1 10 30 https://theses.otagogeology.org.nz/files/original/93312ac64a2262d0b8c7a39b29bb7f5a.pdf 1b773b333ba500b1cec6d3640ea3b4e1 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 ((175.716775744890242 -38.664579028232104,176.134237491884164 -38.651149828262099,176.141269840995818 -38.984659476627264,175.733074844262063 -38.991963953433036,175.716775744890242 -38.664579028232104)) Author last name Last name of the Author Clarkson Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student White, J.D.L. Abstract The Abstract for this thesis Immediate post-c.l800a Taupo eruption secondary deposits occur on and around the margins of the sub-aerial terrace. This terrace formed in response to the transgression and relatively rapid regression of the shoreline after the products of a plinian ultraplinian eruption temporarily dammed the only outlet for Lake Taupo. Between 0.1-0.2 km3 of lacustrine sediments were deposited on the sub-aerial terrace, which covers an area of -80 km2. Over 95% of the lacustrine sediments on the terrace were deposited during the transgression ofthe shoreline. The highest paleoshoreline is marked by truncated Taupo ignimbrite which represents the limit of the landward erosion of between 2-5 vertical meters of Taupo ignimbrite. In some cases the upper paleoshoreline is marked by the presence of cliffs, particularly in the headland regions of northern Lake Taupo. Many intermediate terraces occur on the sub-aerial terrace. Three closely spaced intermediate terraces at heights of between 5-11 m above lake level occur at Whakaipo Bay and Five Mile Beach. These terraces were formed during temporary still-' stands with the relatively rapid regression of the shoreline. The thickest shoreline regression deposits occur at the tops of these intermediate terraces and are up to -1 m thick. Thicknesses of transgressional deposits also vary, with the thickest deposits occurring on steeper slopes and within fluvial channels filled by shoreline transgression. Most of the dry gullies around Lake Taupo were formed immediately after the eruption with many forming before the maximum "filling" of the lake and were either eroded, partially eroded, or partially or fully filled with the transgression of the shoreline. Dry gully formation continued after the partial "emptying" of the lake with many gullies dissecting the sub-aerial terrace and overlying lacustrine sediments. Most dry gullies end at the three closely spaced intermediate terraces. Since the formation of these intermediate terraces recession of the shoreline has continued to the present day. Several zones of deposition are identified from sediments deposited with shoreline transgression. These include lacustrine shoreline, where swash zone and beach berm are both identified. Fully lacustrine deposits include three main zones: surf to build-up breaker zone; nearshore zone (wave-ripple zone); and offshore zone. Appearance and lithofacies assemblages differ between exposed and sheltered shorelines. Sheltered shorelines such as Rotongaio Bay are composed mainly of suspension and slightly reworked Taupo ignimbrite (layer 2). More exposed shorelines contain traction, intermittent suspension and suspension deposits such as found at Tapuaeharuru Bay. The more exposed shorelines show a stronger development of , composition and grainsize variations from the base to the top of lacustrine deposits. For example rhyolite-lithic content decreases from almost pure lithics at the base of some stratigraphic sections to no lithics or 100% pumice at the top. Grainsize also initially decreases from pebbly sands to fine-medium sands from the basal to middle parts of stratigraphic sections, however it becomes coarser near the tops of sections, with lithofacies of planar bedded sands, granules and pebbles common. Within some lacustrine sediments storm deposits are identified as massive rhyolite-lithic sheet deposits. Braided stream deposits were the most common type of fluvial deposits to occur in the northern margins of Lake Taupo and in most cases were formed during intermittent stream flow and erosion. Slumping was also common, and is associated with layer 2 of the Taupo ignimbrite. Slumps were identified in sub-aerial deposits and within lacustrine sediments. Rare turbidite deposits were identified on one steep part of the sub-aerial terrace at Te Hapua Bay. The erosion of the Taupo ignimbrite by fluvial and lacustrine processes resulted in the separation of pumice from the denser rhyolite lithics. These lithics were deposited as lags in higher energy environments such as fluvial and lacustrine shorelines. Pumice dominates in fully lacustrine deposits and were in most cases floated into position and then reworked to produce planar bedded and normally graded pumice pebble units. The comparison of modern Lake Taupo shorelines and immediate post-Taupo eruption shorelines shows that sediments from the paleoshorelines are poorly rounded and have a lower crystal content but a greater pumice content. These differences reflect the transitory nature of the shoreline. Mega-clasts of gray pumice from eruption z are identified within transgressive deposits and therefore were deposited before the maximum filling of the lake. For this reason it is suggested that the initiation of eruption z occurred earlier than previously recognised. