1 10 1 https://theses.otagogeology.org.nz/files/original/7f971e7ea11eaa4070d38e1d63d2d4ca.pdf 5cf8ab101baace6e637d3ac176ca3245 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Geology theses OU Geology thesis Thesis or dissertation completed by University of Otago Geology students Location WKT (WGS84) The location stored in WKT (WGS84) format POLYGON ((167.272391025425435 -45.7166744240455,167.401345597718063 -45.725945405317304,167.392192626017447 -45.79337520995994,167.261557277289398 -45.789011287239646,167.272391025425435 -45.7166744240455)) Author last name Last name of the Author Grieve Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Prior, D.J. Scott, James M. Abstract The Abstract for this thesis Emplacement of the Median Batholith along the Gondwana margin has been argued to have resulted through magmatic and tectonic processes. Analysis of the Grebe Mylonite Zone (GMZ) an amphibolite facies Early Cretaceous ductile shear zone, provides new insight into the kinematics, conditions and processes that played a role in its deformation and exhumation. The GMZ forms the boundary between the Outboard Median Batholith and Eastern Province and the Inboard Median Batholith and the Western Province in Fiordland, New Zealand. Three units derived from Darran Suite magmas, (1) meta-diorite, (2) meta-granodiorite and (3) meta-granite dominate the GMZ and exhibit a north striking steeply west dipping foliation and moderately south plunging lineation. The grain boundary migration (GBM) mechanism dominates quartz recrystallisation and is inferred to represent deformation temperatures of ~ 600?C and stresses of 6 to 22 MPa derived from paleopiezometry of recrystallised quartz size. Crystallographic preferred orientation (CPO) data of quartz, plagioclase and hornblende were obtained using electron backscatter diffraction (EBSD). Hornblende [100] a-axes align preferentially perpendicular to foliation with [001] c-axes aligned parallel to lineation, producing an orthorhombic symmetry that provides no information on shear sense. Plagioclase fabrics are sub divided into three groups: [a](c), hybrid-A and hybrid-B, from these fabrics it is interpreted that crystal plastic slip was accommodated on the (001), (010) and the previously unrecognised (011) planes. Weakening of the plagioclase CPO from east to west is thought to indicate a shift towards grain boundary sliding (GBS) diffusion creep deformation mechanisms. Quartz CPOs show predominantly Y-maxima fabrics, [0001] c-axis directions plot within the plane of foliation indicating < a > prism slip at ~ 600?C. Progressive rotation of quartz CPO fabrics towards the west are thought to represent an increasing temperature/strain rate gradient towards the western contact between the GMZ and the Puteketeke Pluton. Interpretation of quartz fabrics indicate an overall regional oblique sinistral west side down sense of motion relative to the Western Province. However, conflicting kinematics are observed between the units of the GMZ, strain partitioning in a dominantly coaxial strain geometry is proposed as the mechanism for the difference in kinematics. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/5983">http://hdl.handle.net/10523/5983</a> OURArchvive access level Open Access Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Grebe Mylonite Zone Jaquiery Stream central Fiordland Thesis description Number of pages, maps, CDs, etc. xvi, 161 pages A4 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Identifier An unambiguous reference to the resource within a given context 2015Grieve Creator An entity primarily responsible for making the resource Grieve, Jason William Date A point or period of time associated with an event in the lifecycle of the resource 2015 Title A name given to the resource Deformation processes, kinematics and conditions of the Grebe Mylonite Zone, Jaquiery Stream, central Fiordland, New Zealand. Subject The topic of the resource Structural Geology Cretaceous Crystallographic Preferred Orientation (CPO) deformation conditions Fiordland mylonite zone plagioclase quartz