Kinematics and geometry of active detachment faulting beneath the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge

Content Provider	Semantic Scholar
Author	Demartin, Brian J. Sohn, Robert A. Canales, Juan Pablo Humphris, Susan Elizabeth
Copyright Year	2007
Abstract	Newly acquired seismic refraction and microearthquake data from the Trans-Atlantic Geotraverse (TAG) segment of the Mid-Atlantic Ridge at 26°N reveal for the first time the geometry and seismic character of an active oceanic detachment fault. Hypocenters from 19,232 microearthquakes observed during an eight month ocean bottom seismometer deployment form an ∼15-km-long, dome-shaped fault surface that penetrates to depths >7 km below the seafloor on a steeply dipping (∼70°) interface. A tomographic model of compressional-wave velocities demonstrates that lower crustal rocks are being exhumed in the detachment footwall, which appears to roll over to a shallow dip of 20° ± 5° and become aseismic at a depth of ∼3 km. Outboard of the detachment the exhumed lithosphere is deformed by ridge-parallel, antithetical normal faulting. Our results suggest that hydrothermal fluids at the TAG field exploit the detachment fault to extract heat from a region near the crust-mantle interface over long periods of time.
Starting Page	711
Ending Page	714
Page Count	4
File Format	PDF HTM / HTML
Volume Number	35
Alternate Webpage(s)	https://www.ocean.washington.edu/courses/oc410/reading/deMartinetal_Geology_2007.pdf
Alternate Webpage(s)	http://mit.whoi.edu/cms/files/i0091-7613-35-8-711_51737.pdf
Alternate Webpage(s)	https://doi.org/10.1130/G23718A.1
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article