Stratigraphic record of tectonic and climatic impact on orogenic growth: An example from the Hexi Corridor Basin, NE Tibetan Plateau
Bibliographic record
Abstract
Abstract The locus of shortening, accretion, and erosion are key components in modulating the rate, pattern, and magnitude of orogenic wedge growth, but separating their respective roles in the evolution of wedge taper is often difficult because of the absence of exhumation and uplift data from the mountains. However, such information can be preserved in the adjacent basins, and a combination of sediment provenance and accumulation rate records may be able to distinguish tectonic versus climatically caused orogenic wedge evolution. Here we present a joint sediment accumulation rate (SAR) and provenance analysis based on zircon U-Pb ages and heavy mineral composition of a drill core from the foreland of the Qilian Shan (i.e., Hexi Corridor Basin, NE Tibetan Plateau) with the aim to reveal the evolution of the Qilian orogenic wedge and its relationship to tectonics and climate. The provenance data show a gradual increase in sediment attributable to the Yumu Shan in the toe of the orogenic wedge and associated decrease in contribution from the high-elevation hinterland Zoulang Nan Shan source between 7 Ma and 3 Ma, followed by a reverse of these trends from 3 Ma to the modern. The increased contribution from the toe of the orogenic wedge (Yumu Shan) is accompanied by an increase in SAR, and we interpret this joint signal as the result of in-sequence thrusting, which caused flexural subsidence and created more deposition space in the bounding foreland. The increased contribution from the hinterland from 3.0 Ma to 1.8 Ma, accompanied with the decreased SAR, is attributed to the onset of Northern Hemisphere glaciation, which increased glacial erosion of the high-elevation hinterland areas and caused erosional unloading of the orogenic wedge, leading to flexural uplift in the foreland and reduced SAR. After 1.8 Ma, continued increase in the contribution from the hinterland accompanied with the SAR increase is less straightforward to interpret. We suspect that glacial erosion might have activated fault movements in the hinterland area, and tectonic-caused rock uplift was faster than glacial erosion. Therefore, high sediment flux from the hinterland was maintained but flexural subsidence accelerated. Our results demonstrate that both tectonics and climate have shaped regional landscape evolution and emphasize the role of glacial erosion in accounting for orogenic wedge evolution at ca. 3 Ma.
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 | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".