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Central North Island Thesis description Number of pages, maps, CDs, etc. vi, 157 leaves : 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 1996Clarkson Creator An entity primarily responsible for making the resource Clarkson, Roger Allen. Date A point or period of time associated with an event in the lifecycle of the resource 1996 Title A name given to the resource Immediate post-c. 1800a Taupo eruption secondary deposits and shorelines Subject The topic of the resource Petrology geomorphology sedimentology Taupo eruption https://theses.otagogeology.org.nz/files/original/b5274f9dec453112350f517f437a0af1.pdf 120f90935a3571d52b3365328b07be48 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 (((170.758959737724126 -45.470360195247075,170.758762373272617 -45.470747794104049,170.757940411378399 -45.47013625660616,170.758959737724126 -45.470360195247075)),((170.822852668999133 -45.344571471035607,170.952778929943207 -45.370791515641997,170.882999601936092 -45.497530262626874,170.758959737724126 -45.470360195247075,170.822852668999133 -45.344571471035607))) Author last name Last name of the Author Maicher Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PhD Advisers Who supervised/advised this student White, J.D.L. Abstract The Abstract for this thesis Hyaloclastite beds of shelf and seamount: roles of exsolution, entrapment and entrainment at Lookout Bluff and Seamount Six Submarine eruptions of basaltic magma range from highly to mildly explosive eruptions and include passive quenching and quiet lava effusions. Explosivity, increasingly suppressed by hydrostatic pressure, is driven by rapid exsolution of magmatic volatiles and steam explosions during interaction with external water. To assess the limits of phreatomagmatic processes and especially the role of steam at different depth levels, and the change of predominance of fragmentation processes, a shallow marine and a deep marine volcaniclastic rock sequence were studied. Clast characteristics and sedimentary features of the deposits were examined for information on fragmentation and ensuing primary sedimentation processes of the volcaniclastic debris in both settings. At Lookout Bluff, Otago, New Zealand, well bedded, vesicular pyroclastic breccias, lapillistones and tuffs of Eocene- Oligocene age are exposed. The rocks are interbedded with continental shelf siltstones, and are inferred to have been erupted and deposited in a shallow marine setting. Growth of three or more separate monogenetic volcanoes, substantially separated in time, is recorded at Lookout Bluff. Each of the volcanoes produced subaqueous fall and eruption-fed density current deposits, some of which have been modified by resedimentation events. Initial eruptions from each vent were of small volume and clast characteristics suggest that initially hydroclastic fragmentation was predominant. During the last recorded eruption, producing voluminous deposits, magmatic fragmentation became dominant. Deep-marine volaniclastic rocks from Seamount Six, a Pacific seamount on the Cocos plate, were studied with a submersible. The rocks consist of thin, well-bedded sheets of hyaloclastite and occur highly localized on topographic heights and flattish benches on the upper ·flanks of the seamount at ea. 2000 to 1600 m below sealevel. Earlier studies of these rocks propose a submarine fire-fountaining model with small magma jets from a central vent, fragmentation by steam explosivity and quench granulation, and emplacement by lateral density currents. However, observations during this study do not fit this model. V Non-vesicular angular blocky and splinter shard shapes indicate hydroclastic fragmentation. A critical role of steam is demonstated by the occurrence of puzzle shards and limu (Limu O'Pelee are beetle-wing like, broken fragments of lava bubbles stretched by . . trapped water expanding into steam). In this study, (a) detailed consideration of limu formation, including magma-water heat transfer, thermodynamics of seawater and various styles of water entrapment within lava, as well as (b) recognition of several hyaloclastite facies associations and (c) analysis of depositional characteristics of hyaloclastite shards are used to develop an integrated, multi-component model for the origin and deposition of deep-sea hyaloclastites. In conclusion it can be said that processes of violent steam and magmatic explosivity are suppressed at depth of Seamount Six, whereas the processes of limu and sheet hyaloclastite formation, dominant at that depth, are not recognized in the shallow marine setting of Lookout Bluff. Small volume fluxes, a forced, confined style of magma-water interaction combined with minimal exsolution of magmatic volatiles seem to be the controlling factors to generate limu and hyaloclastites studied at Seamount Six, whereas open-vent eruptions and abundant degassing favour surtseyan style eruptions studied at Lookout Bluff. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Lookout Bluff & Seamount Six (Pacific Ocean) Thesis description Number of pages, maps, CDs, etc. xiii, 247 p. : ill. (some col.), maps, 1 folded chart ; 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 1999Maicher Creator An entity primarily responsible for making the resource Maicher. Doris, 1969- Date A point or period of time associated with an event in the lifecycle of the resource 1999 Title A name given to the resource Hyaloclastite beds of shelf and seamount : roles of exsolution, entrapment and entrainment at Lookout Bluff, New Zealand and Seamount Six, Pacific Ocean Subject The topic of the resource Volcanology Igneous Petrology Marine Geology eruptive style fragmentation phreatomagmatism sediment density currents submarine volcanism Waiareka Volcanics https://theses.otagogeology.org.nz/files/original/63ddddce076718516b774eb5f6ce9886.pdf f553d912be6bd20caf2e310339914d2d 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 ((170.564623122649181 -45.870605305241725,170.738538829663781 -45.768444162106924,170.826525841809001 -45.833499856599623,170.649188454152068 -45.934771243664549,170.564623122649181 -45.870605305241725)) Author last name Last name of the Author Martin Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PhD Advisers Who supervised/advised this student White, J.D.L. Reay, A. Abstract The Abstract for this thesis The Otago Peninsula is part of the Dunedin Volcanic Complex and the Dunedin Volcanic Group, of Miocene age. Tephra and a suite of alkali basalt magma began erupting in the Sandfly Bay area. The Dunedin Volcanic Complex built up