The mixing of magmas in plutonic and volcanic environments: Analogies and differences

Magma mixing processes have been widely recognized in both the plutonic and volcanic environments, but the quality and quantity of information that can be extracted from the two environments are substantially different. Understanding the advantages and limits associated with the study of plutonic and volcanic rocks is essential to establish precise methodological approaches to build the most complete conceptual model by merging information from these two complementary igneous environments.In this work we review magmatic interaction processes in the plutonic and volcanic environments by considering several aspects of these geological phenomena. In particular, we first briefly report on the structural and geochemical evidence for magma mixing in both plutonic and volcanic rocks, with the aim to provide a general picture of this natural phenomenon. Successively, we discuss some recent results about magma mixing achieved using the concepts from Chaos Theory and discuss their potential impact on magma differentiation. Finally, we attempt to build a general picture of this igneous process by merging present-day information from both the plutonic and volcanic environments. It emerges from the general picture that the time spent by the magmatic system in the molten or partially molten state is the crucial factor for the preservation of the fingerprints of magma mixing in the two environments. We propose a conceptual model that may be useful to understand what kind of information we can obtain from volcanic and plutonic rocks and, ultimately, to maximize our knowledge about magma mixing.

► Magma mixing is ubiquitous in igneous systems.
► Magma mixing is a chaotic process.
► The composition of igneous rocks is strongly affected by magma mixing.
► Existing models fail in understanding the complexity of magma mixing processes.
► Numerical simulation and newly designed experiments shed new light on magma mixing.