Towards a Law for the Metamorphic Evolution of Mantle-Derived Orogenic Peridotites
详细信息
- 责任者：Yang Jianjun (State Key Laboratory of Lithospheric Evolution ; Institute of Geology and Geophysics ; Chinese Academy of Sciences ; Beijing 100029 ; China) ; Huang Mengxi
- 刊名：Acta Petrologica Sinica
- 出版年：2013
- 卷期：29(5)
- 关键词：变橄榄岩 ; metaperidotite ; 高压变质作用 ; high pressure metamorphism
- 页码：p.1479-1485
- 图表：illus., 42 refs.
- 分类号：0802
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
Serpentinite minerals,including lizardite,chrysotile,antigorite,magnetite,brucite,clinoamphibole,orthoamphible, chlorite,talc,Fe-Ni sulphides,uvarovite,grossular,and brittle micas,are found to be included in the high-pressure minerals in peridotites from the northern Qaidam,the Yarlung-Zangbu,and the Su-Lu ultrahigh-pressure metamorphic belts in China. These indicate that the peridotites were subjected to serpentinization after having emplaced in the crust and subsequently to high-pressure metamorphism,corresponding to the breaking-apart and the collisional stages of the lithospheric evolution. In view of the increasing number of reports about similar observations in the orogenic belts worldwide,it is proposed here that a similar process may be experienced by all orogenic peridotites. As a consequence,the ‘mantle peridotites’in orogenic belts were chemically modified by crustal components and thus can not be taken to be pristine mantle rocks.