1 10 7 https://theses.otagogeology.org.nz/files/original/d2ae031d5ee71805c04aedcd9ed42057.pdf 7c26ebc68e6901692fae26c027598af1 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 ((162.063848854016754 -78.677619506797697,161.75403942069795 -78.675689520625539,161.75582920769719 -78.667524071138914,161.770888177259337 -78.598358380476753,161.777037122366607 -78.5984070832762,161.778897448952762 -78.598421792332886,162.073656435276433 -78.600604425062073,162.064066843191824 -78.67591888426044,162.063848854016754 -78.677619506797697)) Author last name Last name of the Author Wynyard Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Cooper, A.F. Abstract The Abstract for this thesis The Cocks Syenite/Granite Suite (CSGS) occurs over an area of 4km2 north ofthe confluence Cocks and Skelton Glacier confluence in South Victoria Land Antarctica. The CSGS represents the earliest Ross Orogeny plutonism and the oldest intrusion of the Koettlitz Glacier Alkaline Province (KGAP) at 551 ± 4 Ma. New geochemical data show the CSGS comprises a complete fractional crystallisation spectrum from silica-oversaturated syenite to granite. The CSGS is an A-type syenite/granite which shows high Fe/Mg, K +Na, Zr, Nb, Ga/Al, LREE, Y and Zn with low Ca, Eu, Sr, Ba, Cr, V and Ni. The parental syenite magma was metaluminous, anhydrous and relatively hot. Upon emplacement it became hydrated. Evolution to a peraluminous composition was controlled by the crystallisation of alkali feldspar. Sr-Nd isotopic analysis shows anomalous values of 87Sr/86Sri = 0.7201 relative to other A-type granitoids from the KGAP and has a ENd= -3.35. The CSGS is inferred to have been produced from melting of an upper crustal source rock with an inherited negative Eu anomaly at low pressure and high temperature due to mafic underplating during neoProterozoic crustal extension. The Skelton Group represents the basement rocks of the area and comprises: l)Anthill Limestone which consists of limestone, calcareous shale, calc-silicate and quartzite and was deposited in a shallow continental shelf setting. 2) The Cocks Formation which consists of shale, calc-silicate, meta-basite and minor limestone and was deposited by turbidity currents in a deeper marine setting. The Anthill Formation shows at least three folding events, Fl which transposed bedding, F2 produced a tight recumbent phase of folding and F3 a tight to open upright foldingphase. The Cocks Formation shows at least two deformational events, F 1 which transposed bedding and F2 a tight to open upright phase. During the recumbent deformational phase the two formation have been juxtaposed by a major tectonic shear. This Shear has possibly been refolded during the upright folding event. The Skelton Group has been metamorphosed to greenschist facies which has been locally overprinted by hornblendehornfels facies metamorphism during intrusion of the GSGS. Mineralogy and calcite-dolomite geothermometry suggest regional metamorphism of ~450-500°C at 2-3kbar overprinted by contact temperatures to ~550-600°C. One area of the Cocks Formation has contact metamorphism grade of pyroxene-hornfels facies indicating temperatures of~ 700°C. Dolerite dikes which cross-cut the Skelton Group and xenoliths within the CSGS show correlation through geochemical data. This correlation coupled with field relationships shows they are pre-551Ma and post deformation of the Skelton Group and are geochemically similar to the Skelton Dolerite cropping out on the southern confluence of the Cocks and Skelton Glaciers. New geochemical data shows they have high-K calc-alkaline affinities and may represent the dikes and sills emplaced during the initial stages of the extensional event which produced the CSGS. Deformation of the Skelton Group in the Skelton-Koettlitz region followed by extension and alkaline magmatism of the KGAP may be a result of the collision of seamounts and associated OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/3299">http://hdl.handle.net/10523/3299</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. Cocks Glacier area Antarctica Victoria Land south Thesis description Number of pages, maps, CDs, etc. 156 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 2004Wynyard Creator An entity primarily responsible for making the resource Wynyard, Matthew John. 