1 10 9 https://theses.otagogeology.org.nz/files/original/4cf8d43a4eb126535c97786789553cea.pdf 7304c147774e9250aa0993949ee7e8f7 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 MULTIPOLYGON (((170.01732476684 -46.2522487078296,169.986529340236 -46.2347707468098,170.196091498041 -46.0448322899835,170.233040363231 -46.0582359272952,170.01732476684 -46.2522487078296))) Author last name Last name of the Author Taylor-Silva Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Stirling, M.W. Abstract The Abstract for this thesis My thesis documents the first-ever paleoseismic trench investigation of the Akatore Fault, which has long been considered the most active fault to exist near Dunedin City. Two trenches were excavated across the fault in order to investigate the late Quaternary activity (timing, magnitude and recurrence of large ground rupturing earthquakes). Trenching investigations at Big Creek and Rocky Valley have concluded that there have been three ground-rupturing earthquakes in the Holocene. An antepenultimate event has been constrained between 10,400 ± 1,700 and 1,326 ± 22 cal. yr BP, while, the penultimate and most recent events have been constrained between 1,326 ± 22 and 776 ± 22 cal. yr BP. These events resulted in 5 m of dip slip, hence 1 - 2 m of surface displacement per event, which may to have produced earthquakes with moment magnitudes 6.8 - 7.4. Further studies at Taieri Mouth provided information on the longer term behaviour of the Akatore Fault. We estimated only 2 – 3 m of scarp development since the 125 ka marine terrace was formed. Since the Big Creek trench results indicated similar displacements achieved over three Holocene earthquakes, it is plausible that the scarp development has happened by way of these same three Holocene events. This would imply that there has been no activity along the Akatore Fault for a long period prior to these Holocene events i.e. little to no movement between 125,000 – 10,000 cal. yr BP. Furthermore, the Holocene slip rate along the Akatore Fault is significantly greater than the long term slip rate. This suggests the fault does not act in a characteristic fashion. It has an episodic / irregular behaviour. Similar behaviours have been determined for other Otago faults, which is problematic for forecasting future earthquakes. If inception of uplift along the Akatore Fault occurred ~1 Ma, the implied long-term slip rate is such that the fault may not yet have slipped enough in these Holocene events to accommodate the accumulated slip over the previous ~110 ka. The Akatore Fault needs to become the focus of a time-dependent seismic hazard calculation for Dunedin. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/7488">http://hdl.handle.net/10523/7488</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. Taieri Mouth East Otago Thesis description Number of pages, maps, CDs, etc. 184 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 2017Taylor-Silva Creator An entity primarily responsible for making the resource Taylor-Silva, Briar Date A point or period of time associated with an event in the lifecycle of the resource 2017 Title A name given to the resource Akatore Fault; Reverse Fault; Fault Trenching; Holocene; Paleoseismology; East Otago; New Zealand Subject The topic of the resource Earthquake Geology Akatore Fault east Otago Fault Trenching Holocene New Zealand Paleoseismology Reverse Fault https://theses.otagogeology.org.nz/files/original/f06af3fa489d98e689bbd57592507e2c.pdf 7da04b88a3e927c999f189bc9e6a4bb7 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 MULTIPOLYGON (((166.864244699598 -46.2818901015963,166.50238372477 -46.2046502717622,166.297096151373 -45.6925382954109,166.90887147674 -45.0338320586348,167.485457196099 -44.6611856168889,167.635745604886 -44.8041266891201,167.675419267766 -44.9179322489729,167.022808338807 -45.802921724531,166.864244699598 -46.2818901015963))) Author last name Last name of the Author Hinojosa Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PhD Advisers Who supervised/advised this student Moy, C. Stirling, C. Wilson, G.S. Abstract The Abstract for this thesis The mid-latitude westerly winds are a strong, zonally symmetric atmospheric circulation feature in the Southern Hemisphere that directly influence climate and carbon cycling in the middle to high latitudes. In order to forecast potential future changes in the Southern Hemisphere westerly winds (SHWW), which would in turn affect regional and global climate, a better understanding of the past variability of the circulation system and associated climate responses is critical. Fiordland, New Zealand (44.5-46.5 degrees S) is a promising but understudied site for reconstructing SHWW variability, located at the northern edge of the modern wind field maximum. Fourteen E-W-oriented fjords sit windward of the Southern Alps mountain range, which intercepts