Details
| Original language | English |
|---|---|
| Article number | 119981 |
| Journal | Chemical Geology |
| Volume | 560 |
| Early online date | 11 Nov 2020 |
| Publication status | Published - 20 Jan 2021 |
Abstract
This paper provides a new parameterization of the temperature and H2O content dependence of the pure liquid viscosities of rhyolitic and dacitic magmas associated with representative volcanic products of the Caxias do Sul and Santa Maria eruptive sequences. The viscosities of silicic volcanic products from the Santa Maria rhyolite (SMr), Caxias do Sul (CSd) and Barros Cassal (BCd) eruptive sequences (Lower Cretaceous volcanism of Parana-Etendeka Large Igneous Province) were measured in the temperature range from ca. 1600 °C to the glass transition (Tg). Anhydrous melt viscosities of representative samples from the main eruptive sequences were determined via concentric cylinder viscometry in the super liquidus regime. The quench products of SMr and CSd were then hydrated using an Internally Heated Pressure Vessel to generate two suites of samples with variable water content of up to 4.41 (CSd) and 5.27 (SMr) wt% as determined by Karl Fischer Titration (KFT). Finally, both anhydrous and hydrous samples were used for micropenetration viscosity measurements near Tg. Both types of samples show a minor amount of Fe-Ti-oxide nanolites identified via Raman spectroscopy, which presence did not substantially interfere with viscosity determinations. Based on the results of the viscosity measurements we parameterized the viscosity dependence as a function of water content using the following Vogel Fulcher Tammann (VFT) expressions accounting for the water and temperature dependence of the viscosity: logη = −4.55 + (10065–176*H2O)/[T-(34.6 + 375.3/(1 + H2O))] for SMr. and logη = −4.55 + (9213–338.1*H2O)/[T-(148.5 + 301.3/(1 + H2O))] for CSd. where η is the viscosity in Pa s, T the absolute temperature and H2O the dissolved water content in wt%. This novel parameterization appears to solve a few inconsistencies associated with the variation of the main descriptive parameters of the effect of H2O, improving the performance of some previous parameterizations. These results are useful for scaling to the conditions extant during ascent and eruption and during flow, emplacement and welding, at temperatures above Tg, for the dacitic and rhyolitic products investigated here.
Keywords
- Brazil, Paranà Volcanic Products, VFT modelling, Viscosity measurements
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Chemical Geology, Vol. 560, 119981, 20.01.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Viscosity of Palmas-type magmas of the Paraná Magmatic Province (Rio Grande do Sul State, Brazil)
T2 - Implications for high-temperature silicic volcanism
AU - Giordano, D.
AU - Vona, A.
AU - Gonzalez-Garcia, D.
AU - Allabar, A.
AU - Kolzenburg, S.
AU - Polo, L.
AU - de Assis Janasic, V.
AU - Behrens, H.
AU - De Campos, C. P.
AU - De Cristofaro, S.
AU - Freitas Guimaraesc, L.
AU - Nowak, M.
AU - Masotta, M.
AU - Roverato, M.
AU - Romano, C.
AU - Dingwell, D. B.
AU - Müller, Dirk
AU - Günther, Amanda
N1 - Funding Information: Financial support for this work was given by Fapesp (ThematicProject 2012/06082-6). LAP acknowledges a post-Doctoral scholarship by FAPESP (proc: 2017/15540-1). DG visits and research at the Universidade de São Paulo (2015-2017) are financed by a PVE (Pesquisador Visitante Especial) Project funded by CAPES (proc:88881.068169/2014-01; PVE: DG; Responsible: VAJ) within the framework of CSF program, Brazil. LFG was supported by a CNPq PhD fellowship (No. 142084/2015-8) and CAPES PDSE fellowship (No. 88881.134384/ 2016-01). We acknowledge the financial support from DAAD Project 57389574 “Large Igneous province Paraná-Etendeka”. SK acknowledges the support of a H2020 Marie Skłodowska-Curie fellowship DYNAVOLC – No.795044. AV and CR acknowledge the Grant of Excellence Departments, MIUR-Italy (ARTICOLO 1, COMMI 314 - 337 LEGGE 232/2016). DGG was supported by a postdoctoral fellowship cofounded by the University of Turin and LMU Munich . AA was funded by the German Science Foundation (DFG NO378/12). Melanie Kaliwoda is acknowledged for assistance during Micro-Raman analyses in Munich. DBD acknowledges the support of ERC-ADV-2018 Grant 834225 (EAVESDROP). We are grateful to two anonymous reviewers for their revision which helped us to improve the quality of this manuscript.
