Evolution Flashcards
Relative Age
tells us the order in which events happen
-superposition-
Absolute Age
tells us exact age of something
-radioactive decay-
Fossils
physical evidence of former life prior to human life
Fossilization Steps
- ) animal dies
- ) decay and burial
- ) sediment accumulation and per-mineralization
- ) uplift and exposure
- ) discovery
Radioactive Decay
- used when determining the absolute age
- isotope: forms of chemical elements that differ in the number of neutrons in their atomic nuclei
- radioactive isotopes will break down into a lighter product over time
- half life: the time it takes for half the product to decay
- by tracking back the decay of the product we can track the age
Geological Time
- a way to map out history of the earth
- presented in a time scale
Isotope
forms of chemical elements that differ in the number of neutrons in their atomic nuclei
Half Life
the time it takes for half the product to decay
Super Position
- stratigraphy is the study of layer of rocks
- rocks are layered like a cake
- younger rocks = top; older = bottom
- unconformities are gaps in the layer of rocks
Unconformities
gaps in the layer of rocks
Stratigraphy
the study of the layer of rocks
Law of Inclusions
inclusions are older
Law of Cross-Cutting
faults and cross-cuts are younger
How old is the Earth?
approximately 4.54 billion years old
What is Carbon-14’s half life?
5,700 years
If Iron-38 is 16,000 years old and it’s half life is 4,000 years - how many half lives is the sample?
4 half lives