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 the Cocks Glacier area, Antarctica : a study of neo-proterozoic metamorphism, deformation and magmatism during the Ross Orogeny in South Victoria land Subject The topic of the resource Metamorphic geology Map deformation magmatism neo-Proterozoic metamorphism Ross Orogeny 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 https://theses.otagogeology.org.nz/files/original/20ddbbd358ec7fea980f65f6585e6ef0.pdf a05d34aae8f58106e1cd5a2a342f000d 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 ((167.679711262052336 -78.121378578449367,167.679693246026687 -78.12286068013735,167.186456692707225 -78.12228951910545,167.190777600579395 -78.099161880598245,167.20049170033775 -78.046841483096202,167.208908879070634 -78.001138088837877,167.209652099689436 -77.997086007567361,167.210371827040632 -77.993159426284649,167.522646671819643 -77.994977870565236,167.679392076314002 -77.995759874008044,167.681222111718881 -77.995768488059127,167.680920555077449 -78.021048326046511,167.680797770689963 -78.031311379951745,167.679894993596633 -78.106241997628814,167.679711262052336 -78.121378578449367)) Author last name Last name of the Author Coulter Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PGDipSci Advisers Who supervised/advised this student Cooper, A.F. Wilson, G.S. Abstract The Abstract for this thesis White Island is a uniquely basanitoid-basanitic volcano in a chain of Cenozoic volcanic islands that parallel the western edge of the West Antarctic Rift System. Glaciatjon and possibly landsliding has eroded the island which, as shown by magnetic surveys, extends several kilometres further to the north under the ice sheet. Two main vent types were identified, lava-shields and maars, formed during a variety of eruption styles ranging from surtseyan to strombolian. All but one sample was found to be basanite, the other rock, a basanitoid, has more groundmass plagioclase and is less enriched in incompatible trace elements. Both rock types are inferred to have resulted from small amounts of partial melting possibly in the spine! lherzolite stability zone (25-60 km). The basanitoid resulted from slightly higher degrees of partial melting than the basanite, but based on Zr/Nb ratios all samples are cogenetic. Up to 50% crystal fractionation has occurred within the basanite spectra. Based on paleomagnetic dating, the island was found to be at least 0.78 my old, approximately four times the age of the single previous K-Ar date of 0.17 Ma (Kyle 1981). The extended age range is more compatible with lithospheric flexure models in the area whicli imply volcanic loading occurred between 1.4 Ma and 11 Ma (Aitkin 2003), and indicates that the island was active for a minimum of 0.6 my. The island occurs in an area of the West Antarctic Rift System (the Erebus Volcanic Province, Southern Victoria Land) interpreted as being a transtensional accommodation zone. This section of the rift boundary is marked by a change in orientation of the Transantarctic Mountains, and has acted as a tectonically separate block to the rest of Victoria Land for the last 800 my. During that time, the area that is now the Erebus Volcanic Province experienced two main tectonic regimes, the Ross Orogeny and the plume-related West Antarctic Rift System. At both times the area is associated with distinctly alkaline magmatism. Geophysical and modelling data indicate that the crust beneath the Ere bus Volcanic Province is very thin (- 20 km) and that Cenozoic uplift may have been localised in Southern Victoria Land, which may be part of the reason that the volcanics have such an alkali-rich signature. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. White Island Antarctica Antarctica Victoria Land southern Thesis description Number of pages, maps, CDs, etc. xi, 121 leaves : col. ill. ; 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 2004Coulter Creator An entity primarily responsible for making the resource Coulter, Roseanne F. 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 northern White Island, Southern Victoria Land, Antarctica Subject The topic of the resource Geomorphology Antarctica Ross Orogeny West Antarctic Rift System. White Island https://theses.otagogeology.org.nz/files/original/d5446c636987461d987c878853183078.pdf 0daff99f5a0b8249e06606c798944d58 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 ((160.054225218050334 -78.909021516065479,159.964218706205344 -78.907905008602114,159.988549792505268 -78.839648972836301,160.174069596234887 -78.841362589513821,160.282810174722073 -78.842313900739825,160.26679069908721 -78.911551855043655,160.054225218050334 -78.909021516065479)) Author last name Last name of the Author Richardson Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Cooper, A.F. Abstract