Hyperspectral cathodoluminescence, trace element, and U-Pb geochronological characterization of apatite from the Ernest Henry iron oxide copper-gold (IOCG) deposit, Cloncurry district, Queensland

Hyperspectral cathodoluminescence (CL), geochemical, and geochronological characterization of a series apatite-bearing samples from within around the Ernest Henry IOCG deposit, NW Queensland, Australia, have revealed complex mineral parageneses spectrum U-Pb ages that point to effects multiple geological processes. No two are identical, either in geochemistry or texture, despite their relative proximity one another (all 5 km Henry). CL maps reveal diverse internal textures emissions ranging near infrared (NIR) ultraviolet (UV) with spectra all samples, requiring fitting more than 40 individual peaks (both sharp broad) capture observed variability. Imaging analyses via LA-ICPMS show apatite district is enriched above background variety trace elements, including Na, Mg, Al, Si, V, Mn, As, Sr, Y, rare Earth elements (REEs), Pb, Th, U. Samples outside ore zone display chondrite-normalized REE profiles consistent magmatic hydrothermal origin, whereas exhibits decidedly nature. Moreover, specific zones grains very As-rich (up 7 wt% As 2 O ), effect such high on hyperspectral signature these pronounced dampening emission, regardless concentrations. Uranium-Pb dating same ( LA-ICPMS) has yielded array overlapping Mesoproterozoic 1,580 ± 34 Ma 1,533 61 Ma. These results correlate published constrain alteration area, both before during Cu-Au mineralization. Collectively, data highlight complexity studies at Henry, broader Cloncurry district, probably analogous terranes elsewhere. A combination micro-scale methods as those used this study shown be essential for accurately deciphering information contained petrogenetic indicator minerals.