Tectonic Transport Directions, Shear Senses and Deformation Temperatures Indicated by Quartz c-Axis Fabrics and Microstructures in a NW-SE Transect across the Moine and Sgurr Beag Thrust Sheets, Caledonian Orogen of Northern Scotland
| dc.contributor.author | Law, Richard D. | en |
| dc.contributor.author | Thigpen, J. Ryan | en |
| dc.contributor.author | Mazza, Sarah E. | en |
| dc.contributor.author | Mako, Calvin A. | en |
| dc.contributor.author | Krabbendam, Maarten | en |
| dc.contributor.author | Spencer, Brandon M. | en |
| dc.contributor.author | Ashley, Kyle T. | en |
| dc.contributor.author | Strachan, Robin A. | en |
| dc.contributor.author | Davis, Ella F. | en |
| dc.date.accessioned | 2021-10-13T12:28:34Z | en |
| dc.date.available | 2021-10-13T12:28:34Z | en |
| dc.date.issued | 2021-09-30 | en |
| dc.date.updated | 2021-10-12T14:18:17Z | en |
| dc.description.abstract | Moine metasedimentary rocks of northern Scotland are characterized by arcuate map patterns of mineral lineations that swing progressively clockwise from orogen-perpendicular E-trending lineations in greenschist facies mylonites above the Moine thrust on the foreland edge of the Caledonian Orogen, to S-trending lineations at higher structural levels and metamorphic grades in the hinterland. Quartz c-axis fabrics measured on a west to east coast transect demonstrate that the lineations developed parallel to the maximum principal extension direction and therefore track the local tectonic transport direction. Microstructures and c-axis fabrics document a progressive change from top to the N shearing in the hinterland to top to the W shearing on the foreland edge. Field relationships indicate that the domain of top to the N shearing was at least 55 km wide before later horizontal shortening on km-scale W-vergent folds that detach on the underlying Moine thrust. Previously published data from the Moine thrust mylonites demonstrate that top to the W shearing had largely ceased by 430 Ma, while preliminary isotopic age data suggest top to the N shearing occurred at ~470–450 Ma. In addition, data from the east coast end of our transect indicate normal-sense top down-SE shearing at close to peak temperatures at ~420 Ma that may be related to the closing stages of Scandian deformation, metamorphism and cooling/exhumation. | en |
| dc.description.version | Published version | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.citation | Law, R.D.; Thigpen, J.R.; Mazza, S.E.; Mako, C.A.; Krabbendam, M.; Spencer, B.M.; Ashley, K.T.; Strachan, R.A.; Davis, E.F. Tectonic Transport Directions, Shear Senses and Deformation Temperatures Indicated by Quartz c-Axis Fabrics and Microstructures in a NW-SE Transect across the Moine and Sgurr Beag Thrust Sheets, Caledonian Orogen of Northern Scotland. Geosciences 2021, 11, 411. | en |
| dc.identifier.doi | https://doi.org/10.3390/geosciences11100411 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/105276 | en |
| dc.language.iso | en | en |
| dc.publisher | MDPI | en |
| dc.rights | Creative Commons Attribution 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | en |
| dc.subject | tectonic transport direction | en |
| dc.subject | shear sense | en |
| dc.subject | deformation temperature | en |
| dc.subject | quartz c-axis fabric | en |
| dc.subject | microstructure | en |
| dc.subject | Caledonian | en |
| dc.subject | Grampian | en |
| dc.subject | Scandian | en |
| dc.subject | Moine thrust | en |
| dc.subject | Sgurr Beag thrust | en |
| dc.title | Tectonic Transport Directions, Shear Senses and Deformation Temperatures Indicated by Quartz c-Axis Fabrics and Microstructures in a NW-SE Transect across the Moine and Sgurr Beag Thrust Sheets, Caledonian Orogen of Northern Scotland | en |
| dc.title.serial | Geosciences | en |
| dc.type | Article - Refereed | en |
| dc.type.dcmitype | Text | en |