The Abstract for this thesis West Worcester Hills is the name given for a seven-kilometre outcrop on the northeast side of the Mulock Glacier, southern Victoria Land, Antarctica. The metasediment basement rocks of this section of the Transantarctic Mountains are predominantly calcareous and calcsilicate rocks correlated with the Anthill Marble, which is part of the Skelton Group of inferred Neoproterozoic, early Cambrian age. Similar marbles occur across the Worcester Range striking northeastwards to the Skelton Glacier. Calcite-dolomite geothermometry shows that the unit was metamorphosed between 470·c to 550"C, corresponding to mid to upper greenschist facies. Closure of the paleo-Pacific ocean during the CambrianOrdovician caused subduction of ocean lithosphere under the East Antarctic craton, leading to the emplacement of the Harvey Pluton during the Ross Orogeny. This non-foliated, calc-alkalic, Cordilleran I-type granite is the first subduction related granitoid occurrence south of the W alcott Glacier. It marks the southern limit of the Koettlitz Glacier Alkaline Province, an extensional regime devoid of Cordilleran-type magmatism. U-Pb isotope dating of the Harvey Pluton gives an emplacement age of 530 ± 8Ma, approximately 30 Ma earlier than similar calc-alkaline magmatism in the Dry Valleys area to the north. The Kehle Pluton is a medium-grained, homogeneous, granodiorite with high Sr and depleted Y signifying its adakitic characteristic. The pluton is similar to other nonfoliated adakites in the Carlyon Glacier and Dry Valleys regions. Late-stage quartz-rich aphanitic dykes crosscut the pluton. Three sills and multiple dykes of Jurassic Ferrar Dolerite intrude the basement lithologies along with the Beacon Sandstone, these intrusions were emplaced in a failed rift between East and West Antarctica during the initial break-up of Gondwana. Emplacement of the sills occurred within a temperature range of 12oo·c to 1000·c. Within the basement sill several samples have been altered under greenschist to lower amphibolite facies conditions, due to the mobilisation of water from the underlying Anthill Marble. The extreme enrichment in compatible elements and depletion in REE of these chlorite-actinolite rocks relative to the host dolerite suggests that the altered dolerite represents an early cumulate fraction. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/3189">http://hdl.handle.net/10523/3189</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. Victoria Land south Antarctica West Worcester Hills Thesis description Number of pages, maps, CDs, etc. 1 v. (various pagings) : col. ill., maps ; 30 cm. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Identifier An unambiguous reference to the resource within a given context 2003Richardson Creator An entity primarily responsible for making the resource Richardson, Charles Doc. Date A point or period of time associated with an event in the lifecycle of the resource 2003 Title A name given to the resource Geology of West Worcester Hills, Southern Victoria Land, Antarctica Subject The topic of the resource Structural geology Ferrar Dolerite Mulock Glacier REEs. West Worcester Hills https://theses.otagogeology.org.nz/files/original/351ab276dfbc8ca6a1c2fe58142ec89b.pdf dbfa30d421ca1446a3f50a1cc19239cf 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 ((159.611075921071176 -76.748316544760868,159.59503935563319 -76.748039960184116,159.5989590931257 -76.734569862430405,159.598978675760151 -76.734502503862643,159.599180922358386 -76.733806741550183,159.602306898959512 -76.72304378433752,159.604374234965746 -76.715916320645661,159.609728851011255 -76.715990491823646,159.669333135702288 -76.716808468619035,159.708671534839027 -76.71734063605183,159.765043185662762 -76.718092571315296,159.763183171099996 -76.725772770284109,159.761360840412294 -76.733288879283279,159.757407528486851 -76.749565288902389,159.75729266893876 -76.750037588018429,159.757110070628499 -76.750788373720212,159.713379693940311 -76.75005702850801,159.665119859742646 -76.74924115017167,159.611075921071176 -76.748316544760868)) Author last name Last name of the Author Lockett Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Abstract The Abstract for this thesis In the Allan Hills, Victoria Land, Antarctica, Beacon Supergroup sedimentary rocks are juxtaposed with volcaniclastic rocks of the Ferrar-age Mawson Formation. The Mawson Formation and its correlatives along the Transantarctic Mountains contain an abundance of rather chaotic rocks consisting