2011) and geochemical characteristics suggest mafic-felsic interaction and mingling (Barbarin & Didier 1992; Barbarin 1999; Ferre & Leake 2001; Kocak 2006) by the injection of hot mafic magma into felsic magma
More recently, it has been observed that differences in initial [epsilon]Hf values between zircon crystals from several gabbroic bodies are in accordance with the heterogeneity of whole-rock Sr-Nd isotopic data, and that within sample [epsilon]Hf variability also indicates that crustal assimilation and felsic magma
hybridization occurred in some of these intrusions (Villaseca et al., 2011).
In comparison with N3 felsic magmas
, the intermediate samples of N1 group have higher contents of [[Ti[O.sub.2]].sub.adj], [[[Fe.sub.2][O.sub.3]].sub.adj], [[FeO].sub.adj], [[MnO].sub.adj], [[MgO].sub.adj], [[CaO].sub.adj], and transition elements (e.g., Co and V).
Several mineralogical lines of evidence confirm the interaction between andesitic magmas, probably originated in the interface between upper and lower crust, and felsic magmas
possibly derived from upper crust partial melting.
Three fundamental properties influence the rate at which arc magma ascends: i) magma is less dense than the wall rocks and is, therefore, buoyant, ii) a magma with lower viscosity rises with greater ease than a more viscous magma (therefore, mafic magma generally rises more readily than felsic magma
, which is likely to be trapped in magma chambers where it cools to form a pluton), and iii) magma rises more rapidly in an extensional environment than in a compressional setting because widening fractures create space for rising magma to exploit.
According to McCutcheon (1990a), the MBG represents the transition between a mafic magma that was contaminated by crystal cumulates from overlying felsic magma
in a compositionally zoned, high-level subvolcanic magma chamber.
(1962) suggested that this morphology is a quench texture, formed by the rapid cooling of mafic globules when they came in contact with cooler, felsic magma
show that differentiation from mafic to intermediate and felsic magmas
in some arc volcanoes may be an unexpectedly rapid process.
Depletion rare-earth elements in felsic magmas
. Geology, 10, pp.
Intermediate to felsic magmas
are derived in a wide variety of ways, including the fractionation of a more mafic parent, mixing between mafic and felsic magmas
(a process supported, in many cases, by field and textural evidence), crustal contamination, or partial melting of the crust.
Ascent mechanisms of felsic magmas
. Transactions of the Royal Society of Edinburgh, Earth Sciences, 87, pp.
The ubiquitous mafic microgranular enclaves, typically with high concentrations of xenocrysts from Monte Capanne magma, provide evidence of a highly dynamic system involving vigorous interaction between mafic and felsic magmas
. The data suggest that rapid dehydration melting, driven by intrusions of fractionating mantle derived magma near the base of the crust, was followed by magma mixing and K-feldspar megacryst growth.