Mineralogy, geochemistry and morphology of Arctic gossans on Axel Heiberg Island, NU, Canada: Spectroscopic investigation and implications for Mars
Bibliographic record
Abstract
Gossans are formed through the oxidation of sulfide ore deposits by fluids, such as meteoric water or hydrothermal solutions, leading to locally acidic conditions. In permafrost regions, gossans undergo seasonal chemical weathering after their initial formation (reactive gossans), potentially providing a sustained energy source for microbial activity. Arctic gossans are therefore considered valuable analogs for Martian paleo-hydrothermal systems and promising astrobiological targets. While hundreds of gossans have been identified in the Arctic, few have been studied in detail, and none using rover-compatible remote sensing techniques. This study aims to characterize the morphological profile of seven Arctic gossans located at Expedition Fiord (Axel Heiberg Island, Nunavut), as well as their geochemistry, mineralogy and organic carbon content using X-ray fluorescence, X-ray diffraction (XRD), Visible (VNIR) to thermal infrared (MIR-TIR) reflectance and Raman spectroscopy. Results showed a dominance of silicon, calcium and iron. Mineralogical analyses revealed gypsum and quartz as major phases, with variable amounts of silicates, sulfates, iron sulfides and iron oxyhydroxides. Raman spectroscopy detected organic carbon in most samples, up to 50 cm deep, in various organo-mineral complexes. XRD was the only technique to detect iron sulfides. VNIR-MIR-TIR reflectance and Raman spectroscopy provided mineralogical results consistent with XRD. All gossans displayed classical profiles, with alteration zones overlying primary sulfides, but showed diverse color and compositional stratification patterns. These variations suggest local mechanisms influence mineral and associated organic carbon distribution. Further investigations should focus on better understanding these local variations, which could guide the search for biosignatures in gossan-like features on Mars. Highlights : • Spectroscopic investigation of Arctic gossans as analogs to Mars • Abundant quartz and/or gypsum detected, with silicates, sulfates, oxides, sulfides • Classic gossan profile is observed with a variety of stratification patterns • Organic carbon was found in most samples at various depths • Oxidized sulfide deposits are key places to look for potential biosignatures on Mars
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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 | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".