Ice? Salt? Pressure? Sediment deformation structures as evidence of late-stage shallow groundwater in Gale crater, Mars
Bibliographic record
Abstract
Abstract Persistence of near-surface water during the late evolution of Gale crater, Mars, would have been fundamental for maintaining a habitable environment. Sedimentation in aqueous conditions is evident during the early stages of crater infilling, where accumulation of lower Mount Sharp group strata is characterized by fluviolacustrine sedimentary rocks. The basal unit of the Siccar Point group—the Stimson formation—which unconformably overlies the Mount Sharp group and represents conditions postdating the exhumation of Aeolis Mons, is characterized by accumulation of aeolian strata under arid conditions. Water was largely absent near the surface during its deposition. At the Feòrachas outcrop, discovery of soft sediment deformation structures in aeolian Stimson strata challenges the notion that Gale crater was devoid of water during its later depositional phase. We identified deformed wind-rippled and vertically laminated sandstones, hosted within erosion-resistant ridges forming boxwork patterns. Broadly, these structures are diagnostic of water (as liquid or as ice) in the shallow subsurface. Comparison with Earth analogues suggests formation by subsurface fluid escape, freeze-thaw processes, or evaporite deformation. Regardless of the mechanism, these structures signify the presence of water at or near the surface much later than previously documented and may extend the habitability window in Gale crater.
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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".