Are plutons assembled over millions of years by amalgamation from small magma chambers?

Field and geochronologic evidence indicate that large and broadly homogeneous plutons can accumulate incrementally over millions of years. This contradicts the common assumption that plutons form from large, mobile bodies of magma. Incremental assembly is consistent with seismic results from active volcanic areas which rarely locate masses that contain more than 10% melt. At such a low melt fraction, a material is incapable of bulk flow as a liquid and perhaps should not even be termed magma. Volumes with higher melt fractions may be present in these areas if they are small, and this is consistent with geologic evidence for plutons growing in small increments. The large melt volumes required for eruption of…

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  National Science Foundation

  Awards: 9814789, 9814787, 9526803, 9814788