Lyell Collection
Journal of the Geological Society
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hounslow, M. W.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Journal of the Geological Society; 1985; v. 142; issue.6; p. 995-1006;
DOI: 10.1144/gsjgs.142.6.0995
© 1985 Geological Society of London

Magnetic fabric arising from paramagnetic phyllosilicate minerals in mudrocks

M. W. Hounslow

Department of Oceanography, Southampton University, University Road, Southampton, UK.

The magnetic fabric of mudrock samples from the Westbury Member of the Penarth Group (Rhaetian), the Blue Lias Formation (Hettangian to Sinemurian) and the Oxford Clay (Callovian to Oxfordian) has been measured, using a high field torque magnetometer. The magnetic susceptibility anisotropy of these mudrocks originates from paramagnetic phyllosilicate minerals, of which the most important is considered to be detrital chlorite. The magnetic fabric preserves both a lineation and a foliation, which are of a primary style. This magnetic fabric is sensitive to the effects of recent weathering, due to the ease with which chlorite is oxidized during weathering. A model is proposed utilizing compaction, to explain the acquisition of this magnetic fabric. This model infers that the magnetic fabric represents, in both degree and direction, a measure of the preferred crystallographic orientation of the paramagnetic phyllosilicate minerals. The magnetic fabric data suggest that the Kmax direction corresponds with the quartz grain long-axis preferred orientation, and therefore may be used as a palaeocurrent indicator as in titanomagnetite-bearing sediments. Evidence is presented to suggest that paramagnetic susceptibility anisotropy may be common in other mudrocks.




This article has been cited by other articles:


Home page
 Journal of the Geological SocietyHome page
G. P. Weedon, G. P. Weedon, A. L. Coe, and R. W. Gallois
Cyclostratigraphy, orbital tuning and inferred productivity for the type Kimmeridge Clay (Late Jurassic), Southern England
Journal of the Geological Society, 2004; 161: 655 - 666.
[Abstract] [Full Text] [PDF]

Home page
 Geological Society, London, Special PublicationsHome page
J. M. Pares
How deformed are weakly deformed mudrocks? Insights from magnetic anisotropy
Geological Society, London, Special Publications, 2004; 238: 191 - 203.
[Abstract] [PDF]

Home page
 Geological Society, London, Special PublicationsHome page
C. Aubourg, C. Klootwijk, and R. J. Korsch
Magnetic fabric constraints on oroclinal bending of the Texas and Coffs Harbour blocks: New England Orogen, eastern Australia
Geological Society, London, Special Publications, 2004; 238: 421 - 445.
[Abstract] [PDF]

Home page
 Clay MineralsHome page
P. DICK and M. BURKHARD
Magnetic anisotropy and X-ray diffraction study of clay minerals in the decollement horizons of the western Helvetic nappes, SW Switzerland
Clay Minerals, 2001; 36: 181 - 196.
[Abstract] [Full Text] [PDF]

Home page
 Journal of the Geological SocietyHome page
E. A. HAILWOOD, R. H. MADDOCK, T. FUNG, and E. H. RUTTER
Palaeomagnetic analysis of fault gouge and dating fault movement, Anglesey, North Wales
Journal of the Geological Society, 1992; 149: 273 - 284.
[Abstract] [PDF]