ANT 2511 Lecture Notes - Lecture 1: Carl Sagan, Dendrochronology, Cosmic Calendar
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carbon-14 courting
- uses the decay of carbon to n in organisms.
- charcoal quality fabric to this point.
- most effective beneficial for sites as old as around 50,000 years.
potassium-argon (ok/ar) relationship
- can date volcanic rock. k decays to ar.
- beneficial again to four.5 billion years (1/2-existence 1.three b.y.).
dendrochronology
tree ring counting
fission-track dating
uranium decays into lead in igneous rock, count number fission tracks (as much as 3my). gives age
estimates for noncrystalline materials which includes volcanic glass.
how long in the past did the primary primates appear?
50 mya
how lengthy in the past did the primary hominins appear?
6 mya
how old is the planet?
four.6 billion years
who developed the 'cosmic calendar?'
carl sagan