关键词: 华南板块, 早侏罗世金鸡组, 碎屑锆石, 源区分析, 构造背景

Abstract: Early Mesozoic geodynamic background of the South China Block (SCB) is still controversial. The Late Triassic-Early
Jurassic Eastern Guangdong basin locates at southeastern margin of the SCB and contains key records of its geodynamic background.
Detrital zircon LA-ICP-MS dating was carried on the Lower Jurassic Jinji Formation in the basin in this study. The results display eight
age peaks, i.e. ca. 196 Ma, 247 Ma, 320 Ma, 432 Ma, 770 Ma, 1060 Ma, 1820 Ma, and 2430 Ma. Provenance analysis suggests that the
sources of the Lower Jurassic Jinji Formation were mainly derived from the northeast and north directions. Correlation of the detrital
zircon age spectra reflects that the studied basin resembles the Yongan basin to the northeast and Dongkeng basin to the north.
Integrated analysis of the sediment provenance, petrology and geochemistry of the Jinji Formation reveals that the Early Jurassic basins
in southeastern China, even though bear characteristics of passive continental margin, already received sediment supply from the
uplifts in more eastern region resulted from the northwestern subduction of the paleo-Pacific plate toward the SCB.

Key words: South China Block, Lower Jurassic Jinji Formation, detrital zircon, sediment provenance, tectonic setting