10.6084/m9.figshare.3453287.v1
Sebastian Wiesmaier
Sebastian
Wiesmaier
Valentin R. Troll
Valentin R.
Troll
John A. Wolff
John A.
Wolff
Juan Carlos Carracedo
Juan Carlos
Carracedo
Open-system processes in the differentiation of mafic magma in the Teide–Pico Viejo succession, Tenerife
Geological Society of London
2016
differentiation
trace element variations
succession
magma
fractionation
Viejo
trace elements
crystallization
Zr
plagioclase
Sr
Tenerife Oceanic island basalts
Teide mafic suite
lava
assimilation
model
enrichment
Geology
2016-06-21 11:17:10
Dataset
https://geolsoc.figshare.com/articles/dataset/Open-system_processes_in_the_differentiation_of_mafic_magma_in_the_Teide_Pico_Viejo_succession_Tenerife/3453287
<p>Oceanic island basalts are commonly thought to differentiate by fractional crystallization, yet closed-system fractionation
models have so far failed to reproduce major and trace element variations observed in mafic lavas from the Teide–Pico Viejo
stratovolcano complex on Tenerife. Here, new high-precision plagioclase trace element data are fed into such a fractionation
model. The results confirm that fractionation of phenocrysts found in the lavas does not reproduce trace element variations,
in particular enrichment of Sr and Zr observed in the Teide–Pico Viejo mafic suite. This enrichment of Sr and Zr is tested
by an energy-constrained recharge, assimilation and fractional crystallization (EC-RAFC) model at high <em>T</em> and low Δ<em>T</em> intervals, consistent with previously determined magma storage beneath Tenerife at sub-Moho depths. Published mineral–melt
equilibrium relations using the plagioclase anorthite content (0.4 < <em>X</em><sub>An</sub> < 0.8) constrain the temperature during differentiation. Gabbroic xenoliths found in Tenerife lavas are assumed as contaminant.
Enrichment of Sr and Zr in the Teide mafic suite is reproduced by this combined assimilation and fractional crystallization
model, as assimilation causes higher degrees of enrichment in incompatible trace elements than is possible by crystal fractionation
alone. Recycling of plutonic roots may thus have significantly enriched trace elements in the primitive lavas of the Teide–Pico
Viejo succession.
</p>