Data Publication

Quantitative mineralogy, mineral chemistry and microtex-tural data on the UG2 chromitite intruded by iron-rich ul-tramafic pegmatite (IRUP) at the Thaba Mine, northwest-ern Bushveld Complex, South Africa

Zhou, Haoyang | Appelt, Oona | Tjallingii, Rik | Bachmann, Kai | Trumbull, Robert B.

GFZ Data Services

(2023)

Descriptions

Discordant iron-rich ultramafic pegmatites (IRUPs) intersect the UG2 chromitite at many places in the Bushveld Complex but the effects on ore grade and mineralogy have rarely been studied in detail. We investigated a drillcore profile through the UG2 layer affected by IRUP intrusions at Tha-ba mine, NW Bushveld. The work involved quantitative assessment of the ore mineralogy from mineral liberation analysis (MLA), chemical analyses of the main silicate and oxide minerals by elec-tron microprobe (EPMA) and micro-X-ray fluorescence (micro-XRF) element maps of the UG2-IRUP contacts. The data reveal features of UG2-IRUP interaction at different scales. The micro-XRF study of the contacts shows that a thin layer of Fe-Ti-Cr spinel and ilmenite formed on the IRUP side, while chromite on the UG2 side underwent grain coarsening with loss of interstitial space, and developed chemical gradients in Cr, Al, Fe and Ti. On a larger scale, the MLA data document changes in ore and gangue mineral assemblages through most of the meter-thick UG2 layer. This includes formation of secondary hydrous silicates, replacement of PGE- sulfides by PGE alloys and PGE- As-Sb-Bi-Te-Pb phases, and formation of secondary Ni-Cu-Fe sulfides after pentlandite and chalcopyrite.

Keywords

MSL enriched keywords

igneous rock - intrusive

acidic intrusive

pegmatite

minerals

chemical elements

iron

measured property

iron

Analyzed feature

mineralogy and composition

quantitative mineralogy

sulfide minerals

chalcopyrite

pentlandite

oxide mineral

chromite

ilmenite

spinel

equipment

electron probe micro-analyzer

x-ray spectrometer

x-ray fluorescence spectrometer

aluminium

chromium

Apparatus

microchemical analysis

electron probe micro analyser

Equipment

borehole drilling

drill core

MSL enriched sub domains

geochemistry

microscopy and tomography

geo-energy test beds

Resource Type

Dataset

Source

https://dataservices.gfz.de/panmetaworks/showshort.php?id=ce26d0d3-ee30-11ec-9531-ca1f3ed77ce8

Source publisher

GFZ Data Services

DOI

10.5880/gfz.3.1.2022.005

Creators

Zhou, Haoyang

Personal

Natural History Museum, University of Oslo, Oslo, Norway | GFZ German Research Centre for Geosciences, Potsdam, Germany

Appelt, Oona

Personal