Bibliographic record
Abstract
The trace of the ancestral Susquehanna River across the modern coastline has been displaced over 40 km southward since the middle Pleistocene. High-resolution seismic reflection data from the inner shelf suggest that submerged-channel fill is responsible for at least three time-lagged channel shifting events during regressive parts of Pleistocene eustatic cycles. Traditional models for tidal-inlet shift are dependent on migrating spit platforms that progressively fill a portion of the updrift side of a channel and directly force excavation of an equivalent portion of material from the downdrift side. Channel migration results in a continuous broad channel-scar representing the integrated positions of channels at time scales of 10 0 to 10 2 years. Seismic data adjacent to the southern Delmarva Peninsula illustrate four separate Pleistocene lowstand pathways for the ancestral Susquehanna River. Although regional spits have migrated between these pathways, there is no evidence of continuous channel migration between the channel traces. The mechanism for channel shifting was glacio-eustatically controlled, and occurred at time intervals of 10 5 years. Channel shifting was operative during early regression when fluvial channels were not confined to their previous antecedent lowstand channels and jumped laterally to new locations. Time-lagged channel shifts are indirectly forced by spit growth during major highstand events and widespread regional flooding. During these events, the ancestral Susquehanna River was no longer confined to its fluvial valley but spread into broad ancestral Chesapeake Bays formed in the drowned Chesapeake Basin. Estuarine sediments, migrating spit platforms, and bay-entrance shoals filled the drowned fluvial channels in the seaward parts of the ancestral bays. During subsequent regressions, the bays shrunk and the flow of the ancestral Susquehanna River jumped to adjacent tidal-flushed pathways and subsequently drained to the shelf edge. During late Pliocene and early Pleistocene Iowstands, at least six major rivers drained across the Chesapeake Basin. Time-lagged channel shifts and stream captures have progressively reduced the number of drainways leaving the basin. During the most recent Stage 2 lowstand, only two or possibly three drainways may have crossed the entrance of the Chesapeake Basin.
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.004 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.002 | 0.003 |
| Scholarly communication | 0.005 | 0.006 |
| Open science | 0.004 | 0.005 |
| Research integrity | 0.007 | 0.003 |
| Insufficient payload (model declined to judge) | 0.991 | 0.994 |
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; the direct Gemma label and the distilled Codex classifier agree on what is shown here.
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".