RT Journal Article
T1 Water in cratonic lithosphere: Calibrating laboratory‐determined models of electrical conductivity of mantle minerals using geophysical and petrological observations
A1 Jones, Alan G.
A1 Fullea Urchulutegui, Javier
A1 Evans, Rob L.
A1 Muller, Mark R.
AB Measurements of electrical conductivity of “slightly damp” mantle minerals from different laboratories are inconsistent, requiring geophysicists to make choices between them when interpreting their electrical observations. These choices lead to dramatically different conclusions about the amount of water in the mantle, resulting in conflicting conclusions regarding rheological conditions; this impacts on our understanding of mantle convection, among other processes. To attempt to reconcile these differences, we test the laboratory‐derived proton conduction models by choosing the simplest petrological scenario possible – cratonic lithosphere – from two locations in southern Africa where we have the most complete knowledge. We compare and contrast the models with field observations of electrical conductivity and of the amount of water in olivine and show that none of the models for proton conduction in olivine proposed by three laboratories are consistent with the field observations. We derive statistically model parameters of the general proton conduction equation that satisfy the observations. The pre‐exponent dry proton conduction term σ_0 and the activation enthalpy ΔH_wet are derived with tight bounds, and are both within the broader 2σ errors of the different laboratory measurements. The two other terms used by the experimentalists, one to describe proton hopping (exponent r on pre‐exponent water content C_w and the other to describe H_2O concentration‐dependent activation enthalpy (term αC^ 1/3_w added to the activation energy), are less well defined and further field geophysical and petrological observations are required, especially in regions of higher temperature and higher water content.
PB American Geophysical Union
YR 2012
FD 2012
LK https://hdl.handle.net/20.500.14352/92496
UL https://hdl.handle.net/20.500.14352/92496
LA spa
NO Jones, A. G., Fullea, J., Evans, R. L., & Muller, M. R. (2012). Water in cratonic lithosphere: Calibrating laboratory‐determined models of electrical conductivity of mantle minerals using geophysical and petrological observations. Geochemistry, Geophysics, Geosystems, 13(6).
NO U.S. National Science Foundation
NO South African Department of Science and Technology
NO Science Foundation Ireland
NO Research Council for Science, Engineering and Technology (Irlanda)
DS Docta Complutense
RD 7 abr 2025