The influence of partial melting on the electrical behavior of crustal rocks: laboratory examinations, model calculations and geological interpretations

Partzsch, Georg M.; Schilling, Frank; Arndt, Jörg

doi:10.1016/s0040-1951(99)00320-0

Cited by 89 publications

(74 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The variation of the gradient at elevated temperatures indicates that intrinsic charge transport then dominates the conduction process. and Tyburczy, 1999;Bagdassarov et al,2002;Partzsch et al, 2000;Maumus et al 2001;Poe et al, 2001;Nover et al, 2004aNover et al, , 2004bNover et al, , 2006.…”

Section: Partial Meltsmentioning

confidence: 99%

“…The parallel HS upper bound and the Archie model are both well suited to describe the measured increase in conductivity that was more by than one order of magnitude. Partzsch et al (2000) and Schilling and Partzsch (2001) measured the complex electrical impedance of fine grained, quartz free granulite in the frequency range from 0.1 up to 100 kHz at temperatures between 600 and 1200°C. The sample composition was representative of lower crustal rocks.…”

Section: Partial Meltsmentioning

confidence: 99%

See 1 more Smart Citation

Electrical Properties of Crustal and Mantle Rocks – A Review of Laboratory Measurements and their Explanation

Nover¹

2005

Surv Geophys

110

View full text Add to dashboard Cite

The electrical properties of rocks and minerals are controlled by thermodynamic parameters like pressure and temperature and by the chemistry of the medium in which the charge carriers move. Four different charge transport processes can be distinguished. Electrolytic conduction in fluid saturated porous rocks depends on petrophysical properties, such as porosity, permeability and connectivity of the pore system, and on chemical parameters of the pore fluid like ion species, its concentration in the pore fluid and temperature. Additionally, electrochemical interactions between water dipoles or ions and the negatively charged mineral surface must be considered. In special geological settings electronic conduction can increase rock conductivities by several orders of magnitude if the highly conducting phases (graphite or ores) form an interconnected network. Electronic and electrolytic conduction depend moderately on pressure and temperature changes, while semiconduction in mineral phases forming the Earth's mantle strongly depends on temperature and responds less significantly to pressure changes. Olivine exhibits thermally induced semiconduction under upper mantle conditions; if pressure and temperature exceed $ 14 GPa and 1400°C, the phase transition olivine into spinel will further enhance the conductivity due to structural changes from orthorhombic into cubic symmetry. The thermodynamic parameters (temperature, pressure) and oxygen fugacity control the formation, number and mobility of charge carriers. The conductivity temperature relation follows an Arrhenius behaviour, while oxygen fugacity controls the oxidation state of iron and thus the number of electrons acting as additional charge carriers. In volcanic areas rock conductivities may be enhanced by the formation of partial melts under the restriction that the molten phase is interconnected. These four charge transport mechanisms must be considered for the interpretation of geophysical field and borehole data. Laboratory data provide a reproducible and reliable database of electrical properties of homogenous mineral phases and heterogenous rock samples. The outcome of geoelectric models can thus be enhanced significantly. This review focuses on a compilation of fairly new advances in experimental laboratory work together with their explanation.

show abstract

Section: Partial Meltsmentioning

confidence: 99%

Section: Partial Meltsmentioning

confidence: 99%

Electrical Properties of Crustal and Mantle Rocks – A Review of Laboratory Measurements and their Explanation

Nover¹

2005

Surv Geophys

110

View full text Add to dashboard Cite

show abstract

“…Roberts and Tyburczy [1999] investigated the electrical response of an olivine-basalt partial melt as a function of temperature. The relation of electrical conductivity, degree of partial melting and melt distribution was studied by Partzsch et al [2000]. Electrical conductivity of olivine and its dependence on melt distribution was described by ten Grotenhuis et al [2004Grotenhuis et al [ , 2005.…”

Section: Introductionmentioning

confidence: 99%

Atomic scale view on partially molten rocks: Molecular dynamics simulations of melt-wetted olivine grain boundaries

et al. 2011

View full text Add to dashboard Cite

[1] Partial melting is an important geological process that affects physical, chemical and rheological properties of rocks. Here, atomic scale simulations are used to study the structure and transport properties of ultrathin melt films between olivine grains, which is a simple model system of a partially molten peridotite. The model systems consist of 0.8 to 7.0 nanometer thick layers of magnesium silicate melt with a composition close to MgSiO 3 confined between Mg 2 SiO 4 forsterite crystals. We examine how the atomic structure, the chemistry and the self-diffusion coefficients vary across the interface and investigate their dependence on the thickness of the melt layer and the crystal orientation. Interfacial layers of up to 2 nm thickness show distinctly different physical behavior than the bulk melt and the bulk mineral. The simulation results indicate that for crystal orientations with higher surface energy, the self-diffusion coefficients of all ionic species in the melt decrease. A solid-like charge ordering in the melt is observed close to the crystal-melt interface, which leads to a decrease in mobility of all species. For modeling the petrophysical behavior of partially molten rocks, the effective diameter for the conducting channels is reduced by up to two nanometers, which may effect the rheological and transport properties of the partially molten rocks, especially in the presence of ultrathin melt films in well wetted systems. In the latter case, the electrical conductivity of the confined melt in a partially molten rock could be reduced up to a factor of two due to interfacial effects.Citation: Gurmani, S. F., S. Jahn, H. Brasse, and F. R. Schilling (2011), Atomic scale view on partially molten rocks: Molecular dynamics simulations of melt-wetted olivine grain boundaries,

show abstract

“…Note the dramatic jump of conductivity at 1240, 1188 and 1196°C for 1, 0.5 and 0.3 GPa experiments respectively. Measurements on olivine gabbros of (a) Sato and Ida (1984); (b) Partzsch (1997), Schilling et al (1997), and Partzsch et al (2000) are shown for comparison. Fig.…”

mentioning

confidence: 99%

Electrical conductivity and partial melting of mafic rocks under pressure

Maumus

Bagdassarov

Schmeling

2005

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

The influence of partial melting on the electrical behavior of crustal rocks: laboratory examinations, model calculations and geological interpretations

Cited by 89 publications

References 30 publications

Electrical Properties of Crustal and Mantle Rocks – A Review of Laboratory Measurements and their Explanation

Electrical Properties of Crustal and Mantle Rocks – A Review of Laboratory Measurements and their Explanation

Atomic scale view on partially molten rocks: Molecular dynamics simulations of melt-wetted olivine grain boundaries

Electrical conductivity and partial melting of mafic rocks under pressure

Contact Info

Product

Resources

About