Rare earth elements and the island arc tholeiitic series

Geochemistry of Meso- and Neoproterozoic mafic-ultramafic rocks from northern Guangxi, China: Arc or plume magmatism?

“…Petrochemically, arc volcanics are usually tholeiitic or calc-alkaline. Their geochemistry is dependent on the emplacement location in the convergent plate margin, such that those from immature island arc are generally tholeiitic whereas those from active continental margin are usually calc-alkaline (Jakes and Gill, 1970;Miyashiro, 1974;Plank et al, 1988;Hunter et al, 1995). As mentioned above, the volcanicintrusive rocks from Sibao group generally show calcalkaline signatures.…”

Light REE inclination and distance from volcanic front; a case of volcanic rocks in northeastern Japan.

“…As a peculiar unique case, the pattern of Osore-zan basaltic andesite is relatively chondritic, that is, an almost perfectly flat pattern. Though some terrestrial materials which have relatively chondritic REE patterns have been reported so far (e.g., JAKES and GILL, 1970;SCHILLING, 1971;SHIMOKAWA and MASUDA, 1972;KAY and HUBBARD, 1978), there are very few examples that indicate almost perfectly flat patterns.…”

Trace elements and Nd-Sr isotopes of island arc tholeiites from frontal arc of Northeast Japan.

“…Jakes and Gill (1970) and a number of other authors (Nicholls and Ringwood, 1973;Nakamura et al, 1985;Powell, 1986, Perfit andSakuyama and Nesbitt, 1986) have suggested that the composition of IAB can be explained by the mixing of partial melts or aqueous fluids derived from the resorbed subducted oceanic lithosphere and the overlying upper mantle. On the other hand, Arculus and Johnson (1981) have suggested that the addition of subducted material to the mantle wedge above the descen ding slab is not very important because there is not a positive correlation between the magnitude of Sr enrichment and 87Sr/86Sr ratios in most island arc rock suites.…”

“…However, they differ from N-MORB in their higher concentrations of alkalis and alkaline earths, and lower concentrations of Zr, Hf, Nb and Ta. In addition, they typically have slightly higher concentration ratios of 87Sr / 86Sr and 207Pb/204Pb at a specific 206Pb/204Pb, and lower 143Nd/ 144Nd than do N-MORB (Jakes and Gill, 1970;Perfit et al, 1980;Kay, 1980;Gill, 1981).…”