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
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 NICHOLSON, R.
Right arrow Articles by EJIOFOR, I. B.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Journal of the Geological Society; 1987; v. 144; issue.1; p. 79-83;
DOI: 10.1144/gsjgs.144.1.0079
© 1987 Geological Society of London

Article

The three-dimensional morphology of arrays of echelon and sigmoidal, mineral-filled fractures: data from north Cornwall

R. NICHOLSON1 & I. B. EJIOFOR2

1 Department of Geology, University of Manchester, Manchester M13 9PL, UK
2 Geological Survey of Nigeria, P.M.B. 1423, Ilorin, Nigeria

Arrays of mineral-filled, echelon, sigmoidal fractures in cobbles of sandstone from the Crackington Formation of north Cornwall were examined by cutting serial sections. In three dimensions each array consists of a set of blade-like, mineral-filled fractures. These blades project as a fringe from the single but composite fracture that forms through their linkage. Linkage takes place as the strips of rock (bridges) between blades fail through cross-fracture. Cross-fractures give rise to the steps that mark the margins of the composite fractures so formed. Bridges show little penetrative deformation. Arrays are not zones of high ductile strain. Displacement is a consequence of dilatation. Echelon fractures were formed and opened by intruding hydrothermal fluid.




This article has been cited by other articles:


Home page
 Journal of the Geological SocietyHome page
Discussion on the three-dimensional morphology of arrays of echelon and sigmoidal, mineral-filled fractures from north Cornwall
Journal of the Geological Society, 1988; 145: 185 - 187.
[Abstract] [PDF]