构建高精度年代地层格架：重新认识北疆石炭-二叠系

The Junggar Basin and surrounding areas in the northern Xinjiang region of China are rich in oil and gas resources, and is continuously making outstanding contributions to China's petroleum industry.The basin represents one superimposed basin in west China, which commonly have complicated geological histories and complex petroleum formation conditions and thus are difficult to dissect.One of the key scientific issues related to hydrocarbon exploration and large-scale resource discovery is the precise ages and tectonic setting of deposition of the Carboniferous-Permian black shales (i.e., the Fengcheng Formation) and associated petroleum systems.However, the Fengcheng Formation was deposited during the marine-terrestrial transition along with closure of the Paleo-Asian Ocean, and thus the strata generally lack marine index fossils suitable for dating.This has resulted in ambiguous regional stratigraphic correlations and difficulties in reconstructing the basin history.In turn, this has hindered oil and gas exploration, accurate assessment of the hydrocarbon resource potential, and the development of new exploration areas.Therefore, a high-precision and robust chronostratigraphic framework is strongly needed to better understand the regional geology, ensure future successful oil and gas exploration, and safeguard national energy security.The paper entitled "High-resolution chronostratigraphic framework and spatiotemporal evolution of Carboniferous-Permian source rocks in the Junggar Basin and its periphery" in Science China Earth Sciences (Hou et al., 2026) was co-authored by researchers from multiple institutions in China and overseas.This paper tackled the challenges in dating the Carboniferous-Permian strata of the northern Xinjiang region, including the occurrence of conglomeratic and volcanic rocks, the variable nature of sedimentary facies, and the absence of biostratigraphic type sections.The paper's authors dated volcanic ash layers in these strata in collaboration with the Isotope Laboratory at the Massachusetts Institute of Technology (MIT), USA, which yielded 53 high-precision ages.Based on these data, the stratigraphic framework for the Carboniferous-Permian source rock strata in the Junggar Basin and surrounding areas was redefined.This research has significantly improved the regional stratigraphic correlations in northern Xinjiang, which will lead to improved oil and gas exploration in peripheral depressions and will also provide new geochronological constraints on the evolution of the Paleo-Asian Ocean based on studies of the volcanic rocks.