1 10 4 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 https://theses.otagogeology.org.nz/files/original/5f2bc6b0db044b3c2745438e4800abf1.pdf 8dadf29da60103db3f920a7405d1c093 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 ((171.141993295569534 -43.765957880366102,171.127225220069732 -43.752018963448187,171.147016256960001 -43.749661629394389,171.164890693597584 -43.756203465908939,171.182954471912808 -43.770189975952796,171.189934449726593 -43.783998554506027,171.166435988809894 -43.786303863846456,171.141993295569534 -43.765957880366102)) Author last name Last name of the Author Fittall Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Campbell, J.D. Abstract The Abstract for this thesis An area lying on the west side of the middle reaches of the Rangitata River is mapped and described. Basement Torlesse terrane rocks,·cretaceous conglomerate and Mount Somers Volcanics, an infaulted block of Tertiary sediments, and Quaternary Glacial outwash and alluvium are all present in the area. The basement Torlesse terrane rocks are subdivided into two facies, massive sandstone facies and siltstone facies for mapping purposes. The massive sandstone facies dominates throughout the area. The massive sandstone facies consists of sequences dominated by thick bedded massive sandstones with interbedded siltstone, occasionally graded, amalgamated and showing water escape structures. The massive sandstones are inferred to be of sediment gravity flow origin, deposited from sandy high density turbidity currents. The siltstone facies is subdivided into laminated siltstone and graded siltstone subfacies. These thin bedded laminated or graded siltstone sequences are treated as mappable where they are more than 10m thick. The siltstone beds are inferred to have been deposited from dilute turbidity currents. Measured sections are interpreted in terms of depositional environment. In terms of a submarine fan model the massive sandstone facies is inferred to be upper mid-fan distributory channel deposits and the siltstone facies interchannel deposits. Mineralogically the sandstones are lithic - arkoses and arkoses. The Torlesse terrane sediments are first cycle erosion products. The detrital mineralogy and the internal structures of quartz grains indicate a volcano-plutonic arc source terrane. Development of cleavage is well documented in these sandstones. A Middle Triassic to Permian-? Carboniferous age range is assigned to these rocks using petrographic trends defined by MacKinnon (1980). Three phases or folding are recognised, an initial macroscopic phase, Which is folded into a subregional isoclinal syncline which in turn is gently folded. An axial planar cleavage is developed in the isoclinal subregional syncline. A regional fault, inferred to have both Rangitata Orogeny and Kaikoura Orogeny movement, passes through the area. The Torlesse terrane basement has been subject to prehnite-pumpellyite facies metamoiphism locally reaching the pumpellyite-actinolite facies. Overlying the Torlesse on an angular unconformity is a lense of conglomerate, inferred to be fluviatile in origin. Overlying this conglomerate and lying directly on the Torlesse terrane basement by onlap, is the Mount Somers Volcanics consisting or a lower sequence of andesitic flows and an upper sequence or rhyolitic flows. Differentiation trends indicate that fractional crystallization was acting on the magma. The large volume or rhyolites and the presence or quartz xenoliths out or equilibrium with the surrounding magma may indicate assimilation or basement rocks as an important process. Xenoliths in the andesite also contain an anomalously Al-rich orthopyroxene. A transgressive sequence or Tertiary sediments is infaulted on the eastern border or the area. A zone of very low sedimentation is present within the upper parts or the Tertiary sequence. Glacial outwash also adhering to the slopes in some places, and alluvium cover the valley floors. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Rangitata Valley Thesis description Number of pages, maps, CDs, etc. 142 leaves : ill., maps ; 30 cm. 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 of the mid Rangitata Valley Creator An entity primarily responsible for making the resource Fittall, Alan Matthew. Date A point or period of time associated with an event in the lifecycle of the resource 1982 Identifier An unambiguous reference to the resource within a given context 1982Fittall Subject The topic of the resource Map Metamorphic geology Sedimentary petrology Quaternary geology Structural geology Cretaceous Torlesse Supergroup https://theses.otagogeology.org.nz/files/original/86891e36a68eaf0e97c3f071505743aa.pdf 8a568051a0d6e510ef7301a7fcf113a4 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 ((171.796770978073795 -42.271332177875628,171.824714226861687 -42.280057280274768,171.820752412595425 -42.286021393864409,171.792424881646554 -42.27714831251911,171.796770978073795 -42.271332177875628)) Author last name Last name of the Author Dickie Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Scott, J.M. Abstract The Abstract for this thesis This study presents the first comprehensive analysis of intrusion-related mineralisation within the Reefton Goldfield. Following field, petrographic, EDS, whole rock, LA-ICP-MS and zircon dating analysis, a number of findings relating to both the role and formation of intrusion-related mineralisation in the Reefton Goldfield have been made. The role of granitic intrusions in relation to orogenic gold mineralisation within the Reefton goldfield, New Zealand, is poorly understood. A porphyritic granitic dike intrudes Greenland Group metasediments in the western limb of a north-trending, tightly folded syncline just west of the economically significant historic Blackwater mine. Abundant sulphide-bearing stockwork veins surrounding the granitoid dike define an alteration zone consisting predominately of pyrite ± chalcopyrite with accessory sphalerite ± molybdenite ± arsenopyrite ± galena ± millerite. While gold has not been observed in the alteration zone, it is above background levels, and plentiful molybdenite could be of economic interest. Analysis of the dike and surrounding alteration halo has elucidated the timing and conditions in which mineralisation occurred. Intrusion-related mineralisation occurred following emplacement of the Blackwater Dike into the shallow crust