Chertification ( B/109/Pen/Tx )
 2.5x
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 2.5x cross nicols
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 5x
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 5x wave plate
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 10x
|
 10x wave plate
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 2.5x
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 2.5x wave plate
|
 5x
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 5x wave plate
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| Outstanding feature | Chert replaces bioclastic grains & micrite and spar cement |
| Folk Classification | Chertified spicular biomicrite |
| Dunham Classification | Chertified spicular packstone |
| Common Grains | Spongue spicules and calcispheres |
| Sorting | Poorly sorted |
| Rounding | Well rounded to angular |
| Micritization & envelopes | Micrite envelopes not uncommon |
| Cement & diagenetic fabric | Partial replacement by chert |
| Porosity | 1-4 % leached intraparticle |
| Depositional Setting | Low energy trap close to high energy |
| Diagenetic history | Partial chertification of skeleletal grains and micrite cement |
Replacement of skeletal and micritic materials by chert.
Thursday, November 11, 2021