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Automated image and X-ray analysis, with a scanning electron microscope, has been used to "fingerprint" mineral particles in bituminous coals of the Sydney Coalfield and catalogue their chemical class and size distribution. Four seams (Hub, Harbour, Phalen, and Gardiner) were analyzed quantitatively for some 32 000 mineral particles; these analyses revealed particle-size and weight distributions for 27 chemical classes. Manual searches augmented the computer-automated scans, covering eight seams and recording a total of 35 mineral species, their paragenesis, and sites for 28 elements.Sydney seam mineralogy is dominated by pyrite and kaolinite, but illite, chlorite, siderite, ankerite, and quartz are locally prominent; these are accompanied by a large variety of accessory minerals (zircon, rutile, apatite, barite, gypsum, rare-earth phosphates, and ore minerals) and alteration products (goethite and hydrated sulphates). Individual column benches show geochemical fades with different mineral suites resulting from cyclic sedimentation, hydrologie conditions, and changes in pore-water chemistry during peat accumulation, coalification, and diagenesis. A sulphide facies and a siderite–chlorite facies are recognized within one seam (Harbour); these facies change vertically and laterally within lithotype bands.Stratigraphic correlation is precluded, but quantitative mineralogy can elucidate paleoenvironments and be applied to coal-cleaning technology (beneficiation) or environmental studies.

Rare earths (La to Lu, Y) are investigated for five Archean granitoid stocks of Kenoran age that intrude the Wabigoon volcanic–plutonic belt. Homogeneous granodiorites are characterized by low total rare earth concentrations (ΣREE), with chondrite-normalized REE patterns that show steep negative slopes, no Eu anomalies, and enrichment of Lu. A hypabyssal porphyry of possible volcanic affiliation displays similar REE patterns, but is more depleted in heavy REE. Zone plutons yield patterns of steep slope, no Eu anomalies, with or without Lu enrichment. REE concentrations decrease from monzodioritic margins, to granodioritic cores, to aplitic apophyses.These plutons carry REE concentrations similar to the Canadian Shield average, but notably lower than some published averages for granitoids. No secular change is evident for the Archean interval.ΣREE decreases during differentiation with no appreciable fractionation of heavy over light REE, until the end stages. Late differentiates suffer depletion in heavy REE by hornblende fractionation. Lu enrichment correlates with deuteric metasomatism, as evidenced by microcline megacrysts. Eu anomalies are absent because fractionation of divalent Eu is prevented by high concentrations of Sr and Ba.Quantitative source modeling should consider the complete magma history of emplacement, crystallization, and deuteric metasomatism.

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