Mapping fractures using 1D anisotropic modelling of magnetotelluric data: a case study from the Otway Basin, Victoria, Australia

dc.contributor.authorKirkby, A.
dc.contributor.authorHeinson, G.
dc.contributor.authorHolford, S.
dc.contributor.authorThiel, S.
dc.date.issued2015
dc.description.abstractWe present 1D anisotropic inversion of magnetotelluric (MT) data as a potential tool for mapping structural permeability in sedimentary basins. Using 1D inversions of a 171 site, broadband MT data set from the Koroit region of the Otway Basin, Victoria, Australia, we have delineated an electrically anisotropic layer at approximately 2.5 to 3.5 km depth. The anisotropy strike is consistent between stations at approximately 160° east of north. The depth of anisotropy corresponds to the top depth of the Lower Cretaceous Crayfish Group, and the anisotropy factor increases from west to east. We interpret the anisotropy as resulting from north–northwest oriented, fluid-filled fractures resulting in enhanced electrical and hydraulic conductivity. This interpretation is consistent with permeability data from well formation tests. It is also consistent with the orientation of mapped faults in the area, which are optimally oriented for reactivation in the current stress field.
dc.description.statementofresponsibilityA. Kirkby, G. Heinson, S. Holford and S. Thiel
dc.identifier.citationGeophysical Journal International, 2015; 201(3):1961-1976
dc.identifier.doi10.1093/gji/ggv116
dc.identifier.issn0956-540X
dc.identifier.issn1365-246X
dc.identifier.orcidHeinson, G. [0000-0001-7106-0789]
dc.identifier.orcidHolford, S. [0000-0002-4524-8822]
dc.identifier.orcidThiel, S. [0000-0002-8678-412X]
dc.identifier.urihttp://hdl.handle.net/2440/103149
dc.language.isoen
dc.publisherOxford University Press
dc.rights© The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society.
dc.source.urihttps://doi.org/10.1093/gji/ggv116
dc.subjectElectrical properties; magnetotellurics; permeability and porosity; fracture and flow; fractures and faults
dc.titleMapping fractures using 1D anisotropic modelling of magnetotelluric data: a case study from the Otway Basin, Victoria, Australia
dc.typeJournal article
pubs.publication-statusPublished

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