Paleoclimate background and genetic mechanisms of different soil structures in typical black soil areas of Songliao Plain

The study of the genetic mechanisms of black soil is fundamental to understanding its formation and evolution, and is crucial for enhancing the protection and sustainable use of black soil. Focusing on the LZK-4 borehole in Lishu County, a representative black soil region of the Songliao Plain, paleoclimate sequences since the mid—late Pleistocene were reconstructed using clay mineralogy, elemental geochemistry, ¹⁴C dating, and optically stimulated luminescence dating. This revealed the paleoclimatic contexts of various soil types and elucidated the climatic causes behind the formation of typical black soil. The findings indicated: ①The typical black soil in the study area originated during the Late Holocene, with a bottom age of 2452 cal.a BP; ②LZK-4 drilling unveiled a vertical structure of a black soil layer, followed by a grey-white clay layer, and then a brown-yellow clay layer, reflecting an overall trend in climate from warmth and humidity to dryness and coldness; ③The typical black soil in the study area primarily formed under cold and arid conditions during the Late Holocene. This research contributes to understanding the formation and evolution of black soil in the Lishu region of the Songliao Plain, thereby providing a scientific foundation for the development, utilization, and protection of black soil resources.