Show simple item record

dc.contributor.authorWolfson-Schwehr, Monica  Concept link
dc.contributor.authorBoettcher, Margaret S.  Concept link
dc.contributor.authorBehn, Mark D.  Concept link
dc.date.accessioned2017-11-06T19:11:42Z
dc.date.available2018-03-13T08:51:42Z
dc.date.issued2017-09-13
dc.identifier.citationGeochemistry, Geophysics, Geosystems 18 (2017): 3405–3418en_US
dc.identifier.urihttps://hdl.handle.net/1912/9345
dc.descriptionAuthor Posting. © American Geophysical Union, 2017. 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 18 (2017): 3405–3418, doi:10.1002/2017GC006967.en_US
dc.description.abstract3-D finite element simulations are used to calculate thermal structures and mantle flow fields underlying mid-ocean ridge-transform faults (RTFs) composed of two fault segments separated by an orthogonal step over. Using fault lengths and slip rates, we derive an empirical scaling relation for the critical step over length ( inline image), which marks the transition from predominantly horizontal to predominantly vertical mantle flow at the base of the lithosphere under a step over. Using the ratio of step over length (LS) to inline image, we define three degrees of segmentation: first-degree, corresponding to type I step overs ( inline image ≥ 3); second-degree, corresponding to type II step overs (1 ≤  inline image < 3); and third-degree, corresponding to type III step overs ( inline image <1). In first-degree segmentation, thermal structures and mantle upwelling patterns under a step over are similar to those of mature ridges, where normal mid-ocean ridge basalts (MORBs) form. The seismogenic area under first-degree segmentation is characteristic of two, isolated faults. Second-degree segmentation creates pull-apart basins with subdued melt generation, and intratransform spreading centers with enriched MORBs. The seismogenic area of RTFs under second-degree segmentation is greater than that of two isolated faults, but less than that of an unsegmented RTF. Under third-degree segmentation, mantle flow is predominantly horizontal, resulting in little lithospheric thinning and little to no melt generation. The total seismogenic area under third-degree segmentation approaches that of an unsegmented RTF. Our scaling relations characterize the degree of segmentation due to step overs along transform faults and provide insight into RTF frictional processes, seismogenic behavior, and melt transport.en_US
dc.description.sponsorshipNSF Grant Numbers: OCE-1352565, OCE-14-58201; NOAA. Grant Number: NA10NOS4000073; 2011 ExxonMobil Geosciencesen_US
dc.language.isoen_USen_US
dc.publisherJohn Wiley & Sonsen_US
dc.relation.urihttps://doi.org/10.1002/2017GC006967
dc.subjectOceanic transform faulten_US
dc.subjectIntratransform spreading centeren_US
dc.subjectFault segmentationen_US
dc.subjectFault thermal structureen_US
dc.subjectMelt transporten_US
dc.titleThermal segmentation of mid-ocean ridge-transform faultsen_US
dc.typeArticleen_US
dc.description.embargo2018-03-13en_US
dc.identifier.doi10.1002/2017GC006967


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record