Recognizing tide- and wave-dominated compound deltaic clinothems in the rock record
Bibliographic record
Abstract
Abstract Many modern deltas exhibit a compound geometry that consists of a shoreline clinoform and a larger subaqueous clinoform connected through a subaqueous platform. Despite the ubiquity of compound clinoforms in modern deltas, very few examples have been documented from the ancient sedimentary record. We present recognition criteria for shelf compound-clinoform systems in both tide- and wave-dominated deltas by integration of ancient and modern examples from multiple types of data. The compound clinothem can be identified by using a combination of: (1) the three-dimensional (3-D) configuration identified in bathymetric or seismic data, (2) bipartite stacked regressive units, consisting of a lower muddy coarsening-to-fining-upward (CUFU) or coarsening-upward (CU) unit (30–100 m thick) and an overlying sandier CU unit (5–30 m thick) (together they represent the subaqueous and shoreline clinoform pair), and (3) distinct facies described herein, though both types of delta have highly bioturbated mudstone and siltstone bottomsets. Tide-dominated deltas have muddy foresets with tidal scours containing tidal rhythmites or inclined heterolithic strata in the subaqueous clinothem overlain by river and tidal deposits of the shoreline clinothem. Wave-dominated deltas show mainly wave-enhanced sediment-gravity-flow (WSGF) beds and some thin hummocky/swaley cross-stratified (HCS/SCS) sandstones toward the top in the subaqueous muddy foreset, and upward-thickening HCS/SCS and trough/planar cross-bedded sandstones interbedded with siltstones in the shoreline clinothem. The subaqueous platform, which links the clinoform couplet, shows evidence of frequent tidal or wave reworking and redeposition. The platform in tide-dominated deltas is characterized by tide-generated heterolithic strata (e.g., bidirectional current-rippled and cross-stratified sandstones, spring and neap tidal bundles, tidal rhythmites) with occasional storm-wave–influenced strata. In contrast, the wave-dominated platform comprises small-scale swales with scours and mud clasts and some WSGF deposits. The proposed criteria can aid in the recognition of compound deltaic clinothems in other basins, particularly those with limited amounts and/or types of data.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.004 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| 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".