Coupled major and trace elements as indicators of the extent of melting in mid-ocean-ridge peridotites

摘要: Rocks in the Earth's uppermost sub-oceanic mantle, known as abyssal peridotites, have lost variable but generally large amounts of basaltic melt, which subsequently forms oceanic crust. This process preferentially removes from peridotite some major constituents such aluminium, well trace elements that are incompatible mantle minerals (that is, prefer to enter melt), rare-earth elements. A quantitative understanding this important differentiation has been hampered by lack correlation observed between major- and trace-element depletions peridotites. Here we show heavy clinopyroxenes moderately highly correlated with Cr/(Cr + Al) ratios coexisting spinels. deteriorates only for most elements-probably owing late metasomatic processes. Using electron- ion-microprobe data residual peridotites collected on central Indian ridge, along previously published data, develop a melting indicator residues. procedure should prove useful relating partial geodynamic variables spreading rate temperature.