1 10 1 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