Experimental measurements of the viscosity and melt structure of alkali basalts at high pressure and temperature

Barbara Bonechi; Vincenzo Stagno; Yoshio Kono; Rostislav Hrubiak; Luca Ziberna; Giovanni B Andreozzi; Cristina Perinelli; Mario Gaeta

doi:10.1038/s41598-022-06551-7

Experimental measurements of the viscosity and melt structure of alkali basalts at high pressure and temperature

Sci Rep. 2022 Feb 16;12(1):2599. doi: 10.1038/s41598-022-06551-7.

Authors

Barbara Bonechi¹, Vincenzo Stagno^{2

3}, Yoshio Kono⁴, Rostislav Hrubiak⁵, Luca Ziberna^{6

7}, Giovanni B Andreozzi⁸, Cristina Perinelli⁸, Mario Gaeta⁸

Affiliations

¹ Dipartimento di Scienze della Terra, Sapienza Università di Roma, P.le Aldo Moro, 5, 00185, Rome, Italy. barbara.bonechi@uniroma1.it.
² Dipartimento di Scienze della Terra, Sapienza Università di Roma, P.le Aldo Moro, 5, 00185, Rome, Italy. vincenzo.stagno@uniroma1.it.
³ Istituto Nazionale di Geofisica e Vulcanologia, 00143, Rome, Italy. vincenzo.stagno@uniroma1.it.
⁴ Geodynamics Research Center, Ehime University, Matsuyama, 790-8577, Japan.
⁵ High Pressure Collaborative Access Team, X-Ray Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL, 60439, USA.
⁶ Dipartimento di Matematica e Geoscienze, Università degli Studi di Trieste, Via Weiss 8, 34128, Trieste, Italy.
⁷ Bayerisches Geoinstitut, University of Bayreuth, 95440, Bayreuth, Germany.
⁸ Dipartimento di Scienze della Terra, Sapienza Università di Roma, P.le Aldo Moro, 5, 00185, Rome, Italy.

Abstract

Volcanic eruptions are shallow phenomena that represent the final stage of density- and viscosity- driven processes of melt migration from source rocks at upper mantle depths. In this experimental study, we investigated the effect of pressure (0.7-7.0 GPa) and temperature (1335-2000 °C) on the viscosity and the atomic melt structure of a synthetic anhydrous primitive alkaline basalt, an analogue of the pre-eruptive magma that likely feeds the Campi Flegrei Volcanic District at present day. Obtained viscosities (0.5-3.0 Pa s), mobility (0.1-0.4 g cm³ Pa^-1 s^-1) and ascent velocity (1.5-6.0 m yr^-1) are presented to support geochemical and geophysical observations of Campi Flegrei as a critical volcanic district currently undergoing gradual magma recharge at depth.

Grants and funding

DE-NA0001974/Argonne National Laboratory