on a continental shelf. Activity commenced with the occasional eruption of basaltic tephra and lava. The earliest pyroclastic deposits are accompanied by peperites that formed due to interaction of magma with unconsolidated marine sands. These peperites together with pillow lavas, hyaloclastite and turbidites are evidence of subaqueous activity. Activity from various small vents over several million years has resulted in a complex stratigraphy and produced a wide range of pyroclastic deposits, including tephra from submarine, emergent, and fully subaerial vents. Most of the small volcanoes on the Otago Peninsula seem to represent small short-lived eruption sites but locally there are also eruptive centres that were active for quite a substantial time or were reactivated. A new volcanological map of the Otago Peninsula shows the distribution of these tephra deposits and the eruption sites. Rocks of the Dunedin Volcanic Complex rest on Cretaceous and Tertiary sedimentary rocks, which are underlain by pre-Cretaceous basement of quartzofeldspathic schist (Haast Schist Group). The sedimentary rocks comprise marine sandstones, mudstones and limestones, which were deposited on the continental shelf, and a non-marine-marine basal unit (see chap. 1 & 2). A loosely constrained stratigraphy is based on relationships of volcanic rocks to these marine sedimentary rocks, over- and underlying unit contacts, and correlation with the best available global sealevel curve. Documentation and age dating of features, such as correlative conformities, in seismic, well-log, and outcrop data, in marine outcrops in different parts of the world have led to a new generation of Cenozoic sea level cycle charts with greater event resolution than that obtainable from seismic data alone. This sea level curve has been used together with other available data (analyses of bedding in tephra, fossil content, pillow lavas as indicator for subaqueous environment) to support interpretations of depositional environments, and to infer ages of the deposits by correlation to the sea level curve. Such a correlatin assumes that there has been no or only little uplift or subsidence of the Dunedin Volcanic Complex. The history of the Otago Peninsula includes six stages of volcanic activity, of which four took place in a subaqueous to emergent environment. This result indicates that subaqueous volcanic activity took place over quite a long period of time during the early history of the Dunedin Volcanic Complex. The tephra ranges in composition from basanite and basalt, to phonolite and trachyte, typical for intraplate volcanism. Microprobe glass analyses and whole rock XRF analyses indicate a process of fractionation crystallisation with fractionation trends resulting from processes operating on mantle derived magmas at various levels in the crust. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Otago Peninsula Thesis description Number of pages, maps, CDs, etc. 1 v. (various pagings) : ill. (some col.), maps (some folded); 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 2000Martin Creator An entity primarily responsible for making the resource Martin, Ulrike, 1960- 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 Eruptions and deposition of volcaniclastic rocks in the Dunedin volcanic complex, Otago Peninsula, New Zealand Subject The topic of the resource Volcanology Ignoues Petrology Dunedin Volcanic Complex eruptions volcaniclastics https://theses.otagogeology.org.nz/files/original/171ef8889f87a0771b865ddd58033555.pdf 6773e1ff07fe1944036a9a86e9344595 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 ((175.522216037061327 -39.79124990119832,175.4812579325515 -38.644169169335079,176.368018536508259 -38.614832517611021,176.34761909443921 -38.075258937830661,178.027039773438702 -38.021563317215019,178.05637147964768 -38.68500653607741,178.091137416329104 -39.128135475442363,177.129928103281372 -39.753024704061417,175.522216037061327 -39.79124990119832)) Author last name Last name of the Author Segschneider Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PhD Advisers Who supervised/advised this student Landis, C.A. White, J.D.L. Abstract The Abstract for this thesis The Taupo ignimbrite erupted from the Taupo Volcanic Centre, North Island, New Zealand, circa 1800 years ago. It has an estimated volume of 30 km3 and covered the topography over a circular area approximately 160 km in diameter, centred on a vent beneath Lake Taupo. Primary deposits of loose pyroclastic material reached thicknesses in the Hawke's Bay region of up to 40 m in valleys and topographic depressions (valley pond ignimbrite; VPI), and 1 m on hill slopes (ignimbrite veneer deposit; IVD), destroying hydrological systems and all vegetation throughout the impacted area. Sedimentary response to such large ignimbrite-emplacing eruptions from rhyolitic calderas is poorly understood. This thesis analyses the resedimentation of debris from this voluminous ignimbrite in the Hawke's Bay region, in order to understand post-eruptive surficial processes and as an aid in the assessment of hazards from future eruptions. Pumice pyroclasts behave in unusual ways in the sedimentary environment due to their low, and variable density. This unusual behaviour was addressed here by systematic sieving and automated settling tube analysis of water saturated pumiceous sediment, confirming that sieve analysis are misleading in respect to hydrodynamic behaviour of pumiceous sediments. This distinctive and different behaviour required the use of both lithofacies and petrofacies in the description and classification of the remobilisation deposits (chapter 2). Analysis of preserved remobilisation sediments along Hawke's Bay rivers showed that resedimentation occurred in two main stages, depending on the sediment:water ratio during the response period. Stage one comprised erosion and redeposition of the ignimbrite by lahars. Stage two was marked by decreasing sediment: water