Recording the transition from flare-up to steady-state arc magmatism at the Purico–Chascon volcanic complex, northern Chile

Burns, Dale H.; Silva, De; Tepley, F. J.; Schmitt, Axel K.; Loewen, Matthew W.

doi:10.1016/j.epsl.2015.04.002

Cited by 55 publications

(36 citation statements)

References 52 publications

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“…The anomalies C1 and C2 coincide spatially with the depths of crystallization (approximately 7 km) proposed by Godoy et al (), for the Chao and Paniri volcano. Considering the values of SiO 2 , N a 2 O, temperature, and pressure observed in Chao volcano, we estimated resistivities using Sigmelts (Pommier & Le Trong, ), obtaining values consistent with those observed in the 3‐D inversion models, and consistence with a melt percentage presented by Burns et al (), Watss et al (), and De Silva et al (), all of this information indicates the possible location of a magmatic body below the Paniri and Chao volcanoes. The difference in values of conductivity, depth, and composition indicate a possible separation between the shallower magmatic structure associated with Paniri volcano (C2) and Lavas de Chao (C1); however, the hypothesis of a common deep magmatic source cannot be discarded.…”

Section: Discussionsupporting

confidence: 67%

“…On the other hand, studies carried out at Paniri volcano (De Silva & Francis, ), evidence its recent activity, while our study would provide relevant information regarding the magmatic source of this activity. Finally, studies conducted by Burns et al (), Watss et al (), and De Silva et al () indicate that all dome‐type volcanoes associated with the Altiplano‐Puna volcanic complex (APVC) will present high percentages of partial melt, information that coincides with resistivity analysis for the Chao volcano. This work should be of interest for researchers working in the Central Andes, and geoscientists studying subduction related volcanic systems.…”

Section: Introductionmentioning

confidence: 58%

“…Using modified Archie's law for the resistivity values obtained according to the composition of the Lavas de Chao and comparing them with the resistivities obtained through the inversions, we obtained partial melting values of 67%, considering cementation exponents (m) of 1.5 (Figure ). These values are much larger than typical percentages observed in volcanic areas, but Burns et al (), Watss et al (), and De Silva et al () suggest high values of partial fusion of approximately 40% for dome‐type volcanoes associated with the APVC. However, an alternative explanation would point to the presence of aqueous fluids related to these conductive anomalies, which could reduce the percentage of partial melt to reach more realistic values, as shown by Pritchard et al ().…”

Section: Discussionmentioning

confidence: 86%

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Conductivity Distribution Beneath the San Pedro‐Linzor Volcanic Chain, North Chile, Using 3‐D Magnetotelluric Modeling

et al. 2019

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A magnetotelluric study was carried out in the San Pedro-Linzor volcanic chain, North Chile, to identify possible magmatic structures and hydrothermal systems associated with volcanoes of Holocene activity, considering previous petrochemical studies pointing to crystallization depths of approximately 8 km. Three-dimensional resistivity models based on magnetotellurics data of the San Pedro-Linzor volcanic chain were obtained based on broadband data measured in 2017 and 2018, in addition to long-period data measured in 1990s. The three-dimensional modeling shows two low-resistivity zones (less than 10 m) interpreted as partially molten areas below the Chao Dome and the Paniri volcano, and a shallower low resistivity area (less than 5 m) in the Turi Basin, an active hydrothermal system to the southwest of the volcanic chain.

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Section: Discussionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 58%

Section: Discussionmentioning

confidence: 86%

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Conductivity Distribution Beneath the San Pedro‐Linzor Volcanic Chain, North Chile, Using 3‐D Magnetotelluric Modeling

et al. 2019

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“…The derivative basaltic andesite rises to further differentiate through melting and mixing at higher levels in the crust (Figure ). This would be the common mechanism for generating a large amount of crustal melt [ Burns et al ., ; de Silva , ; Kimura and Nagahashi , ]. Breakdown of hydrous minerals in crustal rocks, e.g., biotite in granitic rocks [ Brown , ] or amphibole in the amphibolitic rocks [ Johannes and Holtz , ], enhances partial melting of the crust.…”

Section: Discussionmentioning

confidence: 99%

Origins of felsic magmas in Japanese subduction zone: Geochemical characterizations of tephra from caldera‐forming eruptions <5 Ma

Kimura

Nagahashi

Satoguchi

et al. 2015

Geochem Geophys Geosyst

120

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Dacitic to rhyolitic glass shards from 80 widespread tephras erupted during the past 5 Mys from calderas in Kyushu, and SW, central, and NE Japan were analyzed. Laser ablation inductively coupled plasma mass spectrometry was used to determine 10 major and 33 trace elements and A few tephras from SW Japan were identified as adakite and alkali rhyolite and were regarded to have originated from slab melt and mantle melt, respectively. The Pb isotope ratios of the tephras are comparable to those of the intermediate lavas in the source areas but are different from the basalts in these areas. The crustal assimilants for the intermediate lavas were largely from crustal melts and are represented by the rhyolitic tephras. A large heat source is required for forming large volumes of felsic crustal melts and is usually supplied by the mantle via basalt. Hydrous arc basalt formed by cold slab subduction is voluminous, and its heat transfer with high water content may have melted crustal rocks leading to effective felsic magma production. Coincidence of basalt and felsic magma activities shown by this study suggests caldera-forming eruptions are ultimately the effect of a mantle-driven cause.

