| In order to understand the Tectonic background of the West Congo Aborted Rift. Using Zircon U-Pb dating and petrogeochemistry in this study to analyze the Quindegi granites. The age of the granites obtained by zircon U-Pb dating is 904.1±7.4Ma and 905.4±5.5Ma suggesting formation age is Neoproterozoic Tonian. The Quindegi granites belong to A-type granite and originate from the fractional crystallization and contamination of Gangila basaltic magma, which are characterized by rich silicon, low aluminum, rich potassium and high TFeO, and the initial temperature of magma source area exhibits high temperature characteristics (tZr =783～891℃,average value is 847℃). The Quindegi granites are enriched with large ionic lithophile elements (LIFE) such as K, light rare earth elements of La and Ce, high field strength elements of Zr and Hf, depleted in high field strength elements such as U, Ta, Nb, P and Ti, large ion lithophile elements of Sr. The deficit of high field strength elements such as Nb may be related to mix in a large amount of crust source materials with the involvement of external heat sources. Through the regional geology, petrogeochemistry and zircon age statistical analysis, they are shown that the Quindegi granites were formed in the continental rift environment which belong to part of the Bahia-Gangila large igneous province and were products of multiple pulse magmatic activitives. The West Congo rift is an aborted rift that went deep into the continent during the formation of Macaúbas Ocean. The massive material supply and high-temperature heat source provided by mantle plume activity created conditions for the Quindegi granites to invade in place along the West Congo aborted rift. |