ratios, and the re-establishment of braided fluvial systems in the former river valleys. This sedimentary response pattern was revealed by grouping characteristic sets of eooccurring lithofacies into 4 lithofacies associations. Resedimentation of debris from the 1.8 ka Taupo ignimbrite is described and interpreted separately for each Hawke's Bay river system (chapters 3 to 5). Pumiceous deposits are preserved in a series of terraces in the ignimbrite covered area and beyond. The rivers are divided into headwaters, middle, and lower reaches due to their different sedimentary responses. The most prominent feature in the headwaters was stepwise incision into VPI. Along the middle reaches, partial erosion of VPI was followed by up to 20 m of aggradation of the valley floor by lahar deposits. Temporary lakes formed in tributary valleys that were dammed by aggradation in the main valley. Erosion of the lahar deposits followed, with up to 15 m of fluvial aggradation downstream from the most distal preserved lahar deposits along the Mohaka River. Similar fluvial aggradation reached up to 10 m along the Ngaruroro River, and up to 8 m along the Waiau River. Final degradation brought the rivers back into their pre-1.8 ka bed. Along the lower reaches of all rivers laharic and fluvial aggradation occurred. Fluvial aggradation averaged 2 m on the Heretaunga Plains. Individual catchment areas received between 3 km3 (Mohaka) and 0.07 km3 (Waiau) of primary ignimbrite. Of this initial volume, between 71 and 96 %respectively was removed by post-eruption remobilisation (chapter 6). Estimated times for the duration of the laharic and fluvial resedimentation periods lie between 3 and 17 years. Variations in resedimentation processes, and the duration of the inferred resedimentation periods between the three catchments are interpreted to reflect differences in: 1) initial ignimbrite volumes; 2) gradient of the rivers; and 3) number and size of tributaries unaffected by ignimbrite emplacement. Future volcanic hazards for the Hawke's Bay region from the emplacement of a similar-sized ignimbrite to the 1.8 ka Taupo ignimbrite at the Taupo Volcanic Centre are assessed based on the results from this study (chapter 7). River valleys downstream from their reaches affected by ignimbrite would experience major flooding events and lahars. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Hawke's Bay region Thesis description Number of pages, maps, CDs, etc. 1 v. (various pagings) : ill., maps (some folded) ; 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 2000Segschneider Creator An entity primarily responsible for making the resource Segschneider, Beate, 1969- 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 Resedimentation of the 1.8 ka Taupo ignimbrite in the Hawke's Bay region, North Island, New Zealand Subject The topic of the resource Sedimentology fluvial resedimentation Taupo Ignimbrite https://theses.otagogeology.org.nz/files/original/721ea0ad9f3b4cc12f12062ee57478a3.pdf 2fb85b3def21e818552944d540fd5c8a 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 ((170.845821911633834 -45.355973015372307,170.87170887119035 -45.350266282770164,170.883647607033794 -45.374304531726061,170.859848784774414 -45.37814781914598,170.845821911633834 -45.355973015372307)) Author last name Last name of the Author Andrews Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PGDipSci Advisers Who supervised/advised this student White, J.D.L. Abstract The Abstract for this thesis Eocene explosive submarine volcanism on the East Otago shelf is reported and discussed. Surtseyan lapilli tuff deposits with maximum stratigraphic thicknesses of at least 175 m record the existence of a volcano that built into storm wave base and may have emerged. A diverse range of large clast types, including schist xenoliths and dike fragments, show that the lapilli tuff was produced through a variety of fragmentation processes including Fuel-Coolant Interaction. Additionally, irregular shaped clasts exhibiting possible fluidal deformation indicate that magma was ejected from the vent while still molten. Stratigraphy also indicates that the volcano experienced two periods of major activity with a relatively quiescent interval between. Though widespread slumping and possible sector collapse have rendered accurate reconstruction of the volcano nearly impossible, orientations of dikes and data from two measured stratigraphic sections indicate that a large island near the centre of the field area may have been the vent. Both basalt and clastic dikes are emplaced in lapilli tuff at Moeraki. The basalt dikes are commonly banded with alternating layers of high and low vesicularity; these textures indicate formation through repeated injection of magma. The innermost bands of the dikes are often discontinuous and pinch out in fold hinges, indicating syndeformational emplacement. Irregular intrusions of basalt also occur at Moeraki and may be large intrusive pillows. The clastic dikes at Moeraki exhibit three textures; porcelainite breccia, mudstone breccia and mudstone. Though mudstone dikes occur discretely on one beach, a progression of all three occurs in association with basalt dikes at another locality. The dikes there grade from basalt through porcelainite to mudstone and indicate formation of clastic dikes as a result of explosive brecciation of sedimentary rocks. The brecciation is generated by the phreatomagmatic interaction of hot basalt dikes with wet low permeability mudstones. Numerical modelling of this process is presented. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Moeraki Peninsula Thesis description Number of pages, maps, CDs, etc. 141 leaves : ill. (some col.), maps ; 30 cm. + 1 CDrom. 