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Updated: Oct 11, 2025
06:55
Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
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Thermochemical anomalies in the upper mantle control Gakkel Ridge accretion.
John M O'Connor1,2,3, Wilfried Jokat4,5, Peter J Michael6
1GeoZentrum Nordbayern, University Erlangen-Nürnberg, Schlossgarten 5, 91054, Erlangen, Germany. j.m.oconnor@vu.nl.
Nature Communications
|November 30, 2021
Summary
Seafloor spreading at ultraslow ridges is driven by mantle thermochemical anomalies. New dating reveals steady volcanic spreading in some areas, while others show varied melt supply, correlating with asthenosphere heat.
Area of Science:
- Geology
- Geophysics
- Isotope Geochemistry
Background:
- Seafloor accretion at ultraslow spreading ridges remains poorly understood.
- The primary drivers of seafloor generation at these geological settings are unknown.
Purpose of the Study:
- To investigate the spatial and temporal distribution of volcanic eruptions at the Gakkel Ridge.
- To constrain the driving forces behind seafloor accretion at ultraslow spreading centers.
Main Methods:
- Utilized Argon-40/Argon-39 (40Ar/39Ar) isotopic dating.
- Analyzed mid-ocean ridge basalts from varying distances along the Gakkel Ridge axis.
Main Results:
- Magmatic sections of the Gakkel Ridge exhibit a steady spreading rate of approximately 11.1 ± 0.9 mm/yr.
- Amagmatic sections display a more dispersed melt supply, leading to less defined spreading rates.
- Spreading rate variations and crustal accretion patterns correlate with underlying asthenospheric thermochemical anomalies.
Conclusions:
- Seafloor generation at ultraslow spreading centers is fundamentally influenced by the distribution of thermochemical anomalies in the upper mantle.
- Mantle dynamics play a crucial role in controlling magmatic activity and crustal formation at these ridges.
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