OceanRep
Evolution of Fine‐Scale Segmentation at Intermediate‐Spreading Rate Ridges.
Le Saout, Morgane , Clague, D. A. and Paduan, J. B. (2019) Evolution of Fine‐Scale Segmentation at Intermediate‐Spreading Rate Ridges. Geochemistry, Geophysics, Geosystems, 20 (8). pp. 3841-3860. DOI 10.1029/2019GC008218.
Preview |
Text
Saout_et_al-2019-Geochemistry,_Geophysics,_Geosystems.pdf - Published Version Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works 4.0. Download (4MB) | Preview |
Abstract
Mid‐ocean ridge axes are marked by segmentation of the axes and underlying magmatic systems. Fine‐scale segmentation has mainly been studied along fast‐spreading ridges. Here we offer insight into the third‐ and fourth‐order segmentation of intermediate‐spreading ridges and their temporal evolution. The Alarcón Rise and the Endeavour Segment have similar spreading rates (49 and 52.5 mm/year, respectively) but contrasting morphologies that vary from an axial high with a relatively narrow axial summit trough to an axial valley. One‐meter resolution bathymetry acquired by autonomous underwater vehicles, lava geochemistry, and ages from sediment cores is combined with available seismic reflection profiles to analyze variations in (1) geometry and orientation of the axial summit trough or valley, (2) seafloor depth near the axis, and (3) distribution of hydrothermal vents, (4) lava chemistry, and (5) flow ages between contiguous axes. Along both intermediate‐spreading segments, third‐ and fourth‐order discontinuities and associated segments are similar in dimension to what has been observed along fast‐spreading ridges. The Alarcón Rise and the Endeavour Segment also allow the study of the evolution of fine‐scale segmentation over periods of 300 to 4,000 years. Comparison between old and young axes reveals that the evolution of fine‐scale segmentation depends on the intensity of the magmatic activity. High magmatic periods are associated with rapid evolution of third‐order segments, while low magmatic activity periods, dominated by tectonic deformation and/or hydrothermal activity, are associated with little to no change in segmentation.
Document Type: | Article |
---|---|
Keywords: | mid-ocean ridge, segmentation, intermediate-spreading rate |
Research affiliation: | OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS |
Refereed: | Yes |
Open Access Journal?: | No |
Publisher: | AGU (American Geophysical Union), Wiley |
Date Deposited: | 05 Aug 2019 11:18 |
Last Modified: | 31 Jan 2022 09:18 |
URI: | https://oceanrep.geomar.de/id/eprint/47351 |
Actions (login required)
View Item |
Copyright 2023 | GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel | All rights reserved
Questions, comments and suggestions regarding the GEOMAR repository are welcomed
at bibliotheksleitung@geomar.de !