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 2001Andrews Creator An entity primarily responsible for making the resource Andrews, Benjamin J. (Benjamin James) Date A point or period of time associated with an event in the lifecycle of the resource 2001 Title A name given to the resource Physical volcanology of Moeraki Peninsula Subject The topic of the resource Volcanology volcanism https://theses.otagogeology.org.nz/files/original/bbeb8ce993feccc415610f7dda148bf1.pdf 31af8ac74fedc763b3785cb8e92e9780 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 McClintock Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student White, J.D.L. Abstract The Abstract for this thesis The Mawson Formation at Coombs Hills, Antarctica comprises mainly massive tuffbreccia (~80% vol.), includes a high proportion of accidentallithics, has steep contacts with country rock, includes rafts of bedded pyroclastic rock and country rock, and is intruded by and intermingled with dikes, sills and peperite. Massive tuffbreccia deposits are cut by steeply dipping to sub-vertical zones oftuffbreccia of contrasting componentry and grainsize to host rocks, tangled with irregular intrusions and peperite. Dikes or pods of coherent basalt metres in diameter grade, via peperite contacts, into rafts of undisrupted country rock, and into surrounding tephra comprising sedimentary debris mixed with glassy basaltic clasts. The Mawson succession is capped by planar and cross-bedded tuff, lapilli tuff and tuff breccia, which comprises ::::;1 0% of the Mawson overall. Componentry suggests quarrying of country rock from relatively shallow levels (?::::;700 m). Coombs Hills outcrop records non-explosive to explosive magma-water interaction and intrusion of associated hypabyssal complexes within a novel type of phreatomagmatic vent complex that is basaltic, large volume (kilometres3 to tens ofkilometres3 ) and oflow to negative relief. This unusual style of volcanism developed as the precursor to Ferrar LIP magmatism during Middle Jurassic fragmentation of Gondwana, when voluminous rising flood basalts intercepted equally abundant water-saturated Beacon Supergroup sediments and sedimentary rocks. Similar rocks elsewhere in the Transantarctic Mountains, and associated with other flood basalt provinces worldwide (Karoo LIP, Siberian Traps), suggest that this style of basaltic volcanism may be characteristic of environments of combined rifling and flood magmatism. Although Coombs Hills is an atypical vent complex, processes of transport and deposition within the complex were like those in other subaerial phreatomagmatic volcanoes. The bulk of deposits at Coombs Hills are most like those of lower diatremes and diatreme root zones, recording tephra jetting and churning of massive vent-filling tephra by phreatomagmatic explosions. Water-magma interaction was driven by interaction of basalt with water hosted in porous country rock and vent-filling debris. Spatial and temporal heterogeneity in availability of external water led to a variety of eruptive styles at many sites both laterally and vertically within the Coombs Hills crater. Some tephra was deposited by base surge and pyroclastic flow beyond active eruption sites, but broadening of craters via lateral quarrying recycled most of this volcaniclastic rock en masse back into the vent. Quarrying was facilitated by unstable country rock collapsing from vent margins, leading to digestion of collapsed blocks into massive vent fill and adding both mass and further external water to the volcanic system. The fundamental controls oflarge-volume phreatomagmatism at Coombs Hills were: (1) An abundant magma supply associated with emplacement and eruption ofFerrar LIP flood basalts; (2) An equally abundant shallow-level external water hosted in poorly consolidated, porous and permeable Beacon Supergroup country rock, with water supply enhanced by moderate rainfall in a humid climate; and (3) Poorly consolidated, fragile wall rock, which facilitated repeated collapse of vent margins into vents to create a broad shallow vent complex most like a nest of diatremes. Wall rock collapse and subsequent crater growth increased the supply of water-saturated sediment available to fuel eruptions, increased the potential capture of local drainage and reduced the escape of water-saturated tephra from craters, allowing recycling of water as well as pyroclasts. Implications for volcanic processes are ( 1) that recycling of water is probably as ubiquitous as recycling of pyroclasts in phreatomagmatic vents, and allows largevolume phreatomagmatic systems to grow beyond constraints imposed by far-field recharge of external water alone; (2) that the proportion of recycled water increases with vent size; and (3) that peperite is an important indicator of, and participant in, phreatomagmatic explosions, and magma-sediment interaction can promote enhanced explosivity of magma-water interaction. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Coombs Hills Antarctica Antarctica Thesis description Number of pages, maps, CDs, etc. 1 v. (various pagings) : col. ill. (3 folded) ; 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 2001McClintock Creator An entity primarily responsible for making the resource McClintock, M. K. (Murray Kevin) Date A point or period of time associated with an event in the lifecycle of the resource 2001 Title A name given to the resource Phreatomagmatism at Coombs Hills, Antarctica : magma-water super-volcanism in a wet, failed rift Subject The topic of the resource Volcanology magma phreatomagmatism https://theses.otagogeology.org.nz/files/original/75b5f961d259e77ab56d70cfa3fb8830.pdf 0807399922b65521b24443691f74fdcb 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 (((170.609321054418956 -45.455228026503654,170.611023917892567 -45.452763714561065,170.716139093469394 -45.531125784359006,170.609321054418956 -45.455228026503654)),((170.321698845852012 -45.867905864741019,170.169807260542541 -46.14620484708496,169.747845574527219 -46.19021751020783,169.904071956453322 -45.874492024406827,169.881739752211161 -44.930247273080035,170.609321054418956 -45.455228026503654,170.321698845852012 -45.867905864741019))) Author last name