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“…Estimates of the volume of partial melt in this zone are >20% ( Comeau et al, 2015), and plutonic:volcanic ratios of ~20:1 have been calculated (Ward et al, 2014), supporting the contention that the APMB is the intrusive equiva- lent of the voluminous APVC volcanics (de Silva et al, 2006). This upper crustal MASH (melting, assimilation, storage, homogenization;after Hildreth and Moorbath, 1988) zone (Burns et al, 2015), represents the largest known continental crustal magmatic zone (Zandt et al, 2003;Ward et al, 2014). Continued magmatic activity in the APMB is inferred from satellite interferometry studies (Pritchard and Simons, 2002;Fialko and Pearse, 2012) that have identified a zone of surface uplift centered on the composite volcano Uturuncu with an outer ring of subsidence that extends the surface deformation to ~150 km in diameter ( Fig.…”

Section: Geologic Backgroundmentioning

confidence: 99%

Geochronological imaging of an episodically constructed subvolcanic batholith: U-Pb in zircon chronochemistry of the Altiplano-Puna Volcanic Complex of the Central Andes

et al. 2016

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Zircons from 15 crystal-rich monotonous intermediate ignimbrites and 1 crystal-poor rhyolite ignimbrite erupted during the 11-1 Ma Altiplano-PunaVolcanic Complex (APVC) ignimbrite flare-up record multiscale episodicity in the magmatic history of the shallowest levels (5-10 km beneath the surface) of the Altiplano-Puna Magma Body (APMB). This record reveals the construction of a subvolcanic batholith and its magmatic and eruptive tempo.More than 750 U-Pb ages of zircon rims and interiors of polished grains determined by secondary ion mass spectrometry define complex age spectra for each ignimbrite with a dominant peak of autocrysts and subsidiary antecryst peaks. Xenocrysts are rare. Weighted averages obtained by pooling the youngest analytically indistinguishable zircon ages mostly correspond to the dominant crystallization ages for zircons in the magma. These magmatic ages are consistent with eruptive stratigraphy, and fall into four groups defining distinct pulses (from older to younger, pulses 1 through 4) of magmatism that correlate with eruptive pulses, but indicate that magmatic construction in each pulse initiated at least 1 m.y. before eruptions began. Magmatism was initially distributed diffusely on the eastern and western flanks of the APVC, but spread out over much of the APVC as activity waxed before focusing in the central part during the peak of the flare-up. Each pulse consists of spatially distinct but temporally sequenced subpulses of magma that represent the construction of pre-eruptive magma reservoirs. Three nested calderas were the main eruptive loci during the peak of the flare-up from ca. 6 to 2.5 Ma. These show broadly synchronous magmatic development but some discordance in their later eruptive histories. These relations are interpreted to indicate that eruptive tempo is controlled locally from the top down, while magmatic tempo is a more systemic, deeper, bottom-up feature. Synchroneity in magmatic history at distinct upper crustal magmatic foci implicates a shared connection deeper within the APMB.Each ignimbrite records the development of a discrete magma. Zircon age distributions of individual ignimbrites become more complex with time, reflecting the carryover of antecrysts in successively younger magmas and attesting to upper crustal assimilation in the APVC. Although present, xenocrysts are rare, suggesting that inheritance is limited. This is attributed to basement assimilation under zircon-undersaturated conditions deeper in the APMB than the pre-eruptive levels, where antecrysts were incorporated in zircon-saturated conditions. Magmatic ages for individual ignimbrites are older than the 40 Ar/ 39 Ar eruption ages. This difference is interpreted as the average minimum Zr-saturated melt-present lifetime for APVC magmas, the magmatic duration or Δ age. The average Δ age of ca. 0.4 Ma indicates that thermochemical conditions for zircon saturation were maintained for several hundreds of thousands of years prior to eruption of APVC magmas. This is consistent with a narrow range of zirc...

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Recording the transition from flare-up to steady-state arc magmatism at the Purico–Chascon volcanic complex, northern Chile

Cited by 55 publications

References 52 publications

Conductivity Distribution Beneath the San Pedro‐Linzor Volcanic Chain, North Chile, Using 3‐D Magnetotelluric Modeling

Conductivity Distribution Beneath the San Pedro‐Linzor Volcanic Chain, North Chile, Using 3‐D Magnetotelluric Modeling

Origins of felsic magmas in Japanese subduction zone: Geochemical characterizations of tephra from caldera‐forming eruptions <5 Ma

Geochronological imaging of an episodically constructed subvolcanic batholith: U-Pb in zircon chronochemistry of the Altiplano-Puna Volcanic Complex of the Central Andes

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