The duration of near-peak metamorphism from diffusion modelling of garnet zoning
The duration of near-peak metamorphism from diffusion modelling of garnet zoning
复制标题
石榴石分带扩散模型的近峰变质作用持续时间
DOI：
10.1111/jmg.12099
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发表时间：
2014
影响因子：
3.4
通讯作者：
Spear, F. S.
中科院分区：
文献类型：
--
作者：
Spear, F. S.
Garnet in a staurolite–kyanite zone sample from central Vermont displays a bell‐shaped Mn growth zoning with diffusional modification over the outer 100μm. The diffusion is driven by the prograde net transfer reaction garnet + chlorite = kyanite + biotite as is evidenced by a well‐defined resorption zone on the rim. Analysis of the reaction history and resorbed garnet composition suggests that the peak temperature attained was 620–660 °C. Diffusional modelling of the rim diffusion provides an estimate of the duration of the metamorphic episode over which significant garnet diffusion occurs. The duration is a function of the assumed peak temperature and garnet diffusivities and range from a few hundred thousand years to a few million years. Such short durations require rapid tectonic burial and exhumation of relatively thin tectonic slices.