PY - 2021/1/20
Y1 - 2021/1/20
N2 - This paper provides a new parameterization of the temperature and H2O content dependence of the pure liquid viscosities of rhyolitic and dacitic magmas associated with representative volcanic products of the Caxias do Sul and Santa Maria eruptive sequences. The viscosities of silicic volcanic products from the Santa Maria rhyolite (SMr), Caxias do Sul (CSd) and Barros Cassal (BCd) eruptive sequences (Lower Cretaceous volcanism of Parana-Etendeka Large Igneous Province) were measured in the temperature range from ca. 1600 °C to the glass transition (Tg). Anhydrous melt viscosities of representative samples from the main eruptive sequences were determined via concentric cylinder viscometry in the super liquidus regime. The quench products of SMr and CSd were then hydrated using an Internally Heated Pressure Vessel to generate two suites of samples with variable water content of up to 4.41 (CSd) and 5.27 (SMr) wt% as determined by Karl Fischer Titration (KFT). Finally, both anhydrous and hydrous samples were used for micropenetration viscosity measurements near Tg. Both types of samples show a minor amount of Fe-Ti-oxide nanolites identified via Raman spectroscopy, which presence did not substantially interfere with viscosity determinations. Based on the results of the viscosity measurements we parameterized the viscosity dependence as a function of water content using the following Vogel Fulcher Tammann (VFT) expressions accounting for the water and temperature dependence of the viscosity: logη = −4.55 + (10065–176*H2O)/[T-(34.6 + 375.3/(1 + H2O))] for SMr. and logη = −4.55 + (9213–338.1*H2O)/[T-(148.5 + 301.3/(1 + H2O))] for CSd. where η is the viscosity in Pa s, T the absolute temperature and H2O the dissolved water content in wt%. This novel parameterization appears to solve a few inconsistencies associated with the variation of the main descriptive parameters of the effect of H2O, improving the performance of some previous parameterizations. These results are useful for scaling to the conditions extant during ascent and eruption and during flow, emplacement and welding, at temperatures above Tg, for the dacitic and rhyolitic products investigated here.
AB - This paper provides a new parameterization of the temperature and H2O content dependence of the pure liquid viscosities of rhyolitic and dacitic magmas associated with representative volcanic products of the Caxias do Sul and Santa Maria eruptive sequences. The viscosities of silicic volcanic products from the Santa Maria rhyolite (SMr), Caxias do Sul (CSd) and Barros Cassal (BCd) eruptive sequences (Lower Cretaceous volcanism of Parana-Etendeka Large Igneous Province) were measured in the temperature range from ca. 1600 °C to the glass transition (Tg). Anhydrous melt viscosities of representative samples from the main eruptive sequences were determined via concentric cylinder viscometry in the super liquidus regime. The quench products of SMr and CSd were then hydrated using an Internally Heated Pressure Vessel to generate two suites of samples with variable water content of up to 4.41 (CSd) and 5.27 (SMr) wt% as determined by Karl Fischer Titration (KFT). Finally, both anhydrous and hydrous samples were used for micropenetration viscosity measurements near Tg. Both types of samples show a minor amount of Fe-Ti-oxide nanolites identified via Raman spectroscopy, which presence did not substantially interfere with viscosity determinations. Based on the results of the viscosity measurements we parameterized the viscosity dependence as a function of water content using the following Vogel Fulcher Tammann (VFT) expressions accounting for the water and temperature dependence of the viscosity: logη = −4.55 + (10065–176*H2O)/[T-(34.6 + 375.3/(1 + H2O))] for SMr. and logη = −4.55 + (9213–338.1*H2O)/[T-(148.5 + 301.3/(1 + H2O))] for CSd. where η is the viscosity in Pa s, T the absolute temperature and H2O the dissolved water content in wt%. This novel parameterization appears to solve a few inconsistencies associated with the variation of the main descriptive parameters of the effect of H2O, improving the performance of some previous parameterizations. These results are useful for scaling to the conditions extant during ascent and eruption and during flow, emplacement and welding, at temperatures above Tg, for the dacitic and rhyolitic products investigated here.
KW - Brazil
KW - Paranà Volcanic Products
KW - VFT modelling
KW - Viscosity measurements
UR - http://www.scopus.com/inward/record.url?scp=85097580489&partnerID=8YFLogxK
U2 - 10.1016/j.chemgeo.2020.119981
DO - 10.1016/j.chemgeo.2020.119981
M3 - Article
AN - SCOPUS:85097580489
VL - 560
JO - Chemical Geology
JF - Chemical Geology
SN - 0009-2541
M1 - 119981
ER -