the incoming SHWW. The resulting extreme orographic precipitation (>6 m/yr) delivers large amounts of terrestrial material to semi-restricted, rapidly accumulating fjord basins. Due to the strong correspondence between SHWW strength and regional precipitation, proxies that reconstruct past precipitation changes should effectively capture SHWW variability. The SHWW also drive the estuarine circulation patterns in the fjords, thus proxies for circulation changes will also provide information on past SHWW strength at this latitude. While a suite of proxies related to precipitation patterns and water column circulation exist, many are influenced by a multitude of factors. Thus, each system must be calibrated in a modern setting to test our conceptual understanding of these tools. I present a thorough modern investigation of proxies for precipitation (concentrations and isotopes of carbon and nitrogen and lipid biomarker distributions), which display predictable behavior in modern fjord sediments. Namely, more terrestrial material is located near fjord heads, and more marine material accumulates near fjord mouths. Additionally, restricted inner basins that are intermittently anoxic are enriched in redox-sensitive trace metals, providing a useful tool for reconstructing past water mass restriction. I demonstrate that the long-term primary control on changes in precipitation and circulation proxies is likely to be shifts in the SHWW rather than other local factors. I further investigate modern circulation processes through radiocarbon cycling in the fjords. The modern marine radiocarbon reservoir age, reconstructed using paired terrestrial and marine macrofossils, is 59 +/- 35 years older than the global modeled reservoir age. In contrast, four reservoir age estimates from throughout the Holocene are younger than the global modeled average. This result suggests that the westerly influence on circulation and delivery of radiocarbon-enriched (i.e., younger) terrestrial material was stronger during the early Holocene, and has potentially decreased in the past millennium. I also demonstrate the unclear signal of the emerging uranium "stable" isotope redox proxy in fjord waters and sediments. Surprisingly, no redox-driven isotopic fractionation is measured in an anoxic water column, and two euxinic basins show fractionation in opposing directions. This result calls into question the assumed fractionation factor between seawater and sediments in anoxic settings, which has been applied in global reconstructions of past ocean oxygenation. Using the modern process studies to guide interpretation and further develop conceptual models, a suite of carefully selected proxies is applied to a sediment core recovered from Deep Cove. The basin has the highest measured carbon accumulation rates in all of Fiordland and provides an unprecedented opportunity to generate a highly resolved record of SHWW change in southwest New Zealand over the last 1,600 years. I find several sub-centennial scale intervals of regional SHWW strength fluctuations. I show that the Deep Cove record agrees well with an existing SHWW reconstruction from Fiordland, but conflicts with others from across the Pacific basin. This comparison highlights the regional variability of the SHWW belt, which, until recently, has been largely overlooked. Further constraints on the asymmetries in wind strength and position are crucial to better forecast the linkages between the SHWW and regional and global climate. OURArchvive access level Abstract Only Department The department where the student is studying primarily. Marine Science Named locality Named locality describing the field area location. Fiordland Thesis description Number of pages, maps, CDs, etc. 251 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 2015Hinojosa Creator An entity primarily responsible for making the resource Hinojosa, Jessica 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 Records of Holocene Southern Hemisphere westerly wind variability in Fiordland, New Zealand Subject The topic of the resource Paleoclimatology Carbon cycling Carbon isotopes Fiordland geochemistry Holocene New Zealand paleoclimate Redox southern hemisphere westerly winds Trace Elements Uranium isotopes https://theses.otagogeology.org.nz/files/original/ddfcab279ab935f3e5fcaded46ef5435.pdf 51d665e1aae6333e6fe6411fd786ea3b 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 MULTIPOLYGON (((165.976317813083085 -50.816368128758739,165.9617005098346 -50.816368128758739,165.960274431468889 -50.804847948576821,165.976317813083085 -50.804847948576821,165.976317813083085 -50.816368128758739)),((166.158618164164665 -50.620665631108764,166.136632789360277 -50.650896937837622,166.11583581319374 -50.650519167153725,166.130096596850734 -50.619909597957836,166.158618164164665 -50.620665631108764))) Author last name Last name of the