-3 processes of geological rifting
- faulting, or earth movement
- active volcanic processes cause rapid sedimentation, which often yields excellent preservation of bone and artifacts that normally would be scattered by carnivore activity and erosion forces
- volcanic activity provides a wealth of radiometrically datable material
-stratigraphy: study of the sequential layering of deposits
-principle of superposition: stratigraphic sequence, the lower layers were deposited before the upper layers, simply put the tuff on top of a heap was put there last
-half-life: time period in which one-half the amount of radioactive isotope is converted chemically to a daughter product.
-thermoluminiscience (TL): technique for dating certain archaeological materials (i.e. stone tools) that were heated in the past and that release stored energy of radioactive decay as light upon reheating
Relative Dating
- i.e. stratigraphy, fluorine dating
- methodological basis: provides a sequence only; i.e. no estimates in actual number of years
- i.e. K/Ar, radiocarbon, fission-track
- methodological basis: most techniques* are radiometric; i.e. study decay of radioactive isotope provides estimate in actual number of years
- *chronometric techniques that are nonradiometric inclue tree-ring dating (scientific method of dating based on the analysis of patterns of tree-rings)
-biostratigraphy: dating technique based on regular changes seen in evolving groups of animals as well as presence or absence of particular species
Geological Dating
Types absolute vs relative
What is half life and how is it useful in geological dating?
What the the key radiometric datable materials that are useful for paleoanthropologists? What are their half lives? What makes these useful vs other types of radioactive material?
Why are volcanoes useful in this process?
How can the geology of one area be useful in identifying the age of an area in a different part of the world?
No comments:
Post a Comment