1 10 3 https://theses.otagogeology.org.nz/files/original/8199aab14f138b54dcfb8693265bde2b.pdf f81ac76ffb59d7629b93a464de823189 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 ((169.359776841146925 -45.259080422426123,169.347242996690483 -45.440877800715739,169.07632715220754 -45.432475295790731,169.088081758988864 -45.250084752184293,169.359776841146925 -45.259080422426123)) Author last name Last name of the Author Stephens Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BAppSci(Hons) Advisers Who supervised/advised this student Craw, D. MacKenzie, D. Abstract The Abstract for this thesis Six structurally controlled gold deposits are hosted within two different structural blocks in the Old Man Range area. The mineralised lodes are hosted in normal faults which cut steeply across the host schistosity. In the East structural block, mineralised faults and the prominent joint set strike northwest and cut steeply across greenschist facies TZ III Caples Terrane schist. In the West structural block, mineralised faults and prominent joint sets strike east-west and cut steeply across upper-greenschist facies TZ IV Wanaka lithologic association schist. These structural blocks are separated by the regional scale Old Man Fault. Orientation of hard rock gold deposits is closely linked to the prominent joints in host schist surrounding the deposits. Mineralised lodes formed along ~1m wide normal fault zones. They are discontinuous but can be traced for up to ~150m, with variable thickness along strike. The lodes comprise brecciated silicified schist and hydrothermal quartz breccia, and minor quartz veins with abundant arsenopyrite. Open cavities with euhedral quartz crystals are common. Euhedral arsenopyrite occurs in quartz and silicified schist clasts within mineralised zones. Gold occurs as micro-particulate blebs in partly oxidised arsenopyrite, and as coarser free grains within quartz, micaceous laminae, micro-faults, and micro-shears within mineralised rock. Hydrothermal alteration is minor, comprises addition of Si, Au and As, and extends only a few centimetres from the mineralised lodes. Mineralisation may have occurred within a few kilometres of the surface during mid-Late Cretaceous extension (~106-101Ma), with estimated formation temperatures between 200-350°C. The mineralised structures within the Old Man Range area are similar to other shallow level, post-metamorphic Otago gold deposits. Magnetic, magnetite bearing greenschist has a high magnetic response and can be successfully mapped using total magnetic intensity surveys over the Old Man Range area. Electromagnetic (EM) surveys can be used successfully to map post-metamorphic faults within the Old Man Range area, where they show up as linear conductive anomalies. These geophysical surveys are a useful tool for geologic mapping. However, there is no direct link between the geophysical features and gold mineralisation within the Old Man Range. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Old Man Range Otago Thesis description Number of pages, maps, CDs, etc. v, 112 pages A4 map in back pocket A1 OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/7295">http://hdl.handle.net/10523/7295</a> OURArchvive access level Open Access 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 2013Stephens Creator An entity primarily responsible for making the resource Stephens, Samuel (Sam) Date A point or period of time associated with an event in the lifecycle of the resource 2013 Title A name given to the resource Characterisation of Gold Mineralisation and Geophysical aided Geologic Mapping in the Old Man Range, Central Otago, New Zealand Subject The topic of the resource Ore Deposits EM gold Magnetics schist veins https://theses.otagogeology.org.nz/files/original/836b0879553f770a469dbcc0284884f4.pdf 49d43ea8529099eef4ced5bf94f48739 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 ((169.288101869000116 -45.370838440999933,169.287778744000093 -45.379511750999939,169.287122315000033 -45.39721381399994,169.232272330000114 -45.395314381999981,169.233145673000081 -45.361102605999974,169.23306948700008 -45.35527187699995,169.233221878000109 -45.354249849999974,169.20389370700002 -45.353068160999953,169.178885690000016 -45.352065107999977,169.180869901000051 -45.312884416999964,169.202671069000075 -45.313607887999979,169.290116838000017 -45.316467666999984,169.288101869000116 -45.370838440999933)) Author last name Last name of the Author McIntyre Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Craw, D. Abstract The Abstract for this thesis Two lithological associations are mapped within a fifty square kilometre area of the Otago Schist, situated on the eastern· flank of the Old Man Range, Central . Otago, New Zealand. The eastern and western lithological associations each have a distinctive outcrop