Author Curtin Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Moy, C. Abstract The Abstract for this thesis The Southern Hemisphere Westerly Winds (SHWW) are one of the primary controllers of air-ocean CO2 flux in the Southern Ocean. As the winds shift poleward and intensify with an increasingly positive Southern Annular Mode (SAM), upwelling of CO2-rich deep ocean water is enhanced, and the ocean's role in reducing the rate at which anthropogenic CO2 accumulates in the atmosphere is diminished. Furthermore, the strength and latitudinal position of the SHWW control storm tracks in the Southern Hemisphere and directly influence precipitation patterns in the South Island of New Zealand and throughout the Southern Hemisphere mid-latitudes. Despite their global significance, past variability of the SHWW is poorly understood. There are few terrestrial paleoclimate records of past SHWW variability, particularly at Sub-Antarctic latitudes where landmasses are scarce and the modern westerly maximum is located. Lake sediment cores from the Auckland Islands (50 deg S) provide an opportunity to study Holocene SHWW variability in this crucial gap. A high-resolution record of environmental change on the Auckland Islands over the last 550 years has been compiled from short sediment cores from three lakes using multiple physical and geochemical methods. The sediments collected are diatom- and plant macrofossil-rich and contain no carbonate. Down-core variations in the bulk sediment C/N ratio, magnetic susceptibility, and n-alkane distributions show an increase in terrestrial components of the sediment at about 300 years BP, while an overall decrease in the biogenic silica component of the sediment reveals a decline in lake productivity. These changes are indicative of an increase in precipitation causing additional influx of terrestrial material from the watershed and increased wind-driven mixing of the lake water column during a period of stronger westerly flow. Observed changes are broadly correlated with shifts in the SAM index as reconstructed by Abram et al. (2014). The dD of the C29 n-alkanes in modern lake sediment obtained from core tops appears to reflect local mean annual precipitation dD, and can potentially be applied as a proxy for the isotopic composition of precipitation, which likely reflects middle to high latitude temperature change and changes in the precipitation source region. When this record is compared to records from the South Island of New Zealand, wind strength appears to have an anti-phase relationship to that inferred in other studies, suggesting that the changes at the Auckland Islands may be due, in part, to latitudinal shifts in the westerly maximum, and not just changes in strength. Longer sediment cores from lakes on the Auckland Islands have the potential to produce high-resolution and continuous records of wind strength and temperature change throughout the Holocene, which will provide a useful comparison to records from the South Island and across the Southern Hemisphere for constructing new regional perspectives of Holocene shifts in the SHWW. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/5789">http://hdl.handle.net/10523/5789</a> OURArchvive access level Abstract Only Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Auckland Islands Thesis description Number of pages, maps, CDs, etc. xiv, 133 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 2015Curtin Creator An entity primarily responsible for making the resource Curtin, Lorelei 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 Geochemistry of Auckland Island Lake Sediments: Assessing Recent Sub-Antarctic Climate Change Subject The topic of the resource Paleoclimatology alkane Auckland Islands geochemistry Holocene lake paleoclimate Southern Hemisphere westerly winds https://theses.otagogeology.org.nz/files/original/e1564af56bb1da23663c128f07a854cc.pdf 9975c712a70fea1a3c6d55f8c1556aa8 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 ((166.09450405764008 -50.735365204086285,166.145902298737013 -50.728765734472937,166.150358793629806 -50.738193262052967,166.103417047425665 -50.745733910616764,166.09450405764008 -50.735365204086285)) Author last name Last name of the Author Browne Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Moy, C. Wilson, G.S. Abstract The Abstract for this thesis The Southern Hemisphere westerly winds (SHWW) play a major role in controlling wind-induced upwelling of Circumpolar Deep Water and outgassing of CO₂ in the Southern Ocean, on interannual to glacial-interglacial timescales. Despite their importance, our understanding of millennial-scale changes in the strength and latitudinal position of the SHWW during the Holocene is limited by few paleoclimate records from sensitive regions, that are often not in agreement, especially after 5,000 yr BP. Paleoclimate records from the Southern