Using Contact Metamorphic Criteria in Contact Aureole to Preliminarily Discriminate Magma Emplacement Mechanisms of Fangshan Pluton, Beijing
Chen Nengsong
Chen Binghan
Roger Mason
Yang Tingting
Xia Bin
Liu Rong
Wang Guoqing
Xu Ran
Abstract：Relationship between metamorphic porphyroblasts and their matrices in the contact aureole of the concentric zoned Fangshan pluton,Beijing,combined with P-T patterns can be used as criteria to distinguish between magmatic diapirism and balloon expansion mechanisms for pluton emplacement in this study.It is found that,pelitic metamorphic rocks in the Xiamaling Formation in the southern part of the aureole display porphyroblast-matrix relationships reflecting intense plane-strain deformation combined with a nearly isobaric heating P-T trajectory towards the contact.Incorporating previously published estimates of final crystallization depths of four successively emplaced magmatic units,the results favor the balloon-inflation intrusion mechanism.
Keywords：magma emplacement mechanismcontact metamorphismP-T pathporphyroblast-matrix relationshipFangshan plutonpetrology
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 99-108 )