Evaluation and modeling of trace elements from drillcore analysis at Kankberg Au-Te mine, Skellefte District, Sweden
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Information derived from 498 drill holes encompassing over 2,6 million sampling points taken from the Kankberg Au-Te mine located in the Skellefte District were used in order to model and evaluate the trace element distribution and association in and around the mine. The modeling software Leapfrog Geo was used, revealing the samples to mainly be confined within the western part of the deposit. A zonation of Al, K, Mg and Fe could be seen possibly representing the andalusite, sericite and chlorite-biotite alteration respectively. By constructing a correlation matrix several element associations could be seen showing elements sharing similar chemical properties or related to minerals known to occur in the deposit. Au was shown to correlate moderately with Ag and slightly with Te, Bi, Sb, Th, La, U and P. The trace elements found within monazite (Ce, La and Th) could be found in the vicinity of Au in the model suggesting a possible genetic link. Immobile-incompatible and immobile-compatible elements were used to determine the precursor lithology in the Kankberg deposit which consisted mainly of dacite but also of rhyolite, andesite and sparse mafic rocks. Mass change calculations were made, using least altered dacite from Maurliden and Petiknäs VMS-deposits, revealing mass losses in Y, Nb and Sc, elements traditionally thought to be immobile. However, these can be mobile under certain conditions like extensive alteration which is known to have occurred in the Kankberg deposit. The losses could also have been enabled by transport of fluoride complexes in the hydrothermal fluid as evident by topaz that can be found in the deposit. A link between element loss in mass and abundance in the model could be observed when comparing to the Petiknäs deposit, with Y and Nb having lost more mass than Sc and subsequently occurring less abundant in the model.
Place, publisher, year, edition, pages
2015. , 26 p.
Technology, Kankberg, gold, tellurium, andalusite, trace element, modeling, mineralization, alteration, Leapfrog Geo, precursor rocks, mass change calculations, element associations
IdentifiersURN: urn:nbn:se:ltu:diva-56287Local ID: d11f5c9d-a00c-4301-ba29-574b6f283418OAI: oai:DiVA.org:ltu-56287DiVA: diva2:1029674
Subject / course
Student thesis, at least 30 credits
Geosciences, master's level
Validerat; 20151007 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved