Js diatom amherst 2014
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Diatoms are unicellular algae with siliceous cell walls that are widely distributed in both marine and freshwater environments. They can be found as plankton in open water or attached to surfaces as periphyton. The document discusses diatom biology, taxonomy, and their use in paleoclimate reconstruction by analyzing fossil diatom assemblages in sediment cores. Diatoms are sensitive to various environmental factors like salinity, temperature, and nutrients, which allows their fossil remains to provide information about past climate conditions through the use of transfer functions.
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Js diatom amherst 2014
- 2. OUTLINE • Basic diatom biology and methods • Local example • Lake El’gygytgyn diatom record
- 3. What are Diatoms? • Unicellular (sometimes forming colonies) • Siliceous cell walls • Algae – Class Bacillariophyceae
- 6. Where do they live? plankton periphyton (benthos)
- 8. How do they reproduce?
- 10. Methods •Sediment processing •Light microscopy •Electron microscopy
- 12. Diatoms are sensitive to: •salinity •ice cover •pH •depth •nutrients •temperature Linking diatoms to paleoclimate?
- 13. Transfer Function Approach: Modern Environmental Conditions Modern Diatom Assemblage+
- 15. Transfer Function Approach: Modern Environmental Conditions Modern Diatom Assemblage Species Optima Core Assemblage Environmental Reconstruction +
- 16. Summary •broad distribution, preservation •diverse and sensitive (+) •not observed to be temperature sensitive •taxonomy complex •taphonomy (-)
- 17. 10μ
- 21. Unique Diatoms
- 22. Plankton Size
- 24. General Patterns
- 27. 2.94 Ma – lacks ornamentation; valve face fultoportulae near center 3.09 Ma – ring of valve face fultoportulae near margin disrupt areolae pattern 3.21 Ma – ornamentation on valve face
- 31. General Patterns
- 33. 1.103 Ma
- 34. 1.095 Ma
- 35. 1.071 Ma
- 36. 1.060 Ma
- 37. 1.057 Ma