Mineralogical Investigation of Mg‐Sulfate at the Canaima Drill Site, Gale Crater, Mars
Bibliographic record
Abstract
Abstract For the first time on Mars, the crystalline magnesium‐sulfate mineral starkeyite (MgSO 4 ‧4H 2 O) was definitively identified using the CheMin X‐ray diffraction instrument at Gale crater. At the Canaima drill site, starkeyite along with amorphous MgSO 4 ‧ n H 2 O are among the “polyhydrated Mg‐sulfates” interpreted in orbital reflectance spectra. Mg‐sulfates are good climate indicators as they are very responsive to changes in temperature and relative humidity. We hypothesize that, through evaporation, Mg‐sulfates formed at the end of brine evolution when ion concentrations became saturated and precipitated on the surface or near sub‐surface as either epsomite or meridianiite. These minerals were subsequently dehydrated later to starkeyite and amorphous MgSO 4 ‧ n H 2 O in response to a drier Mars. At Canaima, starkeyite is stable and would form during the warmer Mars summers. Due to very slow kinetics at the low Mars winter temperatures, starkeyite and amorphous MgSO 4 ‧ n H 2 O would be resistant to recrystallize to more hydrous forms and thus likely persist year‐round. During the course of analyses, starkeyite transforms into amorphous MgSO 4 ‧ n H 2 O inside the rover body due to the elevated temperature and greatly reduced relative humidity compared to the martian surface at the Canaima drill site. It is possible that crystalline sulfate minerals existed in earlier samples measured by CheMin but altered inside the rover before they could be analyzed. Starkeyite is most likely prevalent in the subsurface, whereas both starkeyite and amorphous MgSO 4 ‧ n H 2 O are likely present on the surface as starkeyite could partially transform into amorphous MgSO 4 ‧ n H 2 O due to direct solar heating.
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 | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".