during the Early Cretaceous (119 Ma U-Pb zircon). Prograde contact metamorphism to of Greenland Group country rock was coeval with solidification of the dike. Crystallisation of the Blackwater Dike, led to the development of an aqueous phase with sufficient ore metals bound with chloride, reduced sulphur and other aqueous species to give rise to base metal deposit. Abundant sulphidation consisting of a variable assemblage of pyrite, molybdenite, chalcopyrite, arsenopyrite, sphalerite, galena, and millerite precipitated in association with propylitic and phyllic alteration of the dike and host rock during retrograde alteration. Zoning of alteration assemblages provide a history for the dike localized mineralisation, as rapid cooling from convection and pH increased from wall rock reactions facilitated bulk sulphide precipitation between ~400-200 oC. Trace element analysis of pyrite from Blackwater Dike and surrounding alteration halo to those associated with shear-related mineralisation, suggests that magmatic hydrothermal fluid associated with the dike is not related to gold mineralisation in the Reefton Goldfield. Mineralisation assemblages from the Blackwater Dike alteration halo suggest that it is not related to gold mineralisation in the broader Reefton Goldfield Shear-related mineralisation has a much greater abundance of trace gold within pyrite grains analysed suggesting magmatic fluids sourced from the Blackwater Dike have little role to play in mineralising gold. However, based on the dispersed high sulphidation seen within the Blackwater Dike alteration halo, magmatic hydrothermal systems may have some role to play in remobilizing gold throughout the Reefton Goldfield. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Westland Reefton South Reefton Goldfield Thesis description Number of pages, maps, CDs, etc. 133p 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 2015Dickie Creator An entity primarily responsible for making the resource Dickie, James Edward, 1991 (Jim) 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 Timing and conditions of mineralisation of the Blackwater Dike, Reefton Goldfield, Westland, New Zealand Subject The topic of the resource Geochemistry Metamorphic geology Metamorphic petrology Mineralogy Ore deposits Alteration chalcopyrite Cretaceous Greenland Group Hydrothermal Intrusion-related mineralisation Molybdenite Porphyry pyrite Reefton goldfield Sulphides Western Province https://theses.otagogeology.org.nz/files/original/983586b0d8910f9b67b10f64a8c409d0.pdf 746b3680a61b724e5bc7f5f2fb9a1f43 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 ((172.939303782259941 -40.790983502930409,172.939164341218628 -40.943526761336635,172.885725859684243 -40.944677912880834,172.885987797226051 -40.79213490241208,172.939303782259941 -40.790983502930409)) Author last name Last name of the Author Borcovsky Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Palin, J.M. Abstract The Abstract for this thesis The Wainui shear zone represents a 400-1400 m thick, 20 km long belt of steeply dipping, wellfoliated granitic and schistose rocks that form the western boundary of the Cretaceous Separation Point Batholith in northwest Nelson. The Separation Point Batholith is granitic in composition and makes up the northern-most portion of the Separation Point Suite, which forms the western edge of the greater Median Batholith. Geological units along the western margin of the Wainui shear zone include the Devonian Rameka Gabbro, Paleozoic Mount Arthur Marble and Pikikiruna Schist, and small granitic plutons of the Separation Point Suite. The shear zone preserves evidence for progressive solid-state deformation and fabric development that generally transcends from the lesser-foliated margins into the centre of the shear zone. Microstructural and mineralogical evidence indicates that the ductile fabrics developed during cooling from a minimum of middle amphibolite facies to greenschist facies conditions. Sense of shear was east-side up and the shear zone is interpreted to have initiated at least soon after crystallisation of the granite batholith as a response to convergence and rapid uplift along the western edge of the Median Batholith. Brittle deformation in the centre of the shear zone and constraints on the maximum amount of uplift that could have occurred during ductile deformation indicate that deformation is likely to have continued to temperatures below the brittle-ductile transition. Several faults and subparallel joint sets through out the Separation Point Batholith at a high angle to the shear zone are suggested to have formed during late Cretaceous extension. Retrogressive metamorphism and fluid-rock interaction coupled with intense leaching of base metal cations during deformation of central shear zone rocks implies a pervasive and mobile fluid phase. Quartz-rich foliated rocks exhibiting the distinctive chromium-nickel trace element signature indicate large syntectonic additions of quartz to the rock, which is also consistent with large volumes of fluid moving through the shear zone. These rocks are interpreted to represent later-stage, lower temperature ductile deformation. Extensive schists and many quartz-rich foliated rocks in the centre of the shear zone exhibit a distinctive trace element signature characterised by elevated nickel and chromium, which cannot have been derived from rocks presently exposed along the shear zone margins. A component to the shear zone is thus required to have been derived from depth and strong evidence suggests that it may be mafic to ultramafic rocks of the Riwaka Complex, which is presently exposed ~25 km south of the main study area. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Nelson northwest Separation Point Wainui Thesis description Number of pages, maps, CDs, etc. iv, 104, vii leaves : col. ill., col. maps ; 30 cm. + 1 folded map in pocket. 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 2004Borcovsky Creator An entity primarily responsible for making the resource Borcovsky, Damien Anatol. Date A point or period of time associated with an event in the lifecycle of the resource 2004 Title A name given to the resource Wainui shear zone geology : investigations into a Cretaceous shear zone on the margin of the Separation Point batholith, northwest Nelson Subject The topic of the resource Structural geology Cretaceous Separation Point batholith