Storage and Evolution of Laguna del Maule Rhyolites: Insight From Volatile and Trace Element Contents in Melt Inclusions

Interpreting unrest at silicic volcanoes requires knowledge of the magma storage conditions and dynamics that precede eruptions. The Laguna del Maule volcanic field, Chile, has erupted ~40 km3 of rhyolite over the last 20 ka. Astonishing rates of sustained surface inflation at >25 cm/year for >12 years reveal a large, restless system. Integration of geochronologic, petrologic, geomorphic, and geophysical observations provides an unusually rich context to interpret ongoing and prehistoric processes. We present new volatile (H2O, CO2, S, F, and Cl), trace element, and major element concentrations from 109 melt inclusions hosted in quartz, plagioclase, and olivine from seven eruptions. Silicic melts contain up to 8.0 wt. % H2O and 570 ppm CO2. In rhyolites melt inclusions track decompression‐driven fractional crystallization as magma ascended from ~14 to 4 km. This mirrors teleseismic tomography and magnetotelluric findings that reveal a domain containing partial melt spanning from 14 to 4 km. Ce and Cl contents of rhyolites support the generation of compositionally distinct domains of eruptible rhyolite within the larger reservoir. Heat, volatiles, and melt derived from episodic mafic recharge likely incubate and grow the shallow reservoir. Olivine‐hosted melt inclusions in mafic tephra contain up to 2.5 wt. % H2O and 1,140 ppm CO2 and proxy for the volatile load delivered via recharge into the base of the silicic mush at ~14 to 8 km. We propose that mafic recharge flushes deeper reaches of the magma reservoir with CO2 that propels H2O exsolution, upward accumulation of fluid, pressurization, and triggering of rhyolitic eruptions.

[1]  C. Thurber,et al.  Teleseismic Tomography of the Laguna del Maule Volcanic Field in Chile , 2020, Journal of Geophysical Research: Solid Earth.

[2]  M. Bagnardi,et al.  Using Conceptual Models to Relate Multiparameter Satellite Data to Subsurface Volcanic Processes in Latin America , 2020, Geochemistry, Geophysics, Geosystems.

[3]  W. Degruyter,et al.  Optimal depth of subvolcanic magma chamber growth controlled by volatiles and crust rheology , 2019, Nature Geoscience.

[4]  M. Unsworth,et al.  Fluid and Melt Pathways in the Central Chilean Subduction Zone Near the 2010 Maule Earthquake (35–36°S) as Inferred From Magnetotelluric Data , 2019, Geochemistry, Geophysics, Geosystems.

[5]  B. Singer,et al.  Repeated Rhyolite Eruption From Heterogeneous Hot Zones Embedded Within a Cool, Shallow Magma Reservoir , 2019, Journal of Geophysical Research: Solid Earth.

[6]  G. Williams-Jones,et al.  Magma Reservoir Below Laguna del Maule Volcanic Field, Chile, Imaged With Surface‐Wave Tomography , 2019, Journal of Geophysical Research: Solid Earth.

[7]  L. Caricchi,et al.  The role of H2O on the extraction of melt from crystallising magmas , 2019, Earth and Planetary Science Letters.

[8]  T. Mather,et al.  Thoughts on the criteria to determine the origin of volcanic unrest as magmatic or non-magmatic , 2019, Philosophical Transactions of the Royal Society A.

[9]  R. Sparks,et al.  Chemical differentiation, cold storage and remobilization of magma in the Earth’s crust , 2018, Nature.

[10]  F. Costa,et al.  Petrochronologic perspective on rhyolite volcano unrest at Laguna del Maule, Chile , 2018, Earth and Planetary Science Letters.

[11]  T. Sheldrake,et al.  Modulation of magmatic processes by CO2 flushing , 2018, Earth and Planetary Science Letters.

[12]  K. Feigl,et al.  Geomorphic expression of rapid Holocene silicic magma reservoir growth beneath Laguna del Maule, Chile , 2018, Science Advances.

[13]  M. Unsworth,et al.  Imaging the Laguna del Maule Volcanic Field, central Chile using magnetotellurics: Evidence for crustal melt regions laterally-offset from surface vents and lava flows , 2018 .

[14]  A. Parmigiani,et al.  A Physical Model for Three‐Phase Compaction in Silicic Magma Reservoirs , 2018 .

[15]  J. Fierstein.  Postglacial Eruptive History Established by Mapping and Tephra Stratigraphy Provides Perspectives on Magmatic System beneath Laguna del Maule, Chile , 2018 .

