Imperial College London
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DrRebeccaBell

Faculty of Engineering, Department of Earth Science & Engineering

Reader in Tectonics
 
 
 
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Contact

 

+44 (0)20 7594 0903rebecca.bell

 
 
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Location

 

2.37aRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Bell:2018:10.1130/G39560.1,
author = {Bell, RE and Duclaux, G and Nixon, CW and Gawthorpe, RL and McNeill, LC},
doi = {10.1130/G39560.1},
journal = {Geology},
pages = {115--118},
title = {High-angle, not low-angle, normal faults dominate early rift extension in the Corinth Rift, central Greece},
url = {http://dx.doi.org/10.1130/G39560.1},
volume = {46},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Low-angle normal faults (LANFs) accommodate extension during late-stage rifting and breakup, but what is more difficult to explain is the existence of LANFs in less-stretched continental rifts. A critical example is the <5 Ma Corinth Rift, central Greece, where microseismicity, the geometry of exposed fault planes, and deep seismically imaged faults have been used to argue for the presence of <30°-dipping normal faults. However, new and reinterpreted data call into question whether LANFs have been influential in controlling the observed rift geometry, which involves (1) exposed steep fault planes, (2) significant uplift of the southern rift margin, (3) time-averaged (tens of thousands to hundreds of thousands of years) uplift-to-subsidence ratios across south coast faults of 1:1–1:2, and (4) north margin subsidence. We test whether slip on a mature LANF can reproduce the long-term (tens of thousands of years) geometry and morphology of the Corinth Rift using a finite-element method, to model the uplift and subsidence fields associated with proposed fault geometries. Models involving LANFs at depth produce very minor coseismic uplift of the south margin, and post-seismic relaxation results in net subsidence. In contrast, models involving steep planar faults to the brittle-ductile transition produce displacement fields involving an uplifted south margin with uplift-to-subsidence ratios of ∼1:2–3, compatible with geological observations. We therefore propose that LANFs cannot have controlled the geometry of the Corinth Rift over time scales of tens of thousands of years. We suggest that although LANFs may become important in the transition to breakup, in areas that have undergone mild stretching, do not have significant magmatic activity, and do not have optimally oriented preexisting low-angle structures, high-angle faulting would be the dominant strain accommodation mechanism in the upper crust during early rifting.
AU  - Bell,RE
AU  - Duclaux,G
AU  - Nixon,CW
AU  - Gawthorpe,RL
AU  - McNeill,LC
DO  - 10.1130/G39560.1
EP  - 118
PY  - 2018///
SN  - 0091-7613
SP  - 115
TI  - High-angle, not low-angle, normal faults dominate early rift extension in the Corinth Rift, central Greece
T2  - Geology
UR  - http://dx.doi.org/10.1130/G39560.1
UR  - https://pubs.geoscienceworld.org/gsa/geology/article/46/2/115/524857/High-angle-not-low-angle-normal-faults-dominate
UR  - http://hdl.handle.net/10044/1/53942
VL  - 46
ER  -
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