Geochemistry and mineralogy of Neoproterozoic strata in northeastern Svalbard: Reevaluating the prevalence of basalt weathering during the early Neoproterozoic
Bibliographic record
Abstract
Abstract Neoproterozoic strata of the Lomfjorden and lower Hinlopenstretet Supergroups (early–middle Tonian Veteranen Group, middle–late Tonian Akademikerbreen Group, and Cryogenian–Ediacaran Polarisbreen Group) in northeastern Svalbard, Norway, represent one of the most complete and well-preserved terminal Proterozoic sedimentary successions worldwide. These strata have been used in numerous geochemical compilations to probe Neoproterozoic paleoenvironments, including patterns of global chemical weathering prior to the snowball Earth events. Here, we present a new high-resolution geochemical data set incorporating δ13C, δ18O, and 87Sr/86Sr data from carbonates with mineralogy, major- and trace-element data, and εNd data from mudrocks to critically examine previously published data sets and better ally the succession with global Neoproterozoic records through a refined age model. We found that the geochemistry of Lomfjorden and lower Hinlopenstretet Supergroup mudrocks is greatly affected by carbonate contamination and that rigorous filtering is imperative for extracting reliable provenance and weathering information. Previous studies ascribed relatively juvenile detrital Nd isotope signatures in these units to a mafic detrital source region in support of the hypothesis that basalt weathering contributed to global cooling during the Tonian prior to the Sturtian snowball Earth event. In contrast, we present a new temporally extensive εNd record that, when combined with elemental geochemical data, is best explained by the weathering of a combination of young and old granitic to granodioritic crustal sources, most likely sourced from the Grenville Province of Laurentia or Sveconorwegian Province of Scandinavia. Additionally, this new high-resolution mudrock data set allows us to assess paleoenvironmental and weathering trends within the Lomfjorden and lower Hinlopenstretet Supergroups, including the factors leading to exceptional fossil preservation in the ca. 790 Ma Algal Dolomite member of the Svanbergfjellet Formation, and post–snowball Earth weathering dynamics.
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 | 0.000 | 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) | 0.000 | 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".