Which spider diagrams do we use

Eu) with the less mobile HFS elerhehts (Y, Hf, Zr, Ti, Nb, Ta). On the one hand the LIL element concentrations may be a function of the behaviour of a fluid phase, whilst the HFS element concentrations are controlled by the chemistry of the source and the crystal/melr processes which have taken place during the evolution of the rock. Partition coefficients for the HFS elements in the major rock-forming minerals in a range of melt compositions are summarized in Tables 4.1 to 4.3. 

Of the less mobile elements, raineralogical controls on the distribution of the REE have already been discussed. Other dements are often strongly controlled by individual minerals. For example, Zr concentrations may be controlled by zircon, P by apatite, Sr by plagioclase, Ti, Nb and Ta by ilmenite, rutile or sphene. Negative Nb anomalies are also characteristic of the continental crust and may be an indicator of crustal involvement in magma processes. 

More mobile LIL element concentrations may be controlled by aqueous fluids but these elements are concentrated in the continental crust and can also be used as an indicator of crustal contamination of magmas. 

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