Channelized lava flows at the East Pacific Rise crest 9°–10°N : the importance of off-axis lava transport in developing the architecture of young oceanic crust
Soule, Samuel A.
Fornari, Daniel J.
Perfit, Michael R.
MetadataShow full item record
Submarine lava flows are the building blocks of young oceanic crust. Lava erupted at the ridge axis is transported across the ridge crest in a manner dictated by the rheology of the lava, the characteristics of the eruption, and the topography it encounters. The resulting lava flows can vary dramatically in form and consequently in their impact on the physical characteristics of the seafloor and the architecture of the upper 50–500 m of the oceanic crust. We have mapped and measured numerous submarine channelized lava flows at the East Pacific Rise (EPR) crest 9°–10°N that reflect the high-effusion-rate and high-flow-velocity end-member of lava eruption and transport at mid-ocean ridges. Channel systems composed of identifiable segments 50–1000 m in length extend up to 3 km from the axial summit trough (AST) and have widths of 10–50 m and depths of 2–3 m. Samples collected within the channels are N-MORB with Mg# indicating eruption from the AST. We produce detailed maps of lava surface morphology across the channel surface from mosaics of digital images that show lineated or flat sheets at the channel center bounded by brecciated lava at the channel margins. Modeled velocity profiles across the channel surface allow us to determine flux through the channels from 0.4 to 4.7 × 103 m3/s, and modeled shear rates help explain the surface morphology variation. We suggest that channelized lava flows are a primary mechanism by which lava accumulates in the off-axis region (1–3 km) and produces the layer 2A thickening that is observed at fast and superfast spreading ridges. In addition, the rapid, high-volume-flux eruptions necessary to produce channelized flows may act as an indicator of the local magma budget along the EPR. We find that high concentrations of channelized lava flows correlate with local, across-axis ridge morphology indicative of an elevated magma budget. Additionally, in locations where channelized flows are located dominantly to the east or west of the AST, the ridge crest is asymmetric, and layer 2A appears to thicken over a greater distance from the AST toward the side of the ridge crest where the channels are located.
Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 6 (2005): Q08005, doi:10.1029/2005GC000912.
Suggested CitationArticle: Soule, Samuel A., Fornari, Daniel J., Perfit, Michael R., "Channelized lava flows at the East Pacific Rise crest 9°–10°N : the importance of off-axis lava transport in developing the architecture of young oceanic crust", Geochemistry Geophysics Geosystems 6 (2005): Q08005, DOI:10.1029/2005GC000912, https://hdl.handle.net/1912/450
Showing items related by title, author, creator and subject.
Geochemistry of fluids from Earth’s deepest ridge-crest hot-springs : Piccard hydrothermal field, Mid-Cayman Rise McDermott, Jill M.; Sylva, Sean P.; Ono, Shuhei; German, Christopher R.; Seewald, Jeffrey S. (Elsevier, 2018-02-13)Hosted in basaltic substrate on the ultra-slow spreading Mid-Cayman Rise, the Piccard hydrothermal field is the deepest currently known seafloor hot-spring (4957–4987 m). Due to its great depth, the Piccard site is an ...
Submeter bathymetric mapping of volcanic and hydrothermal features on the East Pacific Rise crest at 9°50′N Ferrini, Vicki L.; Fornari, Daniel J.; Shank, Timothy M.; Kinsey, James C.; Tivey, Maurice A.; Soule, Samuel A.; Carbotte, Suzanne M.; Whitcomb, Louis L.; Yoerger, Dana R.; Howland, Jonathan C. (American Geophysical Union, 2007-01-19)Recent advances in underwater vehicle navigation and sonar technology now permit detailed mapping of complex seafloor bathymetry found at mid-ocean ridge crests. Imagenex 881 (675 kHz) scanning sonar data collected during ...
Interplay between faults and lava flows in construction of the upper oceanic crust : the East Pacific Rise crest 9°25′–9°58′N Escartin, Javier E.; Soule, Samuel A.; Fornari, Daniel J.; Tivey, Maurice A.; Schouten, Hans A.; Perfit, Michael R. (American Geophysical Union, 2007-06-07)The distribution of faults and fault characteristics along the East Pacific Rise (EPR) crest between 9°25′N and 9°58′N were studied using high-resolution side-scan sonar data and near-bottom bathymetric profiles. The ...