Last name of the Author Németh Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PhD Advisers Who supervised/advised this student White, J.D.L. Reay, A. Abstract The Abstract for this thesis The Miocene Waipiata Volcanic Field (WVF), New Zealand, is an eroded phreatomagmatic volcanic field. Three different types of vent or vent complex were recognized. Vent-filling deposits comprising predominantly lava, preserved in the form of plugs, necks, lava lake remnants, lava flows, or dykes, were classified as Type 1 vents. Type 1 vents are inferred to be the remnants of scoria cones, most of them with thin basal phreatomagmatic pyroclastic deposits. Vents represented by predominantly pyroclastic infill are classified as Type 2 vents. Type 2 vents are inferred to have been the substructures of phreatomagmatic tuff ring/maar volcanoes, many of which may have had associated scoria cones. Type 3 vent complexes are groups of closely spaced or overlapping vents, with voluminous preserved lava flows. Type 3 vent complexes are the remnants nested maars and tuff rings with associated magmatic explosive and effusive products. Pyroclastic rocks of most of the Waipiata vents record initial phreatomagmatic explosive activity fuelled by groundwater followed by Strombolian-style eruptions. Erosion rates for the WVF are 5 to 50 m per million years. Cenozoic sedimentary cover was widespread and still complete ( e.g. 200 – 400 m thick Oligocene marine units) at the time of volcanism, although over much of the field no Cenozoic sedimentary rock units remain today . Vent alignments largely follow the basement structural pattern of the Otago Schist, defining NESW and NW-SE trends. The longest vent alignment, traceable in ~ 30 km, coincides with and is parallel to the largest fault zone in the Otago region, the NW-SE trending Waihemo- fault zone. The total volume of magma erupted in the WVF is estimated to have been ~ 9 to 40 km^3 DRE. A systematic compositional sequence exists at each volcano, with initial phreatomagmatic eruptive products being differentiated tephrite and phonotephrite composition, whereas subsequent lava flows and dykes are of primarily basanite. Basanite was parental to the tephrite and phonotephrite. Basanite generated beneath WVF appears to have “failed” to reach the surface, instead being captured en route and stored to produce tephrite phonotephrite via 15-25 % crystal fractionation of olivine and clinopyroxene. Many attempted eruptions of parental basanite "failed", and that each successful eruption at the surface involved both a newly-injected basanite from depth, and a transected and entrained remnant of melt evolved from magma captured at shallower depths from a preceding "failed" eruption. Significant amount of magma was underplated beneath or injected into the crust of the WVF. The Otago crust is density and rheologically stratified, and in the Miocene lay within a mild extensional (strike- slip) tectonic regime; this combination was responsible for the entrapment of magma at various levels in the Waipiata – Dunedin region. The WVF-wide trend in magma evolution at individual vents has also been demonstrated from the mild extension-related Late Miocene Bakony- Balaton Highland Volcanic Field (BBHVF), Hungary. Recognition of this pattern at two unrelated fields may suggest that initial injection, with subsequent entrainment to produce dual-source monogenetic eruptions may be common in intracontinental alkaline basaltic volcanic fields. It is suggested that the lithospheric density and rheological structure, together with the state of stress, play an important role in fostering magma injection and entrapment in areas where the crust is 1) strongly density stratified, 2) relatively thin, 3) hot (high heat flow), and 4) the crustal stress regime mildly extensional, preferably with strike slip movements. These conditions were shared by the WVF and the BBHVF, with the result that magmas, processes of storage and differentiation, and ultimate eruption and volcano formation were in many ways remarkably similar. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Waipiata Otago north Thesis description Number of pages, maps, CDs, etc. 2 v. : ill. (some col.), maps (1 folded, col.) ; 30 cm. + 1 computer disk. 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 2001Nemeth Creator An entity primarily responsible for making the resource Németh, Károly, 1969- Date A point or period of time associated with an event in the lifecycle of the resource 2001 Title A name given to the resource Phreatomagmatic volcanism at the Waipiata volcanic field, Otago, New Zealand Subject The topic of the resource Volcanology Igneous geology Structural geology Map basanite erosion Hungary maar New Zealand phreatomagmatic scoria tephrite vent https://theses.otagogeology.org.nz/files/original/b439a02e201307969a64200964352929.pdf 2004c133cbecab7ca4987d86e0d74720 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 ((169.623945752000054 -46.361348229999976,169.586018962000026 -46.339589546999946,169.588986728000123 -46.289717161999931,169.610120442000039 -46.271260832999985,169.629175126000064 -46.272122759999945,169.623945752000054 -46.361348229999976)) Author last name Last name of the Author Simpson Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Landis, C.A. White, J.D.L. Abstract The Abstract for this thesis This project examines the boundary between the Murihiku and Dun Mountain - Maitai Terranes, as well as the intervening strata of the Kaka Point Structural Belt, South-East Otago. Strata ofthe Murihiku and Dun Mountain -Maitai Terranes can be correlated with previously mapped units found inland, whereas the Kaka Point Structural Belt lacks clear correlatives. The Kaka Point Structural Belt shows both similarities and differences to both the Murihiku and Dun Mountain -Maitai Terranes, with previous authors provisionally including it within the Dun Mountain -Maitai Terrane. However, based on evidence from this