Hemisphere mid-latitudes utilise the strong positive correlation between precipitation and wind speed to track changes in the SHWW field over the Holocene. Sediment cores recovered from fjords located in the modern core of the westerly wind belt, along the eastern margin of the subantarctic Auckland Islands (51°S, 166°E) are ideally located to reconstruct changes in westerly wind-derived precipitation. Here, drainage basin and fjord responses to variability in the strength and position of the SHWW are reconstructed from bulk organic δ¹⁵N, and the δ¹⁸O and paleoecology of benthic foraminifera, which monitor the influx of terrestrial organic matter (OMterr) and changes in salinity, respectively. The response of these proxies to strengthened winds is informed by modern fjord process studies, which reveal that increased delivery of OMterr and lowered salinity (as a result of wind-induced mixing of fjord waters) occurs during high winds in Hanfield Inlet. Holocene benthic assemblages from Hanfield Inlet are dominated by Nonionellina flemingi, with subdominant Cassidulina carinata and Quinqueloculina seminula. Species-specific vital offsets from equilibrium for stable carbon and oxygen isotopic composition (Δδ¹³C and Δδ¹⁸O) of foraminiferal calcite are reported here for five species. The first record for New Zealand endemic N. flemingi is provided, where Δδ¹³C is -2.63 ±0.59‰ and Δδ¹⁸O is +0.73 ±0.32‰. Epifaunal Cibicides spp. consistently precipitates both carbon and oxygen isotopes in near equilibrium with ambient bottom water, and is considered the most reliable recorder of fjord water δ¹³CDIC and δ¹⁸O. Because infaunal N. flemingi shows consistent downcore offsets of δ¹⁸O relative to Cibicides spp., it is used in paleoceanographic reconstructions of fjord water salinity downcore. Downcore multiproxy reconstructions reveal evidence for millennial-scale westerly wind variability, a general strengthening of westerlies over the past 5,000 years, and consistently strong winds from 2,000 to 500 yr BP at the Auckland Islands. Comparison with contemporaneous paleoclimate records from southern South America suggests that SHWW were zonally symmetric across the Pacific south of 50 degrees S, with multi-millennial scale strengthening of the westerlies since 2,000 yr BP, and a poleward shift from 800 to 500 yr BP. Concomitant increases in benthic foraminiferal δ¹³C of epifaunal Cibicides spp. and the bulk sediment δ¹³C since 2,000 yr BP may be associated with increased δ¹³CDIC of oceanic water external to the fjord. This may reflect increased rates of air-sea CO₂ exchange, related to increased westerly wind speeds over the Southern Ocean. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/5933">http://hdl.handle.net/10523/5933</a> OURArchvive access level Abstract Only Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Auckland Islands Thesis description Number of pages, maps, CDs, etc. xvii, 187 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 2015Browne Creator An entity primarily responsible for making the resource Browne, Imogen Mireille (Imogen) 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 A Holocene Paleoclimatic Record of Westerly Wind Variability from the Subantarctic Auckland Islands, New Zealand Subject The topic of the resource Paleoclimatology Auckland Islands Foraminifera Holocene New Zealand paleoceanography paleoclimate stable isotopes Sub-Antarctic subantarctic westerlies westerly winds https://theses.otagogeology.org.nz/files/original/d3fc6493a25094a8fc4ad66f3586ab27.pdf fd6fbacdc75d5de676eb34208efa777d 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 MULTIPOLYGON (((165.459024571345026 -78.260975887577573,165.930153403187717 -78.275458748374291,165.880470623272714 -78.384796163202211,165.32149895585971 -78.358351090289432,165.459024571345026 -78.260975887577573)),((163.391037909385147 -78.228595263547234,163.887357474306356 -78.243236626491793,163.784154488444841 -78.350120025240315,163.240067291074126 -78.322582660464377,163.391037909385147 -78.228595263547234)),((159.226884147374847 -78.499508349075626,159.985105885787448 -78.550457251856272,159.699927940592261 -78.766278258193182,158.840943766587714 -78.705339607664101,159.226884147374847 -78.499508349075626))) Author last name Last name of the Author Anderson Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Wilson, G.S. Abstract The Abstract for this thesis Retreat of the Antarctic ice sheets since the Last Glacial Maximum (LGM) has been associated with sea-level rise and ocean warming on the ice sheet margins, but the significance and relative contribution to eustatic sea-level rise since this time has been difficult to quantify. This thesis presents new constraints for the timing and retreat of the Skelton Glacier in the Ross Embayment and grounded ice in the Ross Sea, the Ross Sea Ice Sheet (RSIS). Using two nunataks, Escalade