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Initiation of a Proto-transform Fault Prior to Seafloor Spreading

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posted on 14.10.2020 by Finnigan Illsley-Kemp, JM Bull, D Keir, T Gerya, C Pagli, T Gernon, A Ayele, B Goitom, JOS Hammond, JM Kendall
©2018. The Authors. Transform faults are a fundamental tenet of plate tectonics, connecting offset extensional segments of mid-ocean ridges in ocean basins worldwide. The current consensus is that oceanic transform faults initiate after the onset of seafloor spreading. However, this inference has been difficult to test given the lack of direct observations of transform fault formation. Here we integrate evidence from surface faults, geodetic measurements, local seismicity, and numerical modeling of the subaerial Afar continental rift and show that a proto-transform fault is initiating during the final stages of continental breakup. This is the first direct observation of proto-transform fault initiation in a continental rift and sheds unprecedented light on their formation mechanisms. We demonstrate that they can initiate during late-stage continental rifting, earlier in the rifting cycle than previously thought. Future studies of volcanic rifted margins cannot assume that oceanic transform faults initiated after the onset of seafloor spreading.

History

Preferred citation

Illsley-Kemp, F., Bull, J. M., Keir, D., Gerya, T., Pagli, C., Gernon, T., Ayele, A., Goitom, B., Hammond, J. O. S. & Kendall, J. M. (2018). Initiation of a Proto-transform Fault Prior to Seafloor Spreading. Geochemistry, Geophysics, Geosystems, 19(12), 4744-4756. https://doi.org/10.1029/2018GC007947

Journal title

Geochemistry, Geophysics, Geosystems

Volume

19

Issue

12

Publication date

01/12/2018

Pagination

4744-4756

Publisher

American Geophysical Union (AGU)

Publication status

Published

Online publication date

07/12/2018

ISSN

1525-2027

eISSN

1525-2027

Article number

2018GC007947

Language

en

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