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dc.contributor.authorMcGladrey, Alexandra Jane
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2014-03-27 13:32:54.132en
dc.date.accessioned2014-03-27T17:47:07Z
dc.date.available2014-03-27T17:47:07Z
dc.date.issued2014-03-27
dc.identifier.urihttp://hdl.handle.net/1974/8671
dc.descriptionThesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-03-27 13:32:54.132en
dc.description.abstractExploration for large zinc silicate deposits is more challenging than zinc sulfide deposits, as they do not exhibit similar geophysical anomalies. The Vazante deposit, which is the world’s largest zinc silicate deposit, occurs in brecciated dolomite and comprises mainly willemite with various proportions of hematite, and minor franklinite and sphalerite. In the Vazante region, the exploration challenge is enhanced as outcrops are rare, bedrock generally sits below 10s of metres of laterite cover and barren hematite-rich breccias have a similar geophysical signature to willemite ore bodies. In order to evaluate the applications of geophysical surveys in the exploration of this type of deposit, data from 475 samples were investigated from drill holes representative of the various types of ore, host rocks and zones of known geophysical anomalies in the Vazante District. Geochemical (ICP-MS and XRF) and mineralogical (optical, EMPA, SEM and MLA) data were integrated with physical rock properties (density, magnetic susceptibility and K-U-Th gamma ray spectrometry) to assist in finding new ore zones. The most distinct physical property of the ore is density (3.0-4.3 g/cm3), compared with the host rocks (2.7-3.0 g/cm3). This is due to high proportion of denser minerals (hematite and willemite) in the ore. However, barren hematite breccias also have high densities (3.0-4.5 g/cm3). The zinc ore and hematite breccias yielded higher magnetic susceptibilities (0.1-38 x10-3 SI) than the surrounding host rocks, with the highest values associated with greater proportions of franklinite and magnetite (7-38 x10-3 SI). The zinc ore has an elevated U concentration (up to 33ppm) relative to the various host rocks (up to 7 ppm), yielding higher gamma spectrometric values. The results of this investigation indicate that an integration of magnetic, gravimetric and radiometric surveys would be required to identify zinc silicate ore zones and potentially differentiate them from barren hematite breccias and host rocks.en_US
dc.languageenen
dc.language.isoenen_US
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectGamma Ray Spectrometryen_US
dc.subjectMineral Explorationen_US
dc.subjectPhysical Rock Propertiesen_US
dc.subjectBrasilia Fold Belten_US
dc.subjectZinc Silicate Depositsen_US
dc.titleTHE INTEGRATION OF PHYSICAL ROCK PROPERTIES, MINERALOGY AND GEOCHEMISTRY FOR THE EXPLORATION OF LARGE HYPOGENE ZINC SILICATE DEPOSITS: A CASE STUDY OF THE VAZANTE ZINC DEPOSITS, MINAS GERAIS, BRAZILen_US
dc.typeThesisen_US
dc.description.degreeMasteren
dc.contributor.supervisorOlivo, Gema Ribeiroen
dc.contributor.departmentGeological Sciences and Geological Engineeringen


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