Once a fractionation trend is established using a suite of least altered samples from a particular volcanic sequence, the altered samples can be superimposed on a binary immobile-element plot to examine the effects of alteration. In the diagram, the effects of net mass gains and losses of mobile elements are shown for a dacite to rhyolite series. Samples plotting in the mass loss field have generally experienced leaching due to hot fluids, leaving sericite-chlorite-rich residues. Samples plotting in the mass gain field have experienced precipitation of components such as silica, carbonates and sulfides, commonly at cooler temperatures.





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