- journal_title：Elements
- Contributor：William C. McClelland ; Thomas J. Lapen
- Publisher：Mineralogical Association of Canada
- Date：2013-08-01
- Format：text/html
- Language：en
- Identifier：10.2113/gselements.9.4.273
- journal_abbrev：ELEMENTS
- issn：1811-5209
- volume：9
- issue：4
- firstpage：273
- section：Articles
Establishing the timing and duration of ultrahigh-pressure metamorphism (UHP) for crustal rocks subducted to mantle depths of over 100 km requires high-precision geochronology directly coupled with pressure-sensitive indicators. The best links between UHP conditions and an age estimate are inclusions of the UHP indicator minerals coesite and/or diamond in datable zircon or garnet. Lu–Hf and Sm–Nd garnet ages define the prograde and peak portions of the pressure–temperature path for cold (<700 °C), fast (>1 cm/y) UHP systems. UHP metamorphism in hotter (>800 °C) and slower (<1 cm/y) terranes is best dated by U–Pb analysis of coesite-bearing zircon domains coupled with Sm–Nd and Lu–Hf garnet analysis.