Thesis Format
Integrated Article
Degree
Doctor of Philosophy
Program
Geology
Supervisor
Banerjee, Neil R.
2nd Supervisor
Van Loon, Lisa, L
Co-Supervisor
Abstract
The application of biogeochemical techniques in mineral exploration is to use the chemistry of plants to identify the presence and characterizations of concealed mineralization. Gold prospecting using biogeochemical techniques is found to be a viable geochemical tool in the early stages of exploration. This study aims to use a systematic two-phase statistical approach, including process discovery and process validation, to evaluate the multi-element biogeochemical dataset and identify the geochemical process controlling elemental occurrence and distribution in plant samples. To achieve these objectives, three biogeochemical surveys were conducted over the early and advanced gold targets located at two economically promising Archean greenstone-hosted orogenic gold deposits: including the Monument Bay Gold Project (MBGP) and Yellowknife City Gold Project (YCGP). The MBGP is a highly prospective gold deposit located in the northeastern part of Manitoba. The YCGP is a region of intense exploration and drilling near the extensions of the gold-bearing shear zones that host the historic Giant and Con Mines, located close to the city of Yellowknife, Northwest Territories.
Exploratory data analysis (EDA), including univariate and multivariate statistical analysis, was used to interpret biogeochemical data and identify the plant-substrate relationship and, subsequently, zones of gold enrichment. The results of EDA indicated that black spruce can successfully accumulate anomalous values of Au and its pathfinder elements, including As, Ag, Bi, Se, Sb, and Tl. Therefore, it is the preferred plant species for biogeochemical exploration in Canadian boreal forests. In addition, the Inverse distance weighted (IDW) interpolation method demonstrated strong associations between Au and its pathfinder elements. It is revealed that zones of Au enrichments are associated with different sets of pathfinder elements based on the bedrock composition and mineralization style. Arsenic, Se, Tl, and Sb signatures accompanied Au in both MBGP and YCGP. According to the principal component analysis (PCA), the geochemical/ mineralization and physiological factors control elemental distribution in black spruce. The results of this study attest to the robustness of multivariate statistical analysis in detecting zones of Au enrichment using biogeochemical exploration methods.
Summary for Lay Audience
Biogeochemical techniques in mineral exploration use plants' chemistry to identify the buried mineralization presence. This method is a viable geochemical tool in the early stages of exploration. This study aims to use a statistical approach to evaluate the multi-element biogeochemical dataset and identify the geochemical process controlling elemental occurrence and distribution in plant samples. Three biogeochemical surveys were conducted at the two gold (Au) deposits, including the Monument Bay Gold Project (MBGP) and Yellowknife City Gold Project (YCGP), to achieve these objectives. The MBGP is a highly prospective Au deposit located in the northeastern part of Manitoba. The YCGP contains high-grade Au targets located close to the city of Yellowknife, Northwest Territories.
Exploratory data analysis (EDA), including univariate and multivariate statistical analysis, was used to interpret biogeochemical data and identify the plant-substrate relationship and, subsequently, zones of Au enrichment. The results of EDA indicated that black spruce samples can successfully accumulate high values of Au and its indicator elements, including arsenic (As), silver (Ag), bismuth (Bi), selenium (Se), antimony (Sb), and Thallium (Tl). Therefore, it is the preferred plant species for biogeochemical exploration in Canadian boreal forests. According to the EDA, the geochemical/mineralization and physiological factors control elemental distribution in black spruce. The results of this study attest to the robustness of multivariate statistical analysis in detecting zones of Au enrichment using biogeochemical exploration.
Recommended Citation
Ghorbani, Zohreh, "Biogeochemical Prospecting for Gold using Robust Multivariate Statistical Analysis" (2022). Electronic Thesis and Dissertation Repository. 9021.
https://ir.lib.uwo.ca/etd/9021
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