Rheological properties of magma from the 1538 eruption of Monte Nuovo (Phlegrean Fields, Italy): An experimental study

被引：46

作者：

Caricchi, Luca ^{[1
]}

Giordano, Daniele ^{[2
]}

Burlini, Luigi ^{[1
]}

Ulmer, Peter ^{[1
]}

Romano, Claudia ^{[2
]}

机构：

[1] ETH, Dept Earth Sci, CH-8092 Zurich, Switzerland

[2] Univ Roma Tre, Dipartimento Sci Geol, I-00146 Rome, Italy

来源：

CHEMICAL GEOLOGY | 2008年 / 256卷 / 3-4期

基金：

瑞士国家科学基金会;

关键词：

Magma rheology; Shear thinning; Shear weakening; Eruption dynamics;

D O I：

10.1016/j.chemgeo.2008.06.035

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The rheology of natural, partially crystallized samples from Monte Nuovo (1538 AD) eruption have been investigated Using a high temperature, high pressure internally heated pressure vessel. Within the temperature interval of investigation the samples exhibited Newtonian theology at deformation strain rates up to 10(-4) s(-1). At higher strain rates a decrease of viscosity with increasing strain rate (shear thinning), eventually terminating in a sudden viscosity drop (stress weakening), was observed. Stress weakening occurred at higher applied strain rates and stresses with increasing temperature. The microstructural analyses of the samples revealed that stress weakening resulted from strain localization, which occurred in brittle and viscous regimes at the lowest and highest temperatures investigated respectively. The different rheological behaviors of the investigated material is likely responsible for the changes in the dynamics of magma ascent within the volcanic conduit during the eruption of Monte Nuovo volcano. We infer that the occurrence of syn-eruptive decompression driven crystallization, observed in previous studies, induced strong variations in the rheological properties of magma, which in turn was responsible for the changes of eruptive style observed during the Monte Nuovo eruption. (c) 2008 Elsevier B.V. All rights reserved.

引用

页码：158 / 171

页数：14

共 49 条

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