Open AccessPossible mid‐crustal shears at the edge of the London Platform
Author(s) -
Reston T.J.,
Blundell D.J.
Publication year - 1987
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1987.tb04416.x
Subject(s) - geology , crust , extensional definition , reflection (computer programming) , shear zone , upper crust , shear (geology) , structural basin , seismology , orientation (vector space) , geomorphology , geometry , petrology , paleontology , tectonics , mathematics , computer science , programming language
Summary. A reflection survey across part of the southern North Sea has revealed SW‐dipping bands of reflection segments in the midcrust under the edge of the London Platform. The upper limit of each group of reflection segments has been contoured in TWT to give a three dimensional impression of the shape of the features. The shape, position and orientation of these groups, together with the reflection character within each group, suggest that they represent large‐scale extensional, probably dilatant shear zones. It is proposed that they developed at the edge of the North Sea Basin due to relative movement between an undeformed brittle upper crust and a more ductile lower crust which has been stretched towards the basin to the NE. The shears are thus caused by heterogeneous crustal stretching.