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 Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
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 Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Debacker, T.N.
Right arrow Articles by Verniers, J.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Journal of the Geological Society; 2004; v. 161; issue.4; p. 641-652;
DOI: 10.1144/0016-764903-143
© 2004 Geological Society of London

Original Article

Transitional geometries between gently plunging and steeply plunging folds: an example from the Lower Palaeozoic Brabant Massif, Anglo-Brabant deformation belt, Belgium

T.N. Debacker1, M. Sintubin1 & J. Verniers2

1 1Structural Geology and Tectonics Group, Katholieke Universiteit Leuven, Redingenstraat 16, B-3000 Leuven, Belgium (e-mail: timothy.debacker@geo.kuleuven.ac.be)
2 2Laboratory of Palaeontology, Universiteit Gent, Krijgslaan 281, S8, B-9000 Gent, Belgium

Although many studies have dealt with markedly different fold orientations and associated cleavage–fold relationships within individual, single-phase deformed fold belts, there are very few descriptions of possible gradual, transitional fold geometries. The Lower Cambrian steep core of the single-phase deformed Brabant Massif contains steeply plunging, west-facing folds with a Z-shaped asymmetry, whereas the Ordovician–Silurian southern rim consists of gently plunging, upward facing folds. A gradual transition is observed between these end-member orientations, in a NW–SE-trending zone 1–1.5 km wide, in which the folds appear to be strongly curvilinear and locally downward facing. The structural geometries within this transition zone are described in detail and the geometric changes analysed in the light of the fold transition. The strongly variable fold orientations are tentatively attributed to a bulk oblate tectonic strain. The transition zone overlies an aeromagnetic lineament, classically interpreted as a dextral shear zone. The steeply plunging folds, the transition zone and the aeromagnetic lineaments are all attributed to a local dextral transpression, in which deformation is partitioned both vertically and laterally. The results indicate that within zones of heterogeneous transpression, the different deformation domains are not necessarily always fault bounded.


Keywords: Brabant Massif, magnetic anomalies, folds, strain, transpression.




This article has been cited by other articles:


Home page
 Journal of the Geological SocietyHome page
R. Beckers and T.N. Debacker
Influence of slump folds on tectonic folds: an example from the Lower Ordovician of the Anglo-Brabant Deformation Belt (Belgium)
Journal of the Geological Society, 2006; 163: 37 - 46.
[Abstract] [Full Text] [PDF]

Home page
 Geological Society, London, Special PublicationsHome page
T. N. Debacker, P. Robion, and M. Sintubin
The anisotropy of magnetic susceptibility (AMS) in low-grade, cleaved pelitic rocks: influence of cleavage/bedding angle and type and relative orientation of magnetic carriers
Geological Society, London, Special Publications, 2004; 238: 77 - 107.
[Abstract] [PDF]