Kwangsian and Indosinian crustal reworking of north Cathaysia inferred from multiphase deformation and metamorphism

Professor Zhao, Guochun   (Principal Investigator (PI))

Dr Yao Jinlong   (Co-Investigator)

Professor Zhang Jian   (Co-Investigator)

Dr Li Jianhua   (Co-Investigator)

Professor Yin Changqing   (Co-Investigator)

36

2018-01-01

522898

Kwangsian and Indosinian crustal reworking of north Cathaysia inferred from multiphase deformation and metamorphism

Cathaysia, Deformation, Metamorphism, Plate Tectonics, Reworking

Earth Sciences

Physical Sciences (P)

17306217

General Research Fund (GRF)

2017

Completed

1 To determine the spatial distribution of major structural and metamorphic units of the north Cathaysia through broad-based field reconnaissance along two NW-trending transects; to clarify the geometric, kinematic features, mineral assemblages of individual structural/metamorphic zones through field investigations; to delineate the tectonic boundary between Indosinian and Kwangsian metamorphic/structural zones through field mapping 2 To carry out extensive microstructural and quartz lattice-preferred orientation studies, aiming at determining the kinematics and deformation temperatures of individual ductile shear zones, and establishing correlations with adjacent kinematically compatible structures by considering strain partitioning 3 To undertake metamorphic studies on mineral assemblages, reaction relations, mineral compositions and thermobarometric P-T calculations of amphibolite facies metamorphic rocks in the Badu complex, aiming at reconstructing their metamorphic sequences and P-T paths during Indosinian reworking 4 To determine the timing of deformation and metamorphism by dating pre- to post-kinematic igneous dykes/veins and metamorphic rocks using the U-Pb zircon geochronology 5 To clarify the synkinematic flow and tectonic exhumation of the north Cathaysia during crustal reworking, by conducting Ar-Ar dating of minerals (amphibole, muscovite, and biotite) with overlapping closure temperatures from ductile shear zones 6 Based on the integral interpretations of various data, we will establish a well-constrained, Ordovician-Triassic tectono-thermal history of the north Cathaysia. Synthesis of our work combined with previous studies in many other regions will enable us to give more plausible explanations for the Kwangsian and Indosinian crustal reworking of South China