https://theses.otagogeology.org.nz/files/original/7394ba8fd860c50f0429bdf1dae50e5d.pdf a2f1d35e922072dec0c2cb148a394ba4 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 ((162.8008986239563 -77.887000650389709,162.052841233592943 -77.887999542136114,162.056630664101846 -77.849997137977354,162.057057002181722 -77.84570688359068,162.057725051706342 -77.83897826730103,162.05799718189698 -77.83623527351233,162.058168262786836 -77.834510172330127,162.058889418526206 -77.827233129595115,162.061991178874706 -77.795835924395178,162.063127373599542 -77.784294914043102,162.065112996682899 -77.764074028394077,162.071207758640156 -77.701593065515866,162.071653145308659 -77.697002461093348,162.071886839357887 -77.694592439389339,162.149587901846076 -77.69447056526711,162.162962216033208 -77.694447370554997,162.247016737403811 -77.694286691123864,162.330638038378765 -77.694101316000669,162.415451277028978 -77.693887293206885,162.447095583066158 -77.693800730437658,162.497039417420496 -77.693656690930965,162.531429582961891 -77.693552228298188,162.713855469159853 -77.69292607121271,162.744042375350944 -77.692810769690396,162.801776775230138 -77.692581001706003,162.80174167464375 -77.700469474979073,162.801703488704192 -77.709041005691688,162.801699053856822 -77.710035974424102,162.801613156380199 -77.72927022530466,162.801605888666529 -77.73089511735725,162.801566288688917 -77.739740554410488,162.801374139594259 -77.782481264962229,162.801172298662664 -77.827061850624773,162.80116331962742 -77.829037626826405,162.801123524105606 -77.837786601190288,162.801071381677417 -77.849232117058563,162.8008986239563 -77.887000650389709)) Author last name Last name of the Author Allibone Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Craw, Dave Norris, Richard J. Abstract The Abstract for this thesis Koettlitz Group rocks and intercalated orthogneisses in the mid Taylor Valley and Ferrar Glacier regions form a 1-4km wide, north-northwest trending belt, intruded by a variety of undeformed granitoid pIutons along either side. Two phases of deformation affect the Koettlitz Group and intercalated orthogneisses. The earlier phase resulted in isoclinal folding, transposition of Koettlitz Group-orthogneiss contacts and development of a pervasive foliation in all lithologies, while the second phase produced open to tight, upright, shallow plunging, north-northwest trending folds on all scales and minor, sporadic crenulation cleavage in psammitic schists. The Koettlitz Group rocks are dominated by marbles and migmatitic quartzofeldspathic to psammitic schists with lesser amounts of amphibolite, calc-silicate rock, non-migmatitic quartzofeldspathic to psammitic schists and very minor amounts of pelitic and semi-pelitic schist. Field relations and assemblages indicate that calc-silicate rocks are products of metasomatism, but most amphibolites are metamorphosed, basic, igneous rocks. Sporadic development of orthopyroxene-bearing granulite fades assemblages is controlled by metre scale variations in aH₂O and possibly bulk rock composition. Assemblages developed in pelitic and semi-pelitic rocks are characteristic of the uppermost amphibolite facies. Geothermobarometry based on the assemblage; sillimanite - garnet - quartz - cordierite - plagioclase biotite - K-feldspar, found at Nussbaum Riegel , indicate peak metamorphic temperatures between 675°C and 705°C and pressures between 3.8kb and 5.7kb. Garnet-biotite geothermometry using semi-pelitic rocks from other localities and an estimated pressure of 4.8kb yields temperatures between 679°C and 714°C. Granitic to gabbroic orthogneisses intercalated with the Koettlitz Group have chemistries suggestive of active plate margin settings, unlike ultramafic, alkaline amphibolites within the Koettlitz Group whose chemistries are suggestive of intraplate settings. Characteristics of mineral inclusions in augen from augen gneiss intercalated with the Koettlitz Group indicate that augen gneiss is a deformed, pre-F₁ intrusive and not the product of metasomatism. Segregation of leucosome material in some meta-sediments and orthogneisses was promoted by extensional fracturing and tensional shearing on the limbs of some F₂ folds, caused by high grain boundary fluid pressure and appropriate strain rates. Initial segregation of leucosome material by compaction and filter pressing mechanisms may have aided leucosome infiltration of shears and fractures. Boudinage structures in amphibolite and psammitic schist layers surrounded by leucosome indicate leucosomes possessed a much lower yield stress and were therefore molten. Repeated failure along shears and fractures produced dikes, sills and veins of anatectic melt up to 50cm thick. Dilation in fold hinge zones during deformation promoted propogation of these sills and dikes towards the hinges of F₂ folds, resulting in the development of "microplutons" of xenolith-rich anatectic leucogranite up to 50 metres across beneath impermeable, refractory layers of amphibolite and marble. Continuing deformation of fold hinges containing incompressible, molten, "microplutons" of anatectic melt caused refractory "cap rock" layers to fracture and allowed intrusion of anatectic leucogranite dikes through the fold hinge. Low melt fractions prevailing during anatexis prevented the small amounts of anatectic leucogranite from forming pluton scale bodies. OURArchive handle The handle from the Otago University Research Archive (OURArchive) <a href="http://hdl.handle.net/10523/2913">http://hdl.handle.net/10523/2913</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. Dry Valleys South Victoria Land Antarctica Thesis description Number of pages, maps, CDs, etc. xix; 208 p; maps folded in text; ill; 30cm. 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 1988Allibone Creator An entity primarily responsible for making the resource Allibone, Andrew Harold Date A point or period of time associated with an event in the lifecycle of the resource 1988 Title A name given to the resource Koettlitz group meta-sediments and intercalated orthogneisses from the mid Taylor Valley and Ferrar Glacier regions Subject The topic of the resource Map Structural geology Geochemistry Metamorphic geology Igneous petrology geothermobarometry Koettlitz Group migmatites orthogneiss