- Home
- Search Results
- Page 1 of 1
Search for: All records
-
Total Resources2
- Resource Type
-
00020
- Availability
-
20
- Author / Contributor
- Filter by Author / Creator
-
-
Ruprecht, Philipp (2)
-
First, Emily C (1)
-
Ghiorso, Mark S. (1)
-
Hammer, Julia E (1)
-
Huggins, Ellyn G. (1)
-
Rutherford, Malcolm (1)
-
#Tyler Phillips, Kenneth E. (0)
-
#Willis, Ciara (0)
-
& Abreu-Ramos, E. D. (0)
-
& Abramson, C. I. (0)
-
& Abreu-Ramos, E. D. (0)
-
& Adams, S.G. (0)
-
& Ahmed, K. (0)
-
& Ahmed, Khadija. (0)
-
& Akcil-Okan, O. (0)
-
& Akuom, D. (0)
-
& Aleven, V. (0)
-
& Andrews-Larson, C. (0)
-
& Archibald, J. (0)
-
& Arnett, N. (0)
-
- Filter by Editor
-
-
null (2)
-
& Spizer, S. M. (0)
-
& . Spizer, S. (0)
-
& Ahn, J. (0)
-
& Bateiha, S. (0)
-
& Bosch, N. (0)
-
& Brennan K. (0)
-
& Brennan, K. (0)
-
& Chen, B. (0)
-
& Chen, Bodong (0)
-
& Drown, S. (0)
-
& Ferretti, F. (0)
-
& Higgins, A. (0)
-
& J. Peters (0)
-
& Kali, Y. (0)
-
& Ruiz-Arias, P.M. (0)
-
& S. Spitzer (0)
-
& Spitzer, S. (0)
-
& Spitzer, S.M. (0)
-
(submitted - in Review for IEEE ICASSP-2024) (0)
-
-
Have feedback or suggestions for a way to improve these results?
!
Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
First, Emily C ; Hammer, Julia E ; Ruprecht, Philipp ; Rutherford, Malcolm ( , Journal of Petrology)null (Ed.)Abstract Volcán Quizapu, Chile, is an under-monitored volcano that was the site of two historical eruptions: an effusive eruption in 1846–1847 and a Plinian eruption in 1932, both of which discharged ∼5 km3 (dense rock equivalent) of lava and/or tephra. The majority of material erupted in both cases is trachydacite, nearly identical for each event. We present H2O-saturated, phase equilibrium experiments on this end-member dacite magma, using a pumice sample from the 1932 eruption as the main starting material. At an oxygen fugacity (fO2) of ∼NNO + 0·2 (where NNO is the nickel–nickel oxide buffer), the phase assemblage of An25–30 plagioclase + amphibole + orthopyroxene, without biotite, is stable at 865 ± 10 °C and 110 ± 20 MPa H2O pressure (PH2O), corresponding to ∼4 km depth. At these conditions, experiments also reproduce the quenched glass composition of the starting pumice. At slightly higher PH2O and below 860 °C, biotite joins the equilibrium assemblage. Because biotite is not part of the observed Quizapu phase assemblage, its presence places an upper limit on PH2O. At the determined storage PH2O of ∼110 MPa, H2O undersaturation of the magma with XH2Ofluid = 0·87 would align Ptotal to mineral-based geobarometry estimates of ∼130 MPa. However, XH2Ofluid < 1 is not required to reproduce the Quizapu dacite phase assemblage and compositions. A second suite of experiments at lower fO2 shows that the stability fields of the hydrous silicates (amphibole and biotite) are significantly restricted at NNO – 2 relative to NNO + 0·2. Additional observations of Quizapu lava and pumice samples support the existing hypothesis that rapid pre-eruptive heating drove the effusive 1846–1847 eruption, with important refinements. We demonstrate that microlites in the end-member dacite lavas are consistent with in situ crystallization (during ascent), rather than transfer from an andesite. In one end-member dacite lava, newly identified reverse zoning in orthopyroxene and incipient destabilization of amphibole are consistent with small degrees of heating. Our work articulates a clear direction for future Quizapu studies, which are warranted given the active nature of the Cerro Azul–Descabezado Grande volcanic axis.more » « less