and Tate peaks as a gauge for past ice sheet levels, glacial geologic evidence and ¹⁰Be and ²⁶Al cosmogenic-nuclide exposure ages provide new and direct constraints on the past extent and timing of retreat of the Skelton Névé over the Late Quaternary. Glacial geological and geochronological evidence from Escalade and Tate peaks show that between 288 ka and 40.3 ka, the ice surface experienced slow deflation, lowering from ≥1431 to 1363 metres above sea level (masl). Ice in the southern Skelton Névé lowered by ~50 m between 40.3 ka and ~13.6 ka. Records from the eastern margin of Escalade Peak indicate the ice surface of the Skelton Névé was between 50 and 106 m higher than present during the LGM. The ice surface elevation remained close to its maximum ice level prior to 17.2 ka and has thinned by at least 50 m to the present-day level since ~13.6 ka. Thinning continued after 8.7 ka, and likely reached the present-day ice level ~2 - 3 ka. This lateglacial-Holocene ice-surface lowering is asynchronous from other sites in the Transantarctic Mountains where increased snow accumulation has been reported to have caused thickening up glacier in the early to mid-Holocene. ¹⁰Be exposure ages from large (>1 m) boulders in southern McMurdo Sound show that the RSIS had an ice surface elevation ~520 masl on the eastern side of Mount Discovery during the LGM and the onset of deglaciation was ~13.1 ka. The ice surface lowered from ~520 to 234 masl between 13.6 ka and 9.3 ka; and from 234 masl to the present ice shelf between 9.3 ka and 6.6 ka. This late-glacial and Holocene chronology from southern McMurdo Sound is consistent with other records in the Ross Embayment, and implies the RSIS experienced rapid retreat during the early to middle Holocene. These results suggest that the majority of ice sheet thinning and retreat in the Skelton Névé and in southern McMurdo Sound began just after meltwater pulse 1A (MWP-1A), a period of abrupt sea-level rise of up to 20 m that occurred between ~14.7 ka and 14.3 ka. Thus, it is unlikely that the RSIS and outlet glaciers from the East Antarctic Ice Sheet (EAIS) that drain into the Ross Embayment made a significant contribution to eustatic sea-level rise at this time. From the distribution and petrography of glacial deposits and the retreat chronology in southern McMurdo Sound a two-stage ice flow model for McMurdo Sound was reconstructed: (1) Prior to ~18 ka an expanded Koettlitz Glacier lobe of ice owed north and northeast through the Brown Saddle during the LGM and coalesced with northward owing ice from the Ross Sea. (2) Retreat of the Koettlitz Glacier and perhaps other outlet glaciers then accommodated westward and northward ice flow north of Brown Peninsula, fed from grounded ice in the Ross Sea. These findings reveal that components of both the EAIS and West Antarctic Ice Sheet (WAIS) that drained into the Ross Sea contributed to lateglacial-Holocene sea-level rise. However, it is likely to be in response to warming of the Southern Ocean and sea-level rise from the retreat of the Northern Hemisphere ice sheets and the outer margins of the Antarctic. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/5613">http://hdl.handle.net/10523/5613</a> OURArchvive access level Abstract Only Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Antarctica McMurdo Sound Ross Sea Thesis description Number of pages, maps, CDs, etc. xii, 215 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 2015Anderson Creator An entity primarily responsible for making the resource Anderson, Jacob Thomas Herd (Jacob) 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 Late Quaternary ice sheet thinning and retreat in southern Victoria Land, Antarctica Subject The topic of the resource Paleoclimatology Antarctica Exposure dating Holocene Last Glacial Maximum McMurdo Sound Ross Sea Skelton Glacier https://theses.otagogeology.org.nz/files/original/729bc8f856bc2972df381425d44f9bb3.pdf 487485504695e8b5f0115beac8325460 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 ((166.091533061044828 -50.734988116718661,166.162539879670106 -50.722165330054374,166.174423866050915 -50.71990211904938,166.181257158219893 -50.733291185792147,166.109061940956565 -50.748184358540186,166.091533061044828 -50.734988116718661)) Author last name Last name of the Author Einvik-Heitmann Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PGDipSci Advisers Who supervised/advised this student Moy, C. Ohneiser, C. Abstract The Abstract for this thesis A sediment core (14PL001 – 39P4), collected from the Hanfield Inlet on the subantarctic Island of Auckland Island by a scientific research group from the University of Otago, have been subject to an environmental magnetic study by the use of u-channel samples. Lithostratigraphic analyses was carried out on the core, which contain the transition from a lacustrine environment to a marine