[16]  W. Hildreth,et al.  Incremental heating of Bishop Tuff sanidine reveals preeruptive radiogenic Ar and rapid remobilization from cold storage , 2017, Proceedings of the National Academy of Sciences.

[17]  A. Kent,et al.  Influence of Exsolved Volatiles on Reheating Silicic Magmas by Recharge and Consequences for Eruptive Style at Volcán Quizapu (Chile) , 2017 .

[18]  J. Cole,et al.  Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals , 2017, Science.

[19]  T. Thordarson,et al.  Volatile and light lithophile elements in high-anorthite plagioclase-hosted melt inclusions from Iceland , 2017 .

[20]  G. Williams-Jones,et al.  Microgravity changes at the Laguna del Maule volcanic field: Magma‐induced stress changes facilitate mass addition , 2017 .

[21]  R. Sparks,et al.  Vertically extensive and unstable magmatic systems: A unified view of igneous processes , 2017, Science.

[22]  Matthew E. Pritchard,et al.  Global Volcano Monitoring: What Does It Mean When Volcanoes Deform? , 2017 .

[23]  G. Williams-Jones,et al.  3D gravity inversion and thermodynamic modelling reveal properties of shallow silicic magma reservoir beneath Laguna del Maule, Chile , 2017 .

[24]  T. M. Harrison,et al.  Warm storage for arc magmas , 2016, Proceedings of the National Academy of Sciences.

[25]  F. Costa,et al.  The timing of compositionally-zoned magma reservoirs and mafic 'priming' weeks before the 1912 Novarupta-Katmai rhyolite eruption , 2016 .

[26]  Katherine A. Kelley,et al.  From Passive Degassing to Violent Strombolian Eruption: the Case of the 2008 Eruption of Llaima Volcano, Chile , 2016 .

[27]  K. Feigl,et al.  Magma injection into a long‐lived reservoir to explain geodetically measured uplift: Application to the 2007–2014 unrest episode at Laguna del Maule volcanic field, Chile , 2016, Journal of geophysical research. Solid earth.

[28]  A. Parmigiani,et al.  Bubble accumulation and its role in the evolution of magma reservoirs in the upper crust , 2016, Nature.

[29]  K. Feigl,et al.  Evolution of unrest at Laguna del Maule volcanic field (Chile) from InSAR and GPS measurements, 2003 to 2014 , 2015 .

[30]  J. Vazquez,et al.  Months between rejuvenation and volcanic eruption at Yellowstone caldera, Wyoming , 2015 .

[31]  M. Ghiorso,et al.  An H2O–CO2 mixed fluid saturation model compatible with rhyolite-MELTS , 2015, Contributions to Mineralogy and Petrology.

[32]  R. Esposito,et al.  Special Collection: Glasses, Melts, and Fluids, as Tools for Understanding Volcanic Processes and Hazards. Bubbles matter: An assessment of the contribution of vapor bubbles to melt inclusion volatile budgets , 2015 .

[33]  Basil Tikoff,et al.  Dynamics of a large, restless, rhyolitic magma system at Laguna del Maule, southern Andes, Chile , 2014 .

[34]  A. Kent,et al.  Rapid remobilization of magmatic crystals kept in cold storage , 2014, Nature.

[35]  V. Pinel,et al.  Frequency and magnitude of volcanic eruptions controlled by magma injection and buoyancy , 2014 .

[36]  Kurt L. Feigl,et al.  Rapid uplift in Laguna del Maule volcanic field of the Andean Southern Volcanic zone (Chile) 2007–2012 , 2014 .

[37]  J. Lowenstern,et al.  Amorphous Materials: Properties, structure, and durability. Analysis of H2O in silicate glass using attenuated total reflectance (ATR) micro-FTIR spectroscopy , 2013 .

[38]  F. Gutiérrez,et al.  On the longevity of large upper crustal silicic magma reservoirs , 2013 .

[39]  N. Rogers,et al.  Lying in wait: deep and shallow evolution of dacite beneath Volcán de Santa María, Guatemala , 2013 .

[40]  A. Kent,et al.  Magmatic processes in the Bishop Tuff rhyolitic magma based on trace elements in melt inclusions and pumice matrix glass , 2013, Contributions to Mineralogy and Petrology.

[41]  M. Newville,et al.  Rapid reequilibration of H2O and oxygen fugacity in olivine-hosted melt inclusions , 2012 .

[42]  F. Costa,et al.  Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano , 2012, Nature.

[43]  Alain Burgisser,et al.  Insights into shallow magma storage and crystallization at Volcán Llaima (Andean Southern Volcanic Zone, Chile) , 2012 .

