PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines
Ni-laterites have the potential to become unconventional ore deposits for platinum group elements (PGE). This study was conducted to determine enrichment trends of PGE as a result of the Ni-laterization process. 6 samples were selected by mine workers from the protolith, saprolite, and limonite hori...
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Luleå tekniska universitet, Geovetenskap och miljöteknik
2023
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ftluleatu:oai:DiVA.org:ltu-95281 2023-05-15T17:09:18+02:00 PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines Dossey, Michelle 2023 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-95281 eng eng Luleå tekniska universitet, Geovetenskap och miljöteknik http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-95281 info:eu-repo/semantics/openAccess PGM PGE laterite limonite chromitite dunite platinum group minerals platinum group elements Acoje Philippines Geochemistry Geokemi Student thesis info:eu-repo/semantics/bachelorThesis text 2023 ftluleatu 2023-01-19T17:10:37Z Ni-laterites have the potential to become unconventional ore deposits for platinum group elements (PGE). This study was conducted to determine enrichment trends of PGE as a result of the Ni-laterization process. 6 samples were selected by mine workers from the protolith, saprolite, and limonite horizons of the Ni-laterite profile from the Acoje ophiolite block, Luzon, Philippines, and sent to Luleå University of Technology (LTU). 2 samples representing the protolith are described as dunite having undergone serpentinization, 1 sample is a massive chromitite from the saprolite layer of the laterite profile, 1 sample is a massive chromitite from the limonite layer of the laterite profile, and 2 samples are limonitic soils. Total PGE contents of the investigated Acoje samples range from 161-1180 ppb with the highest contents of PGE occurring in the limonite hosted chromitite, and the lowest contents in the saprolite hosted chromitite. C1 chondrite-normalized patterns reveal distinct trends of the PGE in the different sample types: dunite samples have a positive trend from Ir-Pd, the chromitite samples have a negative trend from Ru-Pd with a negative Ir anomaly and the limonite samples have a strong positive trend from Ir-Pd. Rare earth elements (REE) chondrite-normalized patterns of the samples show a negative Ce anomaly in the limonite while the dunite and saprolite-hosted chromitite have negative Eu anomalies. Cr# (Cr/[Al+Cr]) and Mg# (Mg/[Fe2++Mg]) were analyzed using automated mineralogy and produced Cr# values ranging from 0.67 – 0.77 and Mg# values from 0.46 – 0.59. 17 platinum group minerals (PGM) were identified from the Acoje samples: 9 from the dunite, 1 from the saprolite-hosted chromitite, 6 from the limonite-hosted chromitite and 1 from the limonite. Laurite ((Ru,Os)S2) was identified in samples A-02 and A-07 and is the only primary mineral identified. Secondary PGM, thought to have formed due to alteration processes during serpentinization, were identified as alloys composed of: Cu-Pd, Cu-Pt, Pt-Ni-Cu, ... Bachelor Thesis Luleå Luleå Luleå Luleå University of Technology Publications (DiVA) |
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Luleå University of Technology Publications (DiVA) |
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ftluleatu |
language |
English |
topic |
PGM PGE laterite limonite chromitite dunite platinum group minerals platinum group elements Acoje Philippines Geochemistry Geokemi |
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PGM PGE laterite limonite chromitite dunite platinum group minerals platinum group elements Acoje Philippines Geochemistry Geokemi Dossey, Michelle PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines |
topic_facet |
PGM PGE laterite limonite chromitite dunite platinum group minerals platinum group elements Acoje Philippines Geochemistry Geokemi |
description |
Ni-laterites have the potential to become unconventional ore deposits for platinum group elements (PGE). This study was conducted to determine enrichment trends of PGE as a result of the Ni-laterization process. 6 samples were selected by mine workers from the protolith, saprolite, and limonite horizons of the Ni-laterite profile from the Acoje ophiolite block, Luzon, Philippines, and sent to Luleå University of Technology (LTU). 2 samples representing the protolith are described as dunite having undergone serpentinization, 1 sample is a massive chromitite from the saprolite layer of the laterite profile, 1 sample is a massive chromitite from the limonite layer of the laterite profile, and 2 samples are limonitic soils. Total PGE contents of the investigated Acoje samples range from 161-1180 ppb with the highest contents of PGE occurring in the limonite hosted chromitite, and the lowest contents in the saprolite hosted chromitite. C1 chondrite-normalized patterns reveal distinct trends of the PGE in the different sample types: dunite samples have a positive trend from Ir-Pd, the chromitite samples have a negative trend from Ru-Pd with a negative Ir anomaly and the limonite samples have a strong positive trend from Ir-Pd. Rare earth elements (REE) chondrite-normalized patterns of the samples show a negative Ce anomaly in the limonite while the dunite and saprolite-hosted chromitite have negative Eu anomalies. Cr# (Cr/[Al+Cr]) and Mg# (Mg/[Fe2++Mg]) were analyzed using automated mineralogy and produced Cr# values ranging from 0.67 – 0.77 and Mg# values from 0.46 – 0.59. 17 platinum group minerals (PGM) were identified from the Acoje samples: 9 from the dunite, 1 from the saprolite-hosted chromitite, 6 from the limonite-hosted chromitite and 1 from the limonite. Laurite ((Ru,Os)S2) was identified in samples A-02 and A-07 and is the only primary mineral identified. Secondary PGM, thought to have formed due to alteration processes during serpentinization, were identified as alloys composed of: Cu-Pd, Cu-Pt, Pt-Ni-Cu, ... |
format |
Bachelor Thesis |
author |
Dossey, Michelle |
author_facet |
Dossey, Michelle |
author_sort |
Dossey, Michelle |
title |
PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines |
title_short |
PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines |
title_full |
PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines |
title_fullStr |
PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines |
title_full_unstemmed |
PGE Geochemistry and Mineralogy of Dunite, Chromitite, and Laterite Samples from the Acoje Ophiolite Block, Philippines |
title_sort |
pge geochemistry and mineralogy of dunite, chromitite, and laterite samples from the acoje ophiolite block, philippines |
publisher |
Luleå tekniska universitet, Geovetenskap och miljöteknik |
publishDate |
2023 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-95281 |
genre |
Luleå Luleå Luleå |
genre_facet |
Luleå Luleå Luleå |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-95281 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766065350014664704 |