Lecture 7 Flashcards
5 steps of using fossil protists for paleoenvironmental reconstructions
Preparation
Concepts
Assemblage composition
Phenotypic variations
Geochemical analyses
What kind of chemical composition(s) does the physical treatment of sieving take care of?
CaCO3
Refractory organic material
What kind(s) of chemical compositions does the chemical treatment of HCl take care of?
CaCO3
What kind(s) of chemical compositions does the chemical treatment of HF take care of?
SiO2
What kind(s) of chemical compositions does the chemical treatment of hydrogen peroxide take care of?
Organic material
What protists are included under CaCO3?
Foraminifera
Coccoliths
What kind of protists are included under SiO2?
Diatoms
Silicoflagellates
Radiolarians
What kind of protists are included under refractory organic material?
Acritarchs
Dinoflagellate cysts
Tintinnids (most of them)
3 types of environmental and oceanographic reconstructions and assessments
Assemblage composition
Phenotypic variations
Geochemical analyses
Assemblage composition
See what organisms dominate the assemblage
Phenotypic variations
Morphological (observable) characteristics of one organism or one species
Geochemical analyses
E.g., isotopic analyses
Foraminifer distribution
Mirror environmental parameters such as T, salinity, turbidity, oxygenation, nutrient availability
Give specific examples of how assemblage composition can help us reconstruct paleoclimate?
Climate reconstructions (population analyses)
Sea ice reconstructions
Sea surface T across the K-Pg Boundary
Phenotype
Characteristics (morphology, development, behaviour, etc.) displayed by an organism under a set of environmental factors, regardless of the genotype of the organism
What does O-18 tell us about seawater temperature and glaciation?
Increased levels of O-18 = colder climate
More O-16 in ice sheet means less evaporation
