Fig. 4: Fractional melting model of incompatible elements titanium and ytterbium in clinopyroxene.
From: Recycled arc mantle recovered from the Mid-Atlantic Ridge
Anhydrous melting alone cannot replicate the ultra-refractory Cpx compositions before Cpx is exhausted, whether one considers spinel field or garnet followed by spinel field (black ticked line) melting. However, changes in melting modes and partition coefficients in a hydrous melting environment permit extreme depletions in Ti, matching observations (blue lines). Cyan squares represent each individual measurement from 16°N Cpx (Supplementary Data 2). Red dashed line is approximate spinel-field Cpx-out boundary based on modeled anhydrous melting of DMM spinel bearing peridotite. Model details, including melting modes and partition coefficients, can be found in the Methods section and Supplementary Data 5. SSZ peridotites are thought to have undergone extreme degrees of melting in a mantle wedge setting, often resulting in the exhaustion of Cpx; SSZ Cpx Ti and Yb abundances are very similar to those observed in 16°N Cpx. Abyssal peridotite data from the literature as compiled by Warren42. SSZ peridotite data from the literature36,37,38,39.
