Dendrochemical Analysis as a Method to Identify Mineralized Zones: Insights from the Marathon Cu-PGE Deposit
Bibliographic record
Abstract
The Marathon Cu-platinum-group element (PGE) deposit is located within the Eastern Gabbro Series of the Proterozoic Coldwell Alkalic Complex, 10 km north of Marathon, Ontario. The Cu-PGE mineralization occurs within the Two Duck Lake Gabbro, an olivine gabbro intrusion. This geochemical orientation study tested the trace element analysis of tree cores as a method of identifying mineralized versus background areas in the Marathon deposit, focusing on copper (Cu), sulfur (S), palladium (Pd), and silver (Ag). Tree core samples (n=25) were collected with an increment borer from black spruce (Picea mariana) trees and dated by counting growth rings. Fifteen cores, 12 near/overtop the deposit and three distal control samples, were analysed with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) over a 10-year interval (1992-2002). Data normalization to 88Sr like in other dendrochemical studies corrected for tree health and growth effects. 32S, 63Cu, and 105Pd were found to have the highest concentrations at 94.198, 2.224, and 0.055 ppm, respectively, in control sample 23KPA2-3004. This tree is located beside the Pic River and receives large amounts of run-off from the entire Eastern Gabbro Series, possibly enhancing the chemical composition of the tree core. Excluding this anomalous sample, significant concentrations of Cu and Ag were found moving SSW along the deposit, aligning with the direction of movement of the Pleistocene Laurentide Ice Sheet. While this study did not clearly identify mineralized zones in the Marathon deposit, it has identified the possibility of mineralized run-off in the Pic River affecting nearshore tree chemical composition. The influence of local terrain and glacial till must be also considered when using this method. Future research will continue to study the factors influencing the uptake of elements in trees and refine methods for detecting mineralization through tree core analysis.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".