Spores and Pollen Colour Changes and Thermal Maturation of Mid-Cretaceous Lacustrine Organic-rich Sediments in the Mamfe Basin, S.W. Cameroon
Bibliographic record
Abstract
Repeated palynological analyses of samples collected from lacustrine black organic rich shales and carbonate rocks which are abound in the Mamfe Basin have consistently yielded extremely low count of palynomorphs. Geochemical analysis of the same rocks revealed very high Total Organic Carbon (TOC) content of up to 16.10wt%, whereas similar rocks elsewhere as expected, yielded high abundance and diversity of palynomorphs. Several geologic factors involved in the burial history of sedimentary rocks may account for this low sporomorphs count, however, microscopic analyses of the changes in their colour, provides a quick and relatively cheap approach by which the thermal alteration of the sediments can be reconstructed. Palynomorphs data from this and previous studies of the same sediments were compared and confirmed to be very poor in abundance however, the few recognizable species undoubtedly permitted the assignment of an Albian-Turonian age to these sediments under study. Spore-pollen colour variation (Munsell colour standards) has proven to have a positive correlation with thermal alteration hence, sediments and organic matter maturation. Using a three sporomorph group (SG) that include: (1) leiotrilete spores of the genera Cyathidites, Deltoidospora, Dictyophyllidites, Gleicheniidites, and Leiotriletes (SG-1) with sporoderm thicknesses <1μm, 1–1.5μm and >1.5μm, respectively); (2) trilete, regulate spores of the genus Lycopodiacidites (SG-2); (3) trilete, striate spores of the genus Cicatricosisporites (SG-3); and (4) the gymnosperm-pollen taxon Classopollis torosus (SG-4). Results show here that the colour index varied from 2.5 to 5.0, indicating low to high maturity with Kerogen types I, II and III corresponding to a paloetemparature range of 60 to 140oC for an estimated stratigraphic interval of 1000 to 3000m in the Mamfe Basin.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".