第八届青年地学论坛

How refertilization geochemically distinguishes from melt depletion, how large in length-scale this mechanism affects the subcontinental lithospheric mantle (SCLM), and how to precisely constrain the timing of this mantle-melt interaction remain long-standing issues, despite that a plethora of studies have demonstrated the existence of refertilization and its importance to the upper mantle heterogeneity and the stability and preservation of the SCLM. Here we utilize alphaMELTS thermodynamic modeling to revisit the geochemical variations of the Pyrenean orogenic mantle rocks that refertilization and adiabatic melting have generated, and develop a novel solution to addressing the timing of melt depletion (~ 1.5 – 1.9 Ga) and refertilization (~ 0.5 Ga). Refertilization induced by large-scale asthenospheric upwelling, relative to small-scale metasomatic agents (i.e., carbonatite), will profoundly affect the stability and rigidness of the SCLM with secondary products having higher density and lower viscosity, which is eventually fatal to the longevity of the SCLM.

melt refertilization,thermodynamic modeling,subcontinental lithospheric mantle,Orogenic massif