[44]  R. Esposito,et al.  Thermodynamic Model for the Effect of Post-entrapment Crystallization on the H2O–CO2 Systematics of Vapor-saturated, Silicate Melt Inclusions , 2011 .

[45]  L. Danyushevsky,et al.  Petrolog3: Integrated software for modeling crystallization processes , 2011 .

[46]  O. Bachmann,et al.  Thermo-mechanical reactivation of locked crystal mushes: Melting-induced internal fracturing and assimilation processes in magmas , 2011 .

[47]  J. Maclennan,et al.  Melt inclusions track pre-eruption storage and dehydration of magmas at Etna , 2009 .

[48]  C. Heinrich,et al.  Diffusive reequilibration of quartz-hosted silicate melt and fluid inclusions: Are all metal concentrations unmodified? , 2009 .

[49]  E. Watson,et al.  Pre-eruption recharge of the Bishop magma system , 2007 .

[50]  R. Sparks,et al.  The Genesis of Intermediate and Silicic Magmas in Deep Crustal Hot Zones , 2006 .

[51]  K. Herwig,et al.  MPI‐DING reference glasses for in situ microanalysis: New reference values for element concentrations and isotope ratios , 2006 .

[52]  J. Blundy,et al.  Rapid decompression-driven crystallization recorded by melt inclusions from Mount St Helens volcano , 2005 .

[53]  P. Wallace.  Volatiles in subduction zone magmas: concentrations and fluxes based on melt inclusion and volcanic gas data , 2005 .

[54]  W. Hildreth.  Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: several contiguous but discrete systems , 2004 .

[55]  O. Bachmann,et al.  On the Origin of Crystal-poor Rhyolites: Extracted from Batholithic Crystal Mushes , 2004 .

[56]  J. Lowenstern,et al.  VOLATILECALC: a silicate melt-H 2 O-CO 2 solution model written in Visual Basic for excel , 2002 .

[57]  A. Sobolev,et al.  Experimental and petrological studies of melt inclusions in phenocrysts from mantle-derived magmas: an overview of techniques, advantages and complications , 2002 .

[58]  T. Sisson,et al.  Delayed, disequilibrium degassing in rhyolite magma: Decompression experiments and implications for explosive volcanism , 2000 .

[59]  P. McMillan,et al.  Solubility, speciation and dissolution mechanisms for CO2 in melts on the NaAlO2–SiO2 join , 1999 .

[60]  W. Wagner,et al.  A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple‐Point Temperature to 1100 K at Pressures up to 800 MPa , 1996 .

[61]  C. W. Ponader,et al.  Rare earth elements in silicate glassmelt systems: II. Interactions of La, Gd, and Yb with halogens , 1989 .

[62]  Darcy Cordell.  Imaging the Laguna del Maule Volcanic Field, Central Chile Using Magnetotellurics: Evidence For Upper-to-mid Crustal Melt Regions Laterally-offset From Surface Vents and Holocene Lava Flows , 2018 .

[63]  B. Jicha,et al.  Pleistocene to Holocene Growth of a Large Upper Crustal Rhyolitic Magma Reservoir beneath the Active Laguna del Maule Volcanic Field, Central Chile , 2017 .

[64]  Paul J. Wallace,et al.  Volatiles in Magmas , 2015 .

[65]  Analysis of H 2 O in silicate glass using attenuated total reflectance ( ATR ) micro-FTIR spectroscopy , 2013 .

[66]  W. Hildreth,et al.  Laguna del Maule Volcanic Field: Eruptive history of a Quaternary basalt-to-rhyolite distributed volcanic field on the Andean rangecrest in central Chile , 2010 .

[67]  J. Blundy,et al.  Petrologic Reconstruction of Magmatic System Variables and Processes , 2008 .

[68]  G. Moore.  Interpreting H2O and CO2 Contents in Melt Inclusions: Constraints from Solubility Experiments and Modeling , 2008 .

[69]  A. T. Anderson,et al.  Mixing and differentiation in the Oruanui rhyolitic magma, Taupo, New Zealand: evidence from volatiles and trace elements in melt inclusions , 2006 .

[70]  O. Bachmann,et al.  Gas percolation in upper-crustal silicic crystal mushes as a mechanism for upward heat advection and rejuvenation of near-solidus magma bodies , 2006 .

[71]  S. Sokolov,et al.  Re-equilibration of melt inclusions trapped by magnesian olivine phenocrysts from subduction-related magmas: petrological implications , 2000 .

[72]  William A. Wakeham,et al.  A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple-Point Temperature to 1100 K at Pressures up to 800 MPa , 1998 .