of once-glassy, juvenile basaltic grains mixed with broken country rock from the Beacon. Many of these rocks, including those at Allan Hills, have been interpreted in terms of a large vent complex that formed in advance of Kirkpatrick flood-basalt eruptions of the Ferrar large igneous province. New Watters peak, the Mawson Formation at Allan Hills can be divided into two units. One unit ("Mawson A") contains little or no juvenile basaltic material. Mawson B is more typical Mawson Formation tuff breccia, containing a variably high concentration of glassy juvenile material; it forms most of the Allan Hills and much of the nearby Coombs Hills. Mawson B is interpreted to be a intra-vent deposit, within a large shallow vent complex. Mawson A has a sharp to gradational contacts with unit B, and a gradational contact with Beacon Supergroup country rock. There are two main facies within Mawson A. The lower facies (Mawson Al) consists entirely of blocks of medium grained sandstone. Nearest the contact, blocks are of decimeter scale, rotated only slightly or not all, and beds within blocks can be traced from block to block for metres. Thin seams of sand matrix separate the blocks, and the sand consists of the same grains as the sand constituting the sandstone in the blocks. Further from the contact, blocks are commonly rotated and squeezed back together with little or no matrix between them. This unit is interpreted to have formed at the vent margin due to marginal subsidence caused by the removal of fragmented rock from the site of phreatomagmatic eruptions. A second facies (Mawson A2) lies further from the contact with the Beacon Supergroup, is more chaotic in appearance, and comprises predominately medium grained sandstone, but also contains clasts of coarse-medium sand pebbly congmplerate, fine grained sandstone, coal and glassy juvenile material. Clasts are randomly orientated and no internal structures are visible. This unit is interpreted to a debris flow Analysis on coal within this unit suggests that it was sourced from high in the Lashly Formation. The flow travelled into the vent complex implying it had negative relief. The flow was most likely the result of continued volcanic/tectonic seismicity causing failure along incipient weaknesses in the country rock surrounding the vent. After the flow volcanic activity continued and new intra-vent Mawson B was formed which incorporated some of the debris of the flow. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Antarctica Victoria Land south Allan Hills Thesis description Number of pages, maps, CDs, etc. viii, 105 leaves : ill. (some col.), maps (some col., 1 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 2003Lockett Creator An entity primarily responsible for making the resource Lockett, Gillian M. (Gillian Mary) Date A point or period of time associated with an event in the lifecycle of the resource 2003 Title A name given to the resource Landslide and debris flow deposits at the margin of a large vent complex, Mawson Formation, Allan Hills, southern Victoria Land, Antarctica Subject The topic of the resource Geomorphology debris flow deposits landslide Mawson Formation rock debris slopes vent complex https://theses.otagogeology.org.nz/files/original/6279cac6fb69bb4609900f3c7edc6fe1.pdf 7a02e8437b1010f56664f47201e79c2e 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 (((158.993449395400006 -79.735258197643702,158.754854260704491 -79.877806800436062,158.159144860415523 -79.854172651910858,158.318101894431635 -79.705587536873963,158.319739492141082 -79.704034044285706,158.355067491472738 -79.705710474847251,158.993449395400006 -79.735258197643702)),((160.049938819079472 -79.675026854113071,159.25923456086349 -79.664773579880091,159.330800300991569 -79.504022821515292,159.560981854694745 -79.507191108817565,160.206677084122845 -79.515190413626058,160.19976352000171 -79.531726525777572,160.174000952035072 -79.592894600171263,160.138491440410775 -79.67605479174162,160.049938819079472 -79.675026854113071))) Author last name Last name of the Author Cottle Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Palin, J.M. Abstract The Abstract for this thesis The Fontaine Pluton outcrops over an area of 0.5km2 at Fontaine Bluff in the Carlyon Glacier area of southern Victoria Land, Antarctica. The pluton comprises subalkaline gabbro with a distinctive calc-alkaline chemical affinity. Thermobarometry indicates emplacement occurred at 4kbar pressure and at a minimum temperature of 710 ± 21°C. U-Pb isotopic systematics of zircon