environment through an inter-bedded sequence which was correlated to regional sea-level curves, indicating a date of ~8ka. High-resolution magnetic measurements of natural remanent magnetisation intensity, anhysteric remanent magnetisation intensity and magnetic susceptibility, and a stepwise alternating field demagnetisation were performed on the u-channels. Declination, inclination and median destructive field were determined throughout the core by the use of a principal component analysis of orthogonal component vectors. Chemical alteration of titanomagnetites and authigenic growth of pyrrhotite and greigite dominated a larger interval, complicating environmental interpretations. Magnetic mineralogy were therefore further investigated on sub samples by measuring thermomagnetic behaviour and isothermal remanent magnetisation together with energy dispersive spectroscopy. A proxy sensitive to magnetic grain size changes, related to the Holocene westerly wind variability was developed by plotting the measurements of the anhysteric remanent magnetisation intensity on the magnetic susceptibility measurements. The proxy together with sedimentary and mineralogical observations support the suggested pattern of a strong core in the westerly winds for the early Holocene, succeeded by a weak core for the late Holocene. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Hanfield Inlet Auckland Islands Thesis description Number of pages, maps, CDs, etc. 86 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 2014Einvik-Heitmann Creator An entity primarily responsible for making the resource Einvik-Heitmann, Vegar Date A point or period of time associated with an event in the lifecycle of the resource 2014 Title A name given to the resource Unravelling the Secrets of the Subantarctic Auckland Island Inlets: An Environmental Magnetic Study of a Holocene Sediment Core Subject The topic of the resource Paleoclimatology 14PL001-39P4 Environmental magnetism Holocene paleomagnetism sediment core https://theses.otagogeology.org.nz/files/original/e44119c5af3c8692ab037f4ed98e5de6.pdf 85226151c74753a6a99f83d1de16029c 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 ((167.259646746856504 -46.415309077940364,166.431061125963225 -46.318139174598308,166.302882524695576 -45.734238362985522,166.441027862000425 -45.251626457190071,168.349307731852775 -43.835503326968364,168.699644889412497 -43.99693269196635,168.225698016450963 -44.79742736703777,167.259646746856504 -46.415309077940364)) Author last name Last name of the Author Dlabola Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Wilson, G.S. Gorman, A.R. Abstract The Abstract for this thesis During the sea level lowstand of the Last Glacial Maximum, the entrance sills of the New Zealand fiords were above sea level. With de-glacial onset, stranded lakes developed behind the sills in the fiord basins, and as sea level rose, basins were flooded with marine water. The fiords are an example of ingression basins, which are a useful method for studying sea level rise because chronology and sea level elevation data are readily available. The impounding entrance sill is used to track the marine incursion into the basin, where sediment contains a dateable record of the lacustrine to marine transition. A wide range of paleo-sea level magnitudes are possible to find in Fiordland because the sill depths range from -30m to -120 m. Using seismic data and sediment cores obtained in Fiordland on three cruises, the marine incursion is identified in seven fiords. In three of these fiords, six sediment cores reveal paleoenvironmental change from non-marine to marine using sedimentary facies analysis. Combining physical properties, visual observations, and microfossil assemblages, five sedimentary facies are identified. The vertical stacking of the sedimentary facies allows four fiord facies models to be developed. The facies models are then used to constrain the marine incursion and construct a relative sea level curve where chronology is compiled with radiocarbon dating. As a mid-latitude, far-field site in the Southern Hemisphere, a sea level curve from New Zealand is a valuable record from a location where only a few sea level records exist. A relative sea level curve is constructed for Fiordland from -107m 14.9-14.2 ka to -43m 8.5-8.0 ka in a stepwise transgression. No direct evidence of Meltwater Pulse 1a is confirmed, but a pulse of sea level rise (at least 5 m) between 11.7-11.4 ka is identified as Meltwater Pulse 1b. Compared with other New Zealand sea level records, another pulse of sea level rise is identified between 9.8 and 7.0 ka culminating in the modern stillstand. The Fiordland curve is compared with global records to resolve the Southern Hemisphere as the dominant source of meltwater from 14-12 ka during the Antarctic Cold Reversal. Subsequently, the Northern Hemisphere was the main meltwater source from 10-7 ka. