Synchrotron (+neutron) geoscience

From the field to the lab – using high intensity X-ray and neutron sources at local and overseas facilities we can investigate samples at the micron to the atomic level.

Example: Nataljamalikiite, TlI, a new thallium mineral for an active fumarole at Avacha Volcano, Kamchatka Peninsula, Russia

High resolution SEM image of an unpolished sample, showing occurrence of pseudo-cubic nanocrystals of nataljamalikiite within vacuoles in an As-(Te)-rich sulfur matrix.

The crystal structure of nataljamalikiite – determined from data collected at the MX2 beam line at the Australian Synchrotron. Thallium(I) in gold, and I(-I) in purple.

Megapixel Synchrotron X-ray Fluorescence Imaging (MSXRF) imaging of sample G555 from the Moonta IOCG deposit (South Australia). (a) Fe-U-Cu RGB MSXRF map. Inset (1), BSE image showing a relict bornite grain with a thin U-rich coating in a F2 veinlet. Inset (2), BSE image showing relict bornite and siderite in a F1 vein. (b) Copper MSXRF map, with inset (1) showing the Fe map. (c) BSE images showing replacement of siderite by pyrite and thin chalcopyrite coating along grains boundaries in a F1 vein (images taken with the area of inset (1) in panel (b). Abbreviations: Bn-bornite; Ccp-chalcopyrite; Hem-hematite; Py-pyrite; Sd-siderite; U-uranium-rich phase (probably uraninite).

Reference: Ore Petrography Using Megapixel X-Ray Imaging: Rapid Insights into Element Distribution and Mobilization in Complex Pt and U-Ge-Cu Ores. K Li et al. 2016 Economic Geology 111 (2), 487-501

Analysis of the X-ray absorption near edge spectroscopy stack for sample B3 using a linear combination fit, using the dataset smoothed over 2x2 pixels. (a) Red–green–blue (RGB) image showing the distribution of the three components Cu2S (red), CuFe2S3 (green) and Cu on humic acid (Cu_HA; blue). Black pixels were excluded based on low Cu counts. (b) Individual spectra and corresponding fits for the points labelled in (a). (c) Map of the values of cred2. D.L., detection level.

Reference: Speciation mapping of environmental samples using XANES imaging. B Etschmann et al. 2014 Environmental Chemistry 11 (3), 341-350