Mapping Tectonic Features Along and Across Axis at the Mid-Atlantic Ridge at 14N
Abstract
Tectonism at mid-ocean ridges provides a primary control on ridge morphology, influences the physical properties of the oceanic crust, and records the relative contribution of magmatic injection to plate separation. Although large-scale faults are visible in ship-based bathymetry, these features originate as small faults and fissures within the axial valley. This study will examine the three-dimensional properties of small scale faults within a slow-spreading mid-ocean ridge segment. We are focused on the Mid-Atlantic Ridge around 14 N, known for hosting distinctive basaltic lavas with high gas concentrations, known as popping rocks. Popping rocks have been recovered between 13N and 14N, the "Popping Rocks" site, on a non-transform offset adjacent to an extinct oceanic core complex. Two research expeditions aboard the R/V Atlantis (AT33-03 in 2016 and AT40-02 in 2018) used the autonomous underwater vehicle Sentry to characterize the geologic setting of the "Popping Rocks" site. Sentry collected high-resolution (one meter) bathymetry in several regions including the non-transform offset "Popping Rocks" site, and three across-axis transects: the magmatic center, a magma-rich to magma-poor transitional zone, and a region adjacent to an extinct oceanic core complex. To quantify the tectonic setting of this slow-spreading segment, we will construct a GIS database of digitized faults and fissures from the Sentry data and use spatial statistics to characterize fault population properties along the segment. The data collected will provide insight into plate kinematics and physical properties of this slow-spreading ridge segment. The digitized tectonic database will be combined with geochemical and geomorphic data to better understand the "Popping Rocks" site. This analysis will also allow use to investigate the style and extent of fault growth in regions of varying magma supplies along axis.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.T33G0496L
- Keywords:
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- 3035 Midocean ridge processes;
- MARINE GEOLOGY AND GEOPHYSICSDE: 8034 Rheology and friction of fault zones;
- STRUCTURAL GEOLOGYDE: 8135 Hydrothermal systems;
- TECTONOPHYSICSDE: 8178 Tectonics and magmatism;
- TECTONOPHYSICS