|Title||Tracking ore fluid pathways by in situ synchrotron-XRF analysis of fluid inclusions|
|Author||Rabiei, M; Chi, G; Potter, E G; Feng, R|
|Source||Goldschmidt Virtual 2021; 2021 p. 1 Open Access|
|Links||Online - En direct|
|Alt Series||Natural Resources Canada, Contribution Series 20210209|
|Publisher||European Association of Geochemistry|
|Meeting||Goldschmidt Virtual 2021; July 4-9, 2021|
|File format||html; pdf|
|Area||Forest Lake; Murison Lake|
|Lat/Long WENS||-109.5000 -109.0000 58.0000 57.5000|
|Subjects||economic geology; geochemistry; Science and Technology; Nature and Environment; mineral deposits; uranium; lanthanum; cerium; bromine; iron; strontium; metals; base metals; manganese; nickel; copper;
zinc; lead; mineralization; ore mineral genesis; ore controls; fluid flow; fluid inclusions; x-ray fluorescence analyses; brine; diagenesis; permeability; flow rates; host rocks; bedrock geology; lithology; sedimentary rocks; sandstones; structural
features; faults; quartz; Athabasca Basin; McArthur River Deposit|
|Program||Targeted Geoscience Initiative (TGI-5) Uranium ore systems - fluid pathways|
|Released||2021 07 01|
|Abstract||The Athabasca Basin (Canada) hosts numerous unconformity-related U (URU) deposits located along structural corridors that developed at intersections between basement-rooted reverse faults and the
basin-basement unconformity. LA-ICP-MS and synchrotron-XRF (SXRF) analyses of fluid inclusions indicate that ore fluid(s) in mineralized zones were significantly enriched in U, REEs (La and Ce), Br, Fe, Sr, transition metals (Mn, Ni, Cu, Zn) and Pb.
However, it is not clear whether this U-rich fluid circulated only in the mineralized zones or along entire corridors, which is important in order to understand the key factors controlling formation of URU deposits.|
SXRF analysis indicates that
primary fluid inclusions entrapped in syn-ore quartz veins from the McArthur River deposit and P2 fault zone (Fig. 1) contain high Br and similar concentrations of U, Ca, Sr, REEs, base metals and Zr, regardless of proximity to mineralized zones
(Fig. 1). This finding is consistent with the basin-scale circulation of U-bearing diagenetic brines which were documented in quartz overgrowth far from URU deposits in the Athabasca sandstone . In addition, the positive correlations between U,
base metals (e.g., Cu in Figs. 1a and 1b), REEs and Zr, suggest a similar origin for these elements along the entire corridor. These results suggest that localization of ore zones in certain segments of the corridors was independent of the
geochemical composition of the ore-forming fluid(s). We propose that other factors such as permeability and flow rate of U-bearing and/or reducing fluids played more important roles in localizing U mineralization.
 G. Chi, H. Chu, D. Petts, E.
Potter, S. Jackson, and A. Williams-Jones (2019), Uranium-rich diagenetic fluids provide the key to unconformity-related uranium mineralization in the Athabasca Basin, Scientific reports, vol. 9, no. 1, p. 5530, 2019.
Fig. 1. Photomicrographs and
SXRF elemental maps of fluid inclusion-rich growth zones in drusy quartz veins proximal (a) and distal (b) to the McArthur River URU deposit.
|Summary||(Plain Language Summary, not published)|
The Targeted Geoscience Initiative (TGI) is a collaborative federal geoscience program that provides industry with the next generation of geoscience
knowledge and innovative techniques to better detect buried mineral deposits, thereby reducing some of the risks of exploration. This contribution summaries results from novel, in-situ microanalyses of fluids trapped in the mineral quartz from the
Athabasca Basin to understand the fluid chemistry and fluid pathways during formation of the unconformity-related uranium deposits.