suggest an emplacement age for the pluton of 544 ± 10 Ma. Geochemistry, geochronology and Sr-Nd isotope systematics indicate that the Fontaine Pluton has close affinities with other mafic plutons in the Royal Society Range to Skelton Glacier area of southern Victoria Land. The pluton contains numerous ultramafic xenoliths inferred to be remnants of an earlier intrusive phase. The previously undescribed Cape Murray and North Carlyon granitoids are calc-alkaline, K-series, I-type, volcanic arc intrusives. Zircon from the Cape Murray granodiorite yields a U-Pb date of 548 ± 2.5 Ma. This places the Cape Murray rock as the oldest Ross orogeny calc-alkaline granitoid yet described from the Transantarctic Mountains. Calc-alkaline lamprophyres and tholeiitic amphibolite dikes post-date calc-alkaline granitoid emplacement. These dikes formed as a result of mantle melting that was synchronous with, or immediately post-dated subduction. In terms of both geochemistry and age the dikes appear not to have correlatives elsewhere in southern Victoria Land. Granitoids with adakitic affinities crop out on the south side of the Carlyon Glacier. U-Pb isotope systematics of zircon and titanite indicate that the adakite at south Fontaine Bluff crystallised at 491 ± 3.3 Ma. Adakitic plutonism is inferred to be the result of partial melting of a mafic underplate beneath a thickened continental root. The emplacement of these relatively voluminous magmas is interpreted to post-date subduction in this area of southern Victoria Land. The Mulock Granite is a previously undescribed A-type intrusion that outcrops on the north side of the Mulock Glacier. U-Pb geochronology on zircon indicates an emplacement age of 546 ± 3 Ma, coeval with A-type granitoids in the Skelton Glacier area. Emplacement of the Mulock Granite post-dates deformation and metamorphism of the host Skelton Group calc-silicate metasediments. The Carlyon Glacier area represents a distinct magmatic province within the Ross Orogen of the Transantarctic Mountains. Magmatism was initiated within a convergent margin setting at ea. 548 Ma as recorded by the emplacement of calc-alkaline granitoid and mafic magmas. Continued subduction produced calcic and calc-alkaline granitoids which appear to have a petrologicaIly unique association with A-type granites. Emplacement of voluminous calcalkaline magmas caused significant crustal thickening, this, combined with mafic underplating enabled the production of widespread adakitic magmas between ea. 515 Ma and ca. 491 Ma. Subduction related plutonism in the Carlyon Glacier area pre-dates ca. 90% of magmatic activity in the Dry Valleys area but appears to be broadly synchronous with alkaline magmatism in the Walcott to Mulock Glacier region and calc-alkaline granitoid magmatism in the central Transantarctic Mountains. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/3946">http://hdl.handle.net/10523/3946</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 Victoria Land south Carlyon Glacier region Thesis description Number of pages, maps, CDs, etc. x, 200, 7, 18, 5, 6, 11, 1 leaves : ill. (some col.), maps (some col.) ; 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 2003Cottle Creator An entity primarily responsible for making the resource Cottle, John M. (John Malcolm) Date A point or period of time associated with an event in the lifecycle of the resource 2003 Title A name given to the resource Magmatic evolution of a convergent margin : a study of Ross Orogeny magmatism in the Carlyon Glacier Region, Southern Victoria Land, Antarctica Subject The topic of the resource Petrology Mineralogy Map Antarctica Carlyon Glacier Mamatism Ross Orogeny subduction U-Pb geochronology https://theses.otagogeology.org.nz/files/original/5b55df9a739483b7a0cc992bf018ee5f.pdf c2bd7ed85f0dbf3c83460220e539b7fd 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 ((159.197382204920615 -79.530408195386258,159.126464180605353 -79.673187000366241,158.527105590044698 -79.66170051755833,158.609990528201791 -79.519125605647758,159.197382204920615 -79.530408195386258)) Author last name Last name of the Author Barber Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Cooper, A.F. Abstract The Abstract for this thesis In the Reeves Bluffs area, southern Victoria Land, Antarctica, metasediments and metabasalts belonging to the Skelton Group are the oldest rock types. Lithologies include pelite/psammite pairs, calc-silicate skarns and amphibolite bands. The mineralogy of these lithologies is consistent with amphibolite facies