field area, the Kaka Point Structural Belt is interpreted as a separate, "suspect" terrane. Within this field area the Dun Mountain -Maitai Terrane is represented by ophiolitic sea floor that was metamorphosed (Otanomomo Complex), then brecciated (Telford Breccia), and overlain by sedimentary rocks derived from a volcanic arc. Sedimentary features indicate deposition via storm-generated currents. The Kaka Point Structural Belt represents the deformed remnants of a turbidite filled basin, with the volcanic arc derived sediment originating from the east. Sediments were deposited either in a forearc or backarc basin setting. The Murihiku Terrane represents a large turbidite filled basin in which a regressive wedge propagated from southeast (arcwards) to the northeast (trenchwards). Most evidence favours a forearc basin setting although some evidence suggests it may have been a backarc basin. Outcrops of the Dun Mountain -Maitai Terrane and Kaka Point Structural Belt appear to be structurally controlled, with the structure developed during terrane amalgamation. Terrane amalgamation is responsible for the large scale folding of the Southland Syncline. Minor faulting and folding may also be the result of this terrane amalgamation during the Rangitata Orogeny. Evidence is also presented from mineral assemblages that suggest far greater burial depths for the Murihiku Terrane than for the adjacent Kaka Point Structural Belt and Dun Mountain -Maitai Terrane, thus implying a "boundary fault" is present between the Murihiku Terrane and the Kaka Point Structural Belt. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Murihiku Terrane Maitai Terrane Kaka Point structural belt Dun Mountain Thesis description Number of pages, maps, CDs, etc. ix, 144 leaves : ill. (some col., some folded), maps (some col, some folded) ; 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 2002Simpson_B Creator An entity primarily responsible for making the resource Simpson, Brent Andrew. Date A point or period of time associated with an event in the lifecycle of the resource 2002 Title A name given to the resource Murihiku-Maitai terrane boundary, South East Otago Subject The topic of the resource Structural geology Otanomomo Complex Telford Breccia terranes turbidites https://theses.otagogeology.org.nz/files/original/3ac028f15e11063bba06e663fc110842.pdf 136f0c665aefec4a4b91b5a9882d8843 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 ((167.959021582402954 -78.133657246351646,167.813813352878668 -78.243964566749312,167.694329938859738 -78.23848297192859,167.114084538619977 -78.211081494710129,166.861651554291001 -78.198753679606199,166.838150260308424 -78.197593346716857,166.859241483882641 -78.179501574902503,166.964281011110501 -78.088556363570348,167.081883068072642 -78.094087867801022,167.190777600579395 -78.099161880598245,167.20590498446208 -78.099863110718772,167.387375763308285 -78.108206101675776,167.679711262052336 -78.121378578449367,167.687068036730153 -78.12170582592708,167.959021582402954 -78.133657246351646)) Author last name Last name of the Author Adam Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student White, J.D.L. Palin, J.M. Craw, D. Read, S. Abstract The Abstract for this thesis White Island is a glaciated volcanic island in the western Ross Embayment of the Ross Ice Shelf, Antarctica. The interests of this research are the extrusive volcanic rocks, shallow intrusive rocks, deep crusta! xenoliths, and pyroclastic deposits that characterise the southern half of White Island. The flow rocks, dykes, and plugs of southern White Island comprise predominant basanite and minor tephriphonolite. The basanites contain phenocrysts of olivine and titanaugite, and variable abundances of kaersutite, aegirine, magnetite, apatite and plagioclase xenocrysts in a fine grained groundmass. The tephriphonolite comprises phenocrysts and xenocrysts of kaersutite and microphenocrysts of aegirine-augite and plagioclase in a sideromelane groundmass. The rocks of the southern White Island suite are related by fractional crystallisation involving the early removal of olivine and titanaugite and late fractionation of magnetite. Trends are comparable to those from alkali basaltic suites of Antarctica, and to geochemical trends of the Dunedin Volcanic Province, New Zealand. Two basanites are not considered to be related by fractional crystallisation, and originate from different degrees of partial melting of the mantle. Lower crusta! xenoliths are found in the aforementioned basanitic flow rocks, and are defined petrographically into three types: Type One xenoliths, which are unmetamorphosed gabbro; Type Two xenoliths, which are partially recrystallised granulites displaying a mortar texture; and Type Three xenoliths, which are fully recrystallised granulites. Features of their whole rock geochemistry indicate these xenoliths originated as cumulates from an evolving alkaline magma. Crusta! xenoliths do not represent cumulates of their host magmas; however, they may originate from alkaline magmas associated with rift-related volcanism of the McMurdo Volcanic Group. Following igneous crystallisation, these rocks were variably recrystallised under granulite facies metamorphic conditions. Secondary fluid inclusions provide evidence of fluxes of C02- rich fluids both preceding and following recrystallisation. This fluid flux may be related to the crystallisation of metasomatic kaersutite and biotite, which is shown by whole rock geochemistry to occur by the infiltration of a volatile-rich fluid rather than an alkaline melt. Mineral chemistry shows the Type One xenolith analysed does not represent the unmetamorphosed protolith of the Type Two and Three xenoliths analysed; however, this does not necessarily preclude such a relationship between other xenoliths. The Type Two and Three xenoliths analysed are related by different degrees of recrystallisation of the same protolith. Lapilli tuffs rich in basanitic accidental fragments comprise two of the peaks in the field area, and were formed during phreatomagmatic eruption, and subsequently transported and deposited by a series of hydroclastic base surges. Subordinate tuff occurs in one location, and is thought to also have originated during phreatomagmatic eruption. Spatter lapillistone comprising several small outcrops was deposited during Hawaiian or Strombolian eruptions, throughout which quenched juvenile ejecta impacted onto a solid substrate to form welded deposits. Ejecta from the centre of eruption columns retained sufficient heat to coalesce upon landing, forming spatter-fed lava flows. Keywords: White Island, Antarctica, basanite, tephriphonolite, fractional crystallisation, lower crustal xenolith, cumulate, lapilli tuff, spatter, phreatomagmatic, base surge. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. White Island Antarctica Antarctica Thesis description Number of pages, maps, CDs, etc. 156 leaves : col. ill., maps (1 folded) ; 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 2004Adam Creator An entity primarily responsible for making the resource Adam, Lotte J. 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 Geology of southern White Island, Antarctica Subject The topic of the resource Map Geomorphology Antarctica basinite fractional crystallisation tephriphonolite White Island https://theses.otagogeology.org.nz/files/original/5e7099bd4d2a0d7c0302f4c780d082bc.pdf 00d8c01817a9e57dc9c3d2d73b1871bb 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 ((159.611042297072686 -76.747334877898581,159.59952317493844 -76.747155749513155,159.60364731091903 -76.734579204102531,159.603661093366412 -76.734537135035197,159.603904830747211 -76.733793115918758,159.607394514329997 -76.723131658338772,159.609728851011255 -76.715990491823646,159.61016919719259 -76.714642541076586,159.669508573285327 -76.715454613706413,159.708653558025588 -76.715982703436609,159.769040595726864 -76.716785488101934,159.767177065568944 -76.725839214640857,159.765644925912881 -76.733273801862936,159.762266606988646 -76.749637883736639,159.757407528486851 -76.749565288902389,159.665259214356865 -76.748170937708153,159.611042297072686 -76.747334877898581)) Author last name Last name of the Author Hood Hills Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student White, J.D.L. Abstract The Abstract for this thesis Jurassic fragmentation of Gondwanaland initiated the widespread voluminous outpouring of tholeiitic magma that is recorded on four continents. In Antarctica the Ferrar Supergroup, which outcrops along the length of the Transantarctic Mountains, formed within a wet failed rift during this break-up. It includes the extensive Ferrar Dolerite sills and dykes, and the extrusive Kirkpatrick flood basalt, and explosive volcanic deposits of the Mawson Formation. The Allan Hills, in southern Victoria Land, provides excellent exposure of these volcaniclastic deposits and was the site of study for this project. A small area was mapped in detail to determine the mode of origin of a part of the Mawson Formation and its relationship to the recently described 'phreatocauldron' in the nearby Coombs Hills. The Mawson Formation in the Allan Hills has previously been interpreted as part of a regional lahar field that formed as a precursor to Kirkpatrick flood-basalt eruption. Structural relationships and componentry of the Mawson Formation in the area, supplemented with results of coal vitrinite analysis, are difficult to reconcile with a laharic origin. During field work three different lithofacies were defined; a) thick, structureless, lithic-rich ponded pyroclastic density current deposits, b) several block-rich explosion or lag breccia horizons, and; c) a diatreme-like breccia-filled conduit (Ninnis Neck), one of the sources of other Mawson Formation deposits. These deposits are here interpreted to have formed within a phreatomagmatic vent complex, created by the coalescence of multiple vents similar to and including Ninnis Neck. Phreatomagmatic activity was fuelled by Fuel-Coolant-Interaction (FCI) as Ferrar Supergroup magmas intercepted water-saturated sedimentary materials of the Beacon Supergroup. Abundant peperite fragments formed by incomplete FCI, involving mingling of Beacon Supergroup clastic debris with magma preceding explosive fragmentation. Peperitic margins on basaltic dykes provide further evidence for involvement of wet sedimentary debris. Ninnis Neck was formed by upwards-directed tephra jets late in the overall complex's history. Recycling of tephra within individual vents, such as Ninnis Neck, was important in slowing the 'drying out' process and lengthening explosive activity. Growth of the Allan Hills vent complex occurred by lateral expansion facilitated by repeated failure of Beacon Supergroup strata along the margins due to volcanic and/or tectonic activity. The vent complex is interpreted to be relatively shallow, indicated by the limited sampling depth of accidental lithic clasts. The style of volcanism expressed in the Allan Hills of a shallow, possibly broad phreatomagmatic vent complex is comparable to that of the nearby Coombs Hills, and appears to have been widespread through much of the area covered by Kirkpatrick la vas now exposed in the Transantarctic Mountains. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Victoria Land south Antarctica Allan Hills Antarctica Thesis description Number of pages, maps, CDs, etc. viii, 107, [22] leaves : col. ill., 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 2004Hood_Hills Creator An entity primarily responsible for making the resource Hood Hills, Simone Belinda. 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 Wright dykes : a geochemical study of the dyke-forming rock types of the Wright Valley, Southern Victoria Land, Antarctica Subject The topic of the resource Volcanology Igneous geology Structural geology mafic volcaniclastics magma Mawson Formation phreatomagmatic volcanic complex