The compositions and formation history of basement metamorphic rocks are the key to understanding crust evolution. Based on zircon U-Pb-Hf isotopic studies and the compositions of basement metamorphic rocks in northeastern Guangdong Province and southern Jiangxi Province, this paper indicates that the protoliths of these metamorphic rocks are sedimentary rocks deposited in the Late Neoproterozoic. They have high SiO2, Rb, Zr, Y and transitional metal concentrations and relatively low Al2O3, CaO, Na2O, Sr and Nb contents. They were deposited in an active continental margin basin near a volcanic arc. The basin formation was closely related with the extensional regime during the breakup of the supercontinent Rodinia. Neoproterozoic sediments in the Longchuan area of northeastern Guangdong Province are mainly composed of Neoarchaean and Mesoproterozoic clastic constituents with small amounts of Mesoarchaean and Neoproterozoic fragments, quite distinct from those in southwestern Fujian Province and northern Guangdong Province, showing different provenances. The basement metamorphic rocks in northeastern Guangdong Province were not influenced by the Early Paleozoic Caledonian movement, but underwent strong Indosinian metamorphism and anatexis.
|Number of pages||11|
|Journal||Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences|
|Publication status||Published - Jan 2006|
- Basement metamorphic rock
- Northeastern Guangdong Province
- Tectonic setting of Neoproterozoic sedimentary basin
- Zircon U-Pb-Hf study