The Jixi Basin of eastern Heilongjiang Province is a prominent Cretaceous coal-bearing basin in Northeast China, characterized by alternating non-marine and marine strata affected by the transgression in the Early Cretaceous. However, the age of the Muling Formation, an important coal-bearing stratum in Jixi Basin, has been debated for nearly half a century, mainly due to the lack of reliable isotopic dating evidence. Three new LA-ICP-MS zircon U–Pb ages (110.9 ±1.0 Ma, 109.0 ±0.8 Ma, 108.1 ±1.3 Ma) obtained from the Qinglong Mt. Section of Jixi, the typical profile of the Muling Formation, constrain the Muling Formation as an early Albian age, with supporting evidenced from the fossil assemblages (dinoflagellates, plants, bivalves, and conchostraca) within the strata. The new ages also indicate the sedimentation period of the Muling Formation (from ca. 110.9 Ma to ca. 108.1 Ma, averaging ca. 109.0 Ma) matches the time of its upper and lower limits, i.e. the underlying Chengzihe Formation (111.1 ±1.1 Ma at its top) and the overlying Dongshan Formation (107.2 ±0.7 Ma at its base), which very benefits accurately understanding the coalforming time of the Muling Formation for the first time. Additionally, at least three volcanic eruptions during the Muling Formation are confirmed in this study, providing critical constraints for paleoenvironmental reconstruction of the Albian coal-forming environment in Northeast Asia. Notably, these eruptions exhibit compositional (acidic volcanic rocks) and temporal similarities to volcanic rocks from the lower Yingcheng Formation in the Songliao Basin’s SK2 borehole, which represents early Albian giant explosive volcanic events linked to Pacific Plate subduction. This correlation not only implies that these volcanic events may share a common magmatic source but also bridges critical gaps in the volcanic record of the eastern SinoRussian border region. The findings thus establish three precise geochronological markers for highresolution regional correlations across Northeast China and adjacent areas, while advancing our understanding of Cretaceous basin evolution and magmatic-tectonic processes in Northeast Asia during the late Early Cretaceous.
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