MODELING OF HUANGZHEN LOW-T ECLOGITE WITH DIFFUSION KINETICS THEORY
Received date: 2003-09-27
Revised date: 2004-08-20
Online published: 2005-04-25
We determined the compositions of various sizes of garnets in so-called cold Huangzhen eclogites from Southern Dabie with electron microprobe, and observed that it shows intriguing zoning patterns. We find these zoning patterns can be interpreted by a relaxation diffusion mechanism. Using relaxation diffusion model, with the determined PT condition by means of traditional petrologic methods by others and numerically model of the profile’s adjusting, the result suggests the adjustment of the smallest garnet in this study cost 23Ma until the process ceased. This means that the rocks of Huangzhen suffered an exhumation velocity about 6℃/Ma after the peak metamorphism. This result supports the idea that the Huangzhen eclogites did not experienced UHPM, and also provides important information on the tectonic mechanism for the mountain Dabie eclogites exhumation.
Key words： Garnet; Diffusion; Numerical model; Cold eclogite
CHENG Hao , CHEN Dao-gong , ZHOU Zu-yi . MODELING OF HUANGZHEN LOW-T ECLOGITE WITH DIFFUSION KINETICS THEORY[J]. Advances in Earth Science, 2005 , 20(4) : 421 -426 . DOI: 10.11867/j.issn.1001-8166.2005.04.0421
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