Changes

==Methods==

==Methods==

[[File:Cartoon zoned and unzoned zircon.jpeg|thumbnail|right|Cartoon version of unzoned (left) and zoned (right) zircons. Red dots represent ion microprobe scan locations. White bar is about 50 μm.]]

[[File:Cartoon zoned and unzoned zircon.jpeg|thumbnail|right|Cartoon version of unzoned (left) and zoned (right) zircons. Red dots represent ion microprobe scan locations. White bar is about 50 μm.]]

[[File:Shrimp and SEM CL.jpeg|420px|thumbnail|right|Top: Shows a Sensitive High-Resolution Ion Microprobe (SHRIMP) at the Beijing Microprobe Center. This machine is commonly used to radiometrically date minerals using U/Pb, but can be used to measure Ti content of zircons. Bottom: Shows a Scanning Electron Microscope (SEM) equipped with Cathodoluminescence imaging at the Beijing Microprobe Center.<ref name=UMB>"S[http://www.geo.unimib.it/SROS/beijing.html HRIMP Remote Operations System (SROS)]". University of Milano-Bicocca. Retrieved 13 November 2014.</ref>]]

[[File:Shrimp and SEM CL.jpeg|420px|thumbnail|right|Top: Shows a Sensitive High-Resolution Ion Microprobe (SHRIMP) at the Beijing Microprobe Center. This machine is commonly used to radiometrically date minerals using U/Pb, but can be used to measure Ti content of zircons. Bottom: Shows a Scanning Electron Microscope (SEM) equipped with Cathodoluminescence imaging at the Beijing Microprobe Center.<ref name=UMB>"[http://www.geo.unimib.it/SROS/beijing.html SHRIMP Remote Operations System (SROS)]". University of Milano-Bicocca. Retrieved 13 November 2014.</ref>]]

Once a rock has been collected, zircons are extracted using a series of techniques such as using a [[sieve]], [[heavy liquid]], shaking table, and [[magnetic separation]] to separate minerals based on differing densities and properties. Zircon crystals are then mounted to an epoxy or metal disc-shaped slide,<ref name="Microprobe prep"> "[http://shrimprg.stanford.edu/ Sample Preparation]". SHRIMP RG Sample Preparation. USGS. Retrieved 8 Oct 2014.</ref> where they can be shaved to about half thickness to reveal their internal structure. From here, they can be imaged using [[cathodoluminescence]] to make any zonations in the mineral visible. If zonation is apparent, multiple measurements of Ti abundance can be taken from the center to the rim to give the temperature evolution of the crystal.  

Once a rock has been collected, zircons are extracted using a series of techniques such as using a [[sieve]], [[heavy liquid]], shaking table, and [[magnetic separation]] to separate minerals based on differing densities and properties. Zircon crystals are then mounted to an epoxy or metal disc-shaped slide,<ref name="Microprobe prep"> "[http://shrimprg.stanford.edu/ Sample Preparation]". SHRIMP RG Sample Preparation. USGS. Retrieved 8 Oct 2014.</ref> where they can be shaved to about half thickness to reveal their internal structure. From here, they can be imaged using [[cathodoluminescence]] to make any zonations in the mineral visible. If zonation is apparent, multiple measurements of Ti abundance can be taken from the center to the rim to give the temperature evolution of the crystal.