https://theses.otagogeology.org.nz/files/original/74ad481c3c4bfae47c792593f361ce9e.pdf 0e75dc946b801b5edb392bc9f4f59de6 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 ((170.527722753241335 -45.41899398961386,170.564826689551666 -45.421220501760686,170.565451611305633 -45.438143293248309,170.527291495008882 -45.436608607435289,170.527722753241335 -45.41899398961386)) Author last name Last name of the Author McCann Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? PGDipSci Advisers Who supervised/advised this student Craw, D. Abstract The Abstract for this thesis The Bonanza mine, East Otago is a disused gold mine that operated during the later part of the 19th century. It is a hard rock quartz mine situated about lOkm southeast of Dunback. In the steep schist basement in the area, there are deeply incised valleys. These valleys have concentrated gravels eroded from the catchment area, with Bonanza mine being at the head. The largest of these valleys, which is about 3km long by 1 OOm wide contains up to 4m of alluvial gravels. The sediments consist of the Otago Schist basement (Permian) and Taratu Formation (Cretaceous) conglomerates derived from remnants of the regional unconformity preserved on ridge crests. The aims of this study are 1. To find whether grains of alluvial gold sampled from a 12km length of river change in composition downstream; 2. To determine if all alluvial gold in the river is derived from Bonanza mine or if there is another source such as Taratu Formation and 3. What is the rate ofliberation of free gold from the Bonanza mine. The Bonanza quartz vein is known to be about 500 metres long, strikes northwest and dips 40° to the southwest. The vein has visible gold, with some arsenopyrite and pyrite mineralisation. Gold is primarily liberated from the vein by erosion. Palm-sized vein fragments found up to 12km downstream of the mine contain visible gold. Further downstream fragments containing free gold become smaller indicating a progressive liberation of Bonanza gold within the Back Creek catchment. There are no other mineralised veins which have been mapped in the area. The other source of gold in the catchment area is from the eroded Taratu formation. This population has a different silver content than that of the Bonanza gold. The malleable gold grains have been extensively deformed during transport showing distinctly differing morphologies between the sources. The differing methods of source identification are supported by each other; in this study differing silver content is supported by that of specific morphologies. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Otago east Thesis description Number of pages, maps, CDs, etc. 49 leaves : 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 2008McCann Creator An entity primarily responsible for making the resource McCann, Robert Michael. Date A point or period of time associated with an event in the lifecycle of the resource 2008 Title A name given to the resource Alluvial gold liberation and compositions downstream of Bonanza mine, east Otago Subject The topic of the resource Metal-ore deposits alluvial fans Bonanza Mine gold alloys