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/5024">http://hdl.handle.net/10523/5024</a> OURArchvive access level Open Access Department The department where the student is studying primarily. Marine Science Geology Named locality Named locality describing the field area location. Fiordland 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 2014Dlabola Creator An entity primarily responsible for making the resource Dlabola, Erin Date A point or period of time associated with an event in the lifecycle of the resource 2014 Title A name given to the resource A post-glacial relative sea level curve for Fiordland, New Zealand Subject The topic of the resource Paleoclimatology de-glaciation Fiordland Holocene late Pleistocene New Zealand sea level rise https://theses.otagogeology.org.nz/files/original/48678091fab8042ff201e1d75ee8ff8b.pdf 8a1d6b0518b6680daded62740f6ec017 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 ((168.263441052158385 -45.213781319153199,168.352476411048542 -45.216970924046329,168.341172263764321 -45.272718178665322,168.256005382413235 -45.270633592081893,168.263441052158385 -45.213781319153199)) Author last name Last name of the Author Anderson Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Moy, C. Abstract The Abstract for this thesis The Southern Hemisphere westerly winds (SHWW) control the amount and distribution of precipitation in the southern mid latitudes and is a key component in the global climate system, yet little is known about how the SHWW has varied in the past. Understanding past variability is crucial to evaluating present and future general circulation models forecasting Southern Hemisphere climate change. Lake Von is a topographically closed lake in southern central Otago situated in the rainshadow of the Southern Alps and is ideally located for reconstructing late Pleistocene and Holocene variability in hydrologic change. A multi-­‐proxy approach incorporating bulk sedimentary organic carbon and nitrogen stable isotopes and concentrations, terrestrial and lacustrine derived biomarkers, and sediment physical properties were measured on multiple sediment cores obtained from the lake. A radiocarbon chronology consisting of 10 dates was applied to the Lake Von composite stratigraphy and produced an age model spanning the last 17,600 years. The age model and down-­‐core geochemical and physical properties were combined to define four hydrologically distinct periods. A deglacial period from 17,600 to 14,500 cal yr BP is characterised by high δ13C and magnetic susceptibility, as sediment transitions from grey inorganic silts to brown organic rich sediments. Relatively low δ13C, δD and the low abundance of green algae biomarkers were observed from 14,500 to 8,500 cal yr BP and is inferred to be a period of low productivity and increased precipitation caused by an intensification and/or equator-­‐ward shift of the SHWW. At 8,500 cal yr Bp an abrupt shift to relatively higher δ13C, δD, and higher abundance of aquatic algae biomarkers occurs, which continues to 4,000 cal yr BP inferring a more productive system driven by warmer summer temperatures that were perhaps driven by increasing summer insolation. From ~4,000 cal yr BP to present, enhanced hydrologic variability is interpreted from all proxies is likely related to increased El-­‐Niño Southern Oscillation variability in the eastern equatorial Pacific. These results are broadly similar to other New Zealand and southern South American paleoclimate records, suggesting a common response to SHWW forcing along similar latitudes during the Holocene and Late Glacial. Department The department where the student is studying primarily. Geology Marine Science Named locality Named locality describing the field area location. Lake Von Central Otago New Zealand Thesis description Number of pages, maps, CDs, etc. iii, 83 pages, maps and illustrations 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 2013Anderson Creator An entity primarily responsible for making the resource Anderson, Harris 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 A 16,000 year Record of Paleoclimate Variability from Lake Von, Southern Central Otago, New Zealand. Subject The topic of the resource Paleoclimatology Chronology El nino Holocene Paeloclimate SHWW https://theses.otagogeology.org.nz/files/original/2d7e2e254b1187ad319b1c5e5ac4518c.pdf 959a4898301884eedb256eab673118d8 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 Author last name Last name of the Author Thomas Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Landis, C.A. Reay, A. Abstract The Abstract for this thesis The Holocene stratigraphy of the Blueskin Bay estuary was investigated using percussion cores. The Blueskin Bay estuary Holocene sequence comprises eight lithofacies arranged into a central estuarine basin consisting of an exposed