Raman spectroscopic analysis of carbonaceous matter and silica in the test walls of recent and fossil agglutinated foraminifera
Bibliographic record
Abstract
ABSTRACT Raman spectroscopy has been used extensively in thermal maturation studies of kerogen, but has not been used to examine the maturation of organic cements in agglutinated foraminifera. Here, we use Raman spectroscopy to document the existence of carbonaceous matter and silica in recent and fossil agglutinated foraminifera, and to measure thermal alteration effects in fossil foraminifera. The distribution of carbonaceous matter through the test (shell) walls of agglutinated foraminifera suggests that this carbonaceous material is derived from primary organic cement and not from random contamination. Fossil specimens exhibit three broad stages of maturation: (1) Immature specimens are characterized by moderately strong fluorescence, broad, low intensity Raman peaks (relative to fluorescence), and a tendency for the G-band to occur at lower wave numbers. These attributes are consistent with the presence of amorphous carbonaceous matter and minor organic degradation. (2) Mature samples (oil window) exhibit high fluorescence, increased relative D- and G-band intensities, and a decreased width of the D-band. (3) Postmature samples exhibit low levels of fluorescence and high relative D- and G-band intensities, a tendency for the G-band to be located at higher wave numbers, an increase in the D:G band ratio, and an increase of the relative intensity of the silica peak. This stage is consistent with the presence of highly ordered carbonaceous matter and diagenetic quartz. These findings indicate that Raman spectroscopic analysis of fossil agglutinated foraminifera can be used as a quick and easy tool to assess thermal maturity and estimate optimal temperatures for hydrocarbon generation.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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) | 0.000 | 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".