45 D32. Recent Advances in Structural Geology (Posters)

Sunday, 22 September 2019
9:00 AM - 5:30 PM
Hall AB, North Building

FEATURES OF SYN-TECTONIC MAGMATIC FLOW IN THRUST AND STRIKE-SLIP BELTS: COMPARED WITH MYLONITE AND GNEISS IN CHINA

Paper number: 45-1
Program: Technical Sessions
Time: 9:00 AM – 5:30 PM

Authors

  • Liyun Zhou Presenting Author
    China University of Geosciences (Beijing), Beijing
  • Yu Wang
    China University of Geosciences (Beijing), Beijing

Abstract

Syn-tectonic magmatic flow, which typically occurs along continental margins or in orogenic belts constrained by tectonic stresses, may indicate re-melting of middle-lower crust, tectonic setting of the magmatic plutons or the reactivation of cratonic basement. Also, the differences between magmatic flow and metamorphic gneiss and mylonite constitute important problems that should be reconsidered in modern petrology and structural geology. The northern margin of the North China block hosts Late Carboniferous granitoid plutons (320-300 Ma) showing evidence of magmatic flow contain a south-vergent shallow-dipping transposition foliation and recumbent folds. The occurrence of southward magmatic flow formed in compressional tectonic setting from north to south indicates the reactivation of North China cratonic basement.

Granitoid plutons emplaced at Early Cretaceous with NE-SW trending distribution, which scattered along Changle-Nanao ductile shear zone in southeastern China are syn-strike-slip magmatic/sub-magmatic flow. These granitoids, same time as the ductile shear zone, show intense schlieren layering of mafic and felsic minerals, k-feldspar phenocrysts aligned, elongated and lenticular microgranitoid enclaves aligned parallel to the magmatic fabrics without internally deformation. Syn-ductile shear magmatic flow was contemporaneous with oblique subduction of the West Pacific Plate beneath the Eurasian continent.

Geological Society of America Abstracts with Programs. Vol. 51, No. 5

doi: 10.1130/abs/2019AM-332545

© Copyright 2019 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.