Lesson plan
Inertinite
Inertinites are a group of partially oxidized organic (mainly plant) materials or fossilized charcoals, all sharing the characteristic that they typically are inert (i.e., not altered) when heated in the absence of oxygen. Inertinite is a common maceral in most types of coal. The main inertinite submacerals are fusinite, semifusinite, micrinite, macrinite, and funginite, with semifusinite being the most common. From the perspective of coal combustion, inertinite can be burned to yield heat but does not yield significant volatile fractions during coking. Inertinite is also found as tiny flakes within sedimentary rocks. The presence of inertinite in this context is significant in the geological record, as it signifies that wildfires may have occurred at the time that the host sediment was deposited. It can also be an indication of oxidation due to atmospheric exposure or fungal decomposition during deposition. The optical properties of semifusinite are very similar to those of vitrinite. They differ in that semifusinite displays a folded texture compared to vitrinite, which generally maintains its composed structure. Inertinites also display higher reflectance than vitrinite, except when approaching an anthracitic or graphite state. Biochar, produced by pyrolysis at temperatures over 600°C, resembles inertinite.
Article summary
Inertinites are a group of partially oxidized organic (mainly plant) materials or fossilized charcoals, all sharing the characteristic that they typically are inert (i.e., not altered) when heated in the absence of oxygen. Inertinite is a common maceral in most types of coal. The main inertinite submacerals are fusinite, semifusinite, micrinite, macrinite, and funginite, with semifusinite being the most common. From the perspective of coal combustion, inertinite can be burned to yield heat but does not yield significant volatile fractions during coking. Inertinite is also found as tiny flakes within sedimentary rocks. The presence of inertinite in this context is significant in the geological record, as it signifies that wildfires may have occurred at the time that the host sediment was deposited. It can also be an indication of oxidation due to atmospheric exposure or fungal decomposition during deposition. The optical properties of semifusinite are very similar to those of vitrinite. They differ in that semifusinite displays a folded texture compared to vitrinite, which generally maintains its composed structure. Inertinites also display higher reflectance than vitrinite, except when approaching an anthracitic or graphite state. Biochar, produced by pyrolysis at temperatures over 600°C, resembles inertinite.
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.