intertidal flat, a sheltered intertidal flat and two estuarine bay head deltas. The exposed and sheltered intertidal flats are occupied by marine-influenced to paralic sand accumulations consisting of transgressive to highstand open-bay/estuarine deposits. The estuarine bay head deltas are dominated by tidalfluvial highstand point-bar and channel-lag deposits. Radiocarbon ages from in-situ and reworked shell and organics are used to establish the chronology of the Holocene stratigraphy. Holocene marine deposition commenced during the post-glacial transgression (ea. 9-7ka) and was dominated by an open-bay depositional environment in the position of the present central estuarine basin. At the time of the maximum transgression (ea. 6.2 ka) the majority of the Holocene estuarine sediment was in place. Hightsand deposition has been characterised by a period of erosion within the central estuarine basin and the episodic accretion and progradation of the estuarine bay-head deltas and around the bay margins. A database of 18 radiocarbon dates from estuarine sediments of the Blueskin Bay estuary, of which 8 are unpublished, is presented in this study. The elevation data have been reduced to a common datum (Mean Sea Level, MSL) and the sources of error assessed. Using modern lithological and biological relationships relative to present sea-level, radiocarbon dates can be converted into paleosea-level indicators. The upper and lower limits of the paleosea-level dataset provide an envelope representing local relative sea-levels. The envelope is consistent with a culmination of the post-glacial transgression after 6.5 ka BP, followed by a minor regression of -1.4 m from 5.5-5 ka BP, followed by a minor transgression of+ 1.4 m between 5-3.2 ka BP. Twelve radiocarbon dates from estuarine sediments of the Papanui and Hoopers Inlets located on the Otago Peninsula, corrected to a common datum (MSL), are used to constrain a relative sea-level curve and provide a proxy for the relative sea-level curve of the Blueskin Bay estuary. The paleosea-level dataset for the Papanui and Hoopers Inlets indicates a stillstand of +0.2m occurred at ~6 ka BP, followed by a minor regression of -0.7 m between 6 and 3.8 ka BP, followed by a minor transgression of +0.5 m from 3.8 to 3 ka BP. As with the newly proposed Blueskin Bay estuary relative sea-level curve, the last 3 ka BP of the sea-level curve for the Papanui and Hoopers Inlets has been stable. Newly proposed relative and eustatic sea level curves for the Blueskin Bay estuary, Papanui and Hoopers Inlets provide additional reference localities for New Zealand Holocene regional sea-level studies. All available data from the Holocene sediments infilling the estuary of Blueskin Bay and the Papanui and Hoopers Inlets suggest there has been no tectonic uplift or subsidence of the East Otago coast or Otago Peninsula during the mid to late Holocene. The large core and radiocarbon database from the Blueskin Bay estuary allowed an analysis and interpretation of the systems tracts and parasequences developed during the late Holocene. Within this interpreted sequence stratigraphy, the transgressive systems tract (TST) corresponds to the sequence boundary between the basal Holocene/Pliestocene superimposed by a ravinement surface and/or marine erosion surface (MES-1 ). The maximum flooding horizon (MFH), peak eustatic sea-level horizon (PESH), and/or peak relative sea-level horizon (PRSH), defined as isochrons equivalent to the maximum transgression of the shoreline and peak eustatic or relative sea level [within a cycle] respectively (after Larcombe & Carter, 1998), are not necessarily marked by a physical surface/sedimentary boundary within the Blueskin Bay estuary. The majority of the Holocene sediments deposited within the Blueskin Bay estuary correspond to the highstand systems tract (HST) of the post-glacial sea-level cycle. A geochemical study of the Blueskin Bay estuary sediments reveals distinct provenance signatures and some evidence for trace metal contamination proximal to possible pollution point sources. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/3245">http://hdl.handle.net/10523/3245</a> OURArchvive access level Abstract Only Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Blueskin Bay (East Otago) Thesis description Number of pages, maps, CDs, etc. 2 v. : ill. (some col.), 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 2000Thomas Creator An entity primarily responsible for making the resource Thomas, David Gregory, 1975- Date A point or period of time associated with an event in the lifecycle of the resource 2000 Title A name given to the resource Holocene stratigraphy and sequence architecture of the Blueskin Bay estuary, East Otago Subject The topic of the resource Quaternary Geology Marine Geology Sedimentology Blueskin Bay Estuary Holocene sequence stratigraphy