Detailed Analysis of Near Tectonic Features Along the East Pacific Rise at 16 degrees N, Near the Mathematician Hot Spot

Type Article
Date 2018-06
Language English
Author(s) Le Saout M1, 2, Thibaud R.3, Gente Pascal1
Affiliation(s) 1 : CNRS, IUEM, UBS, UBO,Lab Geosci Ocean, Plouzane, France.
2 : Geomar Helmholtz Ctr Ocean Res, Kiel, Germany.
3 : IRENav, Ecole Navale, Brest, France.
Source Journal Of Geophysical Research-solid Earth (2169-9313) (Amer Geophysical Union), 2018-06 , Vol. 123 , N. 6 , P. 4478-4499
DOI 10.1029/2017JB015301
WOS© Times Cited 1
Keyword(s) faulting, dike intrusion, brittle deformation, mid-ocean ridge, East Pacific Rise
Abstract

Spreading processes at the axes of fast spreading ridges are mainly controlled by magmatic activity, whereas tectonic activity dominates further away from the axis. High-resolution near-bottom bathymetry data, photographs, videos, and human observations from submersible surveys are used to develop a detailed tectonic analysis of the 16 degrees N segment of the East Pacific Rise (EPR). These data are used to evaluate how a highly magmatic segment, close to a hot spot, affects the nucleation and evolution of faulting patterns and impacts the evaluation of tectonic strain within 2km of the spreading axis. Our study shows that (1) the growth of tectonic features differs in response to dike intrusion and tectonic extension, (2) the initiation of brittle extension is strongly controlled by the location of the axial magma lens and the development of layer 2A, and (3) the high magmatic budget and the off-axis magma lens in the west part of the plateau do not significantly impact the initiation of brittle extension along the central portion of the 16 degrees N segment. Within the axial summit region, more than 2% of plate separation at 16 degrees N on the EPR is accommodated by brittle extension, as is observed at other EPR segments. The interaction of the Mathematician hot spot with this EPR segment has no significant influence on the initiation of the tectonic deformation, but it does reduce the development of the brittle deformation.

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