metamorphism, which occurred during the early stages of the late Neoproterozoic-early Paleozoic Ross Orogeny. Detrital zircon U-Pb ages from a psammite sample reveal a significant Grenville-aged (c. 1.1-1.3 Ga) sedimentary source component. Potential Grenville-aged sources for the Skelton Group sediments in the area include the East Antarctic Craton and Laurentia (which was possibly in close proximity to East Antarctica during the Neoproterozoic). Based on geochemistry and petrography, three distinct granitoid types intruded the Skelton Group in the Reeves Bluffs area during the Ross Orogeny: The Reeves Bluffs calc-alkaline suite, which has I-type calc-alkaline affinities, is the most voluminous of the granitoid types. This suite has been subdivided into at least four plutons of which the Reeves Bluffs granite is the largest, occurring throughout the area. The Northface and Rhino granites and the Camp Ridge granodiorite are smaller plutons that are less than 1.5 km across. A U-Pb age of 540 ± 3.8 Ma was obtained from the Camp Ridge granodiorite, which is similar to a previously obtained age of 548 Ma from the calc-alkaline Cape Murray granodiorite from the nearby Fontaine Bluff. These are the oldest granitoid ages from the Carlyon-Darwin area, suggesting magmatism associated with the Ross Orogeny was initiated along this segment of the East Antarctic Craton margin at 548-540 Ma. Field relations show that calc-alkaline magmatism continued in the Carlyon-Darwin area until at least 536 Ma. The A-type West Carlyon leucogranite occurs as small intrusions and dikes throughout the northern half of the Reeves Bluffs area and is the second oldest granite type in the Reeves Bluffs area based on a previous U-Pb age of 536 Ma from the nearby 'A-type' Foggy Dog Granite suite in the Brown Hills. These granites are characterized by high SiO₂, alkalis, Ga/Al, HFSE and low CaO, Ba and Sr relative to other granitoid types. A-type granitoids typically occur in extensional-anorogenic tectonic settings and have been inferred to form by high-temperature melting of depleted crust from which a previous melt has been extracted. In the Reeves Bluffs area, earlier calc-alkaline magmatism would have depleted the local crust. The gabbroic Fontaine Pluton in the Carlyon Glacier area, which is broadly synchronous with A-type magmatism in the area, is perhaps representative of a high temperature magmatic episode capable of melting depleted crust. The Reeves Bluff adakite represents the youngest and second most voluminous granitoid type in the Reeves Bluff area. Based on mapping and previous work, a large adakite pluton or series of plutons are interpreted to exist to the east of Reeves Bluffs. Relative to other granitoid types these rocks contain high Sr/Y ratio and low Y and HREE, which can be attributed to a melt derived from below the garnet-in transition (>40 km depth), in the absence of residual or fractionating plagioclase. The partial melting of basaltic underplate at a depth exceeding 40 km, which may have developed during voluminous calc-alkaline magmatism in the area, is the inferred model for adakitic magmatism in the area. Based on two previous U-Pb ages on adakites in the Carlyon-Darwin area, the Reeves Bluffs adakite is probably aged between 515 and 491 Ma. The broadly synchronous relationship between convergent-related calc-alkaline and extensional-related A-type magmatism in the Carlyon-Darwin area also occurs c. 60 km to the northeast in the Mulock Glacier area. The Mulock-Darwin area may therefore represent a transitional zone between the extensional Koettlitz Glacier Alkaline Province (c. 70 km to the north of Reeves Bluffs, which is dominated by alkaline magmatism) and a more convergent margin to the south. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/5010">http://hdl.handle.net/10523/5010</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. Antarctica Ross dependency Victoria Land south Thesis description Number of pages, maps, CDs, etc. xi, 211, A48 p. : ill. (some col.), col. maps (1 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 2003Barber Creator An entity primarily responsible for making the resource Barber, Anton Joshua William. Date A point or period of time associated with an event in the lifecycle of the resource 2003 Title A name given to the resource Neoproterozoic-early Paleozoic evolution of the Ross orogeny in the Reeves Bluff area, southern Victoria Land, Antarctica Subject The topic of the resource Paleozoic Structural geology Metamorphic geology Neoproterozoic Ross Orogeny