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Unformatted text preview: on. Primarily
for detrital mineral
Evolving rapidly geochronology (e.g., technique of the
future to replace
SHRIMP. From Stern (1999)
Wednesday, 15 August, 12 Diffusion and Closure Temperatures
• Closure Temperature: temperature at which an element
derived from radioactive decay cannot diffuse out of a
crystal (also called a Blocking Temperature). • When you read about a U-Pb age (or any age for that
matter) in the literature it reﬂects the age at which the rock
cooled below the closure temperature for the mineral in
question. • Example: Zircon has a closure T of ~900oC. Thus, if you
have an age of 100 Ma this age reﬂects the age when the
rock (and zircon) crystallized beneath 900oC. • Closure temperature is based on diffusion and different
minerals have different closure temperatures, thus
different minerals can give you the timing of different
events. Wednesday, 15 August, 12 http://earth.leeds.ac.uk/dynamicearth/d...
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This document was uploaded on 03/06/2014 for the course ES 4502 at Memorial University.
- Fall '12