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Rb-Sr geochronology and thermal history
- Used as an auxiliary tool to determine emplacement ages or
cooling ages of specific minerals. Used normally in conjunction
with U-Pb or 40Ar-39Ar ages.
- Age range: Tertiary (last 65 million yrs) through Archean
(last 3.8 billion yrs), but of limited use in highly-metamorphic
terranes.
Sr-isotope geochronology
- Age of sea water-deposited pure carbonates--generally fossil
corals.
- Based on Sr isotopic composition of sample relative to that
estimated for sea water for a given time interval.
- Quaternary (last 2 million yrs) through Tertiary (last 65
million yrs).
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