收稿日期: 2003-09-27
修回日期: 2004-08-20
网络出版日期: 2005-04-25
基金资助
中国博士后科学基金项目“大别山石榴石成分环带的扩散动力学研究”；国家自然科学基金项目“大别山冷却史:地质年代学和扩散动力学研究”（编号：40273028）资助.
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
程昊 , 陈道公 , 周祖翼 . 黄镇低温榴辉岩中石榴石成分分带的扩散动力学研究[J]. 地球科学进展, 2005 , 20(4) : 421 -426 . DOI: 10.11867/j.issn.1001-8166.2005.04.0421
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
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