appearance, mineralogy and geochemistry, and have been juxtaposed by the north trending Old Man Fault. Five structural generations are recognised within the schists of the Old Man Range area. The first structural generation involved total greenschist fades metamorphic reconstitution of a variety of sedimentary and volcanic protoliths, accompanied by transposition of bedding parallel to a penetrative schistosity. The second structural generation was associated with the development of a macroscopic nappe within the western lithological association. Segregated and massive greyschists were thrust southward over platy greyschists along the highly strained lower limb of this nappe. Variation in deformation style, rotation of mesoscopic structures, and progressive fabric development are attributed to a finite strain gradient across the nappe. The third structural generation is inferred to be associated with the northward thrusting of the eastern lithological association over the western lithological association. Subsequent faulting out of section by the Old Man Fault prevents detailed mapping of an inferred high strain zone separating the two lithological associations. The fourth structural generation postdated metamorphism, and involved the formation of east trending vertical quartz vein systems with associated localised brittle deformation. Two quartz reefs containing economic concentrations of gold occur in the study area, both hosted in low displacement normal faults. The fifth structural generation followed uplift of the metamorphic pile, and involved near surface brittle deformation of the schist. The Old Man Fault developed prior to the Miocene, most likely as a discrete normal fault, uplifting the western lithological association by at least two kilometres relative to the eastern lithological association. Following the subsequent peneplanation of the schist, and deposition of the Miocene Manuherikia Group, the Old Man Fault was reactivated as a c. one kilometre wide low displacement reverse shear zone. Uplift of the Old Man Range occurred dominantly by flexure of the preMiocene peneplain surface. The eastern and western lithological associations have distinct major and trace element geochemical signatures. Geochemical discriminant diagrams show the eastern and western lithological associations to belong to the Caples and Torlesse terranes respectively. The association of platy greyschists and greenschists, underlying the D2 nappe within the western lithological association, is proposed to be a small exposure of the Aspiring terrane, exposed through uplift and erosion. Geochemical analyses of greenschists indicate they .were ~erive.d from tho;9tic basalts, erupted in a mid ocean ridge or intraplate / tectomc settmg. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Old Man Range Thesis description Number of pages, maps, CDs, etc. 57 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/. Identifier An unambiguous reference to the resource within a given context 1993McIntyre_CL Creator An entity primarily responsible for making the resource McIntyre, Calan. Date A point or period of time associated with an event in the lifecycle of the resource 1993 Title A name given to the resource Old Man Range geology Subject The topic of the resource Structural Geology Metamorphic petrology Alexandra Aspiring Terrane Caples Terrane gold Old Man Range Torlesse Terrane https://theses.otagogeology.org.nz/files/original/006ecb959ca117640469abd2e5e2154f.pdf a0810ae20438b609dc86b5a52f3fc3cd 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 ((169.282590345000017 -45.458336478999968,169.282536356000037 -45.459280576999959,169.282524856000123 -45.459460366999963,169.282495305000111 -45.460022411999944,169.282185535000053 -45.460012597999935,169.164147104000108 -45.457202475999964,169.109240897000063 -45.454464881999968,169.105110935000084 -45.454255616999944,169.011116757000082 -45.450921536999942,168.974504028000069 -45.449600961999977,168.968946740000092 -45.449400734999983,168.869013238000093 -45.445731160999969,168.875109721000058 -45.372194341999943,168.875256578000062 -45.370397502999936,168.875328407000097 -45.369521551999981,168.875681772000121 -45.365222683999946,168.876023160000045 -45.356188563999979,168.876358167000035 -45.352461183999935,168.881775157000106 -45.282071228999939,168.881928583000104 -45.280085393999968,168.881962960000124 -45.279600056999982,168.882933856000022 -45.266474934999962,168.894343970000023 -45.266791579999961,168.899412534000021 -45.266974398999935,168.899628908000068 -45.266982005999978,168.906021220000071 -45.267211060999955,169.176069845000029 -45.277499553999974,169.177531469000087 -45.277538365999931,169.29449176300011 -45.280403413999977,169.289546832000042 -45.370875209999951,169.288860097000111 -45.379541502999984,169.282590345000017 -45.458336478999968)) Author last name Last name of the Author Stirling Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Landis, C.A Norris, R.J. Abstract The Abstract for this thesis The late Cenozoic tectonics and geomorphology of a 700 square kilometre area of remnant peneplain topography comprising the Old Man Range, Obelisk Range and Garvie Mountains, Central Otago, have been investigated. This study combined with existing data from Otago show that the peneplain was originally devoid of significant relief (maximum paleorelief = 500m/10km, in west) and is underlain by a broadly low angle schistosity (c. 0-20°). Tertiary sediments in the area indicate that the peneplain surface has been vertically offset by up to c. 1500 metres. Quartzose Potters Gravels (new name) have a palynologically determined Waipipian maximum age, and were reworked from Manuherikia Group sediments during early uplift of the schist ranges. Mapping has revealed a consistently low angle relationship between schistosity and peneplain attitude, and dominance of distributed deformation (flexure) over fault displacement deformation. Undulations in topography are thus mirrored by equivalent undulations in underlying schistosity, and the study area has been divided into nine fault bounded tectonotopographic blocks (new term). Three fault provinces are also recognised. Tabulation of joint orientations shows D (ESE) sets to dominate in the west and C and D (ENE-ESE) sets to dominate in the east. They are geometrically and genetically related to pre-Cenozoic faults (Nevis-Cardrona and Old Man fault systems, the latter of which does not displace the peneplain significantly), and reactivated according to flexure of blocks. Fold axes of blocks trend north-northeast in the west and north-northwest in the east. Heterogeneous strain distribution is evidenced by variable shortening percentages/axes of blocks and contrasts with bordering tectonic basins. Shortening by folding is calculated through measurement of angular spread of poles to topography and schistosity attitudes on stereonets. Shortening values of 3.1% (schistosity-derived) and 3.8% (peneplain-derived) on an axis 081 are calculated for the study area. The axis is similar to geodetic PHS directions and plate convergence vectors for Central Otago (Blick 1986, Walcott 1978). A transpressional en echelon folding model has been developed with the aid of Surface II graphics and Fourier analysis. Regional peneplain and schistosity-derived values of 1% shortening are calculated in the east (Taieri Ridge area), and up to 26% in the west (Cardrona-Moonlight block). Shortening values are similar to those required by the crustal bending model (Norris 1979). Late Cenozoic bending and rotation is evidenced by a c. 10° northward convergence in schist lineation trend (equivalent to Old Man and Nevis fault convergence). Considerable shortening is indicated by steep schistosity attitudes in west Otago/Northern Southland, where the peneplain is not preserved. Schistosity attitude could be used in late Cenozoic strain analysis outside Otago (e.g. Marlborough schists). Landform studies show the upland peneplain to have suffered minimal degradation in the late Cenozoic. Tors have been formed by erosion of a weathered zone of irregular depth (0 to 10 metre depth at the Potters depression), and are thus genetically inseparable from lower altitude tors. They occur where jointing is well developed (i.e. dependant on degree of flexure) and in areas relatively sheltered from the southwest. XRD analysis of clays from the study area and from Quaternary-late Tertiary sediments in the upper Clutha Valley has constrained kaolinite age as pre dating deposition of the Maori Bottom Formation. Additionally, erosion of the peneplain has been limited to removal of the weathered zone. A degradation rate (3-10 mm/1000 y) is calculated, based on known thicknesses of the weathered zone. This degradation rate is similar to rates determined in tectonically inactive cold temperate and arctic environments. Clay and landform studies could be used for identification of the peneplain surface outside Central Otago. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Old Man Range Garvie Mountains Thesis description Number of pages, maps, CDs, etc. xiv. 179 p., 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/. Identifier An unambiguous reference to the resource within a given context 1988Stirling Creator An entity primarily responsible for making the resource Stirling, MW Date A point or period of time associated with an event in the lifecycle of the resource 1988 Title A name given to the resource Tectonic Geomorphology of the Old Man Range and Garvie Mountains, Central Otago. Subject The topic of the resource Geomorphology Tectonics Fraser River Garvie Mountains Old Man Range Otago Region tectonics