The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data
A 3-D model of the crustal electrical resistivity was constructed from the inversion of magnetotelluric data in the Kristineberg area, Skellefte district, the location of one of Sweden's most successful mining activities. Forward modelling of vertical magnetic transfer data supports our model w...
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fthighwire:oai:open-archive.highwire.org:gji:192/2/500 2023-05-15T17:44:58+02:00 The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data Hübert, Juliane Juanatey, María de los Ángeles García Malehmir, Alireza Tryggvason, Ari Pedersen, Laust B. 2013-02-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/192/2/500 https://doi.org/10.1093/gji/ggs044 en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/192/2/500 http://dx.doi.org/10.1093/gji/ggs044 Copyright (C) 2013, Oxford University Press Geomagnetism rock magnetism and palaeomagnetism TEXT 2013 fthighwire https://doi.org/10.1093/gji/ggs044 2015-02-28T20:39:51Z A 3-D model of the crustal electrical resistivity was constructed from the inversion of magnetotelluric data in the Kristineberg area, Skellefte district, the location of one of Sweden's most successful mining activities. Forward modelling of vertical magnetic transfer data supports our model which was derived from the magnetotelluric impedance only. The dominant features in the 3-D model are the strong conductors at various depth levels and resistive bodies of variable thickness occurring in the shallower subsurface. The deepest conductor, previously associated with the Skellefte crustal conductivity anomaly, is imaged in the southern part of the area as a north-dipping feature starting at ∼4 km depth. Several shallow conductors are attributed to graphite in the black shales defining the contact between the metasedimentary rocks and the underlying metavolcanic rocks. Furthermore, an elongated intermediate depth conductor is possibly associated with alteration zones in the metavolcanic rocks that host the ore occurrences. The most prominent crustal resistors occur in the southern and northern part of the area, where their lateral extent on the surface coincides with the late-orogenic Revsund type intrusions. To the east, a resistive feature can be correlated to the early-orogenic Viterliden intrusion. The 3-D model is compared with two previous 2-D inversion models along two perpendicular profiles. The main electrical features are confirmed with the new model and previous uncertainties regarding 3-D effects, caused by off-profile conductors, can be better assessed in 3-D, although the resolution is lower due to a coarser model discretization. The comparison with seismic sections along two north–south profiles reveals structural correspondence between electrical features, zones of different reflectivity and geological units. Text Northern Sweden HighWire Press (Stanford University) Kristineberg ENVELOPE(18.667,18.667,79.483,79.483) Geophysical Journal International 192 2 500 513 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Geomagnetism rock magnetism and palaeomagnetism |
spellingShingle |
Geomagnetism rock magnetism and palaeomagnetism Hübert, Juliane Juanatey, María de los Ángeles García Malehmir, Alireza Tryggvason, Ari Pedersen, Laust B. The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data |
topic_facet |
Geomagnetism rock magnetism and palaeomagnetism |
description |
A 3-D model of the crustal electrical resistivity was constructed from the inversion of magnetotelluric data in the Kristineberg area, Skellefte district, the location of one of Sweden's most successful mining activities. Forward modelling of vertical magnetic transfer data supports our model which was derived from the magnetotelluric impedance only. The dominant features in the 3-D model are the strong conductors at various depth levels and resistive bodies of variable thickness occurring in the shallower subsurface. The deepest conductor, previously associated with the Skellefte crustal conductivity anomaly, is imaged in the southern part of the area as a north-dipping feature starting at ∼4 km depth. Several shallow conductors are attributed to graphite in the black shales defining the contact between the metasedimentary rocks and the underlying metavolcanic rocks. Furthermore, an elongated intermediate depth conductor is possibly associated with alteration zones in the metavolcanic rocks that host the ore occurrences. The most prominent crustal resistors occur in the southern and northern part of the area, where their lateral extent on the surface coincides with the late-orogenic Revsund type intrusions. To the east, a resistive feature can be correlated to the early-orogenic Viterliden intrusion. The 3-D model is compared with two previous 2-D inversion models along two perpendicular profiles. The main electrical features are confirmed with the new model and previous uncertainties regarding 3-D effects, caused by off-profile conductors, can be better assessed in 3-D, although the resolution is lower due to a coarser model discretization. The comparison with seismic sections along two north–south profiles reveals structural correspondence between electrical features, zones of different reflectivity and geological units. |
format |
Text |
author |
Hübert, Juliane Juanatey, María de los Ángeles García Malehmir, Alireza Tryggvason, Ari Pedersen, Laust B. |
author_facet |
Hübert, Juliane Juanatey, María de los Ángeles García Malehmir, Alireza Tryggvason, Ari Pedersen, Laust B. |
author_sort |
Hübert, Juliane |
title |
The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data |
title_short |
The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data |
title_full |
The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data |
title_fullStr |
The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data |
title_full_unstemmed |
The upper crustal 3-D resistivity structure of the Kristineberg area, Skellefte district, northern Sweden revealed by magnetotelluric data |
title_sort |
upper crustal 3-d resistivity structure of the kristineberg area, skellefte district, northern sweden revealed by magnetotelluric data |
publisher |
Oxford University Press |
publishDate |
2013 |
url |
http://gji.oxfordjournals.org/cgi/content/short/192/2/500 https://doi.org/10.1093/gji/ggs044 |
long_lat |
ENVELOPE(18.667,18.667,79.483,79.483) |
geographic |
Kristineberg |
geographic_facet |
Kristineberg |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/192/2/500 http://dx.doi.org/10.1093/gji/ggs044 |
op_rights |
Copyright (C) 2013, Oxford University Press |
op_doi |
https://doi.org/10.1093/gji/ggs044 |
container_title |
Geophysical Journal International |
container_volume |
192 |
container_issue |
2 |
container_start_page |
500 |
op_container_end_page |
513 |
_version_ |
1766147655567671296 |