Skip to Main Content
Book Chapter

Propagating rifts and spreading centers

By
R. N. Hey
R. N. Hey
Search for other works by this author on:
J. M. Sinton
J. M. Sinton
Search for other works by this author on:
F. K. Duennebier
F. K. Duennebier
Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822
Search for other works by this author on:
Published:
January 01, 1989

Abstract

Propagating rifts are extensional plate boundaries that progressively break through rigid lithosphere. If the rifting advances to the sea-floor spreading stage, propagating sea-floor spreading centers follow behind, gradually extending through the rifted lithosphere. The combination of sea-floor spreading and propagation produces a characteristic V-shaped wedge of lithosphere formed at the propagating spreading center, with progressively younger and longer isochrons abutting the pseudofaults that bound this wedge. Figure 1 shows several variations of this geometry.

Although conceptually simple, the propagating rift hypothesis has important implications for both large-scale and fine-scale plate tectonic evolution. It explains: (1) the existence of several classes of structures that are oblique to both relative and absolute plate motion and that previously seemed incompatible with plate tectonic theory; (2) why some continental margins are not parallel to sea-floor isochrons and why some continental drift reconstructions are inaccurate; and (3) the large-scale reorganization of some sea-floor spreading systems, including both the onset and termination of many fracture zones as well as the formation of some transient microplates. The hypothesis provides a mechanistic explanation for the way in which many (if not all) spreading center jumps occur and why they occur in systematic patterns, how spreading centers reorient when the direction of sea-floor spreading changes, and the origin of large areas of sea floor with high petrologic diversity, including the major abyssal ferrobasalt provinces.

You do not currently have access to this article.

Figures & Tables

Contents

DNAG, Geology of North America

The Eastern Pacific Ocean and Hawaii

E. L. Winterer
E. L. Winterer
Scripps Institution of Oceanography La Jolla, California 92093
Search for other works by this author on:
Donald M. Hussong
Donald M. Hussong
University of Hawaii Department of Geology and Geophysics Honolulu, Hawaii 96822
Search for other works by this author on:
Robert W. Decker
Robert W. Decker
4087 Silver Bar Road Mariposa, California 95338
Search for other works by this author on:
Geological Society of America
Volume
N
ISBN electronic:
9780813754659
Publication date:
January 01, 1989

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