KAJIAN TEKNIS PELEDAKAN TERKONTROL UNTUKPENGUPASAN OVERBURDEN DI PIT A PADA PENAMBANGAN BATUBARAPT. BERAU BARA ENERGI
Bibliographic record
Abstract
Although biomineralized skeletal elements dominate the Phanerozoic fossil record, they did not become common until ~550-520 Ma when independent acquisitions of biomineralization appeared in multiple lineages of animals and a few protists (single-celled eukaryotes). Evidence of biomineralization preceding the late Ediacaran is spotty aside from the apatitic scale microfossils of the ~811 Ma Fifteenmile Group, northwestern Canada. Here, we describe scale-shaped microfossils from four vase-shaped microfossil (VSM)-bearing units of later Tonian age: the Togari Group of Tasmania, Chuar and Pahrump groups of southwestern United States, and the Roaldtoppen Group of Svalbard. These scale-shaped microfossils consist of thin, ~13 micron-long plates typically surrounded by a 1-3 micron-thick colorless envelope; they are found singly and in heterotypic and monotypic clusters of a few to >20 specimens. Raman spectroscopy and confocal laser scanning microscopy indicate these microfossils are composed of apatite and kerogen, just as is seen in the Fifteenmile Group scale microfossils. Despite compositional similarity, however, these scales are probably not homologous, representing instead, an independent acquisition of apatite mineralization. We propose that these apatite-kerogen scale-shaped microfossils are skeletal elements of a protistan cell. In particular, their consistent co-occurrence with VSMs, and similarities with scales of arcellinid testate amoebae, a group to which the VSMs are thought to belong, suggest the possibility that these microfossils may be test-forming scales of ancient arcellinid testate amoebae. The apparent apatite biomineralization in both these microfossils and the Fifteenmile scales is unexpected given its exceedingly rare use in skeletons of modern protists. This modern absence is attributed to the extravagance of using a limiting nutrient in a structural element, but multiple occurrences of apatite biomineralization in the Tonian suggest that phosphorus was not a limiting nutrient for these organisms, a suggestion consistent with the idea that dissolved seawater phosphate concentrations may have been higher at this time.
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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 | 0.000 |
| 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) | 0.002 | 0.001 |
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; both teacher heads agree on what is shown here.
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".