain adjacent to the northeast Hikurangi Plateau margin have extremely depleted incompatible element compositions, but incompatible element characteristics similar to the Hikurangi and Ontong Java Plateau lavas and enriched isotopic compositions intermediate between normal mid-ocean-ridge basalt (N-MORB) and the plateau basement. These younger ($52 Ma) seamounts may have formed through remelting of mafic cumulate rocks associated with the plateau formation. The similarity in age and geochemistry of the Hikurangi, Ontong Java and Manihiki Plateaus suggest derivation from a common mantle source. We propose that the Greater Ontong Java Event, during which $1% of the Earth's surface was covered with volcanism, resulted from a thermo-chemical superplume/dome that stalled at the transition zone, similar to but larger than the structure imaged presently beneath the South Pacific superswell. The later alkalic volcanism on the Hikurangi Plateau and the Zealandia micro-continent may have been part of a second large-scale volcanic event that may have also triggered the final breakup stage of Gondwana, which resulted in the separation of Zealandia fragments from West Antarctica.

Boron isotope evidence for devolatilized and rehydrated recycled materials in the Icelandic mantle source

“…Finally, the low B/Ce, depleted compositions, and MORB-like δ 11 B values of the melt inclusions may reflect the composition of recycled depleted, and devolatilized slab gabbros (Stracke et al, 2003a). This model is consistent with previous recycled gabbro-invoking models for explaining the observed positive Ba and Sr anomalies in depleted Icelandic melts (Kokfelt et al, 2006).…”

“…Enriched components in the mantle sources of Iceland and other OIB localities are often considered to be materials carried into the mantle by subducted slabs (Kokfelt et al, 2006;Halldórsson et al, 2016b;Halldórsson et al, 2016a).…”

A younger and protracted emplacement of the Ontong Java Plateau

“…2). This age agrees with previously published ages from this site but reduces the reported 2s standard error by an order of magnitude (31).…”

Lithospheric thinning beneath the Tengchong volcanic field, Southern China: Insight from Cenozoic calc-alkaline basalts

“…The first model is partial melting of the asthenosphere owing to the thinning and rifting of the continental lithosphere (White, et al, 1987;McKenzie and Bickle, 1988;Tang et al, 2006;Acocella, 2014;Zhang et al, 2021). The second model is decompression melting caused by lithospheric mantle removal and asthenospheric upwelling (Hoernle et al, 2006;Xu et al, 2008;Timm et al, 2009;Zhu et al, 2012). The third model is buoyant upwellings driven by deep subducted slabs (Davies and Bunge, 2006;Chen et al, 2017;Kuritani et al, 2019;Xu et al, 2021).…”