Milankovitch cycles reveal where ancient shale oil formed

Researchers link Milankovitch orbital cycles to the formation of shale oil in the Sichuan Basin, showing that wetter periods during high orbital eccentricity produced organic-rich lake muds that later became shale reservoirs. By combining crust/mantle data, rock cores, and Jurassic lake-mud gamma-ray records, they align sediment layers with orbital timing to better predict where high-quality shale oil formed. The study, published Sept. 30, 2025, notes shale oil’s extraction via fracking and related environmental concerns, but the method could improve exploration targeting.