Shahrestani, S., Tang, J., Sami, M., Sanislav, I.V., and Kumar, A. (2026) Catchment basin analysis of regional geochemical gold data in Queensland. Australian Journal of Earth Sciences, 73 (3). pp. 373-382.

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Abstract

This study incorporates background correction and dilution correction methods for delineating Au geochemical anomalies using data of catchment outlet sediments from two horizons: top outlet sediments (TOS, 0–10 cm) and bottom outlet sediments (BOS, 60–90 cm), collected across the entire Queensland region as part of the National Geochemical Survey of Australia (NGSA) project. The dataset comprises Au concentrations from catchments covering numerous lithological units, which were merged into seven dominant lithologies for analysis. Multiple regression analysis was applied to estimate background Au values owing to lithology, enabling separation of background signals from mineralisation-related anomalies. Results show that dilution-corrected Au residuals improve anomaly detection, with BOS samples outperforming TOS in spatial alignment with 26 of 30 known gold deposit clusters, compared with 14 clusters identified by raw TOS data. The BOS horizon benefits from enrichment in fine sediment fractions (<75 µm) and reduced effects of surface weathering, providing a more stable and representative geochemical signal. Elevated Au levels associated with dominant lithologies may mask true anomalies, underscoring the importance of background correction.

Item ID:	92426
Item Type:	Article (Research - C1)
ISSN:	1440-0952
Copyright Information:	© 2026 the Author(s). Published by Informa UK limited, trading as Taylor & Francis Group. This is an open Access article distributed under the terms of the creative commons Attribution license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. the terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Date Deposited:	23 Jun 2026 23:45
FoR Codes:	37 EARTH SCIENCES > 3703 Geochemistry > 370301 Exploration geochemistry @ 60% 37 EARTH SCIENCES > 3705 Geology > 370508 Resource geoscience @ 40%
SEO Codes:	28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280107 Expanding knowledge in the earth sciences @ 100%
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