PMC

Schematic diagram for Cordón Caulle plumbing system (not to vertical scale). Inferred mafic injections fuel overlying crystal mush. Shades of orange-red in mafic injections and crystal mush represent compositional heterogeneity observed in chemistry. Stippled texture in crystal mush represents different levels of crystallinity. Black portions of crystal mush represent low-melt content or inactive heterogeneities within the mush. Crystal mush is overlain by crystal-poor rhyolite (orange). Coarsely-crystalline fragments are entrained into rhyolite prior to or upon eruption preserving remnants of the mush in the form of mafic enclaves. Some injections bypass the mush chemically unobstructed and interact directly with rhyolite to form porphyritic enclave population. Arrows in rhyolite melt cap represent June 4–7, 2011 magma flux. Dashed purple line: surficial uplift from laccolith emplacement. Circular outsets are BSE images of enclave-host boundary for both enclave populations. Schematic does not infer magmatic architecture underlying Puyehue volcano.

(Color online) Comparison of the Neumann-series RTE (L = 3) and MC results for the transmitted and reflected fluxes, respectively, with different values of μ_sH. The different cases are (a), (b) μ_sH = 5; (c), (d) μ_sH = 6; (e), (f) μ_sH = 8; (g), (h) μ_sH = 9; (i), (j) μ_sH = 10. The value of Δx is 0.2 mfp for these experiments, and the optical parameters of the medium are μ_a = 0.1 cm⁻¹ and g = 0.

Schematic of a lower oceanic crustal crystal mush. Melt lens 1 is formed by replenishment of the crystal mush by primary melt, leading to reaction with the surrounding mush and mixing of interstitial melts into the melt lens. Melt lens 2 forms by the segregation of interstitial melts in the mush. Melt transport occurs both by reactive porous flow, aided by compaction, and by channelized focused flow. The latter, which drains melt lens 3, feeds eruptions of MORB, picking up crystal cargo and producing fabrics in the mush en route. (Online version in colour.)

a A highly schematic cartoon showing the structure of a gabbroic mush layer at the moment the overlying bulk magma saturates in a new liquidus phase. The base of the mush is the horizon at which all dihedral angles between two grains of plagioclase (denoted by the white rectangles) and a grain of either pyroxene or olivine (denoted by the grey regions) are formed. The top of the mush is defined by the horizon at which the new liquidus phase forms abundant and homogeneously distributed grains. To the right are photomicrographs illustrating the extent of solidification through the upper crust of the Kilauea Iki lava lake: all possible three-grain clinopyroxene–plagioclase junctions are formed at the base of the mush, whereas almost none have been created near the top. b A cartoon showing the fully solidified mush zone, with an illustration of the variation through the stratigraphy of the fully solidified cumulate of the median value of dihedral angle formed at the junctions of two grains of plagioclase (p) and one grain of either pyroxene or olivine (x), Θ_xpp