We firstly report geochronological and geochemical data obtained for the Baiyu granite from the Beiba area in the northwestern margin of the Yangtze Block. Zircon LA-ICP-MS U-Pb dating results show that the Baiyu granite crystallized at ~1790 Ma. The Baiyu granite is characterized by high Si, alkali and FeOT/(FeOT＋MgO) ratio, low Mg, Ca, Mn and P, with A/CNK=0.92~0.96, suggesting its metaluminous characteristics. REEs data show that the granite is characterized by enrichment of Ga, Th, Zr and Y, depletion of Sr, P and Ti, high total REE concentration, high LREE/HREE ratio, and strongly negative Eu anomalies, and all these characteristics are consistent with that of A-type granite. The negative εHf(t) values ranging from -12.66 to -10.69 in zircons indicate that the Baiyu granite may derive from partial melting of ancient crust. The geochemical analysis and existing researches show that the Baiyu granite likely formed in the intracontinental rift basin. Combined with previous research results, we propose that in South China exits the records of subduction, collision and rifting related to the Columbia supercontinent. The arc-related granitoid rocks of the Houhe Group in the Beiba area have confirmed that the northwestern margin of the Yangtze Block was an active continental margin environment at about 2.10 Ga; the collision related to the amalgamation of Columbia supercontinent occurred in South China during 2.00~1.88 Ga; the continent-continent collision happened in the Kongling area of Yichang city at 2.00~1.94 Ga and should be earlier than in the southwestern area of Zhejiang Province (1.93~1.88 Ga); the Yangtze Block itself (the western and eastern parts of the Yangtze Block) and the Cathaysia Block (at least the western part) had amalgamated into a unified block in the Paleoproterozoic, associated with the assembling of the Columbia supercontinent. During 1.87~1.82 Ga, the A-type acidic rocks in South China were formed in the postcollisional setting, and were the product of oceanic lithosphere delamination following the collision. The South China entered the intracontinental breakup stage at about 1.79 Ga, which is consistent with that recording the time of Columbia supercontinent breakup in North China and other continents.