Skip to Main Content
Book Chapter

Effects of initial weakness on rift architecture

By
S. Dyksterhuis
S. Dyksterhuis
1
University of Sydney School of Geosciences
,
Baxter Building (H11), University of Sydney
,
NSW 2006
,
Australia
(e-mail: scottd@geosci.usyd.edu.au)
Search for other works by this author on:
P. Rey
P. Rey
1
University of Sydney School of Geosciences
,
Baxter Building (H11), University of Sydney
,
NSW 2006
,
Australia
(e-mail: scottd@geosci.usyd.edu.au)
Search for other works by this author on:
R. D. Müller
R. D. Müller
1
University of Sydney School of Geosciences
,
Baxter Building (H11), University of Sydney
,
NSW 2006
,
Australia
(e-mail: scottd@geosci.usyd.edu.au)
Search for other works by this author on:
L. Moresi
L. Moresi
2
Room 301, Building 28
,
Monash University Clayton Campus
,
Victoria 3800
,
Australia
Search for other works by this author on:
Published:
January 01, 2007

Abstract

Much work has been conducted investigating the primary factors controlling rift architecture, using both computational and laboratory methods. Here, we examine the effects and relative importance that different types of initial weaknesses have on extensional lithospheric deformation style. We find that the type of initial weakness included in the model plays a primary role in determining the subsequent rift mode. Models using single localized weak seeds produce symmetric narrow rifts, irrespective of whether or not strain softening is included, while models that include regions of diffuse weaknesses produce a wide rift mode. Models that include an initial weak fault tend to produce more asymmetric rifting leading to a core complex mode. By distributing the strain laterally over large areas, the ductile lower crust tends to oppose the narrow rift mode forced by the initial weakness. These results suggest that initial weaknesses may play a major role in determining the mode of rifting. Our numerical experiments confirm that low-angle faults can form as the result of rotation of initially high-angle faults. While previous studies have suggested that the rheological and thermal profiles of the lithosphere play the most important role in rift mode determination, our results illustrate that initial weaknesses could play a major role in rift mode determination, highlighting the need to make initial weaknesses a primary consideration when modelling the extensional deformation of the lithosphere.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Imaging, Mapping and Modelling Continental Lithosphere Extension and Breakup

G. D. Karner
G. D. Karner
ExxonMobil Upstream Research Company, Houston, USA
Search for other works by this author on:
G. Manatschal
G. Manatschal
Université Louis Pasteur, Strasbourg, France
Search for other works by this author on:
L. M. Pinheiro
L. M. Pinheiro
Universidade de Aveiro, Aveiro, Portugal
Search for other works by this author on:
Geological Society of London
Volume
282
ISBN electronic:
9781862395305
Publication date:
January 01, 2007

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal