TY - JOUR

T1 - Viscosity of Pyroxenite Melt and Its Evolution During Cooling

AU - Vetere, Francesco

AU - Murri, M.

AU - Alvaro, M.

AU - Domeneghetti, M. C.

AU - Rossi, S.

AU - Pisello, A.

AU - Perugini, Diego

AU - Holtz, Francois

N1 - Funding information: [ This research was funded by the European Research Council Consolidator Grant ERC-2013-COG No. 612776 (CHRONOS project) to D. Perugini and by the F.R.B. TESLA to F. Vetere. Alexander von Humboldt Foundation Senior Research Grant to F. Vetere is also acknowledged. M. A. and M. M. are supported by the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement 714936 for the project TRUE DEPTHS to M. Alvaro). M. C. D. has been supported by the PNRA 2016 Antartic Meteorites to Luigi Folco. Data of experiments are reported in Tables and, in Figures, and in the supporting information as Tables S1–S5 and Figures S1–S3. This research was funded by the European Research Council Consolidator Grant ERC?2013?COG No. 612776 (CHRONOS project) to D. Perugini and by the F.R.B. TESLA to F. Vetere. Alexander von Humboldt Foundation Senior Research Grant to F. Vetere is also acknowledged. M. A. and M. M. are supported by the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement 714936 for the project TRUE DEPTHS to M. Alvaro). M. C. D. has been supported by the PNRA 2016 Antartic Meteorites to Luigi Folco. Data of experiments are reported in Tables 1 and 2, in Figures 1–9, and in the supporting information as Tables S1–S5 and Figures S1–S3.

PY - 2019/6/14

Y1 - 2019/6/14

N2 - New viscosity experiments at superliquidus temperatures and during cooling at a rate of 10 K/hr have been performed at different shear rates on a synthetic pyroxenite melt. Results revealed that this melt is extremely fluid at temperature between 1646 and 1530 K and measured viscosities are between 2.2 and 7.8 Pa·s. Such very low viscosities allow the lava to flow in turbulent regime as confirmed by the high Reynolds numbers, which are always >2,000. As a consequence, very long distance could be covered by the lava flow. If we consider this studied composition as proxy for Mars lava flows coupled with very high effusion rates, our results might explain the presence of extraordinary large volcanic channels, as recently hypothesized for the Kasei Valles on Mars, even considering that the gravity is approximately one third that of Earth. Few literature data tracking viscosity during cooling are available, and they reported shear thinning effect on different compositions. Our experiments performed at 0.1 and 1 s−1 have shown complex variation in the apparent viscosity, confirming that nonequilibrium rheology represents a still unexplored field of investigation useful to better understand the real geological scenarios occurring in magmatic and volcanic systems.

AB - New viscosity experiments at superliquidus temperatures and during cooling at a rate of 10 K/hr have been performed at different shear rates on a synthetic pyroxenite melt. Results revealed that this melt is extremely fluid at temperature between 1646 and 1530 K and measured viscosities are between 2.2 and 7.8 Pa·s. Such very low viscosities allow the lava to flow in turbulent regime as confirmed by the high Reynolds numbers, which are always >2,000. As a consequence, very long distance could be covered by the lava flow. If we consider this studied composition as proxy for Mars lava flows coupled with very high effusion rates, our results might explain the presence of extraordinary large volcanic channels, as recently hypothesized for the Kasei Valles on Mars, even considering that the gravity is approximately one third that of Earth. Few literature data tracking viscosity during cooling are available, and they reported shear thinning effect on different compositions. Our experiments performed at 0.1 and 1 s−1 have shown complex variation in the apparent viscosity, confirming that nonequilibrium rheology represents a still unexplored field of investigation useful to better understand the real geological scenarios occurring in magmatic and volcanic systems.

KW - crystallization

KW - magma

KW - Mars

KW - melt

KW - rheology

KW - viscosity

UR - http://www.scopus.com/inward/record.url?scp=85066477213&partnerID=8YFLogxK

U2 - 10.15488/10184

DO - 10.15488/10184

M3 - Article

AN - SCOPUS:85066477213

VL - 124

SP - 1451

EP - 1469

JO - Journal of Geophysical Research: Planets

JF - Journal of Geophysical Research: Planets

SN - 2169-9097

IS - 5

ER -