Strengths and limitations of using radiogenic isotope signatures of marine sediments from Baffin Bay for the reconstruction of ice dynamics and paleoenvironments in the Canadian Arctic and Greenland
Bibliographic record
Abstract
Radiogenic Sr, Nd, and Pb isotope compositions in marine sediments are widely used as provenance tracers delivering valuable information about past environmental conditions. Over the last ten years, several studies performing radiogenic isotope analysis on marine sediment records from Baffin Bay and Labrador Sea highlighted the strength of this method in shedding light upon past glacier dynamics and related environmental changes in Greenland and the Canadian Arctic. The main outcomes of our studies include precise information on the opening of Arctic gateways and the setting of oceanic connection from the Arctic Ocean to the Atlantic through Baffin Bay. At a more regional scale, these tracers document the late glacial to Holocene dynamics of Baffin Island glaciers, helping to understand how climate and oceanic conditions impacted glacier margin fluctuations. As importantly, our study also highlighted limitations in the sensitivity of radiogenic isotopes from Baffin Bay marine sediments as tracers. Most important for interpreting radiogenic isotope compositions is the availability of a sufficiently dense cover of their properties in bedrock and reference isotope signatures from such remote areas to better resolve potential sediment sources. Another challenge for sediment records obtained from core sites at near-proximity to ice margins is the effect of glacier dynamics on the sediment composition. Intense meltwater discharge can lead to grain size and mineral sorting, which could bias the radiogenic isotope composition of the sediment. Nonetheless, radiogenic isotopes present a significant advantage over lesser availability tracers, such as biological proxies, which can be restricted due to the harsh climate conditions. In several cases, radiogenic isotope analysis also reveals more information about sediment provenance than mineralogical assemblages. All in all, in combination with sedimentological and mineralogical features, the radiogenic Sr, Nd, and Pb isotope compositions of Arctic marine sequences can be used as reliable tracers for changes in sediment provenance.
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 | 0.025 | 0.034 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.004 | 0.007 |
| Science and technology studies | 0.003 | 0.002 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.003 | 0.003 |
| Research integrity | 0.001 | 0.001 |
| 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".