Magnetic anisotropy reveals Acadian transpressional fabrics in an Appalachian ophiolite (Thetford Mines, Canada)
dc.contributor.author | Di Chiara, A | |
dc.contributor.author | Morris, A | |
dc.contributor.author | Anderson, Mark | |
dc.contributor.author | Menegon, Luca | |
dc.contributor.author | Tremblay, A | |
dc.date.accessioned | 2020-08-25T15:31:24Z | |
dc.date.available | 2020-08-25T15:31:24Z | |
dc.date.issued | 2020-08 | |
dc.identifier.issn | 0956-540X | |
dc.identifier.issn | 1365-246X | |
dc.identifier.uri | http://hdl.handle.net/10026.1/16195 | |
dc.description.abstract |
<jats:title>SUMMARY</jats:title> <jats:p>Magnetic anisotropy has proved effective in characterizing primary, spreading-related magmatic fabrics in Mesozoic (Tethyan) ophiolites, for example in documenting lower oceanic crustal flow. The potential for preservation of primary magnetic fabrics has not been tested, however, in older Palaeozoic ophiolites, where anisotropy may record regional strain during polyphase deformation. Here, we present anisotropy of magnetic susceptibility results from the Ordovician Thetford Mines ophiolite (Canada) that experienced two major phases of post-accretion deformation, during the Taconian and Acadian orogenic events. Magnetic fabrics consistent with modal layering in gabbros are observed at one locality, suggesting that primary fabrics may survive deformation locally in low strain zones. However, at remaining sites rocks with different magmatic origins have consistent magnetic fabrics, reflecting structurally controlled shape preferred orientations of iron-rich phases. Subhorizontal NW-SE-oriented minimum principal susceptibility axes correlate with poles to cleavage observed in overlying post-obduction, pre-Acadian sedimentary formations, indicating that the magnetic foliation in the ophiolite formed during regional NW-SE Acadian shortening. Maximum principal susceptibility axes plunging steeply to the NE are orthogonal to the orientation of regional Acadian fold axes, and are consistent with subvertical tectonic stretching. This magnetic lineation is parallel to the shape preferred orientation of secondary amphibole crystals and is interpreted to reflect grain growth during Acadian dextral transpression. This structural style has been widely reported along the Appalachian orogen, but the magnetic fabric data presented here provide the first evidence for transpression recorded in an Appalachian ophiolite.</jats:p> | |
dc.format.extent | 1034-1045 | |
dc.language | en | |
dc.language.iso | en | |
dc.publisher | Oxford University Press (OUP) | |
dc.subject | Magnetic properties | |
dc.subject | North America | |
dc.subject | Magnetic fabrics and anisotropy | |
dc.subject | Folds and folding | |
dc.title | Magnetic anisotropy reveals Acadian transpressional fabrics in an Appalachian ophiolite (Thetford Mines, Canada) | |
dc.type | journal-article | |
dc.type | Journal Article | |
plymouth.author-url | https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000565896700023&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=11bb513d99f797142bcfeffcc58ea008 | |
plymouth.issue | 2 | |
plymouth.volume | 222 | |
plymouth.publication-status | Published | |
plymouth.journal | Geophysical Journal International | |
dc.identifier.doi | 10.1093/gji/ggaa173 | |
plymouth.organisational-group | /Plymouth | |
plymouth.organisational-group | /Plymouth/Faculty of Science and Engineering | |
plymouth.organisational-group | /Plymouth/Faculty of Science and Engineering/School of Geography, Earth and Environmental Sciences | |
plymouth.organisational-group | /Plymouth/REF 2021 Researchers by UoA | |
plymouth.organisational-group | /Plymouth/REF 2021 Researchers by UoA/UoA07 Earth Systems and Environmental Sciences | |
plymouth.organisational-group | /Plymouth/Research Groups | |
plymouth.organisational-group | /Plymouth/Research Groups/Marine Institute | |
plymouth.organisational-group | /Plymouth/Users by role | |
plymouth.organisational-group | /Plymouth/Users by role/Academics | |
plymouth.organisational-group | /Plymouth/Users by role/Researchers in ResearchFish submission | |
dcterms.dateAccepted | 2020-04-07 | |
dc.rights.embargodate | 2020-8-28 | |
dc.identifier.eissn | 1365-246X | |
dc.rights.embargoperiod | Not known | |
rioxxterms.versionofrecord | 10.1093/gji/ggaa173 | |
rioxxterms.licenseref.uri | http://www.rioxx.net/licenses/all-rights-reserved | |
rioxxterms.licenseref.startdate | 2020-08 | |
rioxxterms.type | Journal Article/Review |